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The Basis Of Browsing Tolerance In Shrubs Of The Intermountain West: Growth Rates And Meristematic Potential, Jackson L. Wandera

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Relative growth rates (RGRs) and meristematic potential of big sagebrush (Artemisia tridentata, in some experiments ssp. tridentata Nutt. and in other experiments ssp. vaseyana [Rydb] Beetls), bitterbrush (Purshia tridentata [Pursh] DC), serviceberry (Amelanchier alnifolia Nutt.), birchleaf mountain mahogany (Cercocarpus montanus Raf.), curlleaf mountain mahogany (C. ledifolius Nutt.) and big tooth maple (Acer grandidentatum Nutt.) were quantified under both glasshouse and field conditions. The relationships between the RGRs, meristematic potential and regrowth capacity of the shrub species were then determined. Sagebrush exhibited a significantly higher RGR than the other species at both high and low …

Reproductive Ecology Of Wyoming Big Sagebrush (Artemisia Tridentata Ssp. Wyomingensis) : Effects Of Herbivory And Competition, Richard T. Decker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Herbivory and plant competition affect sexual reproduction of plants in various ways. Exclusion of mule deer (Odocoileus hemionus) and cattle, removal of plant competition (both inter- and intraspecific), and all combinations of the above treatments were used to examine the individual and combined affects on Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) reproduction. Reproduction of Artemisia tridentata ssp. wyomingensis was divided into hierarchical levels of the number of: (1) modules per current-year ' s growth (CYG), (2) nodes per module, (3) inflorescence heads per node, (4) achenes per inflorescence head and (5) percent viable achenes. Counts at hierarchical …

Effects Of Cannulation, Bst Administration And Protein Degradability On Rumen And Duodenal Characteristics And Milk Production Response In Holstein Dairy Cows, Margaret D. Winsryg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bovine somatotropin (bST) is a protein synthesized at the base of the brain and released by the pituitary gland into the circulatory system. BST is transported by the circulatory system and absorbed only by cells of target organs that possess cell surface receptors for the protein (11, 41). Its effect is initiated via a protein receptor initiation and cyclic AMP cascade. This effect on the cell continues well past the degradation of the bST molecule. BST is likely transported into the cell, where it is degraded. Its constituent blocks, amino acids, are used to synthesize new proteins or converted to …

Endocrine Interrelationships During Early Postpartum In St. Croix Sheep, Richard Michael Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The relationships of estradiol-17-beta, progesterone, and LH in the early postpartum St. Croix ewe were monitored during the breeding season in 1988. A second group of non-postpartum, ovariectomized St. Croix ewes were used to determine non-ovarian levels of progesterone for comparison. Results of this study indicate that:

1. The short duration rise in progesterone exhibited by some ewes is indicative of an ovulation.
2. Ewes that do exhibit a short luteal phase prior to the first "normal" luteal phase have a longer period from parturition to the first "normal" luteal phase.
3. Serum levels of LH increase beginning 3 days postpartum.
4. There is …

A Comparison Of Three Estrous Detection Management Schemes For Dairy Heifers, Ann Lagerstedt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heifers should represent the greatest genetic potential within a dairy herd. To maximize this potential, heifers must be inseminated to proven sires, a practice requiring management changes on many dairies. Holstein heifers (n=115) were allotted to one of three groups to compare alternatives to daily estrous detection that may facilitate the management of a program of artificial insemination for heifers. Group 1 heifers (Controls) received no treatment but were observed twice daily for signs of estrus. Group 2 heifers (2X-PGF) were synchronized with two injections of prostaglandin F2 alpha given 11 days apart and observed for estrus. Group 3 heifers …

Immunosuppression By Aflatoxin B1 In C57bl/6 Mice And Its Relationship With Neuroendocrine Mechanisms, Yasuhiko Hatori

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aflatoxin B₁ (AFB₁), a secondary metabolite of Aspergillus flavus and Aspergillus parasiticus, is known for its potent carcinogenicity and immunosuppressive effects. It is also known that AFB₁ toxicity appears in different degrees in different animal species and strains.

The present study was performed to reveal the involvement of the hypothalamus-pituitary-adrenal gland (HPA) axis in the immunosuppressive effects of AFB₁ on C57BL/6 mice. Splenic lymphocytes were assayed to investigate their phenotyping using flow cytometry, proliferative response against mitogen and allogenic lymphocytes, cytolytic cell activity, and IL-2 production. In addition, antibody-mediated immunocompetence was checked using sheep …

Burning, Flaming And Herbicides For Control Of Jointed Goatgrass (Aegilops Cylindrica Host.), Blake D. Willis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Winter wheat stubble and dried plant residue in Conservation Reserve Program (CRP) fields were burned in the fall and spring to evaluate effects on jointed goatgrass (Aegilops cylindrica Host.) seed survival and germination. Laboratory studies were also conducted to determine minimum temperatures and heat duration needed to reduce jointed goatgrass seed viability. Maximum air temperatures attained during various field burns reached from 74 C to over 700 C. Temperatures 2.5 cm above the soil surface remained above 400 C for over 10 seconds and above 600 C for 2 to 8 seconds in burning CRP stubble. Results for the …

Irrigation Management Considering Soil Variability And Climatic Uncertainty, Dani Or

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The increase in multipurpose use of water resources, dwindling xii water supplies, and a decline in the economic viability of many agricultural operations make efficient irrigation management imperative. Soil variability and climatic uncertainty are major obstacles to efficient irrigation management due to a lack of reliable information for decision making. This study was aimed at identifying sources of uncertainty and examining methods for reducing the effects of uncertainty on irrigation scheduling schemes.

A method for spatial-temporal estimation that combines spatial information from few measurements with a physically based model of the system dynamics is proposed. The spatial phase of the …

Morphology Of Polyanhydride Microsphere Delivery Systems, E. Mathiowitz, D. Kline, R. Langer

Scanning Microscopy

Scanning electron microscopy (SEM) was used to elucidate the mechanism of polymer degradation and drug release in polyanhydride microspheres. Three different fabrication methods — solvent removal, solvent evaporation, and hot melt microencapsulation — were used to prepare polyanhydride microspheres containing a variety of drugs. The morphology of these microspheres releasing drug in vitro and in vivo was studied by SEM and compared with degradation and release data measured by conventional methods. Microspheres prepared by the three techniques were shown to have distinctive morphological characteristics induced by the nature of the fabrication method. In addition, SEM analysis could be used to …

X-Ray Microanalysis Of Ca And K In Corn Bran And Oat Hulls, F. R. Dintzis, F. L. Baker, T. C. Nelsen

Scanning Microscopy

Oat hulls and dry-milled corn bran were loaded with calcium or potassium and made into either sectioned bulk specimens of intact tissue embedded in resin or into non-sectioned bulk specimens made from powdered-compressed tissue formed into disks without resin. Regression lines of X-ray count versus mineral concentration were similar for both Ca and K. X-ray count versus mineral concentration relationships were similar for intact oat hulls and powdered-compressed specimens of either oat hulls or corn bran. However, the relationship for intact corn bran embedded in resin was significantly different. While the reason for this difference is not known, the result …

Gelatin Standards For Elemental Quantification In Biological X-Ray Microanalysis, A. T. Sumner

Scanning Microscopy

Standards for X-ray microanalysis (XRMA) can be prepared simply by dissolving measured amounts of gelatin and an appropriate salt in water, dipping grids in the solution, and allowing them to gel and dry. The present study was intended to assess the uniformity, reproducibility, and stability during irradiation of such standards.

Visually, the gelatin films appear homogeneous, and XRMA measurements of different grid squares are generally in good agreement. The gelatin standards are susceptible to radiation damage, as judged by several criteria. These are: visible damage; variation of peak/continuum ratios with electron dose; anomalous values obtained with very thin standards; and …

Osteoclast Cytomorphometry And Scanning Electron Microscopy Of Bone Eroded Surfaces During Leukemic Disorders, Daniel Chappard, Jean François Rossi, Régis Bataillle, Christian Alexandre

Scanning Microscopy

Tartrate resistant acid phosphatase (TRAP) is a reliable histochemical marker of osteoclasts when used on tissue sections of undecalcified bone. This paper presents an original morphometric analysis which can be done after histochemical identification of osteoclasts. These bone resorbing cells were demonstrated on undecalcified bone biopsies from control subjects and patients presenting a malignant disease of the lymphocyte B lineage. Computerized analysis of the osteoclastic population revealed that: (1) all TRAP positive cells along bone trabeculae belong to a osteoclastic population; (2) that B cell malignancies had an increased bone resorption. At the scanning electron microscopic level small resorption bays …

On The Horns Of A Dilemma, The Uneasy Partnership Between Advocacy And Social Science, Karl R. White

Faculty Honor Lectures

Most of us living in the United States enjoy the highest standard of living in the history of the world. Taken together, the technological, cultural, recreational, medical, and educational opportunities of our society are unsurpassed. But we also face an abundance of critical social problems. Widely quoted and seemingly accurate statistics which describe such problems include, but are not limited to the following.

A Review On The Extension Of Hall’S Method Of Quantification To Bulk Specimen X-Ray Microanalysis, Imre Zs. -Nagy, T. Casoli

Scanning Microscopy

The theoretical background and the experimental data described in this paper justify the application of the Hall's continuum method of quantitation and the use of bulk crystals of known composition as standards, without ZAF correction, for the biological bulk specimen X-ray microanalysis, provided that proper criteria are respected during the realization of such measurements. The most important points are as follows: (i) Only crystals can be selected where the electrostatic charging is negligible or absent. This depends in part on the own characteristics of the crystals, and can also be facilitated by using low accelerating voltage, e.g. 10 kV, well-conducting …

Techniques For The Microanalysis Of Higher Plants With Particular Reference To Silicon In Cryofixed Wheat Tissues, M. J. Hodson, A. G. Sangster

Scanning Microscopy

The applications of x-ray microanalysis in research into silicon in higher plants are reviewed, recent developments are assessed, and new data are presented. Conventionally prepared material [air or freeze drying for scanning electron microscopy (SEM), and glutaraldehyde/osmium tetroxide fixation for transmission electron microscopy (TEM)) has been studied using both wavelength and energy dispersive microanalysis. These techniques are reliable provided that the deposited form of silica is the major focus of investigation. Recently, studies concerning the soluble, mobile forms of silica, and the ionic environment at deposition sites have been initiated. In these investigations x -ray microanalysis has been carried out …

Bladder Stone In A Human Female: The Case Of An Abnormally Located Intrauterine Contraceptive Device, Saeed R. Khan, Edward J. Wilkinson

Scanning Microscopy

A single 4.7 x 3.3 x 1.5 cm solid nodule was removed from the bladder of a 24 years old white female who had lost an intrauterine contraceptive device (IUD) installed approximately four years ago. The nodule showed no external evidence of an IUD or its string. An examination of the nodular surface by scanning electron microscopy (SEM) showed mostly amorphous material with some adherent filamentous structures. Its energy dispersive x-ray microanalysis revealed the presence of calcium and phosphorus suggesting that the nodule was actually a urolith. Fracturing the nodule exposed an embedded entity consistent with being a copper IUD. …

Studies Of Epithelial Electrolyte Transport By Marker Ions, A. Dörge, R. Rick

Scanning Microscopy

The paper reviews several recent studies in which marker ions, such as Rb and Br, were used to identify ion transport pathways and membrane properties in epithelia. In the frog skin epithelium, using Rb as a substitute for K, Cl transport mechanisms across the basolateral membranes of principal cells were studied. The data suggest that intracellular Cl is maintained above electrochemical equilibrium by an Na-K-2Cl cotransport system which, under non-stimulated conditions, is normally quiescent.

In toad and frog skins, the route of transepithelial Cl movement was investigated. A subpopulation of mitochondria-rich cells demonstrated a ready exchange of Br with the …

A Comparison Of Three Low Temperature Techniques Of Specimen Preparation For X-Ray Microanalysis, R. J. Condron, A. T. Marshall

Scanning Microscopy

A quantitative x-ray microanalytical comparison of intracellular ion concentrations in two tissues (chicken kidney and duck nasal salt gland), prepared as bulk frozen-hydrated, embedded freeze-dried and freeze-substituted samples, shows that there are similar losses of K⁺ and Pin freeze-dried and freeze-substituted samples in both types of tissue. It is suggested that this may be due to extraction by chloride-free Spurr's resin during infiltration. There was also an indication of an increase in Na⁺ concentration in freeze-dried samples.

In chicken kidney cells there was a reduction in Mg⁺⁺ and Ca⁺⁺ concentrations in freeze-dried and freeze-substituted samples and …

Scanning Electron Microscopy Analysis Of Polyethylene Oxide Hydrogels For Blood Contact, Sylvie Laliberté Verdon, Elliot L. Chaikof, James E. Coleman, Lori L. Hayes, Raymond J. Connolly, Karen Ramberg, Edward W. Merrill, Allan D. Callow

Scanning Microscopy

Hydrogels are a class of synthetic material, composed of a polymer-water matrix and have been proposed as tissue substitutes and drug delivery vehicles. Polyethylene oxide (PEO) hydrogels were synthesized and used to produce coated wires and conduits for baboon blood compatibility studies. Blood-material interactions were studied both by Scanning Electron Microscopy (SEM) and ¹¹¹In labeled platelet deposition.

SEM processing modifications were first evaluated in order to reduce shrinkage and surface distortion incurred during sample preparation of these high water content materials. Pretreatment with 1% tannic acid reduced bulk shrinkage associated with critical point drying by 10-20%. This effect is …

Approximate Solutions Of The Boltzmann Equation For Secondary Electron Emission: Results And Comparisons To Experiments, A. Dubus, J. Devooght, J. C. Dehaes

Scanning Microscopy

The aim of the present paper is to survey the theoretical work performed in Brussels about secondary electron emission (SEE). Two new approximate solutions of the Boltzmann equation for internal secondary electrons are applied to both electron and ion induced SEE. Using a realistic set of interaction cross sections, most calculated characteristics of electron emission compare fairly well to experiments.

The "improved age-diffusion" model can be used to calculate the electron yield, the energy and angular spectrum and also the depth and radial distributions of outgoing electrons for incident electrons and ions.

The "transport-albedo" model assumes an uniform internal electron …

On The Varied Appearances Of The Human Placental Villous Surface Visualised By Scanning Electron Microscopy, G. J. Burton

Scanning Microscopy

Scanning electron microscopy enables extensive areas of the human placental villous tree to be viewed at high resolution in a relatively quick and easy manner. It is therefore an invaluable aid to the study of normal placental structure, and may have a potential role to play in pathological diagnosis. However, with increasing experience an awareness of the possible artefacts that may be introduced during fixation and tissue preparation is gradually developing. Some of these artefacts are common to other organs and applications of scanning electron microscopy, whereas others result from the unique structure and three-dimensional configuration of the placenta. Examples …

Survival Of Trout Strains As Affected By Limnological Parameters, Wayne A. Wurtsbaugh, Timothy Modde, Chris Luecke, Cheryl Courtney

Watershed Sciences Faculty Publications

Juvenile rainbow trout Oncorhynchus mykiss. (ca. 80 mm S.L.) stocked into mid-elevation reservoirs in Utah are vulnerable to predation from piscivorous fish and birds. I determined how effectively juvenile trout used cover to avoid these predators by using direct observations (snorkel transects) on habitat selection in two reservoirs. Observations of juvenile trout were conducted within five weeks of stocking in 1988 and 1989. During the day juvenile trout were abundant in complex inshore habitats. Juvenile trout actively fed during the day but the time of peak feeding was variable. Large Daphnia made of > 95% of the diet of juvenile trout. …

Multielement Analysis Of Biological Materials By Particle-Induced X-Ray Emission (Pixe), Willy Maenhaut

Scanning Microscopy

An analytical particle-induced X-ray emission (PIXE) procedure for the multielement analysis of biological materials consists of various stages. These include sample and specimen preparation, specimen bombardment, spectral data processing, quantification and correction for matrix effects. Critical aspects of the procedure are contamination and/or losses during sample and specimen preparation and the danger of radiation or heat-induced losses during specimen bombardment. With optimized PIXE procedures precisions of 1-2% and an accuracy of better than 5% are obtainable, whereas the detection limits are down to 0.1 μg/g. Because of its inherent characteristics, PIXE offers great potential for trace element analysis in the …

Scanning Electron Microscope Study Of Wohlfahrtia Magnifica (Schiner, 1862) (Diptera: Sarcophagidae) I. Structures With Parasitic And Possible Taxonomic Meaning, I. Ruíz-Martínez, M. D. Soler-Cruz, R. Benítez-Rodríguez, J. M. Pérez-Jiménez, C. Adalid-Fuentes, M. Díaz-López

Scanning Microscopy

The larval development of Wohlfahrtia magnifica (the most important dipteran causing sheep myiasis in the Palearctic region) has been studied by means of scanning electron microscopy. The ultrastructure of mouth-hooks, oral ridges, labial lobes, body spines and anterior and posterior peritremes is described for the first time. Their possible adaptations to a parasitic lifeway are also discussed. Thus, the use of new structures in the Sarcophagidae taxonomy is proposed from the point of view of their ultrastructure and adaptative morphology.

Responses Of Astrocytes In Culture After Low Dose Laser Irradiation, David T. Yew, D. R. Zheng, C. Au, W. W. Y. Li

Scanning Microscopy

The effect of Helium-Neon low dose laser on astrocytes was investigated in cultures of isolated astrocytes from albino neonatal rats. The laser appeared to inhibit the growth of astrocytes as exemplified by the smaller sizes of the cells and the decreased leucine uptake in each cell after treatment. Temporary decrease in the number of mitoses was also observed, but this trend was reversed soon after. Electron microscopic studies revealed an increase in buddings from cell bodies and processes (branches) after irradiation.

Detector Arrays In Confocal Scanning Microscopes, T. Wilson

Scanning Microscopy

We consider the use of detector arrays in scanning microscopes and show that confocal operation may be achieved in a variety of ways. We base our analysis on a consideration of the form of the optical transfer function or transmission cross coefficient. This reveals that the Fourier transform of the detector sensitivity function is the function of importance. It is not necessary that this function be constant over the whole space and hence a variety of detector sensitivity functions will give fully confocal imaging. The traditional method of a limiting point-like detector is a special case, but one which has …

Crystal Growth Of Calcium Oxalate Monohydrate And Calcium Carbonate From Dilute Solutions, Sergio Deganello, Livia Di Franco

Scanning Microscopy

By controlling evaporation, calcium carbonate (calcite) is precipitated together with calcium oxalate monohydrate from equimolar (1 x 10^-5 M) solutions of calcium chloride and sodium oxalate under decreasing (37.5° - 32.7°C) and increasing temperature (22°-42°, 22°-45°, 22°-50°C), and initial pH's of 6.6 and 6, respectively. If, however, the pH of the solutions is, respectively, 8 and 8.5 and the temperature is 32°C, oxalate breaks down to carbonate and calcium precipitates solely as calcite. This process materializes as the pH of both solutions initially adjusts to about 7.5. Both the quality and the size of the crystals of calcite and …

Particle Induced X-Ray Emission Elemental Analysis: Sample Preparation For A Versatile Instrumental Method, N. F. Mangelson, M. W. Hill

Scanning Microscopy

Particle induced X-ray emission (PIXE) has found extensive application as a multi-element analysis tool. The energetic nature of both the incident particle beam and the emitted characteristic X-rays has lead to considerable versatility in regard to samples which may be analyzed by the PIXE technique. This paper does not deal with the theory, equipment, or data analysis for PIXE, but it should bring to the reader a broad perspective of methods for sample preparation and should point the way into the literature where more complete details are given. Both physical and chemical processes for sample preparation are outlined. Preparation often …

Evidence That A Major Portion Of Cellular Potassium Is "Bound", Ivan L. Cameron, W. Elaine Hardman, Keithley E. Hunter, Christine Haskin, Nancy K. R. Smith, Gary D. Fullerton

Scanning Microscopy

In this report we briefly review recent evidence which shows that a substantial proportion of intracellular K⁺ is "bound" or perturbed from the physicochemical properties expected in dilute aqueous solutions. In addition, we present evidence from electron probe x-ray microanalysis of thin cryosections of cells which indicates that the binding of K⁺ to anionic groups either carboxyl groups (HCO₂) on proteins or to phosphate groups in creatine phosphate (CrP) , in adenosine triphosphate, (ATP), in protein and in nucleic acids, are the main determinants of the maintenance of (as differentiated from the generated of) the well …

Composition Depth Profiles Of High Temperature Superconducting Materials By Energetic Elastic Backscattering, C. R. Gossett

Scanning Microscopy

A review is given of the application of high energy elastic backscattering spectrometry techniques for profiling high-temperature superconducting (HTSC) materials in thin film form. The use of higher bombarding ion energies provides most of the advantages of the more common lower energy or Rutherford backscattering (RBS) but additionally allows profiling to a greater thickness and, by a much larger sensitivity for light elements, permits profiling carbon and oxygen in the presence of heavier substrates. Examples for HTSC materials are given.