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Prerequisites Of High Resolution Scanning Electron Microscopy, René Hermann, Martin Müller

Scanning Microscopy

Cryotechniques must be employed throughout all preparation and observation steps in order to extract high resolution scanning electron microscopical information from biological material.

Cryoimmobilization, followed by freeze-drying and metal-shadowing at low temperature, yields optimal structural information of T4 polyheads used as a test specimen. Freeze-substitution of frozen T4 polyheads and subsequent freeze-drying renders the substructures recognizable but less crisp than freeze-drying from aequous solutions. Critical point drying of ethanol dehydrated chemically fixed, or freeze-substituted test specimens results in complete loss of discrete polyhead structure.

In-lens field-emission scanning electron microscopes and highly sensitive electron detectors are instrumental prerequisites in achieving transmission …

Beam Sensitivity Of Globoid Crystals Within Seed Protein Bodies And Commercially Prepared Phytates During X-Ray Microanalysis, Irene Ockenden, John N. A. Lott

Scanning Microscopy

Magnesium, potassium, calcium and phosphorus are stored in seed tissues in spherical particles called globoid crystals. The main component of globoid crystals is phytin, a salt of myo-inositol hexaphosphoric acid. Based on chemical similarity, commercially available phytates may be suitable standards for quantitative energy dispersive X-ray (EDX) microanalysis of globoid crystals. The stability of globoid crystals and commercial phytates was different when analyzed under identical conditions. Phytates in globoid crystals from Cucurbita maxima cotyledons, were relatively stable in the electron beam during EDX microanalysis at room temperature, but there was a loss of potassium. No loss of potassium occurred during …

The Vestibular Epithelia In Experimental Hydrops, K. C. Horner, S. Rydmarker

Scanning Microscopy

Morpho-pathological features, observed by scanning electron microscopy, in guinea pigs with endolymphatic hydrops of 4-14 months included shortening of the hair cell tufts, loss of tufts, retraction of sensory hair cells away from the surrounding tissue and hair cell loss. After 22 months of hydrops, there was complete loss of hair cells with indifferentiation of the epithelium. The loss of ciliary tufts involved loss of both stereocilia and kinocilia identified as short stubs and holes respectively. Control macular epithelia showed no hair tuft loss although ampullae in control ears could show some loss.

Morphological Study Of Calcospherites In Rat And Rabbit Incisor Dentin, H. Mishima, T. Sakae, Y. Kozawa

Scanning Microscopy

Calcospherites from incisors of rats and rabbits were studied, by means of secondary and backscattered electron images, using scanning electron microscopy. Part of each incisor specimen was made anorganic to allow observation of the surface of the mineralization front by scanning electron microscopy; the other part was ground on one side for observation by scanning electron microscopy with a backscattered electron image detector. In both species the labial mineralization front was wavy and the image showed fused calcospherites, whereas the lingual mineralization front appeared to consist of a combination of linear and globular forms. In rat labial dentin the calcospherites …

Retention Of Calcium Oxalate Crystals In Renal Tubules, Saeed R. Khan, Raymond L. Hackett

Scanning Microscopy

Crystal retention within the renal tubules is essential for nephrolithiasis and the development of urinary stone disease. We studied the mechanisms involved in this process by inducing calcium oxalate crystal deposition within the rat renal tubules and examining them using various microscopic techniques. Crystals appeared to be retained either by attachment to the tubular epithelium or by aggregating with other crystals thus becoming large enough to be retained by their collective size.

Seed Coat Surface Patterns And Structures Of Oxytropis Riparia, Oxytropis Campestris, Medicago Sativa, And Astragalus Cicer, D. J. Solum, R. H. Lockerman

Scanning Microscopy

Scanning electron microscopy was used to examine external and internal seed coat structures of Oxytropis riparia Litv., Oxytropis campestris L., Medicago sativa L., and Astragalus cicer L. for characteristics useful in taxonomic classification and to identify hard seed coat components which affect permeability. Seed coat surfaces of the four species were distinctly different. Palisade and hourglass cell lengths and parenchyma and endosperm cell layer thicknesses were similar among species with the exception of O. campestris seeds which lacked an identifiable endosperm layer. Surface pattern differences and the presence of a distinct endosperm layer are useful in separating these genera and …

Utah Science Vol. 52 No. 2, Summer 1991

Utah Science

42 A Focus on Natural Resources Range Science Department

43 Determining How Rangeland Plants Get Along

44 Desert Crusts: Irreplaceable Veneer or Ecological Frosting?

47 Rhizomes vs. Tussocks: Which Grow Better?

48 Like Us, Plants will Notice Ozone Depletion

50 Grazing May Be Unfairly Blamed for Changes in Pristine Areas

51 Underground Events May Be Root of Grass Behavior Geography and Earth Resources Department

53 New Geography Simplifies Complexity Fisheries and Wildlife Department

55 Complexity, Human Expectations Alter Fisheries and Wildlife Research

56 Healthy Fish--Barometer of a Healthy Environment

59 USU Program Helps Manage Forests for Fish

60 Millions Flock …

Mormon Crickets: A Brighter Side, Charles Macvean

All Current Publications

In a recent appraisal of Mormon crickets (Anabrus simplex Haldeman), Raffelson (1989) reminds us that these insects are a subject of great concern and dislike among Western ranchers and farmers.

Scanning Electron Microscopy Of Corrosion Casting In Medicine, M. A. Konerding

Scanning Microscopy

The aims of this review are: 1. to provide a bibliography of the publications that have used the corrosion casting technique; 2. to describe the advantages and limitations of the methodology; 3. to illustrate possible applications in the field of medicine, and 4. to highlight the significance of this method in the teaching of medical students. Thus, this paper is primarily focused on the scanning electron microscopical examination of vascular corrosion casts.

The unsurpassed three-dimensionality of the corrosion casting technique compared to any other means stands out in particular. This can be especially useful when complex vascular-anatomical relationships are present. …

A Technique For Correlative Scanning And Transmission Electron Microscopy Of Individual Human Placental Villi: An Example Demonstrating Syncytial Sprouts In Early Gestation, G. J. Burton, K. W. Thurley, J. N. Skepper

Scanning Microscopy

Correlating the surface appearances of certain features with their internal structure is made particularly difficult in the human placenta by the complex three-dimensional branching pattern of the villous tree. This places a possible limitation on the use of the scanning electron microscope in this field, both for basic research purposes and as a tool in pathological diagnosis. To help overcome this problem, a technique for handling individual placental villi has been devised. By attaching single villi to glass pipette tips it has proved possible to scan the villi, embed them in resin and then section them in a known pre-determined …

Preparation Of Inner Ear Sensory Hair Bundles For High Resolution Scanning Electron Microscopy, M. P. Osborne, S. D. Comis

Scanning Microscopy

Chemical fixation techniques for preservation of sensory hair bundles in the mammalian inner ear for scanning electron microscopy (SEM) are reviewed. Fixatives employed were glutaraldehyde, glutaraldehyde-picrate, glutaraldehyde-tannic acid, glutaraldehyde-formaldehyde, glutaraldehyde followed by postfixation with osmium tetroxide and the osmium thiocarbohydrazide (OTOTO) method. Dehydration was routinely accomplished with ascending grades of acetone followed by critical point drying with liquid CO₂ or fluorocarbon sublimation. Specimens other than those prepared by the OTOTO method were metal coated with gold, gold-palladium or platinum. Material was viewed at high resolution (2-3 nm) in a transmission electron microscope (TEM) fitted with a scanning system and …

Thin Sectioning Of Carbonaceous Adsorbent Spheres For Visualization By Light Microscopy And Scanning Electron Microscopy, Samuel H. Cohen, Ronald A. Segars

Scanning Microscopy

Three different types of Rohm and Haas carbonaceous adsorbent spheres (XE-340, XE-347 and XE-348) were prepared for light and scanning electron microscopy by embedding in resin and by thin sectioning. Spurr's low viscosity resin, because of its penetrating and wetting ability, contributed to the production of the most uniform and artifact free thin sections. In addition to thin sectioning, gas adsorption surface area measurements were made on batches of each type of sphere.

There was an apparent relationship between the surface area measurements of 417.8 m²/g for XE-340, 583.4 m²/g for XE-347 and 752.9 m^{2 …}

Scanning Electron Microscopic Analysis Of Dental Wear On The Heavily Worn Second Molars Of The Wild Japanese Monkey (Macaca Fuscata), Teruyuki Hojo

Scanning Microscopy

Microscopic features on scanning electron micro-graphs of epoxy-replicas of the second molars of nine wild-caught adult female Japanese monkeys, Macaca fuscata, from Oita Takasakiyama, Kyushu, were measured using a digitizer. These monkeys had been fed a monkey-diet during three or four days of captivity before replicas were made. Six of these specimens showed such heavily worn second molars that narrow peripheral enamel bands surrounded large dentin exposures and the cusps of the others had been worn off. Microwear measurements from sites near facet 9 were compared with those of facet 9 of three kinds of hard-object feeding primates from …

Elemental Mapping Of Cryosections From Cnidarian Nematocytes, Karl Zierold, Pierre Tardent, Sergey V. Buravkov

Scanning Microscopy

The distribution of elements in stinging capsules containing cells called nematocytes is shown by pseudocoloured maps representing the X-ray intensity collected from freeze-dried cryosections. This method provides a distinct overview in addition to the quantitative evaluation of single X-ray spectra. Selected examples illustrate the elemental compartmentation in various cnidarian animals. In particular the matrix of capsules in Hydra vulgaris contains high amounts of K in comparison to the tubule, the surrounding capsule wall and the cytoplasm, whereas in Actinia eguina capsules have either high concentration of Ca or Mg, the latter accompanied by S.

Backscattered Electron Imaging For High Resolution Surface Scanning Electron Microscopy With A New Type Yag-Detector, Paul Walther, Rudolf Autrata, Ya Chen, James B. Pawley

Scanning Microscopy

Double Layer Coating for backscattered electron imaging is a coating and imaging method especially suitable for high resolution scanning electron microscopy (SEM) of large biological samples. Since the backscattered electron (BSE) signal from thin metal coating layers is quite low, field emission SEM's and very sensitive BSE-detectors are required for this method. In this study an improved BSE-detector of the YAG type was used with an in-lens type field emission SEM. Two samples were investigated in order to demonstrate and to improve the potential of this new approach: (1) cryo-prepared cultured kidney cells were shadowed by electron beam evaporation with …

The Study Of The Surface Geometry Of Renal Stone Fragments After Shock Wave And Ultrasound Disintegration, Roch Thibert, Rashad Tawashi

Scanning Microscopy

Computerized image analysis was used for characterizing the irregular boundaries of calcium oxalate stone fragments resulting from shock wave and ultrasound disintegration. The complexity of the contour of the fragments was determined to evaluate the surface roughness of the rugged profile of the samples. Crack propagation on the crystal surface of the mineral phase was studied using fractal geometry. A significant difference was observed in the boundary variation of the calcium oxalate stone fragments treated by shock wave and ultrasound. Crack propagation in the mineral phase crystal was found to depend on the method of fragmentation used. There is also …

Scanning Tunneling Microscopy Imaging Of Synthetic Oligonucleotides And Oligonucleotide-Metal Complexes, Yun Kim, Charles M. Lieber

Scanning Microscopy

Scanning tunneling microscopy (STM) has been used to image 12-and 24-base pair (bp) synthetic oligonucleotide duplexes alone or with intercalatively-bound metal complexes with submolecular resolution. The sizes of the 12-and 24-bp oligonucleotides determined from STM images are close to expected values, and images of isolated duplexes resolve the two nucleotide strands of these molecules. The variation of duplex size in our images demonstrates that these features are not due to surface artifacts. In addition, images of the 12-bp duplex in the presence of bis(9, 10-phenanthrenequinone diimine)(2, 2'-bipyridyl) rhodium(III) exhibit a new structural feature at 14 ± 2 Å from the …

Error Voltage Components In Quantitative Voltage Contrast Measurement Systems, D. S. H. Chan, T. S. Low, J. C. H. Phang

Scanning Microscopy

This paper presents the results of computer simulation studies into the respective contributions of the potential barrier, the off-normal incidence injection of secondary electrons (SEs) into the retarding field and analyser geometry on Types I and II local field error voltages for a practical 20 mm wide planar retarding field energy analyser. Results show that the error voltage component due to the off-normal incidence injection effect of SEs into the retarding field dominates the Type I local field error. For type II LFE, the error voltage component due to analyser geometry effect is the higher contributing factor. The presence of …

Isolation And Characterization Of A Linear Plasmid From The Entomopathogenic Fungus Ascosphaera Apis, Haiying Qin

Biology

An extrachromosomal DNA plasmid was isolated from both mating types of the entomopathogenic fungus Ascosphaera apis and named pAaL. The subculture first identified to carry pAaL originated from mummified honey bee larvae from an apiary in Wyoming, USA. Very similar, homologous plasmids were found in 13 out of 14 A. apis isolates collected from diverse geographic locations. Only one isolate obtained from New York was found to be plasmid-free. DNA hybridization indicated that pAaL is not homologous with another plasmid we isolated from Ascosphaera aggregata. This represents the first report of the presence of plasmids in entomopathogenic fungi. The …

The Interaction Of Harvester Ants And Vesicular-Arbuscular Mycorrhizal Fungi In A Patchy Environment: The Effects Of Mound Structure On Fungal Dispersion And Establishment, Carl F. Friese

Biology

The major objective of this dissertation was to describe some of the factors that may be important in the establishment of vesicular-arbuscular (VA) mycorrhizal fungi following a disturbance. The specific focus of the dissertation is primarily on the interaction of the western harvester ant and VA mycorrhizal fungi and how this interaction affects the dispersion and establishment of these mutualistic endophytes. Methods were developed to test the use of polyclonal antibodies on field and greenhouse samples. This approach proved viable and allowed me to differentiate between both the extramatrical hyphae and spores of introduced and native VA mycorrhizal fungi. I …

The Effects Of Drought On Yellow-Eyed Junco Breeding Biology And Energetics, Thomas C. Gumbart

Biology

Data presented in this thesis were collected on a population of Yellow-eyed Juncos (Junco phaeonotus) in the Chiricahua Mountains of southeastern Arizona, from 1985 to 1990. Severe drought and an associated reduction in the food supply occurred at the study site in 1989 and 1990. This provided the opportunity to document the effects of stressful environmental conditions on the breeding biology of the juncos. My field work covered the 1989 season, and for comparative purposes these thesis data are combined with data previously collected by Dr. Kimberly A. Sullivan and Dr. Wesley W. Weathers. Clutch size did not …

Utah State University Commencement, 1991 – Main Campus, Utah State University

Commencement Programs

Ninety-Eighth Annual Commencement of Utah State University

Two Potential Biocontrol Strategies: Puccinia Thlaspeos Schub. For Isatis Tinctoria L. (Dyer's Woad), And Sugar Beet Associated Bacteria For Phoma Betae, Branislav R. Lovic

Biology

Use of living organisms as a pest control measure is the essence of biocontrol. This study involves evaluation of the potential biocontrol agents for two organisms: a weedy plant species and a fungal plant pathogen. The weed is dyer's woad (Isatis tinctoria) which is rapidly encroaching on all lands in the Intermountain West. The fungal plant pathogen is Phoma betae, a seed- and soilborne pathogen of sugar beets. Puccinia thlaspeos, a native rust pathogen, causes systemic infection on dyer's woad, resulting in severe deformations of stems and leaves and prevention of seed production. It occurs in …

Immunocytochemical And Histopathological Investigation Of The Hypothalamic-Pituitary-Testicular Axis Of The Primary Infertile Dark Mink (Mustela Vison), Baha M. Alak

Biology

This study was designed to investigate the hypothalamic-pituitary-testicular axis of the primary infertile dark male mink. The specific objectives were (1) to describe the morphology and localization of the neurons containing gonadotropin-releasing hormone (GnRH) and its precursor (proGnRH) within the preoptic-basal hypothalamus (POA-BH) of the sexually mature dark male mink, (2) to ascertain any differences in the number or the distribution of GnRH- and proGnRH-containing neurons between the fertile and infertile dark male mink, (3) to determine if GnRH and proGnRH are produced in insufficient amounts by the hypothalami of primary infertile dark male mink, and (4) to describe the …

Effects Of Selected Insects On Seed Production Of Hycrest Crested Wheatgrass, Ali Yusuf Issa

Biology

Studies were conducted to explore the relationship of common insect pests associated with the cultivar 'Hycrest' crested wheatgrass, Agropyron cristatum (L.) and A. desertorum (Fisher x Link). Insect population surveys were conducted on three farms during three summers to determine relative insect numbers. Thrips, Trigonotylus ruficornis, and Lygus hesperus were found to be the most abundant insect pests infesting Hycrest plants. A broad population peak was observed covering most of July through August for thrips, T. ruficornis, and L. hesperus. In addition to pest insects, the following beneficial insects were collected in significant numbers: Nabidae, Coccinellidae, Collops …

Linear Operators Strongly Preserving Polynomial Equations Over Antinegative Semirings, Sang-Gu Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We characterized the group of linear operators that strongly preserve r-potent matrices over the binary Boolean semiring, nonbinary Boolean semirings, and zero-divisor free antinegative semirings. We extended these results to show that linear operators that strongly preserve r-potent matrices are equivalent to those linear operators that strongly preserve the matrix polynomial equation p(X) = X. where p(X) = X^r₁ + X^r₂ + ... + X^r_t and r₁>r₂>...>r_t≥2.

In addition, we characterized the group of linear operators that strongly preserve r-cyclic matrices over the same semirings. We …

A Descriptive Study Of The Use Of An Education-Sponsored Suicide Riskline, R. Kelly Haws

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study is to provide a descriptive evaluation of Jordan School District's riskline as a step toward assessing the effectiveness of education - sponsored suicide risklines. The riskline received over 1000 calls from mid 1988 to mid 1989 for a variety of problem areas. Demographics and risk assessment for the calls relating to suicide are presented and evaluated. The findings indicate that risk assessment is independent of all variables considered except the age of the counselor and the grade of the caller. The number of calls is independent of every variable considered except the grade level of …

Immunophenotyping Of Lymphoid Cells In Autism, L. Jeanne Yonk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Research into the cause of autism continues without any clear-cut answers. However, recent studies suggest that abnormalities of the immune system are associated with this disorder and autism results from failure of the immune system to regulate itself. Proper immune regulation requires that the host have the appropriate number and percentage of each population of lymphocytes and monocytes. These populations can be distinguished from one another with monoclonal antibodies that react with unique protein structures on the cell surface designated as the "cluster of differentiation" (CD) antigens.

This investigation studied the possibility that the immune abnormalities seen in autism are …

Predictors Of Change For Parents Who Perceive Improvement In Their Family Functioning Following A Parent-Training Program, Linda Gayle Moore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of the present study was to determine if perceptions of improved family functioning following a behavioral parenting program could be predicted by educational background, income, and pretest knowledge of behavioral principles. Subjects for the study were parents of elementary-school-aged children who volunteered for the parenting classes. Parents who perceived their families as dysfunctional, as measured by the pretest FACES II, were selected as subjects for the study. Parents whose perceptions of their families improved after the parenting class were then compared with parents who did not perceive improvement in their families on the predictor variables.

The results demonstrated …

Attention Deficit-Hyperactivity Disorder And Undifferentiated-Attention Deficit Disorder: Differences In Cognitive And Affective Characteristics And Responses To Stimulant Medication, Richard Alan Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cognitive and affective characteristics and responses to stimulant medication of children who were diagnosed as having attention deficit-hyperactivity disorder (AD-HD) or undifferentiated-attention deficit disorder (UADD) were investigated using a pretest-posttest experimental design. Nineteen AD-HD and 17 UADD children were compared using unpaired t-tests, prior to initiation of stimulant medication, on measures of intellectual functioning, impulsivity, problem behavior, and self-reported depression and self-esteem. Children from both the AD-HD (n = 12) and UADD (n = 12) groups were then compared before and after a 3-month trial of stimulant medication on measures of impulsivity, problem behavior, and self-reported depression …