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Ua66/6/2 Bionews From The Hill, Wku Biology

WKU Administration Documents

Newsletter created by and about WKU Biology highlighting the activities of faculty, students and alumni.

Low Voltage Scanning Electron Microscopy Cathodoluminescence Observations Of Gallium Arsenide, S. Myhajlenko

Scanning Microscopy

A series of low voltage ( < 5 keV) and low temperature ( < 20K) cathodoluminescence (CL) measurements were performed on epitaxial gallium arsenide. The purpose of these measurements was to ascertain which factors were important in furthering the development of low voltage scanning electron microscopy (LVSEM) CL. LVSEM CL potentially offers great improvement in spatial resolution and the ability to probe the optical properties of surface states. Anomalous CL effects resulting from contamination at beam voltages below 3.5 keV have been interpreted in terms of cross-over potential phenomena. Luminescence dead layers were reduced to near zero in this regime. Excitonic processes were found to be particularly sensitive to injection level and surface conditions. Very weak free-to-bound transitions persisted down to 200 eV beam voltage.

Small Mammal Demographics In North Dakota Conservation Reserve Program Plantings, Larry A. Lysne

Theses and Dissertations

During the summers of 1989 and 1990, capture-recapture methods were used to de~ermine small mammal demographics and population dynamics in Conservation Reserve Program (CRP) plantings in north central North Dakota. Four age classes (1-4 years) of CRP plantings were sampled. Small mammal species diversity was low (H'=0.057-0.374). Eight species of small mammals were captured on CRP tracts, with deer mice (Peromyscus maniculatus) comprising 92% of all small mammals recorded. Largest deer mouse populations (64/ha .and 51/ha) occurred in late August and early September, 1990. Peak densities in 1990 were over twice as high as those of 1989. Home range sizes …

The Role Of Tamm-Horsfall Glycoprotein And Nephrocalcin In Calcium Oxalate Monohydrate Crystallization Processes, B. Hess

Scanning Microscopy

Theoretical considerations as well as clinical observations suggest that the aggregation of nucleated crystals is the most dangerous step in the formation of calcium oxalate (CaOx) renal stones. The effects of 2 major urinary glycoproteins, Tamm-Horsfall glycoprotein (THP) and Nephrocalcin (NC), on calcium oxalate monohydrate (COM) crystal aggregation in vitro are studied. At low ionic strength (IS) and high pH (within urinary limits), THP is a powerful crystal aggregation inhibitor (90% inhibition at 40 mg/l). Decreasing pH to 5.7 and raising IS to 0.21 increases THP viscosity, thereby lowering THP crystal aggregation inhibition. Upon addition of calcium …

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.

Comparative Ontogeny Of Cranial Ossification In The Spotted Salamander, Ambystoma Maculatum, And The Tailed Frog, Ascaphus Truei, Michael Keith Moore

LSU Historical Dissertations and Theses

The ontogenetic sequence of ossification of the cranium, including descriptions of the development of individual elements, from initial appearance of bone through adulthood, is described for two species of amphibian: the Spotted Salamander, Ambystoma maculatum, and the Tailed Frog, Ascaphus truei. This study is based on cleared-and-stained developmental series of 269 specimens of Ambystoma and 325 of Ascaphus. Nine stages of cranial development are defined for Ambystoma maculatum. By metamorphosis, all bones of the skull of Ambystoma except the articular have begun to ossify. The ossification sequence of Ambystoma shows little interindividual variation; only 6 specimens do not follow the …

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.

Dynamics Of Bacterioplankton Abundance And Production In Seagrass Communities Of A Hypersaline Lagoon, Gerardo Chin-Leo, Ronald Benner

Faculty Publications

The significance of bacterioplankton in the flow of carbon and energy and in trophic dynamics of the upper Laguna Madre, Texas (USA), was estimated by measuring bacterioplankton abundance and production over an 18 mo period and over several diel cycles. Bacterioplankton production was estimated from incorporation rates of thymidine (DNA synthesis) and leucine (protein synthesis). These independent inhces of bacterial growth were generally in agreement and yielded nearly identical annual estimates of bacterial production (25.24 g C m^-2 yr^-1 based on thymidine and 25.12 g C m^-2 yr^-1based on leucine). Assuming a 30 % growth …

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 …

Bolivia 1991 Field Notes, Lila Alejandra Sainz-Bacherer

Division of Mammals - Field Notes and Catalogs

No abstract provided.

Distribution Of Sexual Activities Within Estrus Of Dairy Cattle, Donna Durbin

Masters Theses & Specialist Projects

Previous studies of dairy cattle have indicated that heifers and cows in hot, cold and moderate weather had different patterns of sexual activities. The purpose of this study was to compare distribution of sexual activities within estrus of dairy cattle. Three groups of lactating cows in hot, cold and moderate weather and a group of heifers in cold weather were observed. Estrus for each individual was divided into 12 equal periods. Sexual activities for 3 and 6 hours before and after estrus were also observed. The numbers of mounts and distribution of total sexual activities was analyzed. Mounts received per …

The Submembrane Machinery For Nicotinic Acetylcholine Receptor Clustering, S. C. Froehner

Dartmouth Scholarship

No abstract provided.

Survivorship And Recruitment In A Long-Lived Prairie Perennial, Ipomoea Leptophylla (Convolvulaceae), Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Little is known of the lifespans of herbaceous plants, especially in grasslands, although this information is basic to understanding the dynamics of species and ecosystems. Permanently marked plants of the bush morning glory, Ipomoea leptophylla (Convolvulaceae), in Nebraska sandhills prairie were censused annually from 1979-1989. While the average annual death rate was 2.6 per 100, virtually all the mortality was among smaller and probably younger plants. Recruitment varied greatly among years. Of plants of known age, the median age at first flowering was 6 yr. After 9 yr 30% had never flowered. Larger size classes flowered more frequently than smaller …

Mate Choice In Lekking Sage Grouse Revisited: The Roles Of Vocal Display, Female Site Fidelity, And Copying, Robert M. Gibson, Jack W. Bradbury, Sandra L. Vehrencamp

School of Biological Sciences: Faculty Publications

In lekking sage grouse (Centrocercus urophasianus), females exhibit relatively unanimous mate choice for particular males, but a satisfactory explanation for this unanimity has been elusive. We present analyses of mating distributions from two leks over 4 years that provide evidence for female choice based on differences in vocal display performance of males, the locations at which hens mated in the previous year, and the choices of other females (copying). The unanimity of female choice varied markedly among leks and years in correlation with changes in the mean numbers of hens that mated at the same time and hence …

Ua3/8/1 John Robinson Professorship Report, Wku Ogden College Of Science & Technology

WKU Administration Documents

Report by Dr. John Riley, John Robinson Professor of activities for 1990-1991 funded by Ogden Foundation.

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 Proline-Rich Structural Protein Of The Surface Sheath Of Larval Brugia Filarial Nematode Parasites, Murray E. Selkirk, Maria Yazdanbakhsh, Danie Freedman, Mark L. Blaxter, Edith Cookson, Rosalind E. Jenkins, Steven A. Williams

Biological Sciences: Faculty Publications

Both cDNA and genomic DNA sequences have been isolated which encode a proline-rich precursor protein of the sheath from microfilariae, the first stage larvae of the filarial nematode parasites Brugia pahangi andBrugia malayi. This 22-kDa protein is soluble only under reducing conditions and is extensively cross- linked by both disulfide and nonreducible bonds. Immunogold electron microscopy shows that the protein is localized exclusively in the sheath, a vestigial remnant of the eggshell, which is retained by and encloses the mature microfilaria. Analysis by Western blotting confirms that the protein is expressed only in microfilariae and adult female worms, although transcripts …

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 …}

Species Recognition In Wild-Caught Peromyscus Californicus And Peromyscus Boylii (Rodentia Cricetidae), Sue M. Abraham

Theses, Dissertations, and Projects

Experiments were performed to compare homospecific and heterospecific species choice in sympatric populations of Peromyscus californicus and P. boylii. Mate selection performance of males and females were also compared. For both species there was no significant difference between males and females in mate selection performance, and selection appeared to be random. Female P. boylii showed the highest preference for its own species as indicated by the amount of time spent in the homospecific chamber, but this choice was not statistically significant. When data for the two species are combined, the percent of time in the homospecific chamber is significantly different …

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 …

Anticarcinogenic, Antitumor, And Antifungal Properties Of Allium Sativum (Garlic), Padma P. Tadi

Loma Linda University Electronic Theses, Dissertations & Projects

In this study the antimutagenic/anticarcinogenic, immune enhancing, antitumor and antifungal effects of a crude extract and organosulfur compounds of garlic were determined. Diallyl sulfide (DAS), and ajoene each at 100 /xg/ml, and garlic extract (GE, 12.5 mg/ml) inhibited rat liver 9000 X g supernatant (S- 9) dependent mutagenesis in Salmonella typhimurium TA100 induced by either aflatoxin B1 (AFB^ or benzo[a]pyrene (B[a]P). The garlic compounds were shown to inhibit the binding of [³H]AFB₁ to calf thymus DNA and the formation of specific AFB_1-DNA adducts. These effects on mutagenesis and DNA binding correlated with an inhibition of …

Separate Sex-Influenced And Genetic Components In Spontaneously Hypertensive Rat Hypertension, Monte E. Turner, Mark L. Johnson, Daniel Ely

Biology Faculty Research

Previous results from our laboratory indicated two major genetic components of spontaneously hypertensive rat (SHR) hypertension, an autosomal component and a Y chromosome component. Two new substrains, SHR/a and SHR/y, were developed using a series of backcrosses to isolate each of these components. The SHR/a substrain has the autosomal loci and X chromosome from the SHR strain and the Y chromosome from the Wistar-Kyoto (WKY) rat strain. The SHR/y substrain has only the Y chromosome from the SHR and autosomal loci and X chromosome from the WKY strain. Throughout these breeding programs parents were chosen at random without selection for …

Androgen Receptor And The Testes Influence Hypertension In A Hybrid Rat Model, Daniel Ely, Ron Salisbury, Disha Hadi, Monte E. Turner, Mark L. Johnson

Biology Faculty Research

The objective of this study was to determine if males with a deficient androgen receptor would develop hypertension when crossed with a hypertensive parent. Female King-Holtzman rats (n = 15), heterozygous for the testicular feminization (Tfm) gene, were crossed with male spontaneously hypertensive rats (SHR), and blood pressure was measured weekly from 5-14 weeks in the F1 hybrid males. Approximately 50% of the F1 hybrid males were Tfm males and androgen receptor-deficient, and 50% were normal. Blood pressure in the parent King-Holtzman males, Tfms, and female rats was also followed for the same time period. The F1 normal male hybrids …

Comparison Of The Effects Of The Severe Freezes Of 1983 And 1989 On Native Woody Plants In The Lower Rio Grande Valley, Texas, Robert I. Lonard, Frank W. Judd

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Freeze damage to native woody plants was assessed at the same four sites in the lower Rio Grande Valley, Texas, in 1983 and 1989. The number of severely damaged species was greater in 1989 possibly because temperatures in 1989 were lower and longer in duration below freezing versus 1983. Thirty0five species (48.6%) had the same damage index value for the two freezes, and 24 (33.3%) species showed no damage in either year. More than half of the 72 species analyzed (55.5% in 1983 and 51.3% in 1989) showed no damage or only leaf damage, indicating most of the native woody …

Historical Changes In The Ichthyofauna Of The Lower Rio Grande (Río Bravo Del Norte), Texas And Mexico, Robert J. Edwards, Salvador Contreras-Balderas

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

CT-Collections of fishes from the lower Rio Grande (Rio Bravo del Norte) during the past 138 years suggest two indigenous faunal assemblages. One fauna is upstream, composed of mostly freshwater species, and the other is a downstream assemblage composed of a mixture of the more abundant upstream elements and more estuarine species. Recent collections in the lower Rio Grande indicate that major alterations in these fish communities have occurred. The upstream fauna has lost many of its characteristic freshwater components; native freshwater species have been replaced by exotic (=non-native) or estuarine forms. The downstream fauna has many fewer freshwater taxa …