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X-Ray Microanalysis Of Cells In Suspension And The Application Of This Technique To The Study Of The Thymus Gland, A. Warley

Scanning Microscopy

Although X-ray microanalysis has become a well established technique in the study of tissues there are still relatively few papers reporting results from cells in culture. Our early investigations on freshly isolated murine thymocytes reported higher than expected concentrations of Na and Cl in these cells but subsequent studies have shown that these high concentrations are artefactual. Rat thymocytes that have been isolated and incubated for a short time to allow them to recover from the isolation procedure have lower concentrations of Na and Cl. Sections prepared from pellets of cells which have been concentrated by centrifugation in a microhaematocrit …

Scanning Electron Microscopy Of Vascular Smooth Muscle Cells From Rat Muscular Arteries, William J. Krizmanich, Robert M. K. W. Lee

Scanning Microscopy

The use of scanning electron microscopy (SEM) for the examination of medial smooth muscle cells (SMC) is limited by the presence of connective tissue mass in the adventitia obscuring the detailed structure of the SMC. This study deals with the description of a method which selectively removes the connective tissue, allowing three dimensional observation of SMC using SEM. A number of methods were tried. One method involving post fixation with 2% Os0₄ used in conjunction with HCl proved most successful in removing the extracellular matrix of large mesenteric arteries from spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto normotensive rats …

Multiplane Sectioning And Scanning Electron Microscopy As A Method For Studying The Three-Dimensional Structure Of Mature Dental Enamel, S. Risnes

Scanning Microscopy

A method is described where teeth are sectioned/ground along at least two planes, etched, and viewed at various angles in the SEM in order to study the three-dimensional structure of enamel. This multiplane sectioning-scanning electron microscopy (MPS-SEM) method has been applied to the study of rat and human enamel. The method demonstrates in a direct way the complex three-dimensional structure of rat incisor enamel; the path of prisms and the distribution of interprismatic substance. The different appearance of alternate prism rows as seen in the longitudinal plane is seen to be due to prisms in alternate rows being inclined to …

Analysis Of Clean Transition Metal Surfaces By Core Level Spectroscopy, M. C. Desjonquères, D. Sébilleau, G. Tréglia, D. Spanjaard, C. Guillot, D. Chauveau, J. Lecante

Scanning Microscopy

The shifts in the binding energy of core electrons detected by high resolution X-ray photoelectron spectroscopy are a very sensitive probe of the chemical bonding of the excited atom. Since the surface atoms have their geometrical environment perturbed, their core levels are shifted from their bulk positions. A very large number of experiments have been performed on the 4f core level positions of tantalum and tungsten for various orientations of the surface plane. Systematic trends have been put forward and explained by theoretical models. Furthermore, the analysis of the angular variation of the core level line intensities gives structural information …

Studies On The Occurrence And Elemental Composition Of Bacteria In Freshwater Plankton, K. N. Booth, D. C. Sigee, E. Bellinger

Scanning Microscopy

The occurrence and cation content of bacteria in a eutrophic freshwater lake (Rostherne Mere, Cheshire, UK) were investigated over a one year sampling period in relation to cation changes in the lake surface water and phytoplankton.

Scanning electron microscope examination of trawl-net and filtered samples demonstrated bacterial association with Anabaena, Aphanizomenon and diatoms. Direct counts of associated and unassociated bacteria showed that increases in bacterial population relate to population decline of major algal constituents.

Spectrophotometric determination of selected cation levels in the lake water demonstrated wide fluctuations throughout the sampling period, with elevated levels of transition metals before and at …

The Fine Structure Of The Human Placental Villus As Revealed By Scanning Electron Microscopy, G. J. Burton

Scanning Microscopy

Scanning electron microscopy of the placenta has a history of only twenty years. During that time, however, there have been dramatic advances in instrument technology coupled with the refinement of preparative techniques designed to reduce fixation artifacts to a minimum. As a result many of the early claims must be amended or suitably qualified, and this is one aim of the present review.

Much new data on the internal structure of the placental villus is also presented. By means of the partial digestion technique it is now possible to describe the three dimensional configuration of the various components of the …

Electron Probe Micro-Analysis And Laser Microprobe Mass Analysis Of Material Leached From A Limestone Cathedral, L. A. Leysen, J. K. De Waele, E. J. Roekens, R. E. Van Grieken

Scanning Microscopy

Electron probe X-ray micro-analysis (EPXMA) and Laser microprobe mass analysis (LAMMA), were applied to characterize the leachate of sandy limestones of a Belgian cathedral.

Individual suspended particles, found in water that was sprayed over the cathedral walls ("1 each ate water"), were sized and analyzed by automated EPXMA-analysis, and classified with hierarchical cluster methods. LAMMA was used to gather more information about particles, present in the solution, as well as in suspension.

It was found that the leachate from black walls, had a high sulphate concentration and a large variety of particles in suspension, with different morphology and composition, with …

Leafcutting Ant Diet Selection: The Role Of Nutrients, Water, And Secondary Chemistry, Jerome J. Howard

Biological Sciences Faculty Publications

The relationship of plant secondary chemistry, water content, and nutrient content to the palatability of leaves to the leafcutting ant Atta cephalotes was determined in a study of individuals from 50 woody plant species in tropical dry forest of Costa Rica. The study took place during the yearly period of maximum leaf harvest, in the early rainy season. The palatability of plants was determined by presenting leaf disks to ants on active foraging trails of three ant colonies. The distribution of several classes of polar secondary compounds in leaf samples was determined using chemical spot tests, and that of ant- …

Interaction Of Trace Metal Contaminants On Hematological Responses: Influence Of Infection With Trypanosoma Lewisi, Yvonne Hogan, Clarence Lee

Department of Biology Faculty Publications

The influence of trace metal contaminants (lead, cadmium, and mercury) on Sprague-Dawley rats was investigated to determine whether subclinical levels of these metals might have adverse effects on the host's ability to respond to an infective agent.In the present study, a trace metal contaminant-trypanosome system was employed to observe the hematological changes in rats infected with Trypanosoma lewisi. The animal groups were: (1) lead (Pb), (2) cadmium (Cd), (3) mercury (Hg), and (4) controls (animals not exposed to trace metals).Regardless of the trace metals, infected animals showed decreases in total erythrocyte counts and lower hematocrit values. Generally, infected animals also …

Review Of Flora Fanerogamica Del Valle De Mexico, David J. Keil

Biological Sciences

No abstract provided.

A Description Of Mixed-Species Insectivorous Bird Flocks In Western Mexico, Richard L. Hutto

Biological Sciences Faculty Publications

Insectivorous bird flocks were observed in all types of forested habitats during the nonbreeding season in western Mexico. The species composition of flocks changed markedly and predictably among five categories of habitat type. The average number of species per flock in lowland habitats was 4.7, while a mean of 18.6 species participated in highland flocks, ranking the latter among the most species-rich flocks in the world. The mean proportion of the local insectivorous species that participated in mixed-species flocks was significantly greater in the highlands (61.3%) than in the lowlands (24.6%). About half of the flock participants in both undisturbed …

Thermal Dependence Of Maximal Ca2+-Activated Force In Skinned Muscle Fibres Of The Toad Bufo Marinus Acclimated At Different Temperatures, Bernard Rees

Biological Sciences Faculty Publications

Mechanically skinned muscle fibres from the twitch region of the iliofibularis muscle of cool- (16 +/- 1 degree C) and warm- (32 +/- 1 degree C) acclimated cane toads (Bufo marinus) were activated maximally by Ca2+ in solutions of different pH and at different temperatures (approx. 1-35 degrees C). Acclimation of up to 12 weeks at 16 degrees C and up to 8 weeks at 32 degrees C did not modify the marked thermal dependence of isometric force in the skeletal muscle fibres of the cane toad. The prominent decline of maximum Ca2+-activated force at lower temperatures, a property which …

Comparison Of Littoral And Limnetic Zooplankton Communities Of Lake Mead, Patrick Joseph Sollberger

Publications (WR)

Microfaunal communities were studied in littoral (inshore) and limnetic (offshore) areas of the lower basin in Lake Mead to compare species composition and abundance between the two zones. Planktonic forms (zooplankton) dominated inshore and offshore habitats and the occurrence of littoral species was low. Therefore, high similarity in zooplankton species composition was found among all sampling stations. This was perhaps due to two main factors: (i) the physical and chemical environment among the stations were very similar and (ii) the lack of aquatic vegetation in the littoral zone reduced the occurrence of littoral species.

Although species composition did not vary …

Adaptation Of Striped Bass To Sea Water Following Direct Transfer From Freshwater: Morphological, Biochemical, And Physiological Parameters, Judy A. King

Electronic Theses and Dissertations

There has been heightened interest in the biology of striped bass (Morone saxatilis) because of increased pollution in their native spawning grounds and because of their extensive use in landlocked sport fisheries. Their euryhalinity makes them an excellent species for osmoregulation studies. The objective of this research was to study the rate of adaptation of striped bass gills to sea water (3% salt) after direct transfer from freshwater using biochemical (ion transport enzyme levels), physiological (chloride efflux), and ultrastructural methods. Striped bass have specialized osmoregulatory cells located on the interlamellar and afferent surfaces of their gill filaments as shown by …

Fatigue From High- And Low-Frequency Muscle Stimulation: Contractile And Biochemical Alterations, Joseph Mark Metzger, Robert H. Fitts

Biological Sciences Faculty Research and Publications

This study examined the effect of high- (75 Hz, 1 min) and low- (5 Hz, 1.5 min) frequency stimulation on contractile and biochemical properties of the diaphragm. Tension was reduced to 21 ± 1 and 54 ± 2% (SE) of the initial value after high- and low-frequency stimulation, respectively. After 0, 0.25, 1, and 2 min of recovery from high-frequency stimulation, 5 Hz elicited more force (expressed as % of initial tension) than 75-Hz stimulation. Time 0 recovery values were 21 ± 1 and 78 ± 6% of the initial force for 75- and 5-Hz stimulation, respectively. By 1 min …

The Control Of Myocardial Contraction With Skeletal Fast Muscle Troponin C., A. Babu, Stylianos P. Scordilis, E. H. Sonnenblick, J. Gulati

Biological Sciences: Faculty Publications

The present study describes experiments on the myocardial trabeculae from the right ventricle of Syrian hamsters whose troponin C (TnC) moiety was exchanged with heterologous TnC from fast skeletal muscle of the rabbit. These experiments were designed to help define the role of the various classes of Ca2+-binding sites on TnC in setting the characteristic sensitivities for activations of cardiac and skeletal muscles. Thin trabeculae were skinned and about 75% of their troponin C extracted by chemical treatment. Tension development on activations by Ca2+ and Sr2+ was found to be nearly fully blocked in such TnC extracted preparations. Troponin C …

Behavioral Feeding Specialization In Pinaroloxias Inornata, The “Darwin's Finch” Of Cocos Island, Costa Rica, Tracey K. Werner, Thomas W. Sherry

Dartmouth Scholarship

As a population, Cocos Finches exhibit a broad range of feeding behaviors spanning those of several families of birds on the mainland, while individuals feed as specialists year-round. Although this extreme intraspecific variability occurs as predicted in a tropical oceanic island environment, these specializations challenge contemporary ecological theory in that they are not attributable to individual differences in age, sex, gross morphology, or opportunistic exploitation of patchy resources. Instead, they appear to originate and be maintained behaviorally, possibly via observational learning. This phenomenon adds another direction to the evolutionary radiation of the Darwin's Finches and underscores the necessity for detailed …

Myology Of The Pectoral, Branchial, And Jaw Regions Of The Ratfish Hydrolagus Colliei (Holocephali), Dominique Didier '87

Honors Projects

The musculature of the jaw, branchial, and shoulder regions of the ratfish, Hydrolagus colliei, was dissected and described in an effort to determine possible homologous characters shared by the shark, a member of the subclass Elasmobranchii, and the ratfish, a member of the subclass Holocephali. The musculature of the ratfish jaw differs from the morphological pattern found in sharks in that the jaw muscles of the ratfish are located anterior to the orbit, unlike the jaw muscles of sharks, which are posterior to the orbit. It is suggested that this anterior musculature is a character that was shared by fossil …

Review Of "A History Of Embryology" Edited By T. J. Horder, J. A. Witkowski, And C. C. Wylie, Scott F. Gilbert

Biology Faculty Works

No abstract provided.

Role Of Intracellular Ph In Muscle Fatigue, Joseph Mark Metzger, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Intracellular pH of in vitro diaphragm preparations was determined following low- (5 Hz, 1.5 min) and high- (75 Hz, 1 min) frequency stimulation, using glass microelectrodes of the liquid membrane type (pH_m). Results were compared with values obtained by the standard homogenate technique (pH_h). High- and low-frequency stimulation reduced peak tetanic tension to 21 ± 1 (SE) and 71 ± 2% of initial values, respectively. Peak tetanic tension returned to resting values after 10- to 15-min recovery from high- or low-frequency stimulation. Resting pH_m was 7.063 ± 0.011 (n = 72), and after fatiguing …

Book Review Of Evolution As Religion, Carl J. Bajema

Other Scholarly Publications

No abstract provided.

Heterozygosity And Oxygen-Consumption Rate As Predictors Of Growth And Developmental Rate In Rainbow-Trout, Roy G. Danzmann, Moira M. Ferguson, Fred W. Allendorf

Biological Sciences Faculty Publications

No abstract provided.

Responses To Snake Odors By Laboratory Mice, Paul Weldon, Frances Divita, George Middendorf

Department of Biology Faculty Publications

Male and female laboratory mice (; Harlan Sprague Dawley) were tested for reactions to snake odors. In the first experiment, mice were presented with untreated paper on the floor of one side of a test tank and snake-scented or control (water misted) paper on the other side. The scented papers were obtained from rough earth snakes (), which were fed earthworms, and a rat snake (), which ate mice. Male mice exhibited no differences in response to the three conditions. Female mice showed no response to the control or earth snake odor, but they deposited significantly more fecal boli on …

Contingency Analysis Of The Agonistic Behavioral Sequence In Sceloporus Undulatus Hyacinthinus, Deborah Allison

Masters Theses & Specialist Projects

A contingency analysis of the sequence of actions associated with agonistic behavior of resident and introduced male Sceloporus undulatus nya irthirus was carried out to determine the degree of stereotypy. During the time period April to June 1984 and 1985, caged pairs of adult male and juvenile female lizards were filmed on three occasions in order to gather data on resident males not involved in aggressive interactions. During the same threemonth time period, a different nonresident male was introduced singly into a given resident's cage on three occasions and the interactions filmed. The films were analyzed to determine which actions …

Western Rock Lobster Industry Compensation Study. Report To The Rock Lobster Industry Advisory Committee By Arthur Young Services., Arthur Young Services

Fisheries Management Papers

Terms of reference are outlined in letter dated 11 August 1986. The Fisheries Department seeks to reduce western rock lobster fishing capacity to ensure the long-term viability of the fishery and has asked us to evaluate the financial implications of a number of specific resource management proposals.

Density, Length Frequency Distribution, Growth Rate, And Condition Of The Freshwater Mussel, ̲A̲N̲Od̲O̲N̲T̲A ̲I̲M̲B̲E̲C̲I̲L̲L̲I̲S Say 1829, In Six Ponds At The Clifton F. Mcclintic Public Hunting And Fishing Area, Mason County, West Virginia, Jeff L. Harmon

Theses, Dissertations and Capstones

Populations of the freshwater mussel Anodonta imbecillis Say 1829, were sampled from six ponds at the Clifton F. McClintic Public Hunting and Fishing Area in Mason County West Virginia from April 1986 to May 1987. One of the six ponds, pond 12, is contaminated with byproducts from the manufacture of TNT which occurred at the site during World War II. Population density, length frequency distribution, growth rates and condition indices were examined for each population to establish baseline data for the species and to determine what effects the contaminants might be having on these organisms.

Population densities ranged from 4.8 …

Additions To The Flora Of Connecticut, Gordon Tucker

Faculty Research & Creative Activity

Three species of vascular plant are newly recorded for the flora of Connecticut. These are: Linaria dalmatica 1L. (Scrophulariaceae ): Eupatorium album L., and Aster blakei (Porter) House (Compositae).

Additions To The Flora Of Connecticut, Gordon C. Tucker

Faculty Research & Creative Activity

Three species of vascular plant are newly recorded for the flora of Connecticut. These are: Linaria dalmatica 1L. (Scrophulariaceae ): Eupatorium album L., and Aster blakei (Porter) House (Compositae).

Mammals Of Spanish Peaks State Wildlife Area, Colorado, Ron S. Mellott, Jerry R. Choate, Charles Loeffler

Fort Hays Studies Series

Habitats and relative abundance of small mammals in the Spanish Peaks State Wildlife Area in western Las Animas Co., Colorado, were assessed. A total of 821 mammals of 20 species was collected in 2750 trapnights between 31 May and 19 August of 1981. Eight additional species of mammals were observed on the wildlife area but not documented. The deer mouse (Peromyscus maniculatus) and rock mouse (P. difficilis) were the most abundant small mammals, accounting for 63 and 16%, respectively, of the total catch. The deer mouse was the only species caught in every habitat sampled. Abert's squirrel (Sciurus abert,) previously …

The Genera Of Cyperaceae In The Southeastern United States, Gordon C. Tucker

Faculty Research & Creative Activity

No abstract provided.