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Determinants Of Small Rodent Distribution And Abundance In A Shrub-Steppe Ecosystem: Influences Of Seeds, Ants And Shrubs, Linda Suzanne Broome

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study had two major objectives; firstly to test the hypothesis of ongoing competition for seeds between small rodents and harvester ants, Pogonomyrmex occidental is, in a cold desert ecosystem; secondly to elucidate how seed abundance and shrub cover influence the distribution and abundance of deer mice, Peromyscus maniculatus. The study area was a sagebrush (Artemisia tridentata) dominated shrubsteppe in southwestern Wyoming. Responses of the small mammal community to ant removal and food addition were assessed on replicated study plots between September 1981 and September 1983. Food addition and shrub removal manipulations were continued from September 1983 …

The Cell Water Problem Posed By Electron Microscopic Studies Of Ion Binding In Muscle, L. Edelmann

Scanning Microscopy

The question whether cell K⁺ is free or bound in the striated frog muscle has been investigated during the last 10 years by different cryomethods and electron microscopy. The results support the view that most of cellular ions are osmotically inactive and that therefore the observed cell water activity must be explained by a model which assumes a specific cell water structure. According to the association-induction hypothesis, cell water is influenced by macromolecules and has low solubilities for Na⁺ and other solutes which therefore are partly excluded from cellular water. Autoradiography of frozen hydrated Na⁺ loaded muscles …

A Review Of Dental Microwear And Diet In Modern Mammals, Mark F. Teaford

Scanning Microscopy

Recent work has shown that microscopic wear patterns on teeth may yield insights into variations in diet and tooth use in modern and prehistoric mammals. This paper presents a review of dental microwear and diet in modern mammals, plus a discussion of topics for further research. To date, incisor and molar microwear have been examined, although there are far fewer studies of the former. Facilitated by the use of high-resolution casts and scanning electron microscopy, analyses have ranged from: qualitative to quantitative, low magnification to high magnification, and experimental studies to comparative studies of museum collections. Results are encouraging and …

Industrial Applications Of Auger Surface Analysis, R. E. Chase, G. S. Cole

Scanning Microscopy

Scanning Auger microscopy is distinguished by its unique combination of surface selectivity, high spatial resolution, ease of identifying elements and quantifying composition, and ability to distinguish between chemical states. This paper describes several applications of scanning Auger microscopy, emphasizing the range of industrial research activities:

1. Electronic Materials. Contamination in an integrated circuit processing facility was identified and procedures for its removal determined. Causes for the delamination of printed circuit board foils were identified. Superlattice films were characterized and the deposition process evaluated.

2. Tribology. Analysis of surfaces in lubricated sliding contact revealed the effects of con tact kinematics and …

Microanalytical And Micromorphological Investigations Of High Temperature Materials With And Without Protective Coatings, Volker Thien, W. Voss

Scanning Microscopy

The phenomenon "High Temperature Corrosion" (HTC) is described; three different types (pure oxidation, high temperature hot corrosion, low temperature hot corrosion) are defined. HTC is demonstrated taking gas turbine blades as an example. The results of laboratory HTC tests under defined conditions were compared with those of long time engine experience; the agreement is very satisfactory.

Metallurgical investigations with scanning electron microscopy and EDX-/WDX-analytical techniques gave explanations for the behaviour of protective coatings . The corrosion mechanism of a NiCrAlY-plasma spray coating is explained as consequence of Cr- and Al-oxidation. A special analytical technique - the "integral layer profile analysis" …

Preparation Of Biological Samples For Transmission X-Ray Microanalysis: A Review Of Alternative Procedures To The Use Of Sectioned Material, D. C. Sigee

Scanning Microscopy

Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular.

The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case …

Quantitative Morphology Of Synaptic Plasticity In The Aging Brain, Carlo Bertoni-Freddari, William Meier-Ruge, Jurg Ulrich

Scanning Microscopy

Quantitation of synaptic ultrastructural changes is of great importance in neurobiology, since merely qualitative alterations, if not extreme, are not readily detectable. In the present paper we discuss our previous and present findings on the number (numerical density: Nv), size (average length of the synaptic profiles: L) and surface contact area (surface density: Sv) of the synaptic junctions in aging rodent and human brains. We found that number and size of the synapses are in a close inverse relationship so as to maintain the total surface contact area among the nerve cells constant. These three parameters are closely related to …

Transit Time Effect On Voltage Contrast In The Stroboscopic Scanning Electron Microscope, K. Nakamae, H. Fujioka, K. Ura

Scanning Microscopy

Voltage contrast varies if the specimen voltage changes within the secondary electron transit time through the specimen electric field. This effect would affect the time resolution in stroboscopic scanning electron microscopy. The method to calculate the transit time effect that was described in a previous paper is reviewed. The calculated results agreed well with the experiment in which a specially designed specimen is used to estimate the applied voltage as exactly as possible.

Extraneous Background-Correction Program For Matrix Bound Multiple Point X-Ray Microanalysis, W. C. De Bruijn, M. P. C. Van Miert

Scanning Microscopy

A program is described that allows online determination of extraneous background in multiple point X-ray microanalytical matrices. The program is based upon the calculations of the extraneous background for the film (when present), the standard and the unknown by (100 sec.) point analysis. The program searches for a peak-free part of the spectrum in which the calculated value for the extraneous background is about equal to the value in this region of the spectrum (=b_e). Online the contents of this b_e-region is subtracted from an unmanipulated continuum region in the vicinity of the element present in …

Contrasting Views On The Organization Of Cytoplasm, J. S. Clegg

Scanning Microscopy

The widely held conception of cytoplasm as a concentrated solution of dissolved proteins and other macromolecules, metabolites and inorganic ions, within which the various organelles and other formed elements are suspended appears to be a gross over-simplification. Evidence to be reviewed briefly here, from a wide variety of experiments and cell types, indicates that a much more extensive organization exists, in animal cell cytoplasm at least. Results from experiments on dextran sulfate permeabilized L-929 cells will be presented which support that organized paradigm. It seems likely that this intracellular architecture also exerts a strong influence on the water in the …

Arterial Elastin As Seen With Scanning Electron Microscopy: A Review, Margot R. Roach, S. H. Song

Scanning Microscopy

All large arteries contain elastin, collagen, and muscle which can be seen with light microscopy and transmission electron microscopy. Elastin forms an internal elastic lamina (IEL) in all arteries, but also forms multiple fenestrated sheets in the media of the aorta and other large arteries. The fenestrations in the media are larger than those in the IEL. The adventitial elastin is more fibrous and often contains tubular elastin surrounding vasa vasorum when prepared by removing all non-elastin by placing the aorta in 0.1 N NaOH at 70-75°C for five hours. The fenestrations are larger near branches and in an experimentally …

Deficits And Interests Rates: An Empirical Investigation, Peter J. Saunders

Economic Research Institute Study Papers

Increasing federal government deficits have revived interest in theoretical discussions of the deficits' impact on an economy. This theoretical interest has recently been transformed into an economic policy issue in the form of the Gramm-Rudman-Hollings balanced budget legislation. Within the theoretical framework, the question of effects of increasing deficits on interest rates, and thereby on the level of investment and of economic growth is of special interest. Some economists emphasize the negative impact of deficit financing on private investment. This negative impact is largely due to the "fiscal crowd-out" whereby private investment is crowded-out by public borrowing. According to this …

Interferon-Induced Surface Alterations In Hairy Cells. A Review, Haim Gamliel, Dorit Gurfel, Shi-Hua Wu, Harvey M. Golomb

Scanning Microscopy

Hairy cells (HCs), derived from the peripheral blood and spleen of hairy cell leukemia (HCL) patients, constantly displayed both ruffles and microvilli. HCs which were kept in culture for up to three days exhibited extremely polarized and active surfaces with elongated microvilli and exaggerated "spiked" ruffles. Cells derived from 11 cases of HCL were treated with alpha-interferon (IFN) in-vitro and examined by immuno -scanning electron microscopy (immuno-SEM). In 8 cases, up to one-third of the IFN-treated hairy cells displayed deformed surfaces with "bubbling" membrane and markedly villous bud-like formations. Monoclonal antibodies (MoAb), used in conjunction with immuno-qold labeling, facilitated better …

Enhanced Floral Analysis By Low Temperature Scanning Electron Microscopy, Brenda Brookes, Ernest Small

Scanning Microscopy

Traditional methods of preparation of botanical specimens for scanning electron microscopy (SEM) have proven to induce artifacts in some specimens which often reduce quality of resulting images, and are highly misleading for taxonomic purposes. The advantages of low temperature SEM are illustrated by an investigation of freshly collected flowers, using a cryo-system interfaced to an SEM. This method overcame the deficiencies of traditional procedures to produce exceptional images of floral surfaces in their natural state. Depending on the nature of the material under investigation, the method my be indispensable (e.g., for accurate details of petal surfaces), preferable (e.g., glandular hairs …

Materials Analysis By Mass Spectrometry Of Sputtered Neutrals, Hans Oechsner

Scanning Microscopy

Mass spectrometric detection of neutral surface particles released by ion bombardment has become an important method for surface and depth profile analysis. Its fundamental difference to secondary ion mass spectrometry SIMS is the separation of the formation of the analyzed particles and their ionization. Hence, matrix and selectivity effects influencing SIMS signals in a mostly unknown manner via the ionization process in secondary ion emission are avoided in general.

The different techniques being presently employed for the necessary postionization of the sputtered neutrals are reviewed and discussed with respect to their potentialities. Secondary Neutral Mass Spectrometry (SNMS) using efficient postionization …

Ion And Water Retention By Permeabilized Cells, Carlton F. Hazlewood, Miklos Kellermayer

Scanning Microscopy

Nonionic detergents, Triton X-100 and Brij 58, removed, within 2-5 minutes, lipid membrane of suspended thymus lymphocytes and monolayer H-50 cells grown in culture. Studies of hydration, ionic asymmetry, and ionic and protein release kinetics were conducted on these membraneless cellular preparations. The hydration of nuclei isolated by Triton X-100 procedures appears to be influenced strongly by the monovalent ionic concentration of the buffer bathing the organelles. The putative monovalent ionic concentration of the cellular aqueous phase (i.e., 150 meq/L) caused nuclei to swell and coalesce. Monovalent ionic concentrations of 30 meq/L or less caused minimal changes in volume and …

3-Dimensional Imaging Of Biological Structures By High Resolution Confocal Scanning Laser Microscopy, G. J. Brakenhoff, H. T. M. Van Der Voort, E. A. Van Spronsen, N. Nanninga

Scanning Microscopy

Imaging in confocal microscopy is characterized by the ability to make a selective image of just one plane inside a specimen, virtually unaffected -within certain limits-by the out-of-focus regions above and below it. This property, called optical sectioning, is accompanied by improved imaging transverse to the optical axis. We have coupled a confocal microscope to a computer system, making the combination of both an excellent instrument for mapping the 3-dimensional structure of extended specimens into a computer memory/data array. We measured that the volume element contributing to each data point has, under typical fluorescence conditions, a size of 0.2 x …

Junction Electron-Beam-Induced Current Techniques For The Analysis Of Photovoltaic Devices, R. J. Matson

Scanning Microscopy

A number of useful electron-beam-induced current (EBIC) techniques have evolved through the study of junction behavior in photovoltaic (PV) devices in cross section as a function of light and voltage bias, temperature, and electron beam scanning parameters. The necessary hardware modifications, the techniques themselves, and their applications are presented. In the case of PV devices, light and/or voltage biasing the entire device while electron probing it in cross section permits the observation of the distribution of the narrowing or extension of the space-charge region. Monitoring the junction behavior as a function of temperature has at least two applications. In situ …

The Correction For Extraneous Background In Quantitative X-Ray Microanalysis Of Biological Thin Sections: Some Practical Aspects, Godfried M. Roomans

Scanning Microscopy

The correction for extraneous continuum is of great importance in the quantitative analysis of thin sections of biological tissue. Although a theoretical model for this correction is available, its application in practice meets with problems. In this paper, a model system, consisting of sections of homogeneous plastic on copper mesh grids was used to identify sources of inaccuracies in the quantitative procedures. An unmodified electron microscope was operated under standard analytical conditions. It appeared that geometrical factors connected with the position of the analysis relative to the grid bars were of prime importance. The correction for the contribution of the …

New Uses Of Livestock Guarding Dogs To Reduce Agriculture/Wildlife Conflicts, R. Coppinger, J. Lorenz, Lorna Coppinger

Wildlife Damage Management Conference

Pilot programs in several states have shown that livestock guarding dogs are 70-80% effective in reducing predation on livestock by wildlife, primarily coyotes. In order to increase that percentage, ineffective dogs were studied and new techniques tested that had the potential of turning problems into successes.

From the population of over 1,000 dogs that has been placed on farms and ranches nationwide during the past ten years under the auspices of the Livestock Dog Project at Hampshire College, data was analyzed for each of the three basic behaviors (trustworthy, attentive, protective) that a good guardian needs to exhibit. A wide …

Effectiveness Of Human Hair, Bgr, And A Mixture Of Blood Meal And Peppercorns In Reducing Deer Damage To Young Apple Trees, Michael R. Conover, Gary S. Kania

Wildlife Damage Management Conference

We evaluated the ability of three repellents [human hair, Big Game Repellent (BGR), and a mixture of blood meal and peppercorns] to reduce deer damage on young apple trees in two Connecticut orchards. Most of the deer damage consisted of winter browsing on dormant apple buds. Little browsing occurred on leaves or buds during the growing season and only a few cases of pre-rut rubbing of trees were observed. In one orchard, buds were browsed during the winter on 52% of the untreated control trees, 45% of the trees sprayed with BGR, and 40% of the trees containing a hair …

Drc-6749--An Avian Wetting Agent Of Low Aquatic Toxicity, P. W. Lefebvre, T. D. Bills, A. R. Stickley Jr., R. E. Matteson, L. L. Marking

Wildlife Damage Management Conference

PA-14, the compound presently registered for lethal control of blackbirds and starlings at roosts, is labelled for use only at upland sites. Research was undertaken to identify another wetting agent which might be registered for use at aquatic sites. Of 90 samples received from suppliers, 60 were evaluated for wetting ability in a standard laboratory test. Of these, 10 were chosen for test against an aquatic indicator animal, Daphnia. One of the 10, DRC-6749, a block copolymer, was found significantly low in toxicity, and underwent further aquatic testing against 6 fish and 1 mussel species. Under standard test conditions, …

A Need For Professionalism In Wildlife Damage Control, James E. Miller

Wildlife Damage Management Conference

The need for professionalism in wildlife damage prevention and control is more important today than ever before. It will be even more important in the future as we are faced with increasing interaction between people and their interests which includes many different perceptions about wildlife. Wildlife professionals must change their philosolopy regarding communication with the public about both the positive and negative impacts of wildlife. We can no longer afford the luxury, if indeed we ever could, of avoiding people and their perceptions about wildlife. We must provide scientific, biologically and ecologically sound information in a form which the public …

The Future Of Wildlife Damage Control In An Urban Environment, Gary J. San Julian

Wildlife Damage Management Conference

As the trend towards urbanization escalates, the United States is rapidly becoming a nation of nonfarmers and suburban residents. Consequently, the conflicts between residents and wildlife species are increasing, while the interest in urban wildlife and backyard habitat is growing. These trends, coupled with changes in pesticide regulations, a shortage of trained professionals and relic legislation, create a complex and paradoxical situation for residents and professionals in the area of urban wildlife management. The future of wildlife in the urban environment will depend on our ability to convince and educate wildlife managers, citizens and legislators about the need for control …

The Use Of The T-Culvert Guard To Protect Road Culverts From Plugging Damage By Beavers, K. J. Roblee

Wildlife Damage Management Conference

Since 1978 there has been a continual effort by Region 9 of the New York State Department of Environmental Conservation to develop devices capable of protecting road culverts from plugging damage by beavers (Castor canadensis). Various protective devices were developed. The most successful was the T-culvert guard. Trial installations of T-culvert guards were made at 4 sites experiencing beaver damage. T-culverts consisted of a 4 ft. or larger diameter culvert and a smaller diameter culvert which connected it to the road culvert. Directions for construction, installation and maintenance of T-culverts are given. Costs for a typical 4 ft. …

A Method For Assessing Blackbird Damage To Ripening Rice, Robert G. Wright, Keith A. Arnold, Michael O. Way

Wildlife Damage Management Conference

A method for measuring and mapping the location of blackbird (Icterinae) damage to ripening rice over time was developed and employed in 7 commercial rice fields ranging from 20.6 to 47.4 ha in Matagorda County, Texas, during the 1985 and 1986 growing seasons. Ten evenly-spaced transects were established perpendicular to the longest side of the field and each transect was sampled at pre-determined distances. Transects were subdivided into "edge" ( < = 60 m from field border) and "middle" ( > 60 m from the field border) strata. The measured percent damage was compared to visual estimates for 3 samplings to assess the accuracy and precision of the latter. Measuring the …

Avoiding Controversies That Impede Wildlife Damage Control, B. W. O'Gara

Wildlife Damage Management Conference

Controversies regarding wildlife damage control often result from incorrect perceptions by the general public or conservation groups. Such controversies can usually be settled to most people's satisfaction by indisputable data. In the past, however, data were often lacking. The ban, by Executive order in 1972, of chemical toxicants for predator control on federal lands and by federal agencies is a good case in point. Indisputable data were not available concerning the level of predation. The only data were derived from questionnaires filled out by livestock producers; Government officials and the public simply would not accept such data as unbiased.

Safety And The Small Satellite Builder, James Smith

Small Satellite Conference

The importance of safety and the early understanding and incorporation of safety requirements into all phases of the small satellite's life can not be over-emphasized. Safety is an engineering discipline, a mind set, a conscious practice of all involved in the small satellite. There are numerous safety requirements which must be complied with and there are numerous processes and procedures which the small satellite must be subjected to. Being aware of the requirements and procedures and assuring their accomplishment is a total project responsibility. Risk cannot be totally eliminated, but it can be managed and controlled. This paper was written …

A Ground Station For Use With Small Satellites, Ronald Muller, Charles Vermillion

Small Satellite Conference

NASA has plans to initiate a new series of inexpensive, Scout-sized Explorer satellites to be placed in service starting in the early 1990's. Today's computer technology makes it feasible and economical to build such a satellite so that it can be operated from a single, small ground station. This station would be located at the satellite user's facility and it would operate autonomously. Except for launch and support during operational emergencies, no NASA facilities would be required. We show this way of operating will result in a lower cost mission with no performance penalty.

Single-Station Tracking For Orbit Determination Of Small Satellites, Roger Hart

Small Satellite Conference

Available methods of orbit determination and satellite observation are briefly reviewed and evaluated for suitability in tracking small satellites from a single ground station. Radio interferometer and Doppler tracking appear useful and are discussed in further detail. Distinctions in accuracy and application between the two methods are made.