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The Identification, Distribution, Impacts, Biology And Management Of Noxious Rangeland Weeds, Roger L. Sheley

All U.S. Government Documents (Utah Regional Depository)

This document provides a discussion of the biology and management of exotic rangeland weeds which are a threat to native ecosystems of the western United States. Chapter 1 describes a generalized approach for managing noxious weed infested rangeland, while Chapter 2 focuses on preventing noxious weed invasion. In some cases, noxious weeds readily invade riparian areas, and because of the sensitive nature of these ecosystems Chapter 3 is devoted to riparian weed management. The following 13 chapters describe the identification, origin, history, distribution, potential invasion, impacts, biology and ecology, and management of specific noxious rangeland weeds.

Effects Of Modulated Microwave And X-Ray Irradiation On The Activity And Distribution Of Ca2+-Atpase In Small Intestine Epithelial Cells, Z. Somosy, G. Thuróczy, G. J. Köteles, J. Kovács

Scanning Microscopy

The distribution and activity of Ca²⁺-ATPase were investigated by histochemical methods in small intestine epithelial cells of mice following total body 2450 MHz low frequency (16 Hz) microwave and X-ray irradiation. In the control animals, enzyme activities were found in the brush border and on lateral membranes, including junctional areas of the cells. The enzyme activity of lateral membranes was inhibited by quercetin, a specific inhibitor of Ca²⁺-ATPase.

Immediately after square modulated (16 Hz) 2450 MHz microwave irradiation at 1 mW/cm² power densities, we observed a decreased activity of Ca²⁺-ATPase on the lateral …

Investigation Of Touch-Sensitive Responses By Hyphae Of The Human Pathogenic Fungus Candida Albicans, N. A. R. Gow, T. H. S. Perera, J. Sherwood-Higham, G. W. Gooday, D. W. Gregory, D. Marshall

Scanning Microscopy

Candida albicans is a fungus that commonly infects the mucosal surface of humans. The hyphal growth form of this fungus may initiate the primary invasion of the host. Here we show that hyphae respond thigmotropically and morphologically to cues such as the presence of a surface, pores, grooves and ridges. Growth on some firm surfaces elicits a helical growth response. Hyphae follow grooves and ridges of inert substrates and penetrate pores of filtration membranes. Our in vitro experiments suggest that thigmotropism may enhance the ability of a hypha to invade epithelia of a host at sites of weakened integrity.

Letter To The Editor By M.C. Deruiter And A.C. Gittenberger-De Groot Relating To: "Technical Improvements In Corrosion Casting Of Small Specimens: A Study On Mesonephric Tubules And Vessels Of Chicken Embryos." [By A. Carretero, H. Ditrich, M. Navarro, H. Splechtna, J. Ruberte, Scanning Microscopy Vol. 7(4), P. 1333-1338 (1993)]., M. C. Deruiter, A. C. Gittenberger-De Groot

Scanning Microscopy

Dear Editor,

The topic of scanning electron microscopy (SEM) investigation of casting of vessels in the embryo still holds our interest. We are particularly focused on the possibilities of early injection as a method to support angiogenesis and vasculogenesis research in the embryo. It is questionable whether our technique leads to unreliable results because of severe trauma to the embryo as suggested by the above mentioned authors. The lower success yield might very well be the result of the higher friability of the embryo in general in this young stage.

Utah Science Vol. 55 No. 3 & 4, Fall 1994

Utah Science

2 CROPS FIELD DAY It was a dry year but there was a deluge of ideas at research plots.

12 TH E PLANT CANCER CONNECTION A look at some new wrinkles in the relationship between vegetables and Cancer.

13 DESERT SOILS Desert regions may have a larger role in the global climate than once thought.

14 ALTERNATIVE FORAGES The high yields and quality of alternative forages have renewed these sheep producers' faith in the industry,

20 PUBLIC LAND RANCHERS Survey results show few ranchers are ready for possible Changes in grazing permits.

21 ORIGINS OF FLAVOR IN CHEESE USU researchers …

Proceedings From The 31st Annual Italian And Specialty Cheese Seminar, Various Authors

Cheese Industry Conference

The impact of mixer temperature and mixer screw speeds on fat recovery, protein recovery, and yield of Mozzarella cheese was determined. In the first trial three different cheese temperatures were achieved: 130·F (54.C); 140•F (60.C); and 150.F (66·q. In the mixer temperature trial, a screw speed of 12 rpm (revolutions per minute) was used at all mixer temperatures. In the second trial, three different mixer screw speeds were used for stretching: 5 rpm, slow; 12 rpm, medium (ca. 50o/o of mixer full speed); 19 rpm, fast. Three vats of cheese were made per day. The two trials were conducted at …

Urinary Citrate, Bone Resorption And Intestinal Alkali Absorption In Stone Formers With Fasting Hypercalciuria, Piergiorgio Messa, Giuseppe Mioni, L. Paganin, A. Cruciatti, P. Lo Greco, D. Turrin

Scanning Microscopy

Reduced citrate in urine and increased fasting excretion of calcium are abnormalities frequently reported in stone forming (SF) patients. Increased dietary acid (or reduced alkali) introduction or absorption may be a potential cause of both these pathological findings. To test this hypothesis, we studied 64 SF patients {32 with fasting hypercalciuria (FH) and 32 without FH (NFH)}. After a basal evaluation for nephrolithiasis, while on a 500 mg calcium diet, they were evaluated for: (1) daily intestinal alkali absorption (IAA), by urinary electrolyte excretion; (2) basal concentrations of PTH, calcitonin (CT) and 1,25(OH)2-VitD; (3) oral calcium load for evaluation of …

Chemical Composition Of Gaas Oxide Layers By Auger In-Depth Profiles And X-Ray Photoelectron Spectroscopy Experiments, J. F. Bresse, C. Cardinaud

Scanning Microscopy

GaAs oxide layers resulting from an oxygen plasma etching have been studied by Auger in-depth profiles and angle-resolved XPS experiments. From the Auger profiles, using the sequential layer sputtering (SLS) treatment, a quantitative determination of thickness and composition of the oxide layers has been performed. A model with several layers has been deduced. From the angle-resolved X-ray photoelectron spectroscopy (XPS) experiments, another model with several layers of different chemical compounds has also been deduced. The oxide layer is non-uniform in thickness and composition. Two or three different oxide layers are formed depending on the probed area. The interface layer is …

Characterization Of Metal Aggregates By Scanning Microscopy: Particle Sizes And Space Distribution In Intermetallic Particles, M. O. Delcourt, F. Yala, E. Merlen, S. Remita, N. Keghouche, E. Delarue

Scanning Microscopy

Various metal aggregates prepared using ionizing radiation were studied by microscopy techniques. A metal deposit onto a carbon felt obtained from solutions containing Pt and Ru was shown to consist of nanometric particles containing both metals. Another study deals with a subnanometric silver aggregate. The nuclearity of the aggregate was studied by scanning tunneling microscopy (STM). Additional information from pulse radiolysis experiments allowed the determination of the Ag₇³⁺ stoichiometry.

The third material consisted of Ag/Pd submicron powders (70/30 or 75/25% w/w) used in electronics, and made of spherical bimetallic grains; X-ray diffraction showed segregation. The spatial distribution of …

Molecular Imaging Of Petroleum Asphaltenes By Scanning Tunneling Microscopy: Verification Of Structure From 13c And Proton Nuclear Magnetic Resonance Data, G. W. Zajac, N. K. Sethi, J. T. Joseph

Scanning Microscopy

Scanning tunneling microscopy (STM) was used to verify the molecular structure of Maya asphaltene which had been derived from combined ¹³C and proton nuclear magnetic resonance (NMR) experiments. Petroleum asphaltenes are known to contain large polynuclear aromatic centers with aliphatic sidechains. Average molecular models of Maya asphaltenes were derived using studies which included combined proton and ¹³C NMR data to determine total aromatic carbon content and the ratio of peripheral to internal aromatic ring carbons. These parameters permitted estimating the average number of aromatic rings per condensed cluster.

These Maya asphaltenes were imaged by scanning tunneling microscopy (STM) …

A New Atomic Force Microscopy Technique For The Measurement Of The Elastic Properties Of Biological Materials, W. Xu, P. J. Mulhern, B. L. Blackford, M. H. Jericho, I. Templeton

Scanning Microscopy

We developed a new technique to measure elastic properties by using the atomic force microscope (AFM) tip to press samples into grooves etched in a GaAs substrate.

We measured the Young's modulus of β-chitin fibres with cross-sections less than 40 nm X 20 nm to be 1-2 X 10¹¹ N/m². In the isotropic approximation, the Young's modulus of the S-layer sheath of the archaeobacterium Methanospirillum hungatei was 1-3 X 10¹⁰ N/m². By testing the sheath to breaking strength we estimated the bacterium can sustain an internal pressure as high as 100-200 atmospheres (1-2 x …

Nanowriting On An Atomically Flat Gold Surface With Scanning Tunneling Microscope, C. Lebreton, Z. Z. Wang

Scanning Microscopy

We present new experimental results of writing stable features on atomically flat surfaces of gold films. By applying successive voltage pulses across the tunneling gap in controlled atmosphere, nearly 150 individual holes are produced to record one message. The writing process has a higher success rate in nitrogen gas with the presence of water or ethanol vapour. Written letters remain stable for more than 4 days in dry nitrogen gas, in contrast to some previous STM results of monatomic step movement on the gold surface. By changing the vapour pressure, pulse amplitude and polarity, we succeed in controlling the gold …

Electron Spectroscopy And Atomic Force Microscopy Studies Of Dna Adsorption On Mica, Carol E. Rabke, Lisa A. Wenzler, Thomas P. Beebe Jr.

Scanning Microscopy

Various methods for the deposition of deoxyribonucleic acid (DNA) molecules on mica are investigated to determine their reproducibility, and to quantify their ability to bind DNA. The use of these deposition methods for sample preparation for biological scanning tunneling microscopy (STM) and atomic force microscopy (AFM) studies is discussed. Auger electron spectroscopy (AES) and electron spectroscopy for chemical analysis (ESCA) were used to investigate the quantity of DNA adsorbed. AFM images of DNA deposited using the methods investigated are presented. The combination of AFM results with AES and ESCA results provides a basic understanding of the deposition techniques studied and …

Adsorption Of Fibrinogen On Thin Oriented Poly(Tetrafluoroethylene) (Ptfe) Fibres Studied By Scanning Force Microscopy, J. R. Rasmusson, R. Erlandsson, W. R. Salaneck, M. Schott, D. T. Clark, I. Lundström

Scanning Microscopy

We have investigated fibrinogen adsorption on ordered poly(tetrafluoroethylene), PTFE, fibres deposited on hydrophilic and hydrophobic silicon substrates. Fibrinogen molecules appear to adsorb with their long axis perpendicular to the fibre direction for PTFE fibres having widths of less than 100 nm. On these thin fibres, fibrinogen apparently forms close packed bands or clusters, consisting of small integer numbers of molecules arranged parallel to each other. On broader (> 100 nm) PTFE fibres, the fibrinogen forms two dimensional networks. The orientation of the molecules in these networks is random in the central flat part of the fibres but perpendicular to the …

High Resolution Electron Beam Induced Current Measurements In An Scanning Tunneling Microscope On Gaas-Mesfet, P. Koschinski, V. Dworak, L. J. Balk

Scanning Microscopy

Recently, the first results of electron beam induced current (EBIC) measurements in a scanning tunneling microscope (STM) have been reported. Although the acquired results match with those obtained in conventional EBIC investigations, the interpretation of the obtained results is still restricted solely to a qualitative discussion. In this paper, a quantitative approach is used for two-dimensional numerical simulations of induced currents in GaAs-MESFET leading to a first starting point for a sophisticated interpretation of the dependence of induced currents on experimental and device parameters.

Diluted And Undiluted Mercox Severely Destroy Unfixed Endothelial Cells. A Light And Electron Microscopic Study Using Cultured Endothelial Cells And Tadpole Tail Fin Vessels, J. Gassner, A. Lametschwandtner, T. Weiger, H. C. Bauer

Scanning Microscopy

Mercox is a methylmethacrylate-based resin which is widely used for vascular corrosion casting with subsequent scanning electron microscopic analysis. In the present study the effect of undiluted and diluted Mercox (4+1; volume + volume; Mercox: monomeric methylmethacrylate (MMA); 0.02 g catalyst MA/ml Mercox) and methylmethacrylate with and without catalyst MA (0.625 g/10 ml MMA) on fixed and unfixed endothelial cells was studied. Light microscopy (LM) of cultured capillary endothelial cells (ECs), which were replicated with diluted or undiluted Mercox shows degranulation and membrane perturbation of ECs, while no morphological changes occur in glutaraldehyde-prefixed ECs. Scanning electron microscopy (SEM) of replicas …

Superstructures Of Graphite Intercalation Compound Formed By Sodium-Hydroxide Solution Studied By Scanning Tunneling Microscopy, Koji Miyake, Aiso Yoshiaki, Makoto Komiyama, Hidemi Shigekawa

Scanning Microscopy

Highly oriented pyrolytic graphite (HOPG) treated with sodium hydroxide solution was found to show an X-ray diffraction pattern characteristic of a stage-8 intercalation compound. Superstructures such as 2 X 2, √3 X √3 and noble orthorhombic lattices were observed on the NaOH-treated graphite surfaces by scanning tunneling microscopy, as was previously observed on stage-1 alkali-metal graphite intercalation compound (GIC) surfaces formed by Li, K, Rb and Cs intercalates. The orthorhombic phase has a periodic structure formed by four bright and two dark rows, which were explained by the intercalant arrangement occupying two different sites, in the GIC.

Data Handling In Quantitative Microanalysis In Biology, V. Starý

Scanning Microscopy

In cell biology, electron probe X-ray microanalysis can reveal the distribution of chemical elements inside a single cell. The full description of a biological system (cell population, tissue) requires a great number of spot measurements. In quantitative analysis, the measurements are subject to experimental errors of several types; moreover, the relations between the resulting values are usually more interesting than the absolute concentrations. Nevertheless, the proper evaluation of quantitative values can discover information more on the object of study.

A system of simple statistical tests is suggested here which can solve several problems. Some concentration values can be far from …

Role Of Agglomeration In The Early Stages Of Papillar Stone Formation, O. Söhnel, F. Grases, L. Garcia-Ferragut

Scanning Microscopy

Possible effects of crystal agglomeration on the early stages of calcium oxalate papillar stone formation are evaluated. The collecting ducts are filled with liquid that flows laminarly as established through hydrodynamical and physicochemical considerations. Under such conditions, agglomeration due to laminar shear forces proceeds. Agglomeration of calcium oxalate monohydrate crystals present in urine at a concentration typical for clinically observed crystalluria cannot result in the formation of a particle sufficiently large enough to be retained in the Bellini's duct and become a papillar stone nidus (nucleus). Formation of such an aggregate during the passage time of urine through the duct …

Haights Creek Rpm Pipe Failures, United States Department Of The Interior, Bureau Of Reclamation

Water

In 1989, Haights Creek Irrigation Company replaced 730 linear feet of 24- and 27-inch-diameter RPM (reinforced plastic mortar) pipe because of several failures. Bureau of Reclamation personnel examined the pipe before and after exhumation, the surrounding soil conditions, and measured diametral deflections. Major longitudinal cracks in the pipe invert appear to be the result of hard spots in the pipe foundation. Some of these hard spots were caused from mounding, or using a mound of soil under one end of the pipe to bring it to grade without providing an equivalent uniform support along the remainder of the pipe.

Direct Observation By Scanning Tunneling Microscopy Of The Two-Dimensional Lattice Structure Of The S-Layer Sheath Of The Archaeobacterium Methanospirillum Hungatei Gp1, B. L. Blackford, W. Xu, M. H. Jericho, P. J. Mulhern, M. Firtel, T. J. Beveridge

Scanning Microscopy

Observation of the two-dimensional (2-D) 3 nm x 3 nm lattice structure of the S-layer sheath of the archaeobacterium Methanospirillum hungatei is reported for the first time by scanning tunneling microscopy. The samples consisted of sheath fragments deposited on a TaSe₂ substrate and coated with a Pt/Ir film. In addition to confirming the 2-D structure, the images reveal some new information about the nano-scale details of the sheath structure. A lateral resolution of 1 nm was achieved, suggesting that the grain size of the Pt/Ir films was much less than for similar films deposited on a smooth metal surface.

Etiology Of Experimental Calcium Oxalate Monohydrate Nephrolithiasis In Rats, W. C. De Bruijn, E. R. Boevé, P. R. W. A. Van Run, P. P. M. C. Van Miert, J. C. Romijn, C. F. Verkoelen, L. C. Cao, F. H. Schröder

Scanning Microscopy

In a rat-model system, tubular crystal retention as a possible mechanism for the etiology of nephrolithiasis in man, was studied by conventional transmission electron microscopy. The animals were supplied for nine days with a crystal-inducing diet, with ethylene glycol plus NH₄Cl in their drinking-water. After this induction period, a two day regime with fresh drinking-water was included, to allow crystals to be removed by spontaneous crystalluria. After aldehyde fixation of the rat kidneys, large crystals were seen inside the tubular lumen. The crystals were attached to cell surfaces and covered by neighboring epithelial cells. Some crystals were overgrown …

Electronic Trap Microscopy - A New Mode For Scanning Electron Microscopy (Sem), H. -J. Fitting, Th. Hingst, R. Franz, E. Schreiber

Scanning Microscopy

Insulating layers on conducting substrate are investigated by means of secondary electron field emission SEFE in a digital SEM. The kinetics of charge storage and release with time and temperature are controlled and recorded by an external computer.The evaluation is performed pixel-wise with respect to electronic trap concentration n_t0, trap capture cross section σ_c and thermal activation energy E_t. Mapping of these trap parameters indicates hidden inhomogenities, defects and pre-treatments of the dielectric layers as well as the pattern of thermal bleaching and release of electrons. The latter ones appear as inhomogeneous processes starting with …

Sequencing Of Proteins Extracted From Stones, J. P. Binette, M. B. Binette

Scanning Microscopy

Proteins from urinary tract and gallbladder stones were extracted and characterized to determine the composition of the matrix and possibly unravel the role of the organic phase in stone formation. Proteins from crushed stones were extracted by electrodialysis and concentrated in the Amicon centricon cartridge or by lyophilization after dialysis against distilled water. Aliquots were first analyzed by isoelectric focusing in gel and if suitable subjected to two-dimensional (2D) electrophoresis. The most promising spots were harvested and the N-terminal amino acids sequenced, thus providing maximum information with minimum expenditure of material. The 2D separations and amino acid sequences of several …

Methodological Aspects Of Spontaneous Crystalluria Studies In Calcium Stone Formers, C. A. Bader, A. Chevalier, C. Hennequin, P. Jungers, M. Daudon, O. Beaugendre, M. P. Hoarau

Scanning Microscopy

Despite nearly a half-century of study, the clinical value of spontaneous crystalluria (Cx) examinations in calcium stone formers (CaSF) is still uncertain. The analytical complexity of urine particle study is largely responsible for this situation. As a result, there is no consensus regarding technical methods in Cx with several techniques for urine sampling and three different instruments currently used for particle study, namely, particle counting (PC), light microscopy (LM) and petrographic microscopy (PM). In this work, we first examined urine sampling and instrument methods regarding their appropriateness for Cx studies. Then we performed a comparative analysis of Cx studies in …

Arrangement Of Elastic Fibres In The Integument Of Domesticated Mammals, W. Meyer, K. Neurand, R. Schwarz, T. Bartels, H. Althoff

Scanning Microscopy

The hairy skin of important domesticated mammals (12 species) was studied with scanning electron microscopy, transmission electron microscopy, laser scanning microscopy, and several light microscopical methods, to obtain more information about three-dimensional elastic fibre arrangement. It was obvious that there is a basic construction scheme of the elastic fibre meshwork as present in the upper and mid-dermis, with special regard to the size, number, and grouping of hair follicles. In the densely-haired species, in particular, a typical elastic mat with horizontal fibres is formed. In many of the sparsely-haired animals, the upper and mid-dermis show a sponge-like elastic system. In …

General Pattern And Morphological Specializations Of The Avian Cochlea, Franz Peter Fischer

Scanning Microscopy

In different bird species, there is a common pattern in the hair-cell morphology and innervation of the basilar papilla; the absolute values, however, are species-specific. In the barn-owl papilla, an extreme being case, the basal high-frequency part of the papilla is greatly expanded. In this behaviorally most important frequency range of the barn owl, the number of afferent nerve terminals to neural hair cells is extensively increased. Instead of about 2 afferent terminals as in other species, up to 20 afferents are present. In the bird species studied (chicken, starling, emu, barn owl), the area of the afferent nerve terminals …

Ultrastructural Patterns Of Cell Damage And Death Following Gamma Radiation Exposure Of Murine Erythroleukemia Cells, R. Di Pietro, E. Falcieri, L. Centurione, M. A. Centurione, G. Mazzotti, R. Rana

Scanning Microscopy

Radiation causes damage to cell surface membranes, cytoplasmic organelles, and the nuclear process of DNA synthesis and repair, and this eventually results in different modes of cell death. In this study we examined murine erythroleukemia (MEL) cells, exposed to 15 and 60 Gy of 10 MeV photonic energy, and left in culture for up to 96 hours. Electron microscopical analysis was performed on conventionally embedded samples and freeze-fracture replicas, in order to detect ultrastructural patterns of cell damage and death. Of interest was the observation of chromatin condensates, nuclear membrane associations and nuclear pore redistribution during early apoptosis. Pronounced rearrangements …

Glycol Methacrylate Embedding And Microwave Staining For Light Microscopy Of The Mouse Cochlea, Bharti Katbamna, Atha Ralston

Scanning Microscopy

This study examined the utility of a methacrylate-based embedding medium and microwave staining for light microscopic quantification of hair cells and spiral ganglion cells in the mouse cochlea. The most important phase of the preparation process involved slowing down the polymerization process. The tissue molecules so locked within the plastic matrix produced excellent preservation of the organ of Corti and adjacent structures including the spiral ganglion, as well as tissue ionic charges. Excitable by microwaves, these ionic charges accelerated the movement of the basic dye (hematoxylin) into the tissue, reducing the time for this segment of the staining process from …

Proceedings Of A Symposium On Sustaining Rangeland Ecosystems, W. Daniel Edge, Sally L. Olson-Edge

Aspen Bibliography

No abstract provided.