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Etiology Of Calcium Oxalate Nephrolithiasis In Rats. Ii. The Role Of The Papilla In Stone Formation, W. C. De Bruijn, E. R. Boevé, P. R. W. A. Van Run, P. P. M. C. Van Miert, R. De Water, J. C. Romijn, C. F. Verkoelen, L. C. Cao, J. M. Van 'T Noordende, F. H. Schröder

Scanning Microscopy

In kidneys of healthy rats submitted to a crystal-inducing diet (CID) with ethylene glycol (EG) and NH₄Cl, the fate of retained crystals in the papillar region is studied during a recovery period of one, five or ten days, as model system for human nephrolithiasis. Scanning electron microscopy (SEM) shows, at papillary tips bulging into the calycine space, crystal masses covered either by the epithelium or a thin fibrous veil, or by unidentified mobile cuboidal cells. After CID plus one or five days recovery, small sub-epithelial swellings are seen of large sub-epithelial crystals at or around the papillary tip. …

Assuring A Long Term Groundwater Supply: Issues, Goals And Tools, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Groundwater is a hidden, but important resource. We can practicably define groundwater as water beneath the ground surface that can be extracted by wells. Other water in the ground that is not considered to be available for man’s direct use is commonly called “subsurface water.” Subsurface water includes moisture within the root zone.

Notes On The Microstructure Of The Nautilus Shell, P. R. Mitchell, P. P. Phakey

Scanning Microscopy

The shell of the Nautilus was examined using scanning electron microscopy, transmission electron microscopy and polarized light microscopy. The structure consisted of two major layers: a porcellaneous outer layer and a nacreous inner layer. Most of the porcellaneous layer was composed of granular crystals randomly distributed with a substructure suggestive of bundles of acicular crystallites. A separate prismatic sublayer of the porcellaneous material was composed of a more regular arrangement of crystals. The nacre was composed of alternating crystalline lamellae and films of organic material. The lamellae were formed of many polygonal crystal platelets. The growth surface of the nacre …

Investigation Of Nanoparticles In High Resolution Scanning Electron Microscopy (Sem) And Low Voltage Sem By Digital Image-Analysis, B. Ocker, R. Wurster, H. Seiler

Scanning Microscopy

Small particles (Cu, Ag, In, Sn, Au, also MgO and NaCl) were prepared in the diameter range from 1 nm to 100 nm on different conductive substrates by thermal evaporation in high-vacuum or in an inert gas atmosphere. Imaging of the particles was performed in a high resolution scanning electron microscope (HRSEM) that can also be operated at low beam voltages of a few hundred volts. This mode of operation is called low voltage SEM (LVSEM). Scanning electron micrographs were taken at different beam voltages V_O (0.5-30 kV). The micrographs were digitally recorded and analyzed with an image processing …

High Resolution Electron Microscopy Of Enamel Crystallites Demineralized By Initial Dental Caries, Yoshihiko Hayashi

Scanning Microscopy

Acids produced by various oral bacteria cause mineral loss and crystallite dissolution during the development of enamel caries. In order to demonstrate this phenomenon, the initial disappearance of lattice fringes and the formation of a central perforation in crystallites were examined by high resolution electron microscopy (HREM) in initial enamel caries without macroscopic tissue evidence of destruction. Ultrathin sections were also examined by selected area electron diffraction to reveal the mineral phase of the surface layer in carious enamel.

A marked variation in the dissolution pattern was disclosed in the initial carious lesions. HREM revealed that disappearance of the lattice …

Controlling Influence Of Phosphocitrate In Vitro And In Vivo On Calcium Oxalate Crystal Formation And Growth, John D. Sallis, Nathan F. G. Parry, John D. Meehan, Harold Kamperman, Maree E. Anderson

Scanning Microscopy

Calcium oxalate (CaOx) crystallization in the presence of phosphocitrate (PC) was studied by both in vitro and in vivo techniques. Crystals of the monohydrate (COM) and the dihydrate (COD) forms were generated under controlled conditions in a silica gel matrix. Our data indicated only COD crystals formed when PC was present, inferring that the COD to COM transformation was being impeded. COD crystals were smaller in size than controls and there was evidence of interpenetral twinning. An in vivo study using a rat bladder implant model noted similar findings. Scanning electron microscopy (SEM) revealed that implants recovered from PC treated …

Passageway Around The Redlands Diversion Dam And Interim Agreement To Provide Water For Endangered Fish, Bureau Of Reclamation, Fish And Wildlife Service, U.S. Department Of The Interior

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

This draft environmental assessment (EA) discusses two related actions proposed to assist in the recovery of two Federally-listed endangered fish species. The actions are intended to restore use of historic and designated critical habitat of the Gunnison River by the Colorado squawfish and razorback sucker. The proposed actions are to: construct and operate a fish passageway around the Redlands Diversion Dam; and execute an interim (short-term) memorandum of agreement (water agreement) to supply streamflows needed to operate the passageway and maintain downstream fish habitat and access for fish to the passageway. The EA is prepared jointly by the Bureau of …

Living With Fuel Contamination, Von Jarrett

All Current Publications

No abstract provided.

Is There Slime In Your Fuel, Von Jarrett

All Current Publications

No abstract provided.

Revascularization Of An Excisional Wound In Gingiva And Oral Mucosa. A Scanning Electron Microscopic Study Using Corrosion Casts In Rats, Nils J. Selliseth, Knut A. Selvig

Scanning Microscopy

The purpose of this study was to examine microvascular regeneration associated with gingival wound healing. A full-thickness piece of gingiva and oral mucosa was excised along the palatal aspect of the right maxillary first and second molars in 20 young Wistar rats. The contralateral side served as unoperated control. After 2, 4, 7, 10 or 20 days of healing, microvascular corrosion casts were produced and examined by scanning electron microscopy. At 2 days, vessels surrounding the wound were dilated and impressions representing sites of leukocyte margination were prominent in the walls of venules. Capillary buds were emerging from venules and …

Scanning Electron Microscopy And Transmission Electron Microscopy Aspects Of Synergistic Antitumor Activity Of Vitamin C - Vitamin K3 Combinations Against Human Prostatic Carcinoma Cells, Jacques Gilloteaux, James M. Jamison, Meenaxi Venugopal, David Giammar, Jack L. Summers

Scanning Microscopy

A MTT/formazan assay was used to evaluate the antitumor activity of vitamin C (Vit C), vitamin K₃ (Vit K₃), or vitamin C:vitamin K₃ combinations against a human prostatic carcinoma cell line (DU145). Both Vit C and Vit K₃ alone exhibited antitumor activity, but only at elevated doses. When Vit C and Vit K3 were combined at a C:K₃ ratio of 100:1 and administered to the carcinoma cells, the 50% cytotoxic concentrations (CD50) of the vitamins decreased 10-to 60-fold. Subsequently, the DU145 cells were examined with transmission and scanning electron microscopy (TEM and SEM) following …

Experimental Calcium Oxalate Nephrolithiasis And The Formation Of Human Urinary Stones, Saeed R. Khan

Scanning Microscopy

Calcium oxalate nephrolithiasis in rats requires induction of hyperoxaluria which results in increased urinary calcium oxalate supersaturation. As a result of low to mild chronic hyperoxaluria, calcium oxalate crystals deposit first in the papillary collecting ducts. Crystal deposition in the kidneys is preceded by calcium oxalate crystalluria and starts with the retention of aggregated calcium oxalate crystals in the renal tubules. Retained crystals move from the tubules to the interstitium, and in the process, become anchored to the tubular basement membrane. Crystal aggregates present in the superficial peripheral collecting ducts of the renal papillae ulcerate through to the papillary surface …

Cathodoluminescence Of Rare Earth Doped Zircons. I. Their Possible Use As Reference Materials, F. Cesbron, P. Blanc, D. Ohnenstetter, G. Rémond

Scanning Microscopy

Synthetic zircon crystals (ZrSiO₄), undoped and doped with Y³⁺, La³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Tm³⁺, Yb³⁺, Lu³⁺, were grown from a flux consisting of a mixture of Li₂MoO₄ and MoO₃ heated to 1125°C and then cooled to 750°C. The cathodoluminescence (CL) spectra of these zircons were analyzed at room-temperature and near liquid nitrogen temperature with a CL spectrometer …

Luminescence From Porous Silicon, Yasunori Mochizuki

Scanning Microscopy

Structural and optical properties of porous Si are reviewed with the main emphasis on the radiative recombination mechanisms. Behaviors of the visible photoluminescence and another intense luminescence process (the infrared luminescence) are discussed based on the available data provided by photoluminescence and related techniques. It is demonstrated that a further insight into the interrelation of these luminescence processes can be obtained by the optically-detected magnetic resonance method, in which non-radiative point defects (surface dangling bonds) are used as a local structural probe for the radiative states.

As for the model for the visible light emission, the implication of the quantum …

Diamond Luminescence, R. Heiderhoff, L. J. Balk

Scanning Microscopy

Luminescence spectroscopy is an established tool to investigate natural, high pressure synthesized, and chemical vapour deposited (CVD) diamond. The spectral range extends from 5.3 eV in the ultraviolet to approximately 1.2 eV in the near-infrared. More than 100 optical centres have been observed.

Since the early 1930's, semiconducting diamond for electronic devices has been of interest to science. The large bandgap (5.5 eV), low dielectric constant (5.7), and high thermal conductivity (about 5 times larger then that of Ag), as well as the superior charge-carrier transport properties, such as electron and hole mobility (µ^-: 2200 cm²/Vs, …

Temperature-Dependent Cathodoluminescence Spectroscopy And Microscopy As A Tool For Defect Identification In Semiconducting Ceramics: Application To Batio3 Ceramics, T. Hübner, U. Marx, J. Schreiber

Scanning Microscopy

Cathodoluminescence (CL) spectroscopy and microscopy were applied to investigate the characteristic grain-boundary contrast in semiconducting ferroelectric BaTiO₃ ceramics. It was shown, that "chemically clean" grain boundaries do not reveal any specific CL components neither in the visible nor in the infrared part of the spectrum. Instead, the contrast arises from at least two different non-radiative recombination centers present in the grain and the grain-boundary zones, respectively. Activation thresholds for these centers were determined from the temperature dependence of the integral CL signal down to 30K. The different values found explain the contrast reversal observed in BaTiO₃ ceramics upon …

In Vitro Characterization Of Transforming Growth Factor-Ss1-Loaded Composites Of Biodegradable Polymer And Mesenchymal Cells, S. B. Nicoll, A. E. Denker, R. S. Tuan

Cells and Materials

A porous, biodegradable polymer composite was fabricated from poly(L-lactic acid) (PLLA) using a solvent- casting particulate-leaching technique, and loaded with recombinant human transforming growth factor ß-1 (TGF-ß1). Tissue culture polystyrene (TCPS) and PLLA disks loaded with bovine serum albumin (BSA) served as controls. Polymer specimens were seeded at high cell density with C3H10T1/2 cells, a mouse embryonic cell line capable of differentiating into various connective tissue cell types. The polymer matrices degraded slowly in physiological saline over four weeks, with a sustained yet sporadic release of active TGF-ß1; a more controlled release of TGF-ß1 was observed in serum-containing culture medium …

Los Dos Mundos, Richard Baker

All USU Press Publications

Mexican Americans make up the largest minority in Idaho, yet they seemingly live in a different world from the dominant Anglo population, and because of pervasive stereotypes and exclusive policies, their participation in the community's social, economic, and political life is continually impeded.

This unique ethnographic study of a small Idaho community with a large Hispanic population examines many dimensions of the impact race relations have on everyday life for rural Mexican Americans.

Bedbugs, Alan H. Roe, Jay B. Karren

All Archived Publications

No abstract provided.

Graduate Catalog/Supplement 1995-1998, Utah State University

University Catalogs

Contains course descriptions, University college calendar, and college administration.

The Effects Of Real Exchange Rate Depreciation On Stochastic Producer Prices, Christopher B. Barrett

Economic Research Institute Study Papers

This paper considers the effects of real exchange rate depreciation on stochastic agricultural producer prices. The conventional wisdom, that real depreciation stimulates tradables production, does not hold when one admits price uncertainty and producer income risk aversion. In fact, real depreciation only yields a stiinulative price signal (in the Sandmo sense of higher mean, lower variance) in the case of a partiGular subset of nontradables, "nontraditional exports" which have indeed responded vigorously to contemporary depreciation episodes. GARCH estimation of time..series price data on several commodities from Madagascar support the hypotheses generated by the analytical model.

Out Of The Ordinary, Barbara Walker

All USU Press Publications

This contributed volume explores the functions of belief and supernatural experience within an array of cultures, as well as the stance of academe toward the study of belief and the supernatural. The essays in this volume call into question the idea that supernatural experience is extraordinary.

Post-Operative Carbonate-Apatite Formation In Peo/Pbt Copolymers (Polyactive®), A. M. Radder, J. E. Davies, R. N. S. Sodhi, S. A. T. Van Der Meer, J. G. C. Wolke, C. A. Van Blitterswijk

Cells and Materials

Previous studies have stressed the importance of calcification of the polyethylene oxide (PEO) I polybutylene terephthalate (PBT) copolymer surface by establishing a direct relation with the occurrence of bone-bonding. Here, we characterized the morphology as well as the composition of this post-operative reaction product in PEOIPBT copolymers. X-ray · photoelectron spectroscopical results demonstrated the ability of PEOIPBT copolymers to rapidly adsorb calcium ions from fluids. After subcutaneous implantation in rats, it was shown that polymer calcification comprised plate-shaped crystals, whereas an electron-dense layer was frequently encountered at the interface. Cells with a characteristic morphology were directly apposed to abundantly calcified …

Hip Prosthesis And Bone Mineral Absorptiometry: Effect Of Short-Term Administration Of Calcitriol, Mario Caniggia, Bruno Frediani, Leonardo Osti

Cells and Materials

In this double blind study, seven out of fourteen patients who had received a cementless hydroxyapatitecovered hip prosthesis were given calcitriol (1 p.g daily), and seven an inert placebo for a period of four months. At the end of this period, total body bone densitometry (TBBD) and absorptiometric measurements in the regions of interest (ROIs) close to the prosthesis and in the opposite femur revealed that the TBBD values had decreased in the patients receiving placebo and increased in those receiving calcitriol. Furthermore, bone mineral density in the ROis had increased on the non-operated side of the calcitriol-treated patients (although …

Backscattered Electron Imaging To Enhance Microstructural Contrast In Poly(Methyl Methacrylate) Bone Cement Fracture Analysis, L. D. T. Topoleski, P. Rutledge, X. Lu

Cells and Materials

Poly(methyl methacrylate) (PMMA) bone cement is used as a grout to secure joint replacement prostheses into bone. It has a distinct microstructure made up of: prepolymerized beads, an interbead matrix polymer, a radiopacifier {barium sulphate (BaS04) or zirconium dioxide (Zr02)}, and pores or voids; the radiopacifier is found only in the interbead matrix of the cured bone cement. The mechanism of slow or fatigue crack growth appears to be initial micro-cracking through the interbead matrix, followed by coalescence of the microcracks to form a continuous crack. Thus, distinguishing the interbead matrix from the pre-polymerized beads is important for investigating fatigue …

Cathodoluminescence Of Rare Earth Doped Zircons. Ii. Relationship Between The Distribution Of The Doping Elements And The Contrasts Of Images, G. Rémond, P. Blanc, F. Cesbron, D. Ohnenstetter, O. Rouer

Scanning Microscopy

Cathodoluminescence (CL) color photographs using an optical CL microscope with a cold cathode electron gun are compared with non-spectrally resolved (polychromatic) and selected wavelength CL images obtained by means of a scanning electron microscope equipped with a CL spectrometer. It is the aim of this paper to show how the interpretation of the contrasts of CL images depends on the knowledge of the CL photon energy distributions participating to the observed contrasts as well as the matrix effects modifying the number of emitted photons compared to that of generated photons. It is shown that the impurities different from the rare …

Ultrafast Carrier Capture In Quantum Well Structures, P. W. M. Blom, J. E. M. Haverkort, J. Claes, P. J. Van Hall, J. H. Wolter

Scanning Microscopy

We present an experimental and theoretical study of the carrier capture time into a semiconductor quantum well. The carrier capture time was obtained by measuring both the rise of the quantum well (QW) population using time-resolved luminescence measurements and the decay of the barrier population using pump-probe correlation experiments. In the first technique, we compare the QW rise-times after direct (below the barrier band gap) and indirect (above the barrier band gap) excitation in order to eliminate the effects of relaxation and exciton formation in the quantum well.

We report the first experimental observation of oscillations in the carrier capture …

Fairness, Stewardship, And Sustainable Development, Christopher B. Barrett

Economic Research Institute Study Papers

The welfare economic concept of fairness offers an attractive, axiomatic foundation for the popular notion of stewardship. Fairness emphasizes the ex ante equal standing of all persons, across and within generations. This highlights the inextricability of poverty alleviation and environmental sustainability, especially in the agrarian tropics where biodiversity loss, deforestation, and desertification are growing global concerns.

Biodegradation Of Synthetic Biphasic Calcium Phosphate And Biological Calcified Substratum By Cells Of Hemopoietic Origin, A. Soueidan, O. I. Gan, J. M. Bouler, F. Gouin, G. Daculsi

Cells and Materials

Different types of osteoclastic cells (authentic osteoclasit from human giant cell tumor and bone marrow of newborn rats; newly-formed osteoclasts from adult rat bone marrow), giant multinucleated cells and macrophages were studied for their effect on synthetic and natural mineralized substrata. Biphasic calcium phosphate ceramic consisted of hydroxyapatite and beta tricalcium phosphate was chosen for in vitro experiments, and dentine served as a positive control for cell resorbing activity . Our results show the limited capacity of authentic and newly-formed osteoclasts to resorb synthetic ceramic as compared to that of natural substrata. In vitro cell-mediated biodegradation included also modifications of …

Resorption Of Natural Calcium Carbonate By Avian Osteoclasts In Vitro, G. Guillemin, S. J. Hunter, C. V. Gay

Cells and Materials

Osteoclasts isolated from the endosteum of 2.5 to 3-week chick tibia were cultured on glass coverslips or natural CaC03 (Tridacna) wafers for 2 and 4 days. The cells were exposed to the pH-dependent dye, acridine orange, and fluorescence was measured by a light microscope photometer. Fluorescence intensity values were higher in cells adherent to Tridacna wafers than in those incubated on glass after 2 and 4 days of culture (three and two-fold, respectively). Moreover, osteoclasts on Tridacna wafers were more flattened and were found to produce resorption pits. Acid production by osteoclasts cultured on Tridacna wafers was stimulated …