Digital Commons Network^™

Dentin: A Dynamic Substrate - A Review, David H. Pashley

Scanning Microscopy

The structure of dentin is unusual in that the number and size of its tubules changes as one moves from the periphery toward the pulp chamber. Near the pulp, the tubules are very close together and the water con tent of this deep dentin is high. Near the enamel, the tubules are far apart, occupying less than 1% of the surface area. When enamel or dentin is cut, the surface becomes covered by an adherent layer of cutting debris called the smear layer. Its composition presumably reflects the composition of the underlying dentin. It is only about 1 μm thick …

Scanning Optical Microscopy Of Semiconductor Materials And Devices, C. J. R. Sheppard

Scanning Microscopy

In the scanning optical microscope a focused light spot is used to illuminate the object and some property monitored as the spot is scanned relative to the object to build up an image. By monitoring different properties it is thus possible to use the scanning optical microscope in a wide range of imaging modes, which can be used to give much information concerning the structure and properties of semiconductor materials and devices. In the optical-beam induced current method the focused light spot generates electronic carriers in a semiconductor specimen, and the resultant current monitored. The technique can be used to …

Vascular "Sphincter" And Microangioarchitecture In The Central Nervous System: Constriction Of Intraparenchymal Blood Vessels Following A Treatment Of Vasoconstrictive Neurotransmitter, K. Nakai, Y. Naka, H. Yokote, T. Ikatura, H. Imai, N. Komai, T. Maeda

Scanning Microscopy

The site of action of neuropeptide Y (NPY), a potent vasoconstrictive neurotransmitter, on the intraparenchymal blood vessels in the rat parietal cortex was demonstrated using a corrosion cast technique with scanning electron microscopy. Our observations were confined to the cortical area where the regional cerebral blood flow (rCBF) had been reduced significantly by in situ application of NPY. A striking finding in that area was the diffuse narrowing of the perforating arteries in the upper cortical layers. Ring-like compressions on the corrosion casts, presumably formed by active vascular sphincters along the arteries, capillaries and venules within the brain parenchyma, seemed …

Effect Of Heating To 200 C On Casein Micelles In Milk: A Metal Shadowing And Negative Staining Electron Microscope Study, V. R. Harwalkar, Paula Allan-Wojtas, Miloslav Kalab

Food Structure

Milk was heated to 200 C for 3 min in sealed inverted-Y-shaped glass vials and reacted with a glutaraldehyde solution at that temperature. Electron microscopy of the metal-shadowed and negatively stained samples revealed that casein micelles in the milk did not disintegrate extensively at the high-temperature used but, rather, became enlarged. Some of them were found to be either clustered or distorted.

Proceedings From The 26th Annual Marschall Italian Cheese Seminar, Various Authors

Cheese Industry Conference

No abstract provided.

An Electron Microscopic Study Of The Adherence Of Lactobacillus Acidophilus To Human Intestinal Cells In Vitro, S. K. Hood, E. A. Zottola

Food Structure

In this study, transmission electron microscopy was used to visualize the adherence of Lactobacillus acidophilus to human intestinal tissue cells (HITC) in vitro. There appeared to be a layer of electron dense material on the bacterial cell and on the intestinal cell which may mediate adherence. When L. acidophilus attached to intestinal tissue cells after a short contact period, it did not appear to disrupt the integrity of the intestinal cell. Treatment of the bacterium with sodium periodate and concanavalin A reduced the adherence to HITC, suggesting that a carbohydrate was involved. Electron micrographs of periodate-treated cells revealed that the …

The Size Distribution Of Casein Micelles In Camel Milk, Z. Farah, M. W. Ruegg

Food Structure

The size distribution of casein micelles in camel milk has been determined by electron microscopy. Individual and pooled samples were cryo-fixed by rapid freezing and freeze-fractured. Electron micrographs of the freeze-fracture replica revealed a relatively broad size distribution, with an average micelle dimeter around 280 nm in the volume distribution curve. The distribution was significantly broader than that of the particles of cow's or human milk and showed a greater number of large particles. The submicelles were also somewhat larger than those observed in cow's and human milk (approx. 15, 10 and 7 nm, respectively). The average values for the …

Cereal Structure And Its Relationship To Nutritional Quality, S. H. Yiu

Food Structure

Factors that determine the digestibility of carbohydrates and minerals in cereals are examined . Most carbohydrates and minerals in cereals are structurally bound, either surrounded by or associated with cell wall components not easily digested by non-ruminant animals and humans. Treatments such as mechanical grinding and heat improve the digestibility of nutrient s . Further processing and cooking result in structural and physeochemical changes of cereal starch, phytate, and dietary fiber. Such changes greatly Influence the physiological and metabolic effects in animals and humans. The digestive breakdown of most nutrient components is also dependent on the activities of enzymes in …

Effects Of Protein Concentration In Ultrafiltration Milk Retentates And The Type Of Protease Used For Coagulation On The Microstructure Of Resulting Gels, Dragoljub D.J. Gavaric, Marijana Caric, Miloslav Kalab

Food Structure

Milk retentates (35~ total solids, 13~ protein) obtained by ultrafiltration were diluted with the permeate to 3 . 2, 5.0, 6.5, 10.0, and 13.0% protein and coagulated using conrnerc1al proteases. Rennet or one of microbial proteases isolated from Bacillus potymlxa , Endothla parasfttca, Mucor mtehel, or Mucor pusfllus were used . Coagulation times were decreased with the Mucor proteases as the protein concentrations in the retentates were increased but the coagulation times were increased with B. potymlxa and f. parasltlca proteases under similar conditions . Firmness was higher in gels made from homogenized retentates than from nonhomogenized retentates of the …

Fluorescence Microscopy Studies On (1,3) - B-D-Glucan In Barley Endosperm, A. W. Macgregor, G. M. Ballance, L. Dushnicky

Food Structure

Development of (1,3;1,4)-B-D-glucan and (1,3)-B-D-glucan in kernels of Himalaya and Bonanza barley has been followed by fluorescence microscopy using calcofluor and aniline blue fluorochromes. Specific enzymes were used to confirm the identity of these two polysaccharides in sections of endosperm tissue. All barley lines tested contained both types of B-glucan but (1,3;1,4)-B-glucan was synthesized at an earlier stage of development than was (1,3)-BGlucan. Small bead-like deposits of (1,3)-B-glucan were detected in all cultivars examined. These deposits were present throughout the endosperm and appeared to be associated with the inner walls of endosperm cells. After treatment of sections with (1,3)-B-glucanase, these …

Test Of Rpa Production Coefficients And Local Assumptions For The Pinyon-Juniper Ecosystem In Central Utah, U.S. Forest Service

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

This study fields test production assumptions, such as those for herbage and shrubs, developed in response to the Resources Planning Act.

Mule Deer Diets On A Chained And Seeded Central Utah Pinyon-Juniper Range, United States Department Of Agriculture, Forest Service

Forestry

Study of the seasonal use by mule deer of some native and introduced species on a pinyon-juniper restoration project showed that woody species made up the bulk of pellet samples, followed by forbs and grasses. Land managers are advised on seeding and grazing practices for enhancing big game habitats.

Effects Of Prescribed Fire On Biomass And Plant Succession In Western Aspen, United States Department Of Agriculture, Forest Service

Forestry

Biomass of grasses, forbs, shrubs, and aspen suckers was determined annually for three prescribed fires in aspen and aspen-conifer forests in southeastern Idaho and western Wyoming. Fires ranged from low to high severity and overstory mortality from 20 to 100 percent. Over 4 postburn years, production of grasses and forbs averaged 1.5 to 3.3 times that of controls. After 5 years, shrub biomass was 21 to 100 percent of preburn biomass. The varied patterns of seral vegetation and their management implications are discussed.

Revegetation By Land Imprinter And Rangeland Drill, United States Department Of Agriculture, Forest Service

Wildfires

The land imprinter and rangeland drill were compared for revegetation of a wildfire burn in the Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) vegetation type. Seeding trials were conducted on strips 152 m wide and 1.6 km long. Seeded species were fairway wheatgrass (Agropyron cristatum), luna pubescent wheatgrass (A. trichophorum), Russian wildrye (Elymus junceus), and Ladak alfalfa (Medicago sativa). Severe wind erosion on the study area occurred the first spring. Total seeded plant densities and cover were significantly higher with the imprinting treatment. Production of seeded plants was higher on the imprinted areas the first 2 years; thereafter, compensatory growth …

Lecture 14: Education, The Last Odyssey, Charles M. Lutz

Last Lectures

No abstract provided.

Analysis Of The Potential Energy Surface Of Ar–Nh3, G. Chalasinski, S. M. Cybulski, M. M. Szczesniak, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The combination of supermolecular Møller–Plesset treatment with the perturbation theory of intermolecular forces is applied in the analysis of the potential energy surface of Ar–NH₃. Anisotropy of the self‐consistent field (SCF) potential is determined by the first‐order exchange repulsion. Second‐order dispersion energy, the dominating attractive contribution, is anisotropic in the reciprocal sense to the first‐order exchange, i.e., minima in one nearly coincide with maxima in the other. The estimated second‐order correlation correction to the exchange effect is nearly as large as a half ΔE^SCF in the minimum and has a ‘‘smoothing’’ effect on the anisotropy of …

Centipedes, Reed S. Roberts

All Archived Publications

No abstract provided.

Elm Bark Beetles, Utah State University Extension

All Archived Publications

No abstract provided.

Electron Microscopic Localization Of Cholesterol In Bovine Milk Fat Globules, Robert W. Martin Jr.

Food Structure

An electron microscopic method designed for the detection of cholesterol in milk fat was evaluated for reliability. This method is based on the incubation of cream from raw milk with fillipin (a polyene antibiotic) which has a specific affinity for cholesterol followed by freeze fracturing and electron microscopic examination of fat globules. Cholesterol was localized within the membrane and the triglyceride core of milk fat globules. Cholesterol was highly organized within membrane portions and less organized within triglyceride portions of milk fat globules. The configuration of localized cholesterol was similar to configurations reported for plasma membranes.

Microstructural Changes In Wheat Starch Dispersions During Heating And Cooling, M. Langton, A. M. Hermansson

Food Structure

Microstructural changes in 8-11% wheat starch dispersions during heating, cooling and cold storage have been evaluated by light microscopy and scanning electron microscopy.

Heat treatment of wheat starch dispersions gives rise to two stages of swelling and solubilization. During the first phase of swelling, solubilized amylose was observed ln the centre of the granules and, to some extent, outside the granules. Further swelling deformed the granules and more amylose was released. When the temperature treatment took place under shear, the outer layer of the swo llen granules fra ctured at 94°C and above, and amylopectin fragments were dispersed into the …

Microstructure Of Extruded Mixtures Of Cereals And Oil Seed Processing Residues, A. Salgo, Sz. Torok, Sz. Sandor

Food Structure

The utilization of valuable by-products of seed processing residues as coextrusion materials was investigated. By mixing sunflower, pumpkin, corn or rice germ presscake with cereals (wheat, corn, rice), the good protein quality of the former group might improve the biological value of the resulting coextrudates. The microstructure of such coextruded products was analysed with reference to their chemical compositions, nutritional characteristics and functional properties. As seed processing residue was increased, the microstructure of the products became more compact and uniform and the air/solids ratio decreased considerable. The results showed that the highest acceptable concentration of the additive was not more …

The Structural Basis Of The Water-Holding, Appearance And Toughness Of Meat And Meat Products, Gerald Offer, Peter Knight, Robin Jeacocke, Richard Almond, Tony Cousins, John Elsey, Nick Parsons, Alan Sharp, Roger Starr, Peter Purslow

Food Structure

A structural approach greatly clarifies which components of meat are responsible for its tenderness, water-holding and appearance, and the events occurring during processing.

In living muscle, water is held in the spaces between the thick and thin filaments. Changes in the content and distribution of water within meat originate from changes in this spacing. Myofibrils shrink laterally post mortem . The fluid expelled accumulates between fibre bundles and between fibres and is drain ed by gravity forming drip. In pale, soft and exudative meat, shrinkage of the myosin heads on denaturation increases myofibrillar shrinkage. In salt solutions used in meat …

Food Microstructure

Food Structure

No abstract provided.

Microstructure Of Nunas: Andean Popping Beans (Phaseolus Vulgaris L.), Stephen C. Spaeth, Daniel G. Debouck, Joseph Tohme, Janny Van Beem

Food Structure

Nunas, popping beans (Phaseous vulgaris L.), burst and expand when heated rapidly. Differences in seed microstructure between popping and conventional (non-popping) bean genotypes conceivably contribute to popping in nunas However, the microstructural characteristics which contribute to the popping attribute and sites of expansion have not been identified. Seeds and excised cotyledons of unpopped and popped nunas were examined using scanning electron microscopy (SEM). Protoplasts of unpopped nunas were similar to protoplasts of conventional beans. Intercellular spaces of unpopped nunas were occluded by schizogenous cell walls. The occluded form of intercellular spaces differed distinctively from the open form in popped nunas …

Growth Of Nitrogen-Fertilized And Thinned Quaking Aspen (Populus Tremuloides Michx.), Donald A. Perala, P.R. Laidly

Aspen Bibliography

Crop trees of quaking aspen (Populus tremuloides Michx.) and its Eurasian equivalent, P. tremula L., grow faster after thinning.

Applied Chaotic Dynamics: An Introduction, James Frankenfield

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

These lecture notes served as the basis for a two credit graduate level seminar offered through the USU physics department during the fall quarter of 1989. It was oriented towards graduate students in physics and engineering and assumed no mathematical background beyond introductory differential equations. All problems were attempted by the students and discussed as a group. The seminar appears to have been successful in that the students enjoyed it and learned a lot.

Soil Phase Photodegradation Of Toxic Organics At Contaminated Disposal Sites For Soil Renovation And Groundwater Quality Protection, W. M. Moore, R. Ryan Dupont, J. E. Mclean

Reports

Accurate assessment of the potential for contaminated soil remediation requires detailed knowledge of the fate of waste constituents within the soil environment. For many non-biodegradable organics compounds, photochemical degradation may provide a potential pathway for the removal of such compounds from soil surfaces. A study was conducted to evaluate the rate of photodegradation of ten hazardous organic compounds from three soils, silica gel, and four soil minerals (kaolinite, montmorillonite, illite, and calcite) under conditions of controlled irradiation. In addition, the effect of siz amendment treatments (methylene blue, riboflavin, hydrogen peroxide, diethylamine, peat moss, and silica gel) on the rates of …

Bear River Water Quality: Bioavailable Phosphorus Measurement, Sources, And Control, Kenneth W. Barker, Darwin L. Sorensen, Jay C. Andersen, Jean M. Ihnat

Reports

No abstract provided.

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

All Archived Publications

Groundwater is a hidden, but important resource. We can practicably define groundwater as water be· neath 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.

Measurement Of Fungicide Smoke Application By Electron Beam Analysis, C. R. Krause, C. C. Powell

Scanning Microscopy

Low volume fungicide smoke particle deposits were studied with scanning electron microscopy and energy dispersive X-ray analysis. Under greenhouse conditions, particles deposited on Rhododendron leaf surfaces and onto inert, carbon planchets adjacent to Rhododendron leaves were characterized by electron beam analysis. Angular particles containing chlorine, identified as vinclozolin deposition, were quantified on a per unit area basis. Leaf samples collected from plants immediately adjacent to the smoke applicator had more particles than leaf samples collected elsewhere. More deposition was measured on leaf surfaces than on inert planchet surfaces. This study increased our knowledge about the effectiveness of using less fungicide …