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Preparation Of Cryosections For Biological Microanalysis, Karl Zierold

Scanning Electron Microscopy

The element distribution in biological cells and tissues can be revealed by electron probe microanalysis from ultrathin cryosections. In particular, the distribution of physiologically important and often mobile elements such as Na, Mg, P, S, Cl, K, and Ca can be studied in cryosections on an ultrastructural level. The cryopreparation technique required for this purpose consists of 1. cryofixation, 2. cryosectioning, 3. cryotransfer including freeze-drying and carbon coating if necessary, 4. energy dispersive X-ray microanalysis in a cold stage equipped scanning transmission electron microscope. The lateral analytical resolution of this method is less than 50 nm in freeze-dried ultrathin (about …

Problems Associated With The Preparation Of Cell Suspensions For X-Ray Microanalysis Highlighted By The Comparison Of Results With Those Obtained From Tissue Sections, A. Warley, M. D. Kendall, I. W. Morris

Scanning Electron Microscopy

Fully quantitative X-ray microanalysis of freeze dried frozen sections allowed the concentration of monovalent ions in the nuclei of mouse thymocytes in tissue sections to be compared with those from thymocytes which had been isolated by a simple preparation procedure. Isolated cells showed increased concentrations of Na and Cl. This was further investigated in the rat where the size of the thymus a 11 owed comparison between different isolation media using cells derived from the same animal. Use of autologous serum as the final suspending medium gave reproducible results, whereas with suspension in BSS, or 20% dextran the results were …

Immuno-Cytochemistry With Backscattered Electrons, D. Soligo, E. De Harven, M. T. Nava, G. Lambertenghi-Deliliers

Scanning Electron Microscopy

Some cytochemical reaction products are visible inside the cytoplasm of cells observed with the scanning electron microscope (SEM) using the backscattered electron imaging (BEI) mode. Methods can be utilized whenever they result in the deposition of heavy metal, like silver, lead or osmium at the sites of the enzymatic reaction.

More recently the BEI mode of the SEM has been demonstrated to improve the detection of immunogold labeled cell surface antigens. Colloidal gold particles, 40 to 15 nm in diameter can be efficiently used for immuno-specific labeling. Moreover, cytochemical reactions can be applied to previously immunogold labeled cells, therefore combining …

Evaluating Landowner Assistance Programs And Other Wood Procurement Options, Gary D. Kronrad, C. Franklin, J.E. De Steiquer

Faculty Publications

A major activity of forest industry is supplying their mills with wood. There are four options for wood procurement: fee land, lease land, landowner assistance programs, and open market. The task of the corporate planner is to allocate the limited budget among these options in such a way that the needed volumes of wood are procured at the least cost. A methodology has been developed to aid in this capital budget in process and has been incorporated in an easy-to-use computer program.

Weather And Climate Impacts On Beef Cattle, G. Leroy Hahn

Roman L. Hruska U.S. Meat Animal Research Center: Reports

The pervasive nature of weather and climate and the difficulties in adequately predicting their impact on beef cattle often lead to inadequate management strategies and tactics, resulting in a situation of coping as the need arises. This can lead to "management by crises" rather than rational decisions. The objective of this report is to summarize some of the known responses of cattle to their thermal environment and to address ways by which adverse impacts can be reduced. The discussion is based on results from U.S. Meat Animal Research Center and other research stations.

General observations: Domestic cattle fall into …

Consumption Of Aquatic Plants By The West Indian Manatee, Kay Etheridge, G. B. Rathbun, J. A. Powell, H. I. Kochman

Biology Faculty Publications

Because manatees (Trichechus manatus) are large aquatic herbivores they have often been considered as potential control agents for aquatic plants. Several problems are associated with this concept, and a major one has been the gap in knowledge concerning food consumption rates of manatees. We estimated food consumption by measuring chews per unit time, chews per amount of food consumed, and time spent chewing food. Data were collected on captive manatees of various sizes and used to construct regression equations that predict consumption rates based on body size. Time budget data were obtained by radiotelemetry of free-ranging animals. Estimates of …

Characterization Of Breeds Representing Diverse Biological Types: Reproduction And Maternal Performance Of F1 Cows, Larry V. Cundiff, Keith E. Gregory, Robert M. Koch

Roman L. Hruska U.S. Meat Animal Research Center: Reports

It is estimated that today about 70 percent of the calves narketed from beef cattle herds in the U.S. are crossbred and hat between 50 and 60 percent of the cows are crossbred. This represents a major shift to crossbreeding from the straight-breeding programs which prevailed in the 1950's and early 1960's. This trend has been influenced by research demonstrating the favorable effects of heterosis and other advantages of crossbreeding. Also, increased use of feed grains in growing-finishing diets caused fatter carcasses contributing to increased consumer demand for leaner beef, which stimulated interest in breeds with greater potential for lean …

Autumnal Bird Migration Over The Windward Caribbean Islands, Timothy C. Williams , '64

Biology Faculty Works

No abstract provided.

Water And Watershed In Aspen: Ecology And Management In The Western United States, Norbert V. Debyle

Aspen Bibliography

No abstract provided.

G85-753 Irrigation Scheduling Using Crop Water Use Data, C. Dean Yonts, Norman L. Klocke

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide describes using the "checkbook" method to schedule irrigations based on crop water use data.

Irrigation scheduling determines when and how much water to apply to meet crop demand. Soil water status and current crop water use are key factors for scheduling irrigations. Field observations and crop growth stage are important, but scheduled irrigations result in better rainfall use while avoiding crop water stress or excessive irrigation.

A New Marine Genus Of The Maera Group (Crustacea: Amphipoda) From Belize, James Darwin Thomas, J. L. Barnard

Marine & Environmental Sciences Faculty Articles

A new genus and species, Dumosus atari of the Maera group from coral rubble at Belize is described. It is related to Gammarella and is probably cryptic. The eyes are reduced. Dumosus differs from Gammarella in the loss of medial setation on the maxillae, reduction of article 3 on the mandibular palp, loss of article 2 on the outer ramus ofuropod 3, and in the loss of major spination on the plates of maxilla I and the maxilliped; in contrast to Gammarella, Dumosus retains the plesiomorphic uropod 3 typical of the Maera-group.

Perioculodes Cerasinus, N. Sp., The First Record Of The Genus From The Caribbean Sea (Amphipoda: Oedicerotidae), James Darwin Thomas, J. L. Barnard

Marine & Environmental Sciences Faculty Articles

Perioculodes cerasinus, a probable cryptic fossorial amphipod with embedded white orbicular ommatidia in bright ruby eyes is described from Tobago, Belize, Florida Keys, and Biscayne Bay, Florida. The eyes are separated either into two lunes or combined side to side into one large irregular brow. This is the first western Atlantic record of a generic group heretofore confined to the warm eastern Atlantic and Indian Oceans. Close affinity appears to be with the type-species of the genus, P. longimanus, from the eastern Atlantic Ocean.

Two New Species Of Two New Gammaridan Genera (Crustacea: Amphipoda) From The Florida Keys, James Darwin Thomas, J. L. Barnard

Marine & Environmental Sciences Faculty Articles

Two new species of the new genera Anamaera (A. hixom) and Spathiopus (S looensis), both belonging to the section Gammarida of Amphipoda, are described from the Florida Keys. Anamaera is a new genus close to Maera, Ceradocus, and Ceradomaera, but has an unique combination of minor character expressions. Males of Spathiopus have an unusual paddle-shaped antenna 2 but otherwise Spathiopus appears to be an apomorph of Elasmopus.

Legal Aspects Of Human Genetics, Roger B. Dworkin, Gilbert S. Omenn

Articles by Maurer Faculty

No abstract provided.

Public Response To "Guidelines For Managing Aspen", Norbert V. Debyle

Aspen Bibliography

No abstract provided.

The Oncogene Of Avian Sarcoma Virus Ur2 And Its Cellular Homologue: Structure, Sequence And Expression, Wendi S. Neckameyer

Student Theses and Dissertations

Avian sarcoma virus UR2 is a replication-defective virus that can induce sarcomas in vivo and transforms chicken embryo fibroblasts in culture to a characteristic, extremely elongated morphology. The genome of UR2 contains a 1.2 kb transformation-specific sequence, v-ros, which has a homologous counterpart, c-ros, in normal chicken cellular DNA. The 5' end of v-ros is fused to the helper virus UR2AV-related sequencing coding for one of the viral gag proteins, p19. The fused p19 and ros sequences in UR2 code for a polyprotein of 68 kd, P68^gag-ros, which has an associated tyrosine kinase activity. To elucidate the basis …

Coordinated Control Of Liver-Specific Genes In Cultured Cells From Mice And Rats, David Forrest Clayton

Student Theses and Dissertations

Assays of transcription rate and mRNA concentration were designed and employed to measure the production of a series of liver-specific and common mRNAs in fresh livers, primary hepatocyte cultures, and hepatoma cell lines, derived from mice or rats. The transcription rates of many different liver-specific but no common mRNAs were found to decline sharply within 24 hours when hepatocytes from the liver were explanted and placed into primary culture. Hepatoma cells known to display liver-specific characteristics also transcribed liver-specific genes at low levels similar to primary cultured hepatocytes. In contrast, slices of liver tissue exposed to the same culture conditions …

Introducing The Western Australian Department Of Agriculture, Department Of Agriculture, Western Australia

Farm Systems and Economics published reports

District offices and Research stations

Any big organisation, Government or private, needs an effective Directorate and 'back-up' staff to make full use of its potential. In the Department of Agriculture, the organisational structure has been up-dated to cope with the changing and increasing demands of the State's growing agricultural industries.

Nitrogen And Phosphorus Compound Fertilisers, M G. Mason, J. W. Bowden

Journal of the Department of Agriculture, Western Australia, Series 4

Nitrogen and phosphorus are two vitally important elements for plant growth which are deficient in most soils throughout Western Australia's agricultural areas.

Both nitrogen and phosphorus can also be applied in appropriate compound fertilisers which can be drilled with the seed, thus making their handling much easier. However, excessively high rates can depress plant emergence and may lower crop yields.

Ultrastructural Studies On The Cultivation Processes And Growth And Development Of The Cultivated Mushroom Agaricus Bisporus, D. A. Wood, G. D. Craig, P. T. Atkey, R. J. Newsam, K. Gull

Food Structure

Scanning electron microscopy (SEM) , transmission electron microscopy and light microscopy have been used to study various processes in the cultivation of the edible mushroom Agaricus bisporus . Mushrooms are cultured on composted wheat straw. The microbial degradation processes during composting have been visualised by TEM and SEM and correlated with microbiological studies . Various modes of attack by the microorganisms on the plant cell walls can be seen. Most rapid degradation occurred on the cuticle and phloem and spread to other cell types. Microbial attack was found to be nonuniform between tissue types and individual cells. The mycelium of …

Cryoultramicrotomy And Electron Microanalysis Of Isolated Bovine Adrenal Chromaffin Cells, Richard L. Ornberg

Scanning Electron Microscopy

Instrumentation and techniques have been developed for the cryoultramicrotomy of isolated bovine adrenal chromaffin cells frozen with a liquid helium cooled copper block method. X-ray microanalysis and electron energy loss spectroscopy were used to measure both light and heavy element content of the adrenal storage granule, the chromaffin granule. Ultrathin freeze-dried cryosections usually have a fine compression which in cellular structure compresses the cytoplasm between organelles. Nuclei, chromaffin granules, and vacuoles are relatively free of compression. The mechanism for this distortion is not known al though static charge induced sticking to the knife may be the most probable cause.

The …

The Size Distribution Of Bovine Casein Micelles: A Review, C. Holt

Food Structure

This review considers the average size and size distribution of bovine casein micelles as measured by electron microscopy, light scattering and controlled pore glass chromatography, and the origin and biological function of the size distribution.

Recent work by electron microscopy has given average sizes in reasonable agreement with measurements on the same milk sample by light scattering . It is suggested that natural variations in averaqe micelle size and overestimation of micelle radii by light scattering methods as well as deficiencies in electron microscopical methodology were responsible for past discrepancies.

Electron microscopy and controlled pore glass chromatography provide evidence that …

Ultrastructural Ultilization Of Plants By Herbivores, L. H. Harbers

Food Structure

Study of the patterns of ruminal digestion of forages enhances the nutritional knowledge of how specific plant tissues are digested and adds its own dimension by characterizing the specific cells and the complex interactions of ruminal microflora with those tissues. A common pattern of digestibility exists for mono- and dicotyledon leaves: mesophyll and phloem are degraded readily, and sclerenchyma slowly, whereas cuticle and the remaining vascular tissues are rarely utilized . Digestion of stems is limited to parenchymal tissues in monocotyledons and to cortex and parenchyma in dicotyledons. Epidermal silica and cuticle are undigestible and restrict microbial entrance. Calcium oxalate …

Scanning Electron Microscopic Study Of Rockfish Preserved At Either Ambient Temperature Or By Isothermal Freeze-Fixation, L. E. Lampila, V. Mohr, D. S. Reid

Food Structure

Fresh rockfish (Bocaccio, Sebastus paucispinis) fillets were blast frozen and stored at either -5 °C or -20 °C for 60 days . At defined sampling intervals, speci mens were removed and chemically fixed at either ambient temperature or isothermally, at the respective storage temperatures (-5 °C or -20°C) . The results indicated that isothermally freeze - fixed specimens showed a degree of crushing and/or distortion of the muscle fiber, the deposition of presumed ice crystals in the cell membrane, the multi-dimensionality of connective tissue and the preservation of fine detail . In specimens fixed at ambient temperatures , structura l …

Changes In Typical Organelles In Developing Cotyledons Of Soybean, K. Saio, K. Kondo, T. Sugimoto

Food Structure

Soybean cotyledonary cells harvested every 5-10 days at 15 to 60 days after flowering (OAF), were investigated by means of light and transmission electron microscopy. In the early developing stages (15-20 OAF) most of the cells were occupied by large, centrally located vacuoles while the cytoplasm was restricted to a thin layer against the cell wall and contained numerous ribosomes, mitochondria, plastids, small amounts of endoplasmic reticulum (ER) and minute lipid bodies. At about 25 OAF, spherical organelles which contained protein, lipid and sugar (PLS bodies), appeared and then increased in number and in size. Vacuoles had protein deposits lining …

The Combined Effects Of The Calcium Activated Factor And Cathepsin D On Skeletal Muscle, E. A. Elgasim, M. Koohmaraie, A. F. Anglemier, W. H. Kennick, E. A. Elkhalifa

Food Structure

Myofibrils were isolated from atdeath ovin elongissimus muscles and incubated with crude calcium activated factor prepared from the same muscle and with purified cathepsin D. Myofibrils we reincubated with these enzymes separately (first incubation) and successively (second incubation). The major changes induced by cathepsin D first incubation include degradation of myofibrillar proteins with molecular weight > 200 K, myosin, actin, troponin- T and troponin 1. Also new bands appeared at the 140- 160 K, 80 K, 68 K and 30 K regions. Similar changes were obtained 1v hen myofibrils were incubated first with CAF then with cathepsin D (second incubation). On …

Seed Microstructure: Review Of Water Imbibition In Legumes, Barry G. Swanson, Joe S. Hughes, H. Paul Rasmussen

Food Structure

Scanning electron microscopy (SEM) is an invaluable tool for studying foods and food products. SEM has been particularly va luable in the study of seed microstructure and the ro le of microstructure in water imbibition by legumes. Controversy continues to surround the causes of hard ness in legumes as addi tional research revea ls differences between legumes that imbibe water and legumes that fail to imbibe water. SEM observation of the microstructural changes occurring in legumes during water imbibition ofkrs a better undcrstandi ng of d i ffc rcnces that ex ist betwee n hard and normal beans. Structural changes …

Comparison Of The Microstructure Of Firm And Stem-End Softened Cucumber Pickles Preserved By Brine Fermentation, W. M. Walter Jr., H. P. Fleming, R. N. Trigiano

Food Structure

Soft and firm stem end tissues of cucumbers fermented at a low concentration of sodium chloride were examined by a combination of light microscopy {LM), transmission electron microscopy { TEM), and scanning electron microscopy { SEM) . When compared to firm tissue, softened tissue cell walls were swollen and striated, and the middle lamellae were poorly stained by the uranyl acetate-1 ead citrate used in TEM . When the tissue was penetrated by a circu l ar punch {1.5 mm diameter), cells in soft tissue tore along the middle l arne ll ae rather than across cell walls, as did …

The Ecology Of Foraging Behavior: Implications For Animal Learning And Memory, Alan Kamil, Herbert L. Roitblat

Avian Cognition Papers

In his recent Annual Review of Psychology article, Snowdon (1983) discussed the synthesis of ethology and comparative psychology. A similar synthesis of behavioral ecology and animal learning is beginning to take place. This article reviews developments in the behavioral ecology and ethology of foraging behavior relevant to psychological research on animal learning. The psychological literature shows that animals possess a wide range of learning abilities, including “simple” classical and operant conditioning; they acquire spatial, nonspatial, and temporal discriminations; they exhibit various forms of rule learning (e.g. matching-to-sample and learning set), and may even in certain senses learn language. Why does …

Two Modal Action Patterns With A Continuous Temporal Distribution, Alan B. Bond, George W. Barlow, William Rogers

Papers in Behavior in Biological Sciences

Most methods of quantitative analysis of animal behavior assume that action patterns can be unambiguously classified into discrete, exclusive categories. This is not invariably the case. The digging behavior of the Midas cichlid (Cichlasoma citrinellum), for example, exhibits two functionally distinct modalities, scoop and pi&, that intergrade continuously in form but are separable probabilistically. We present a technique for analyzing such behaviors that provides a reliable basis for formulating and verifying categories and allows a quantitative assessment of functional dissimilarity.

Die meisten Methoden quantitativer Verhaltensanalysen setzen eindeutige Klassifizierung der Verhaltensweisen in sich wechselseitig ausschlieißende Kategorien voraus. Die sind …