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Relative Intranuclear Magnesium And Phosphorus Contents In Normal And Tumor Cells Of The Human Thyroid Gland As Revealed By Energy-Dispersive X-Ray Microanalysis, Geza L. Lukacs, Imre Zs.-Nagy, Janos Steiber, Ferenc Gyori, Gyorgy Balazs Oct 1996

Relative Intranuclear Magnesium And Phosphorus Contents In Normal And Tumor Cells Of The Human Thyroid Gland As Revealed By Energy-Dispersive X-Ray Microanalysis, Geza L. Lukacs, Imre Zs.-Nagy, Janos Steiber, Ferenc Gyori, Gyorgy Balazs

Scanning Microscopy

Energy dispersive X-ray microanalysis was performed on altogether 42 surgically removed tissue specimens of 32 patients, which were taken either from intact thyroid parts or various histopathologically verified tumors of the thyroid gland. The tissue specimens were processed with the freeze-fracture-freeze-drying technique and then analyzed in the so-called bulk specimen form. The studies were carried out during the years 1980-81, when intranuclear monovalent ionic composition was studied in detail. From the retained total elemental peak list, it was possible to calculate retrospectively the relative intranuclear Mg and P contents. The data processed by nested (hierarchical) analysis of variance show that …

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Imaging The Electrocyte Of Torpedo Marmorata By Scanning Force Microscopy, L. I. Pietrasanta, A. Schaper, G. Q. Fox, F. J. Barrantes, T. M. Jovin Oct 1996

Imaging The Electrocyte Of Torpedo Marmorata By Scanning Force Microscopy, L. I. Pietrasanta, A. Schaper, G. Q. Fox, F. J. Barrantes, T. M. Jovin

Scanning Microscopy

Scanning force microscopy (SFM) and scanning electron microscopy (SEM) were used to examine the tissue structure of the electric organ of Torpedo marmorata in air and in liquid after applying fracturing and cryosectioning techniques and chemical fixation. The electric organ is organized in columns of stacked electrocytes, arranged in a honeycomb pattern. The columns were cut along a plane normal to the cell stack and thin sections were transferred to polylysine coated glass coverslips. The polarity of the electrocytes was made apparent by immunofluorescence microscopy directed to different domains of the acetylcholine receptor (AChR), thus revealing the innervated face of …

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Hair Bundle Morphology On Surviving Hair Cells Of The Chick Basilar Papilla Exposed To Intense Sound, J. S. Erulkar, D. A. O'Brien, J. C. Saunders Oct 1996

Hair Bundle Morphology On Surviving Hair Cells Of The Chick Basilar Papilla Exposed To Intense Sound, J. S. Erulkar, D. A. O'Brien, J. C. Saunders

Scanning Microscopy

Exposure to intense sound produces a well-defined "patch" lesion on the chick basilar papilla in which 30-35% of the short hair cells are lost. The present study compares various aspects of sensory hair bundle morphology on surviving hair cells in the patch lesion with hair bundles from matched locations on nonexposed control papilla immediately after removal from the exposure and 12-days post exposure. The height and thickness of the hairs, the total number of hairs in the bundle, the width of the bundle, and the area and perimeter of the apical surface of the hair cell were quantified from scanning …

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Shark Bay World Heritage Property: Summary Of Public Submissions To The Draft Management Plan For Fish Resources, Kevin A. Francesconi Oct 1996

Shark Bay World Heritage Property: Summary Of Public Submissions To The Draft Management Plan For Fish Resources, Kevin A. Francesconi

Fisheries Management Papers

In November 1994, the draft management plan for fish resources for the Shark Bay World Heritage Area (Fisheries Management Paper no 72) was released for public comment. This report summarises and analyses the 28 written public submissions received to the draft fisheries management plan.

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Shark Bay Management Paper For Fish Resources, Fisheries Department Of Western Australia, Department Of Conservation And Land Management Oct 1996

Shark Bay Management Paper For Fish Resources, Fisheries Department Of Western Australia, Department Of Conservation And Land Management

Fisheries Management Papers

This paper deals with the management of fish resources in the Shark Bay World Heritage Property which are the responsibility of the Fisheries Department of Western Australia. It was prepared by the Fisheries Department in close liaison with the Department of Conservation and Land Management. The policies and guidelines proposed in this paper will be followed for a period not exceeding 10 years.

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Modeling Nutrient And Plankton Processes In The California Coastal Transition Zone: 3. Lagrangian Drifters, J. R. Moisan, Eileen E. Hofmann Oct 1996

Modeling Nutrient And Plankton Processes In The California Coastal Transition Zone: 3. Lagrangian Drifters, J. R. Moisan, Eileen E. Hofmann

CCPO Publications

Two types of numerical Lagrangian drifter experiments were conducted, using a set of increasingly complex and sophisticated models, to investigate the processes associated with the plankton distributions in the California coastal transition zone (CTZ). The first experiment used a one-dimensional (1-D; vertical) time-dependent physical-bio-optical model, which contained a nine-component food web. Vertical velocities, along the track of simulated Lagrangian drifters, derived from a three-dimensional (3-D), primitive equation circulation model developed to simulate the flow observed within the CTZ; were used to parameterize the upwelling and downwelling processes. The second experiment used 880 simulated Lagrangian drifters from a 3-D primitive equation …

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Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin Oct 1996

Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin

Faculty Publications

In marine soft-sediment habitats, the sediment surface is altered by activities of sediment dwellers (infauna). Such biogenic disturbance can influence recruitment success if settling larvae and juveniles avoid disturbed sites or if juveniles die as a result of disturbance after settling. Because infauna commonly lose exposed body parts to browsing predators and disturb less sediment as a result, we developed a simulation model to examine the interactions between browsing predation, infaunal adult activity, and recruitment. Sediment disturbance in the model was based on data for the polychaete Abarenicola pacifica. We simulated the activity of two general types of predators: prey …

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Nucleic Acid Detection By In Situ Molecular Immunogold Labeling Procedures, Marc Thiry Sep 1996

Nucleic Acid Detection By In Situ Molecular Immunogold Labeling Procedures, Marc Thiry

Scanning Microscopy

We have recently combined immunogold labeling procedures with molecular biology methods to pinpoint the precise locations of nucleic acids in biological material at the ultrastructural level. These new immunocytological approaches involve the incorporation of labeled nucleotides in the nucleic acids present at the surface of ultrathin sections prior to immunogold labeling. The antibodies used recognize a nucleoside analogue (bromodeoxyuridine) or a hapten (biotin) employed to label nucleotides. Examples of high-resolution detection include DNA or RNA present in different substructures of cell nuclei, and in particular, in adenovirus-induced intranuclear regions of HeLa cells. In addition to being highly sensitive and specific, …

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A Comparison Of The Renal Structures Of The Anaconda And The Ball Python, H. Ditrich Sep 1996

A Comparison Of The Renal Structures Of The Anaconda And The Ball Python, H. Ditrich

Scanning Microscopy

The renal vascular system of the Ball python (Python regius) and the anaconda (Eunectes noteus; Serpentes - Squamata) has been investigated using light microscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) of vascular corrosion casts and critical-point dried non-corroded specimens. The average glomerular diameters of these two species differ significantly (anaconda: 59.1 μm, python: 124.3 μm). Also, the relative proportions of the renal tubules are different. These findings can be related to the different habitats of the two species (aquatic versus terrestrial environment).

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Combined Bronchoalveolar-Vascular Casting Of The Canine Lung, John A. Nettum Sep 1996

Combined Bronchoalveolar-Vascular Casting Of The Canine Lung, John A. Nettum

Scanning Microscopy

Canine bronchoalveolar and vascular corrosion casts were prepared using unfixed tissue and Dow-Corning Room Temperature Vulcanizing Silastic® 734. The casts were observed using stereo light microscopy and scanning electron microscopy. The casts show the relationship between the vasculature and airway and demonstrate intricate microanatomical details. Also, microvasculature filling was enhanced using unfixed tissue as compared to my previously described technique using fixed tissue. Prewashing the microvasculature with cold phosphate buffered saline appeared to facilitate microvascular filling with silicone rubber. The described method is useful for rapidly making durable models for studying the normal respiratory airway and microvasculature. It should be …

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Effects Of Castration Upon The Morphology Of The Accessory Sex Organs Of The Male Rat - A Scanning Electron Microscopy Study, R. Wahlqvist, E. Dahl, K. J. Tveter Sep 1996

Effects Of Castration Upon The Morphology Of The Accessory Sex Organs Of The Male Rat - A Scanning Electron Microscopy Study, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

A systematic, comparative study of the accessory sex glands of the adult male rat after androgen withdrawal was carried out. The changes were investigated by using scanning electron microscopy at different intervals after surgical castration. The main common signs of epithelial cell involution were flattening of the cell surface, reduction of the size and number of microvilli, some blurring of the cell borders, cessation of secretory activity and diminution of the luminal volume of the glands. Overall, confident signs of atrophy were evident after one week, and complete epithelial involution was reached by the third week. The epithelial cell atrophy …

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Scanning Electron Microscopy Of The Accessory Sex Glands Of The Adult Male Rat, R. Wahlqvist, E. Dahl, K. J. Tveter Sep 1996

Scanning Electron Microscopy Of The Accessory Sex Glands Of The Adult Male Rat, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

This study describes the morphology of the accessory sex glands of the adult male rat as observed by scanning electron microscopy (SEM). The purpose was to obtain a systematic and comparative SEM description of these glands and to evaluate different preparation techniques. A common morphological feature is polyhedral delineation of the cells, which exhibited a variable convexity of their apical surface. The cell apices were more or less studded with microvilli. Nevertheless, it was possible to distinguish the glands by their surface morphology. In the ventral prostate, there was a considerable heterogeneity in cell surface appearance. The lateral lobe bad …

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Pearling And Aquaculture In The Dampier Archipelago - Existing And Proposed Operations - A Report For Public Comment, Ben Fraser Sep 1996

Pearling And Aquaculture In The Dampier Archipelago - Existing And Proposed Operations - A Report For Public Comment, Ben Fraser

Fisheries Management Papers

This discussion paper has been prepared by the Fisheries Department of WA as part of a consultative process to enable the public to comment on existing and proposed pearling and aquaculture activities in the Dampier Archipelago. This report follows on from Fisheries Management Report 90 - the Driscoll Report - and provides more detailed information about pearling and aquaculture to enable the public to consider and comment on individual projects.

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Characterization Of Experimentally Induced, Nonaflatoxigenic Variant Strains Of Aspergillus Parasiticus., Shubha Kale Ireland, J. W. Cary, D. Bhatnagar, J. W. Bennett Sep 1996

Characterization Of Experimentally Induced, Nonaflatoxigenic Variant Strains Of Aspergillus Parasiticus., Shubha Kale Ireland, J. W. Cary, D. Bhatnagar, J. W. Bennett

Faculty and Staff Publications

Six previously isolated, nonaflatoxigenic variants of Aspergillus parasiticus, designated sec mutants, were characterized morphologically by electron microscopy, biochemically by biotransformation studies with an aflatoxin precursor, and genetically by Northern (RNA) hybridization analysis of aflatoxin biosynthetic gene transcripts. Scanning electron micrographs clearly demonstrated that compared with the parental sec+ forms, the variant sec forms had an abundance of vegetative mycelia, orders of magnitude reduced number of conidiophores and conidia, and abnormal metulae. Conidiospores were detected in sec cultures only at higher magnifications (x500), in contrast to the sec+ (wild-type) strain, in which abundant conidiospores (masking the vegetative mycelia) were observed even …

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Quantitative Analyses Of Microwear And Honing On The Sloping Crest Of The P3 In Female Japanese Monkeys (Macaca Fuscata), Teruyuki Hojo Aug 1996

Quantitative Analyses Of Microwear And Honing On The Sloping Crest Of The P3 In Female Japanese Monkeys (Macaca Fuscata), Teruyuki Hojo

Scanning Microscopy

Female wild Japanese monkeys (Macaca fuscata), as with all male cercopithecoids, use the mesiobuccal surfaces or the elongated crests of the mandibular third premolars (P3s), as cutting blocks that wear against edges of maxillary canines during threat manifestation or food-eating. In other words, the crests of their P3s are honed with the maxillary canines. The crests become sloped during growth and more heavily striated with the advance of age. The number, directions, lengths, and widths of these striations have been analyzed quantitatively using scanning electron microscopy (SEM). Two samples showed two distinct types of parallel striations, one longer and thicker …

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The Neonatal Chinchilla Cochlea: Morphological And Functional Study, R. V. Harrison, J. R. Cullen, S. Takeno, R. J. Mount Aug 1996

The Neonatal Chinchilla Cochlea: Morphological And Functional Study, R. V. Harrison, J. R. Cullen, S. Takeno, R. J. Mount

Scanning Microscopy

The developmental time scale of the cochlea varies from species to species. We investigate here the condition of the neonatal cochlea in the chinchilla, a species increasingly used in auditory research. We have examined the morphology of cochlear hair cells using scanning microscopy, and the development of auditory function during the first postnatal month by monitoring auditory brainstem evoked responses (ABR). We find that although there were some outer hair cell kinocilia present in middle and apical areas, the hair cells otherwise were mature at 24 hours after birth. Furthermore, cochlear auditory thresholds are adult-like at birth. However, whilst there …

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Advanced Instrumentation And Methodology Related To Cryoultramicrotomy: A Review, H. Sitte Aug 1996

Advanced Instrumentation And Methodology Related To Cryoultramicrotomy: A Review, H. Sitte

Scanning Microscopy

This review is concerned with the considerable progress in the field of cryo-ultramicrotomy (cryofixation, cryosectioning, investigation and analysis of cryosections) during recent years. This progress includes both more efficient instrumentation and methodology. The article is mainly directed to the investigation and analysis of frozen-hydrated sections in the low dose cryo-transmission electron microscopy (TEM) and cryo-energy filtered TEM (EFTEM). A general survey is followed by an evaluation of the different relevant procedures. Both cryo-ultramicrotomy for macromolecular cytochemistry (Tokuyasu technique) and cryo-ultramicrotomy for element analysis are only shortly mentioned without discussion of the chemical and analytical approach. Because of lack of first …

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Thermal Preference Of Spring And Fall Chinook Salmon (Oncorhynchus Tshawytscha) During Smoltification, Sally T. Sauter Aug 1996

Thermal Preference Of Spring And Fall Chinook Salmon (Oncorhynchus Tshawytscha) During Smoltification, Sally T. Sauter

Dissertations and Theses

Innate species-specific temperature preferences of fish are subjected to fluctuations under a variety of environmental, physiological, and developmental conditions. The temperature preference patterns of two ecologically distinct races of chinook salmon (Oncorhynchus tshawytscha) were investigated as laboratory held animals underwent smoltification. Smoltification is a distinct developmental stage in the life history of anadromous salmonids when juvenile fish undergo profound behavioral, morphological, and physiological differentiation prepatory to seawater entry. A group of spring and fall chinook salmon were held under identical conditions of increasing water temperature over the course of smoltification. Another group of spring and fall chinook salmon were held …

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A Protocol For Ecosystem Management, Jack A. Stanford, G. C. Poole Aug 1996

A Protocol For Ecosystem Management, Jack A. Stanford, G. C. Poole

Biological Sciences Faculty Publications

No abstract provided.

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Effects Of Fatiguing Stimulation On Intracellular Na+ And K+ In Frog Skeletal Muscle, Edward Michael Balog, Robert H. Fitts Aug 1996

Effects Of Fatiguing Stimulation On Intracellular Na+ And K+ In Frog Skeletal Muscle, Edward Michael Balog, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The purpose of this study was to describe the alterations in the intracellular concentrations of sodium ([Na+]i) and potassium ([K+]i) and the membrane potential (Em) as a result of fatiguing stimulation of the frog semitendinosus muscle and to relate these changes to the alterations in the sarcolemma action potential and force-generating ability of the muscle. [Na+]i and [K+]i were measured by using ion-selective microelectrodes. Before stimulation (100-ms trains at 150 Hz, 1 stimulus/s for 5 min), [Na+]i, [K+] …

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Molecular Studies Of Restriction Genes In Enteric Bacteria, Obed B. Rutebuka Aug 1996

Molecular Studies Of Restriction Genes In Enteric Bacteria, Obed B. Rutebuka

Loma Linda University Electronic Theses, Dissertations & Projects

Bacterial cells contain various restriction-modification (R-M) systems to protect themselves from incoming foreign DNA. Most bacteria have at least one such system. In this study, the restriction genes and the location of the genes on the chromosome were examined in three enteric bacteria. Salmonella typhimurium LT2, Klebsiella pneumoniae GM 236, and Klebsiella pneumoniae M5al. The 98 minute region of the Salmonella typhimurium LT2 chromosome comprises at least two R-M systems. From genetic data this region was previously thought to be only one minute in length but was found to be larger than two minutes using a physical mapping technique, pulsed …

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Pre-Embedding Staining Of Single Muscle Fibers For Light And Electron Microscopy Studies Of Subcellular Organization, Evelyn Ralston, Thorkil Ploug Jul 1996

Pre-Embedding Staining Of Single Muscle Fibers For Light And Electron Microscopy Studies Of Subcellular Organization, Evelyn Ralston, Thorkil Ploug

Scanning Microscopy

Skeletal muscle fibers are large, multinucleated cells which pose a challenge to the morphologist. In the course of studies of the distribution of the glucose transporter GLUT4, in muscle, we have compared different preparative procedures, for both light (LM) and electron microscopy (EM) immunocytochemistry. Here we show that pre-embedding staining of single teased fibers, or of single enzymatically dissociated fibers, has several advantages over the use of sections for observing discrete patterns that extend over long distances in the cells. We report on an optimization study carried out to establish fixation and permeabilization conditions for EM immunogold labeling of the …

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Interactive Effects Of Inducible Defense And Resource Availability On Phlorotannins In The North Atlantic Brown Alga Fucus Vesiculosus, P. Peckol, J. M. Krane, J. L. Yates Jul 1996

Interactive Effects Of Inducible Defense And Resource Availability On Phlorotannins In The North Atlantic Brown Alga Fucus Vesiculosus, P. Peckol, J. M. Krane, J. L. Yates

Biological Sciences: Faculty Publications

Research seeking to explain the ecological role of polyphenolics (phlorotannins) in plants and brown algae has largely focused on 2 alternative concepts, the carbon/nutrient (C/N) balance and the inducible defense models. We tested the hierarchy of effects of both models on phlorotannin production in the brown alga Fucus vesiculosus (Fucales) by simultaneously manipulating the N environment and simulating herbivory for 2 oceanic (high and low intertidal) and estuarine populations. We measured phlorotannin levels in algae under control, grazed, N-enriched, and grazed + N-enriched treatments with time (0 to 14 d) throughout the year to determine onset and duration of the …

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Impact Of A Parasitic Plant On The Structure And Dynamics Of Salt Marsh Vegetation, Steven C. Pennings, Ragan M. Callaway Jul 1996

Impact Of A Parasitic Plant On The Structure And Dynamics Of Salt Marsh Vegetation, Steven C. Pennings, Ragan M. Callaway

Biological Sciences Faculty Publications

We investigated the effect of a native parasitic plant, Cuscuta salina, on the structure and dynamics of the plant community in a California salt marsh. Cuscuta was common in the middle marsh zones. The abundance of Cuscuta was positively correlated with the abundance of Limonium californicum at two sampling scales (0.25— and ≈\approx40—m2 quadrats). Sampling at the scale of individual plants indicated that the dominant plant in the marsh, Salicornia virginica, was preferred by Cuscuta as a host over Arthrocnemum subterminale, Limonium californicum, and Frankenia salina. This result was confirmed with host—choice experiments in the field. Based on spatial …

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Female Choice In Sage Grouse: The Roles Of Attraction And Active Comparison, Robert M. Gibson Jul 1996

Female Choice In Sage Grouse: The Roles Of Attraction And Active Comparison, Robert M. Gibson

School of Biological Sciences: Faculty Publications

Previous studies of female choice in sage grouse Centrocercus urophasianus have implicated both the acoustic quality and repetition rate of the stereotyped strut display as putative cues for female choice. Stages in the choice process at which specific components of male courtship display influence female decisions were investigated using field observations of female premating behavior. Females visited a subset of territorial males and then actively chose one of these as a mate. The order in which males were visited suggested that females searched until an acceptable mate was found, rather than employing a “best-of-n” tactic. Numbers of females visiting a …

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Microhardness And Scanning Electron Microscopy Analysis Of Nd:Yag Laser And Acid Treatment Effects In Dentin, J. M. White, G. L. Adams Jun 1996

Microhardness And Scanning Electron Microscopy Analysis Of Nd:Yag Laser And Acid Treatment Effects In Dentin, J. M. White, G. L. Adams

Scanning Microscopy

Laser irradiation at and above parameters producing the modification threshold for dentin causes structural changes to the dentin surface. This study determined the microhardness of dentin before and after laser modification and acid treatment using a repeated-measures de-sign. Seven dentin sections (4 mm in thickness) were cut from freshly extracted non-carious third molars using a diamond saw. The middle occlusal third was used as the test dentin surface. One section served as a control (C); three received laser modification (L) and then acid treatment (L + A); and three received acid (A) and then laser treatment (A + L). Laser …

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Experimental Nephrolithiasis In Rats: The Effect Of Ethylene Glycol And Vitamin D3 On The Induction Of Renal Calcium Oxalate Crystals, R. De Water, E. R. Boevé, P. P. M. C. Van Miert, G. Deng, L. C. Cao, Th. Stijnen, W. C. De Bruijn, F. H. Schröder Jun 1996

Experimental Nephrolithiasis In Rats: The Effect Of Ethylene Glycol And Vitamin D3 On The Induction Of Renal Calcium Oxalate Crystals, R. De Water, E. R. Boevé, P. P. M. C. Van Miert, G. Deng, L. C. Cao, Th. Stijnen, W. C. De Bruijn, F. H. Schröder

Scanning Microscopy

Using ethylene glycol (EG) and vitamin D3 as crystal-inducing diet (CID) in rats, we investigated the effect of the dosage of EG on the generation of chronic calcium oxalate (CaOx) nephrolithiasis. We collected weekly 24 hour urines and measured herein the amount of oxalate, calcium, glycosaminoglycans (GAG's), creatinine, protein, alkaline phosphatase (AP), 𝝲-glutamyl transpeptidase (𝝲GT), and N-acetyl-𝝱-glucosaminidase (NAG). The potential of these urines to inhibit crystal growth and agglomeration was also evaluated. After four weeks, the kidneys were screened by histology and radiography for the presence of CaOx crystals and the amount of kidney-associated oxalate was biochemically measured. Using 0.5 …

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Settlement And Early Post-Settlement Survival Of Sessile Marine Invertebrates On Topographically Complex Surfaces: The Importance Of Refuge Dimensions And Adult Morphology, Linda J. Walters, David S. Wethey Jun 1996

Settlement And Early Post-Settlement Survival Of Sessile Marine Invertebrates On Topographically Complex Surfaces: The Importance Of Refuge Dimensions And Adult Morphology, Linda J. Walters, David S. Wethey

Faculty Publications

We predicted that both refuge dimension and growth form would influence settlement and short-term post-settlement success (≤7 d) of sessile marine invertebrates that live attached to hard substrata in low energy environments. Individuals with unlimited attachment to the substrata should rapidly be protected by their growth form, thus decreasing their need to settle in refuges and limiting the length of time any locations on heterogeneous substrata act as refuges. Alternatively, organisms with limited attachment to the substrata should remain susceptible to the causes of mortality for a longer time, and as a result should settle in high quality refuges (sites …

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Abundant Protein-Containing Particles In The Sea, Richard A. Long, Farooq Azam Jun 1996

Abundant Protein-Containing Particles In The Sea, Richard A. Long, Farooq Azam

Faculty Publications

The interaction of bacteria with particulate organic matter has implications for organic matter cycling and bacterial ecology in the ocean. Until recently, the focus has been on 'classical' particles visible by unaided eye (marine snow) or light microscopy. Recent discoveries of several new types of abundant particles, from sub-micrometer to sub-marine snow, are changing our ideas of the physical and chemical nature of the particle field with which pelagic bacteria interact. Previous workers have discovered polysaccharide-containing (Alcian Blue stainable) transparent exopolymer particles (TEP) ranging from 3 to 100s of micrometers. Looking for additional components of the sub-marine snow particle field, …

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Problems In Preparation Of Chromosomes For Scanning Electron Microscopy To Reveal Morphology And To Permit Immunocytochemistry Of Sensitive Antigens, A. T. Sumner Jun 1996

Problems In Preparation Of Chromosomes For Scanning Electron Microscopy To Reveal Morphology And To Permit Immunocytochemistry Of Sensitive Antigens, A. T. Sumner

Scanning Microscopy

Although much information about chromosome structure and behaviour has been obtained using light microscopy, greater resolution is needed for a thorough understanding of chromosome organisation. Scanning electron microscopy (SEM) can provide valuable data about these three-dimensional organelles. The introduction of methods using osmium impregnation of methanol-acetic acid-fixed chromosome spreads revolutionised matters, producing life-like images of chromosomes. Nevertheless, it became clear that osmium impregnation introduced various artefacts, although the resulting images were still useful. Methanol-acetic acid-fixed chromosomes are, in fact, flattened on the glass substratum, and the 3-dimensional appearance obtained after osmium impregnation is the result of swelling during this process. …

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