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Articles 36391 - 36420 of 39312
Full-Text Articles in Entire DC Network
Specimen Catalog, Stephen Davenport
Specimen Catalog, Stephen Davenport
Division of Mammals - Field Notes and Catalogs
No abstract provided.
Environmental Sex Determination With Overlapping Generations, Eric Charnov
Environmental Sex Determination With Overlapping Generations, Eric Charnov
Biology Faculty & Staff Publications
No abstract provided.
Evolution Of The Breeding Sex Ratio Under Partial Sex Change, Eric Charnov
Evolution Of The Breeding Sex Ratio Under Partial Sex Change, Eric Charnov
Biology Faculty & Staff Publications
No abstract provided.
Phytoplankton Composition In A Borrow Pit Lake In Virginia, Seba B. Sheavly, Harold G. Marshall
Phytoplankton Composition In A Borrow Pit Lake In Virginia, Seba B. Sheavly, Harold G. Marshall
Biological Sciences Faculty Publications
The phytoplankton assemblages in Lake Trashmore, Virginia, a borrow pit, were dominated by centric diatoms and cyanobacteria, with seasonal pulses of cryptomonads, euglenoids, and chlorophyceans. Ninety species were identified and their abundance levels noted for a 12-month period.
Seasonal Distribution Of The Ichthyofauna Of Santa Ana National Wildlife Refuge, Alamo, Texas, Matthew Albert Ciomperlik
Seasonal Distribution Of The Ichthyofauna Of Santa Ana National Wildlife Refuge, Alamo, Texas, Matthew Albert Ciomperlik
Theses and Dissertations - UTB/UTPA
This study investigated the small aquatic ecosystems of Santa Ana National Wildlife Refuge, located in a predominantly agricultural area of the Lower Rio Grande Valley, Texas. Fishes and water quality data were collected for 13 months to determine the status of fish populations and the factors which influence their distributions on the refuge.
Sixteen fish species were collected during the study, however, more than 20 species are known to inhabit the Rio Grande in the vicinity of the refuge. Water source played a major role in influencing fish species richness in these aquatic ecosystems. Diverted river water offered the best …
Trichome Development In Arabidopsis Thaliana. 1. T-Dna Tagging Of The Glabrous1 Gene, M. David Marks, Kenneth A. Feldmann
Trichome Development In Arabidopsis Thaliana. 1. T-Dna Tagging Of The Glabrous1 Gene, M. David Marks, Kenneth A. Feldmann
School of Biological Sciences: Faculty Publications
Progeny from a transformed Arabidopsis plant (produced by the Agrobacterium-mediated seed transformation procedure) were found to be segregating for an altered trichome phenotype. The mutant plants have normal leaf trichomes but completely lack trichomes usually found on the stem. The mutation is tightly linked to a T-DNA insert. Complementation analysis with genetically characterized trichome mutants revealed that the new mutation is an allele of the GL1 locus. The new trichome mutant has been designated gl1-43. DNA gel blot analysis indicated that the insert site contains a complex array of at least four tandemly linked T-DNA units oriented as both …
Elaphe Bairdi (Baird’S Rat Snake): Drinking Behavior., Louis A. Somma
Elaphe Bairdi (Baird’S Rat Snake): Drinking Behavior., Louis A. Somma
Papers in Herpetology
On 13 February 1988. at 1600 h. a captive-bred (hatched July 1985) male Elaphe bairdi (TL.136.9 cm, SVL .. 89.54 cm). maintained in a 50.5 x 25 x 30 cm terrerium was accidently splashed with water. As beads of water on the snake's head rolled down to the upper labial sceles. swallowing was observed. The water on the labial scales was drawn Into the mouth while It was closed. This behavior lasted 42 sec. This behavior was repeated 23 out of 24 trials conducted during the next 24 days. The duration of swallowing wes 9-62 sec (avg 35.8, N = …
Seasonal Trailing Behavior And Corticosterone Levels In Male Red-Sided Garter Snakes (Thamnophis Sirtalis Parietalis), Pamela Kay Thinesen
Seasonal Trailing Behavior And Corticosterone Levels In Male Red-Sided Garter Snakes (Thamnophis Sirtalis Parietalis), Pamela Kay Thinesen
Dissertations and Theses
Mechanisms of how red-sided garter snakes (Thamnophis sirtalis parietalis) travel up to 18 km from summer feeding sites to hibernation dens are not understood. In this study, monthly and seasonal trailing behavior were investigated to determine whether red-sided garter snakes prefer to follow trails of snakes from the same den (den-mates) versus trails made by other conspecifics (non-den-mates). Snakes from five different hibernacula in Manitoba, Canada, were involved in the study. Eighteen were adults and 15 were subadults. Subadult red-sided garter snakes do not return to hibernacula until their second year of life, so their trailing behavior was of interest …
Transcriptional Control Of The Inducible Nitrate Reductase Isoform In Soybean, Glycine Max, John J. Callaci
Transcriptional Control Of The Inducible Nitrate Reductase Isoform In Soybean, Glycine Max, John J. Callaci
Master's Theses
No abstract provided.
Polypeptides Associated With Spikelet Development In Zea Mays L. Ear Organogenesis, Teresa A. Schoneman Findlay
Polypeptides Associated With Spikelet Development In Zea Mays L. Ear Organogenesis, Teresa A. Schoneman Findlay
Dissertations and Theses @ UNI
A number of similar models, i.e., Bonner's (1965) switching networks model, Kinet et al.'s (1985) evocation/determination model, Heslop-Harrison (1969) and Poethig's (1988) phytomer model, have been proposed to describe morphogenesis in plants as a product of sequential changes in cellular protein complement resulting from differential gene expression. The switch point model for Zea mays development predicts changes in the protein complements at each successive developmental stage. The objective of this study was to map, using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), the protein complement of three morphological stages of the z. mays ear: spikelet primordia (SP), spikelet primordia with glumes …
Effect Of Swim Exercise Training On Human Muscle Fiber Function, Robert H. Fitts, D. L. Costill, P. R. Gardetto
Effect Of Swim Exercise Training On Human Muscle Fiber Function, Robert H. Fitts, D. L. Costill, P. R. Gardetto
Biological Sciences Faculty Research and Publications
This study examined the effect of a typical collegiate swim-training program and an intensified 10-day training period on the peak tension (Po), negative log molar Ca2+ concentration (pCa)-force, and maximal shortening speed (Vmax) of the slow-twitch type I and fast-twitch type II fibers of the deltoid muscle. Over a 10-wk period, the swimmers averaged 4,266 ± 264 m/day swimming intermittent bouts of front crawl, kicking, or pulling. The training program induced an almost twofold increase in the mitochondrial marker enzyme citrate synthase. Po of the single fibers was not altered by either the training …
Nitrogen And Iron Interactions In Filamentous Cyanobacteria, David Allen Hutchins
Nitrogen And Iron Interactions In Filamentous Cyanobacteria, David Allen Hutchins
Dissertations and Theses
The investigations described in this paper are an attempt to further define and quantify the interrelationship of nitrogen fixation and iron nutritional physiology in these two species. Chapter II will present and compare data on nutritional ratios of field collected Trichodesmium colonies and laboratory Anabaena cultures, with the intent of examining possible correlations between observed iron levels and protein nitrogen and chlorophyll concentrations, as well as nitrogen fixation rates. Chapter Ill is an examination of nitrogen fixation and siderophore production in Anabaena with emphasis on the possible implications of hypothesized synergistic effects of these two physiological capabilities on cyanobacterial dominance …
Measurement Of Fungicide Smoke Application By Electron Beam Analysis, C. R. Krause, C. C. Powell
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 …
The Use Of Scanning Electron Microscopy For Investigations Into The Three Dimensional Organisation Of The Interphase Nucleus, T. D. Allen, P. M. O'Connor
The Use Of Scanning Electron Microscopy For Investigations Into The Three Dimensional Organisation Of The Interphase Nucleus, T. D. Allen, P. M. O'Connor
Scanning Microscopy
In an attempt to elucidate three dimensional information on the organisation of the nucleus, nuclei have been extracted from ascites tumour cells or tissue culture cells by a variety of biochemical techniques, and prepared for high resolution scanning electron microscopy using an osmium-thiocarbo-hydrazide infiltration procedure which has previously proved successful for analysis of chromosome structure. Nuclei were prefixed with either Methanol-Acetic acid, glutaraldehyde or formaldehyde and then extracted by a variety of detergents with the aim of a 'biochemical dissection' of their outer elements to allow surface visualisation of the nuclear lamina. Continued extraction removed all aspects of the nuclear …
Fine Structure And Organ Culture Of Chick Embryo Dorsal Aorta, C. Ward Kischer, Michael Jaqua
Fine Structure And Organ Culture Of Chick Embryo Dorsal Aorta, C. Ward Kischer, Michael Jaqua
Scanning Microscopy
Embryonic blood vessels have not been grown in organ culture, in a way which might easily submit them to studies of vascular organogenesis. The chick embryo dorsal aorta is easily accessible and relatively simple to explant to culture. Its organ culture may provide a model for wounding and repair of the intima and/or media and provide a model for studies of growth (or maintenance) and differentiation. Fresh dorsal aorta and its organ culture from the chick embryo was characterized morphologically by light microscopy scanning (SEM) and transmission electron microscopy (TEM) from days 4 to 18. Explants were incubated up to …
Observations Of Colloidal Gold Labelled Platelet Microtubules: High Voltage Electron Microscopy And Low Voltage-High Resolution Scanning Electron Microscopy, R. M. Albrecht, J. Prudent, S. R. Simmons, J. Pawley, J. J. Choate
Observations Of Colloidal Gold Labelled Platelet Microtubules: High Voltage Electron Microscopy And Low Voltage-High Resolution Scanning Electron Microscopy, R. M. Albrecht, J. Prudent, S. R. Simmons, J. Pawley, J. J. Choate
Scanning Microscopy
18 nm colloidal gold-antitubulin and 4 nm colloidal gold-antitubulin were used to label microtubules in adherent, fully spread platelets. Both sizes of marker effectively labelled microtubules in the partially extracted platelets. However only the 4 nm gold penetrated the dense microfilament matrix of the inner filamentous zone so that portions of microtubules within this cytoskeletal zone could be tracked. The gold marker could be visualized well with 1 MeV high voltage transmission EM and with 5 kV or greater secondary imaging or 20 kV backscattered imaging of carbon only coated samples. 1 kV secondary imaging permitted high resolution imaging of …
Isolation & Characterization Of Dna Polymerase Alpha And Gamma From Turnips (Brassica Rapa) And Etiolated Soybeans (Glycine Max), Donna Hill
Masters Theses & Specialist Projects
DNA polymerase alpha, the enzyme involved in nuclear DMA replication, and DNA polymerase gamma, the enzyme involved in organellular DNA replication, were isolated and purified from soybean and turnip. The enzymes were characterized following ammonium sulfate precipitation, DEAF-cellulcse, phosphocelluloca, and hydroxylapatite chromatography, and by non-denaturing polyacrylamide gel electrophoresis. Protein banct were electropluted and the enzymes characterized using kinetic studies and sensitivity to divalent cations and inhibitors. Molecular weight and subunit composition studies indicated a molecular weight for the catalytic subunit of DNA polymerase alpha in soybean and turnip to be 46kDa. DNA polymeraqe gamma was composed of a catalytic subunit …
The Short Term Effects Of Manganese Toxicity On Isocitrate Dehydrogenase In Wheat & Tobacco, Juergen Pfeiffer
The Short Term Effects Of Manganese Toxicity On Isocitrate Dehydrogenase In Wheat & Tobacco, Juergen Pfeiffer
Masters Theses & Specialist Projects
The short term effects of high manganese levels (80 mg/L) on wheat and tobacco isocitrate dehydrogenase (IDH) activity were compared. The change in activity was then compared to the concentrations of manganese in the tissues.
As the time of manganese exposure increased, the fresh weight IDH activities in wheat and tobacco decreased. In contrast both control groups had similar enzyme activities every 6 hr over the 24 hr test period. The decrease in IDH activity of wheat and tobacco plants in experimental groups seemed to be related to an increase of the manganese in the leaf tissue. The slower decrease …
Receptor Localization And Distribution On Normal And Diabetic Cells By Electron Microscopy, Vance L. Kincaid
Receptor Localization And Distribution On Normal And Diabetic Cells By Electron Microscopy, Vance L. Kincaid
Masters Theses
The objective of this research was to evaluate receptor localization and distribution on normal and diabetic cells by electron microscopic analysis.
To achieve this objective, gold-adsorbed and ferritin-conjugated macromolecules were used to determine the location and concentration of specific receptor binding sites on the cells surfaces. To facilitate the use of these ultra-structural histocytochemical markers, normal and diabetic Chinese hamster and other nondiabetic cells were either grown in vitro on ultra thin plastic films or embedded in Lowicryl K4M and pre- or post-labelled with these marker molecules.
Analysis of the data obtained from electron micrographs of these labelled cells was …
Nonfish Prey Of Wintering Bald Eagles In Lilinois, Given Harper, D. Hopkins, Thomas Dunston
Nonfish Prey Of Wintering Bald Eagles In Lilinois, Given Harper, D. Hopkins, Thomas Dunston
Scholarship
Many Bald Eagles (Haliaeetus leucocephalus) winter in Illinois (Fawks 1979), where they feed primarily on fish (e.g., Southern 1966, Fischer 1982, Harper 1983). However, few reports have been published documenting their use of mammalian and avian prey in the midwestern United States (Lingle and Krapu 1986, Stalmaster 1987). This paper describes the almost exclusive use of nonfish prey in an upland population of Bald Eagles, and discusses related management implications.
The Formation And Function Of Dnase I Hypersensitive Sites In The Process Of Gene Activation, Sarah C.R. Elgin
The Formation And Function Of Dnase I Hypersensitive Sites In The Process Of Gene Activation, Sarah C.R. Elgin
Biology Faculty Research
No abstract provided.
Effect Of Conidia Germination On Infection Of Brown Planthopper (Bph) By Insect Fungi, M. C. Rombach, R. M. Aguda, Donald W. Roberts
Effect Of Conidia Germination On Infection Of Brown Planthopper (Bph) By Insect Fungi, M. C. Rombach, R. M. Aguda, Donald W. Roberts
Biology Faculty Publications
Conidia of insect fungi actively invade BPH [brown planthopper]. After a conidium lands on the insect cuticle, germination takes about 8 to 16 h, depending on the temperature and relative humidity. After the germination, tuber is formed, the conidium produces specific chitinase enzymes to dissolve the insect cuticle. This allows the fungus to enter the insect body cavity, where further fungus growth occurs. At the end of the infection cycle, the mycelium sporulates on the outside of the insect. Conidia produced on the cadaver can infect healthy BPH initiating epizootics of the fungus. To test infection, 50 adult alate BPH …
Probing The Alpha-Sarcin Region Of Escherichia-Coli 23s Rrna With A Cdna Oligomer, Gary A. White, Ted Wood, Walter E. Hill
Probing The Alpha-Sarcin Region Of Escherichia-Coli 23s Rrna With A Cdna Oligomer, Gary A. White, Ted Wood, Walter E. Hill
Biological Sciences Faculty Publications
The cause of 50S ribosomal subunit collapse reportedly triggered by hybridization of a 14-base cDNA probe to the alpha-sarcin region of 23S rRNA was investigated by physical measurement of probe-subunit complexes in varying buffer conditions. The results reported here show that this probe was unable to hybridize to its target site in the intact 50S subunit and the physical characteristics of 50S subunits remained unchanged in its presence. Subunit collapse was induced in buffer containing 20mM Tris-HCl (pH 7.5), 600 mM NH4Cl, 1 mM MgCl2, 1 mM DTT, and 0.1 mM EDTA in the absence of probe. The probe bound …
Quantitative Margin Analysis In The Scanning Electron Microscope., J. F. Roulet, T. Reich, U. Blunck, M. Noack
Quantitative Margin Analysis In The Scanning Electron Microscope., J. F. Roulet, T. Reich, U. Blunck, M. Noack
Scanning Microscopy
Interface between restorative materials and tooth hard substances must be morphologically as perfect as possible to avoid plaque accumulation and subsequent secondary caries or pulpal diseases. Therefore the marginal behavior of restorations is an important parameter to predict their longevity.
Morphologically, the quality of margins is characterized by different well defined criteria. Using a replica technique it is possible to assess the complete marginal circumference of restorations in the SEM. Margins of restorations show a large variety of their morphology. This publication describes a method to quantify the quality of dental restorations.
The restoration margins are traced on the SEM …
Stimulation Of Collagen Formation In The Intestinal Anastomosis By Low Dose He-Ne Laser, David T. Yew, Winnie W. Y. Li, K. M. Pang, Y. C. Mok, C. Au
Stimulation Of Collagen Formation In The Intestinal Anastomosis By Low Dose He-Ne Laser, David T. Yew, Winnie W. Y. Li, K. M. Pang, Y. C. Mok, C. Au
Scanning Microscopy
The effect of low dose He-Ne laser on the healing of intestinal anastomosis was studied in the albino rat. A small piece of jejunum was removed from each rat and the ends sutured back with a simple interrupted pattern. In the experimental animal, the anastomosis was Irradiated through an optic fiber with a He-Ne laser (1 mW) for 15 minutes whereas in the control animal, the anastomosis was not irradiated. The differences between the two groups were compared by histology, transmission electron microscopy, scanning electron microscopy and autoradiography 3 and 7 days after operation. The laser treated experimental animals demonstrated …
Complementary Surface Characterization Of Chalcopyrite By Electron Microscopy, Electron Spectroscopy, And Optical Reflectance, P. H. Ruzakowski, P. H. Holloway, G. Remond
Complementary Surface Characterization Of Chalcopyrite By Electron Microscopy, Electron Spectroscopy, And Optical Reflectance, P. H. Ruzakowski, P. H. Holloway, G. Remond
Scanning Microscopy
Surface oxidation of polished natural specimens of chalcopyrite (CuFeS2) at temperature between 23°C and 300°C in air has been characterized by Auger electron and X-ray photoelectron spectroscopies. The reaction products consisted of an outer iron oxide layer and an intermediate copper rich sulfide layer. Several different oxides and sulfides were consistent with the electron spectroscopy data, so specimens were analyzed as a function of time and temperature at selected 20 μm diameter areas with an optical microreflectometer (OMR). Since the optical properties of a compound are unique, a reflectance model with three homogeneous layers was used to calculate …
Optical Design Considerations In Confocal Scanning Microscopy, T. Wilson
Optical Design Considerations In Confocal Scanning Microscopy, T. Wilson
Scanning Microscopy
We review the properties and applications of confocal optical systems. We concentrate on non-fluorescent reflection systems and on applications which make use of the unique optical sectioning property of these instruments to provide three-dimensional images. A crucial design choice concerns the form and size of the detector. We therefore concentrate on the role of the detector size on the strength of the optical sectioning. We find that although the sectioning becomes weaker as the detector sizes where the sectioning remains essentially constant. We also consider the role of lens aberrations which are inevitably present and find, inter alia, that these …
Trypanosoma Lewisi: Effects Of Trace Metal Contaminants On Immunological Responses, Yvonne Hogan, Clarence Lee
Trypanosoma Lewisi: Effects Of Trace Metal Contaminants On Immunological Responses, Yvonne Hogan, Clarence Lee
Department of Biology Faculty Publications
The effects of trace metal contaminants (lead, cadmium, and mercury) on the immunologic responses of rats infected with Trypanosoma lewisi were investigated to determine whether chronic exposures to subclinical levels of these metals have adverse effects on the host's ability to respond to an infective agent.Earlier and higher levels of parasitemia were detected in animals exposed to cadmium, lead, and mercury. The variability in length of trypanosome cells in metal-exposed animals became constant at a later time and persisted for a longer time, indicating a delay in antibody synthesis. Serum levels of IgG and IgM were increased in infected animals …
Organ-Specific And Development Regulation Of The Nopaline Synthase Promoter In Transgenic Tobacco Plants, Gynheung An, Michael A. Costa, Amitava Mitra, Sam-Bong Ha, László Márton
Organ-Specific And Development Regulation Of The Nopaline Synthase Promoter In Transgenic Tobacco Plants, Gynheung An, Michael A. Costa, Amitava Mitra, Sam-Bong Ha, László Márton
Faculty Publications
Control regions of the nopaline synthase (nos) gene have been widely used to express foreign genes in plants since the promoter is active in a wide variety of plant tissues. We report here the characteristics of the nos promoter activity in transgenic tobacco (Nicotiana tabacum) plants at various developmental stages. The promoter was highly active in the lower parts of a plant and gradually decreased in the upper parts. This vertical gradient was maintained throughout plant growth until the flowering stage when the overall promoter strength decreased significantly in the vegetative organs. However, in various flower …
A New Versatile Holder For The Calibrating Standard Used For Quantitative Analysis In Jeol 840 Sem, Michael Dvorachek
A New Versatile Holder For The Calibrating Standard Used For Quantitative Analysis In Jeol 840 Sem, Michael Dvorachek
Scanning Microscopy
An improved holder has been designed for a cobalt calibrating standard used in an EDS Link 10,000 system attached to a JEOL 840 SEM. This holder allows the calibration of the EDS software for a wide range of samples differing in size, surface and height. These differences usually cause difficulties during quantitative analyses. The new holder allows the position of the cobalt to be adjusted according to the size and height of the sample.