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Postexercise Hypotension (Peh) In The Dog: Possible Role Of Immune System Cytokines., Gerald Dwayne Thompson Jan 1996

Postexercise Hypotension (Peh) In The Dog: Possible Role Of Immune System Cytokines., Gerald Dwayne Thompson

LSU Historical Dissertations and Theses

This study investigated postexercise hypotension (PEH) in five normotensive dogs testing these hypotheses: (1) PEH is present in the dog model; (2) high intensity exercise of 85% HR$\rm\sb{max}$ as compared to moderate intensity exercise of 60% HR$\rm\sb{max}$ induces a greater PEH; and (3) IL-1 and its activation of PGE$\sb2$ are associated with PEH. In experiment I, it was found that 85% HR$\rm\sb{max}$ exercise decreased systolic blood pressure (SBP) and mean arterial blood pressure (MABP) at 30 and 60 minutes postexercise (p $<$ 0.05). Both IL-1 and PGE$\sb2$ increased immediately following intense exercise, although temporal patterns were dissimilar. During non-exercise infusion of ibuprofen or dexamethasone (experiment II), blood pressure was not affected, but ibuprofen led to an overall inhibition of PGE$\sb2$. However, dexamethasone infusion led to a significant increase in PGE$\sb2$ at 180 and 210 minutes postinfusion. In experiment IIIA, after intense exercise following ibuprofen or saline infusion, PGE$\sb2$ increased at 120 to 180 minutes postexercise. Similar results were noted after exercise during dexamethasone treatment (experiment IIIB). In experiment IIIA & B, neither ibuprofen nor dexamethasone significantly affected PEH, although non-significant reductions in PEH was observed in dexamethasone treated animals. However, PGE$\sb2$ significantly increased after exercise at time points when PEH was not observed. These data indicate that (1) the intensity of exercise may have an effect on PEH, (2) there is partial support for the involvement of IL-1 and PGE$\sb2$ in PEH due to their immediate increase after exercise although a direct relationship was not observed, and (3) IL-1 still remains a possible mechanism responsible for PEH because of trends for attenuated PEH and PGE$\sb2$ responses following dexamethasone treatment.

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Biochemical And Biophysical Studies Of Wild-Type And Active-Site Mutants Of Human Adenosine Deaminase., Qing Zeng Jan 1996

Biochemical And Biophysical Studies Of Wild-Type And Active-Site Mutants Of Human Adenosine Deaminase., Qing Zeng

LSU Historical Dissertations and Theses

The focus of this work is structural and functional studies of wild-type and active-site mutants of human adenosine deaminase. Two active-site amino acids, Glu217 and His238, were previously substituted with alanine by site-directed mutagenesis. The Glu217Ala and His238Ala mutants showed little or no changes in Zn content and $\rm K\sb{m}$ value, yet dramatic loss of enzyme activity. Circular dichroism studies of the solution conformation of wild-type and mutant human adenosine deaminases indicate that 30 to 50% of $\alpha$-helical structure is lost in Glu217Ala and His238Ala, respectively, whereas $\beta$-sheet structure is fully retained. Inhibitor binding is measured by a fluorescent assay. …

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Low Carbon Dioxide-Inducible Genes And Proteins In Chlamydomonas Reinhardtii., Zhi-Yuan Chen Jan 1996

Low Carbon Dioxide-Inducible Genes And Proteins In Chlamydomonas Reinhardtii., Zhi-Yuan Chen

LSU Historical Dissertations and Theses

At low CO$\sb2$ conditions, C. reinhardtii, like many other green algae, induces a CO$\sb2$ Concentrating Mechanism (CCM) to raise the internal Ci concentration. During the induction, at least five new polypeptides and six different genes are upregulated and some of the corresponding mRNAs or proteins are absent in high CO$\sb2$ requiring mutants. However the identities and functions of these genes are unknown. In this dissertation, I partially characterized four low CO$\sb2$ inducible genes and one low CO$\sb2$ inducible protein LIP-36. The complete cDNA sequences of clones 11I3 and 2I5 are 1311 bp and 985 bp, respectively. Neither of these two …

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Plant Species Diversity And Community Structure In A Louisiana Coastal Marsh., Laura Gough Jan 1996

Plant Species Diversity And Community Structure In A Louisiana Coastal Marsh., Laura Gough

LSU Historical Dissertations and Theses

The factors that control plant species diversity have been examined by many researchers, but with little consensus as to the causes of diversity patterns. Plant diversity has been correlated with disturbance, competition, soil resources, and other variables. In the research presented here, I investigated the relationship between plant species richness and biomass, competition, nutrient enrichment, flooding, salinity, and herbivory in field studies in Louisiana coastal marshes. Biomass alone was a poor predictor of richness in two Louisiana marshes. When environmental variables (flooding, salinity, and soil fertility) were included with biomass in a multiple regression model, 82% of the variance in …

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Toxicity Of Polycyclic Aromatic Hydrocarbons To Benthic Invertebrates., Guilherme R. Lotufo Jan 1996

Toxicity Of Polycyclic Aromatic Hydrocarbons To Benthic Invertebrates., Guilherme R. Lotufo

LSU Historical Dissertations and Theses

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in aquatic environments. Because of their hydrophobicity, PAHs accumulate in bed sediments and pose a risk to the benthos. Information on the toxicity of sediment-associated PAHs is, however, limited and more information is needed to improve sediment quality-criteria and ecological-risk assessments. My research focused on improving our current knowledge of the acute and, especially, the sublethal effects of sediment-associated PAHs to aquatic invertebrates. Representatives of two phylogenetically distinct benthic invertebrate groups, freshwater tubificid oligochaetes and estuarine meiobenthic harpacticoid copepods, were used. Organisms were exposed to a range of concentrations of sediment-amended contaminants in …

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Characterization Of Ionizing Radiation Sensitive (Irs) Mutants Of Deinococcus Radiodurans R1., Kumaraswamy S. Udupa Jan 1996

Characterization Of Ionizing Radiation Sensitive (Irs) Mutants Of Deinococcus Radiodurans R1., Kumaraswamy S. Udupa

LSU Historical Dissertations and Theses

Deinococcus radiodurans is extremely resistant to ionizing radiation and can withstand 5 kGy $\gamma$ radiation without loss of viability or evidence of mutation. Available evidence argues that an efficient DNA repair mechanism is responsible for the resistance these organisms possess to ionizing radiation. The enzymes which coordinate DNA repair in D. radiodurans are poorly characterized. Two new loci have been detected in D. radiodurans, namely, irrB and irrI which provide resistance. Mutational inactivation of either locus resulted in a partial loss of resistance to ionizing radiation. The extent of sensitivity was locus specific and differentially affected by inactivation of the …

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The Cytoplasmic N,N'-Diacetylchitobiase Gene From Vibrio Parahaemolyticus: Sequence Analysis, Protein Secretion, And Secretion System Development., Michael Hongli Wu Jan 1996

The Cytoplasmic N,N'-Diacetylchitobiase Gene From Vibrio Parahaemolyticus: Sequence Analysis, Protein Secretion, And Secretion System Development., Michael Hongli Wu

LSU Historical Dissertations and Theses

The nucleotide sequence of the gene encoding the cytoplasmic $N,N\sp\prime$-diacetylchitobiase from Vibrio parahaemolyticus has been determined. The deduced peptide sequence surprisingly has minimum evolutionary relationship to two other reported $N,N\sp\prime$-diacetylchitobiases from vibrios, except for highly conserved regions which are also homologous with lysosomal beta-hexosaminidases from eukaryotes including humans. In contrast, the other two sequenced chitobiases from vibrios are much more closely related to each other. This 85 kDa cytoplasmic protein, as revealed from the sequence, appears to be a unique protein, lacking a signal sequence and genetically distant from other known enzymes of similar function. This is consistent with its …

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Community Structure And Habitat Preferences Of Intertidal Fishes Of The Eastern Canary Islands: Fuerteventura, Gran Canaria, And Lanzarote, With A Behavioral Description Of Mauligobius Maderensis (Osteichthyes: Gobiidae)., Richard Patrick Cody Jan 1996

Community Structure And Habitat Preferences Of Intertidal Fishes Of The Eastern Canary Islands: Fuerteventura, Gran Canaria, And Lanzarote, With A Behavioral Description Of Mauligobius Maderensis (Osteichthyes: Gobiidae)., Richard Patrick Cody

LSU Historical Dissertations and Theses

Community structure and relative habitat preferences of intertidal fishes from the eastern Canary Islands of Fuerteventura, Gran Canaria, and Lanzarote were examined in a study of 354 tidepools at 33 localities. Habitat use and behavior of the most abundant fish Mauligobius maderensis were examined on Gran Canaria and Lanzarote. Of the 27 species encountered, 11 were common to each of the islands. The most abundant species were: M. maderensis, Parablennius parvicornis, Gobius paganellus, Coryphoblennius galerita, and Chelon labrosus. In a Two-way indicator species analysis Fuerteventura and Lanzarote localities clustered together. The same analysis differentiated between species that inhabited the upper …

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The Role Of Seed Banks, Disturbance, And Sea Level Rise In Determining The Plant Community Structure Of Oligohaline Coastal Marshes., Andrew Hamilton Baldwin Jan 1996

The Role Of Seed Banks, Disturbance, And Sea Level Rise In Determining The Plant Community Structure Of Oligohaline Coastal Marshes., Andrew Hamilton Baldwin

LSU Historical Dissertations and Theses

Coastal wetlands worldwide are threatened by sea level rise, which is expected to affect the growth and survival of wetland vegetation by increasing water level and salinity. While the effects of salinity and inundation on adult vegetation of oligohaline marshes have been widely studied, the species composition of the seed bank and its response to elevated salinity and water level have not been examined. Additionally, the role of disturbances of different intensities in structuring marsh plant communities and possible interactions between disturbance and rising sea level have received little attention. Disturbances in coastal marshes include nonlethal disturbances such as fire …

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The Relationship Of Hemolymph Sugar, Juvenile Hormone And Biogenic Amines To The Three Behavioral States Of Mature Honey Bees., Janko Bozic Jan 1996

The Relationship Of Hemolymph Sugar, Juvenile Hormone And Biogenic Amines To The Three Behavioral States Of Mature Honey Bees., Janko Bozic

LSU Historical Dissertations and Theses

Differences in sugar titers, JH synthesis rate and biogenic amine metabolism correlated with three distinct activity groups or mature bees: resting bees, followers and dancers. Dancers had lower trehalose titers than followers or resting bees. In absconding bees trehalose titers were even lower, due to greatly elevated locomotor activity. The collecting and transferring of food by dancers and followers resulted in a higher glucose titer than in resting bees. Followers had a higher-JH synthesis rate than dancers, suggesting that JH could be an internal motivational stimulus to recruit followers to forage. Dancers and followers collect and transfer food and therefore …

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The Biology And Ecology Of The Yellowmargined Leaf Beetle, Microtheca Ochroloma Stal, (Coleoptera: Chrysomelidae) On Crucifers., Abdullahi Olod Ameen Jan 1996

The Biology And Ecology Of The Yellowmargined Leaf Beetle, Microtheca Ochroloma Stal, (Coleoptera: Chrysomelidae) On Crucifers., Abdullahi Olod Ameen

LSU Historical Dissertations and Theses

The biology and ecology of the yellowmargined leaf beetle, Microtheca ochroloma Stal, were studied on cabbage, Brassica oleracea var capitata L., collard, B. oleracea var acephala L., mustard, B. juncea Cosson, turnip, B. rapa L., and radish, Raphanus sativus L. The life cycle of the beetle consists of an egg stage, four larval instars, prepupal, pupal and adult stages. There were no significant differences in the effect of host plant on duration of development of immature beetles (p = 0.3353). The mean duration of development from oviposition to adult emergence ranged from 26.6 d on turnip to 27.5 d on …

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Expression And Characterization Of Two Alternatively Spliced Isoforms Of Rat Type I Receptor For Inositol 1,4,5-Trisphosphate, Doris Da May Lin Dec 1995

Expression And Characterization Of Two Alternatively Spliced Isoforms Of Rat Type I Receptor For Inositol 1,4,5-Trisphosphate, Doris Da May Lin

Yale Medicine Thesis Digital Library

The transmembrane receptor for IP3 is a tetrameric calcium channel located in the endoplasmic reticulum. In many cell types the receptor mediates such complex signals as calcium waves and oscillations. There are multiple receptor isoforms, derived by alternative splicing as well as different genes. The functional significance of these many receptor isoforms has not been determined. To this end, I have generated cell lines that express homotetrameric receptors.Stable lines of the human embryonic kidney (HEK293) cells were established by transfection with cDNAs encoding for two splice variants of the rat type I receptor. The two variants differ in the presence …

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The Spleen Focus-Forming Virus Envelope Glycoprotein, Gp55, And The Block In The Erythropoietin-Induced Differentiation Of Friend Murine Erythroleukemia Cells, Thomas Samuel Lin Dec 1995

The Spleen Focus-Forming Virus Envelope Glycoprotein, Gp55, And The Block In The Erythropoietin-Induced Differentiation Of Friend Murine Erythroleukemia Cells, Thomas Samuel Lin

Yale Medicine Thesis Digital Library

Unlike normal committed erythroid progenitor cells, which require erythropoietin (EPO) for both proliferation and terminal differentiation, Friend murine erythroleukemia (MEL) cells are EPO-independent and do not differentiate in response to the cytokine. Dimethylsulfoxide (DMSO) induces differentiation and restores responsiveness to EPO. DMSO-treated Friend cells responded to EPO with both increased proliferation and further hemoglobin synthesis. The effects of DMSO upon the expression of EPO receptor (EPOR) mRNA and cell surface receptor were examined. Clone DMSO/R1, an MEL subline resistant to the differentiation-inducing and EPO-sensitizing effects of DMSO, expressed a higher level of EPOR mRNA than parental Friend cells, and DMSO …

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On Texture Image Analysis Using Fractal Geometry Based Features., Nirupam Sarkar Dr. Nov 1995

On Texture Image Analysis Using Fractal Geometry Based Features., Nirupam Sarkar Dr.

Doctoral Theses

Visual textureTexture is a property to characterize a region of a scene. A set of natural texture images is shown in Fig. 1.1. A specific texture may be generated due to certain organization of several objects in a region, or due to the reflectance pattern caused by color variation or unevenness of an object surface. Since texture provides a lot of information of a region, texture analysis and synthesis are important components of digital image processing.It is difficult to provide a formal definition of texture although we perceive and recognize texture rather easily. According to Sklansky [152) "A region in …

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Effects Of 5-Fiuorouracil On Escherichia Coli Ribosomes., Susan Pelei Belleh Nov 1995

Effects Of 5-Fiuorouracil On Escherichia Coli Ribosomes., Susan Pelei Belleh

Student Work

5-Fluorouracil (FUra), a chemotherapeutic agent, affects the growth of several kinds of tumor cells. It is known to affect DNA as well as RNA. Using Escherichia coli, this study has shown that FUra interferes with the synthesis and assembly of ribosomes. Cells treated in FUra concentrations between 25 ug/ml and 50 ug/ml gave severely retarded growth rates. Sucrose density gradient absorbance profiles of ribosomes from FUra-treated cells indicated altered structural and functional properties. These profiles showed large pools of free ribosomal subunits and few completely associated ribosomes or polyribosomes. The 23S rRNA from FUra-treated ribosomes showed an increases amount of …

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Transport And Metabolism Of Alanine And Palmitic Acid By Field-Collected Larvae Of Tedania Ignis (Porifera, Demospongiae): Estimated Consequences Of Limited Label Translocation, William B. Jaeckle Oct 1995

Transport And Metabolism Of Alanine And Palmitic Acid By Field-Collected Larvae Of Tedania Ignis (Porifera, Demospongiae): Estimated Consequences Of Limited Label Translocation, William B. Jaeckle

Scholarship

The epidermis of larvae of Tedania ignis(Porifera, Demospongiae) is uniformly ciliated except for the posterior pole. The epidermal cells are long, columnar, and monociliate; each cilium arises from an epidermal crypt; symbiotic bacteria were not observed in larval cells. These lecithotrophic ("nonfeeding") larvae can feed by assimilating dissolved organic materials (DOM) from seawater. Larvae transported both the amino acid alanine (mean = 2.73 pmol larva-1 h-1; [S] = 1 µM) and the fatty acid palmitic acid (mean = 16.27 pmol larva-1 h-1; [S] = 1 µM) from seawater. Following assimilation, the …

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Cells Are Not Just Bags Of Water: A Personal Appreciation Of The Work Of Dr. Brij L. Gupta And His Contribution To Biological X-Ray Microanalysis, Alice Warley Aug 1995

Cells Are Not Just Bags Of Water: A Personal Appreciation Of The Work Of Dr. Brij L. Gupta And His Contribution To Biological X-Ray Microanalysis, Alice Warley

Scanning Microscopy

This paper surveys the contribution made by the work of Dr. B.L. Gupta to the science of biological X-ray microanalysis. A brief biographical sketch of Brij's early years is given, this is followed by considerations about the models for water transport across epithelia. The ultrastructural and histochemical studies carried out by Brij Gupta and colleagues are reviewed to introduce the historical need for the use of EPXMA for the study of ion and water transport in epithelia. The outstanding contribution made by Brij Gupta's work in this field is outlined, and his understanding of the subcellular distribution ions in other …

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On Detection And Use Of Reflectional Symmetry In Computer Vision., Dipti Prasad Mukherjee Dr. Jul 1995

On Detection And Use Of Reflectional Symmetry In Computer Vision., Dipti Prasad Mukherjee Dr.

Doctoral Theses

The problems of detection and use of reflectional symmetry in the images of planar shape contours are studied. Symmetry, in general, provides important shape representation cues, some of which we utilise here, to acquire viewpoint information and, towards model based shape matching. We concentrate on local reflectional symmetries of emoothly curved planar objecta, though the methoda are equally applicable to polygonal objects; even this could be extended to certain three-dimensional shapes and for other object relations such as rotational symmetry.Under the affine or perspective approximation to image projection, properties of geometrie invariance are used to find (reflectional) symmetric contour pairs. …

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Impacts Of Seasonality And Nutrients On Microbial Mat Community Structure And Function, James L. Pinckney, Hans W. Paerl, M. Fitzpatrick Jul 1995

Impacts Of Seasonality And Nutrients On Microbial Mat Community Structure And Function, James L. Pinckney, Hans W. Paerl, M. Fitzpatrick

Faculty Publications

To understand the mechanisms responsible for seasonal fluctuations in growth and N2 fixation in intertidal microbial mat communities, we quantified seasonal changes in mat community composition, related these changes to diel and seasonal N2 fixation rates, and evaluated community responses (growth, N2fixation, composition) to long-term (22 d) nutrient addition bioassays. A temperate intertidal cyanobacterial mat community, located in coastal North Carolina, USA, was sampled at monthly intervals for 1 yr (1993-94) to determine changes in community composition. The abundances of major phototrophic groups were quantified based on the relative concentrations of taxaspecific photopigments (chlorophylls and carotenoids). …

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Correspondence, Frederick B. Essig To Betty Castor, University Botanical Garden Concept, July 1, 1995, Frederick B. Essig Jul 1995

Correspondence, Frederick B. Essig To Betty Castor, University Botanical Garden Concept, July 1, 1995, Frederick B. Essig

USF University Archives and Documents

Correspondence and attached concept for the University of South Florida Botanical Gardens, as conceived by Director Frederick B. Essig. Topics include facilities, environmental education, campus partnerships, educational outreach, design, recreation, and landscaping.

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The Criminological Significance Of The Comparative Analysis Of Serum Albumins Using Electrophoresis And Immuno Gel Diffusion, Rhonda E. Ross-Ries May 1995

The Criminological Significance Of The Comparative Analysis Of Serum Albumins Using Electrophoresis And Immuno Gel Diffusion, Rhonda E. Ross-Ries

Whittier Scholars Program

Scientists and forensic experts are making use of macromolecules and their separation. Proteins are unique macromolecules produced by individuals and have provided key evolutionary genetic relationships. Two of the most common techniques used to separate proteins for analyzation electrophoresis and the Ouchterlony technique. The purpose of this comparative analysis project was to broaden the researcher’s laboratory skills to compare the two techniques in terms of efficiency,, cost efficiency, accuracy of results, and interpretation of results. Albumins were chosen for analysis because these proteins are known to be important to biology and are in great concentration in blood plasma.

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The Effect Of Selenium Supplementation On The Immune Response Of Mice With Experimental Chagas' Disease, Cindy Calisi, Lynette Brooks May 1995

The Effect Of Selenium Supplementation On The Immune Response Of Mice With Experimental Chagas' Disease, Cindy Calisi, Lynette Brooks

Mahurin Honors College Capstone Experience/Thesis Projects

No abstract provided.

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The Identification And Characterization Of Protein Tyrosine Phosphatases Expressed In The Developing Rat Brain, Mustafa Sahin May 1995

The Identification And Characterization Of Protein Tyrosine Phosphatases Expressed In The Developing Rat Brain, Mustafa Sahin

Yale Medicine Thesis Digital Library

Previous studies of the developing nervous system have shown that cell-cell and cell-matrix interactions are involved in a variety of processes such as the proliferation, migration and differentiation of neurons. While many cell surface molecules have been identified, the signal transduction mechanisms through which they alter cellular responses are poorly understood. Recent studies have described a new and large family of enzymes, protein tyrosine phosphatases (PTPases), that may play a key role in transduction of cell surface events. Opposing the actions of protein tyrosine kinases (PTKs), PTPases may determine the state of tyrosine phosphorylation of a protein and regulate its …

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Analysis Of Ribosomal Subunit Association Using Mutations At Position 790 Of Escherichia Coli 16s Rrna., William Roberts Staplin Apr 1995

Analysis Of Ribosomal Subunit Association Using Mutations At Position 790 Of Escherichia Coli 16s Rrna., William Roberts Staplin

Student Work

Several phylogenetically conserved single-stranded regions within the secondary structure of 16S ribosomal RNA exhibit essential functional roles in protein synthesis. These dynamic residues adopt several three-dimensional conformations, as they interact with the 50S subunit another intercellular components. The central domain region of 16S ribosomal RNA plays a major role in this process by providing several single-stranded loop regions. The largest and most active of these loop regions surrounds position 790. The 790 loop is universally conserved amongst all sequenced species in specific residues have proven to be highly active. For example, a large body of evidence supports a direct role …

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Community Metabolism And Nutrient Cycling In The Mississippi River Plume: Evidence For Intense Nitrification At Intermediate Salinities, Joseph D. Pakulski, Ronald Benner, Rainer Amon, Brian Eadie, Terry Whitledge Feb 1995

Community Metabolism And Nutrient Cycling In The Mississippi River Plume: Evidence For Intense Nitrification At Intermediate Salinities, Joseph D. Pakulski, Ronald Benner, Rainer Amon, Brian Eadie, Terry Whitledge

Faculty Publications

Community respiration, net nutrient fluxes and heterotrophic bacterial production were investigated in the Mississippi River (USA) plume during May 1992 using dark bottle incubations of unfiltered water. Highest rates of community O2 consumption and dissolved inorganic carbon regeneration were observed at intermediate (10 to 27%0) plume salinities. Plume surface 02 consumption rates were 2- to 4-fold greater than rates reported previously during the summer and winter. Heterotrophic bacterial production ([3H]-leucine incorporation) was also highest at intermediate salinities and 2- to 4-fold greater than rates reported from other seasons. Net regeneration of NH4+ …

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Structure/Function Analyses Of Sex Hormone-Binding Globulin, Wayne Peter Bocchinfuso Jan 1995

Structure/Function Analyses Of Sex Hormone-Binding Globulin, Wayne Peter Bocchinfuso

Digitized Theses

Sex hormone-binding globulin (SHBG) is a homodimeric glycoprotein that transports sex steroids in the blood and extravascular fluids, such as seminiferous tubule fluid, where it is often referred to as androgen-binding protein (ABP). A cDNA for the human SHBG precursor polypeptide was expressed in mammalian cell lines. Recombinant human SHBG bound steroids with the same affinity and specificity as natural SHBG, and was immunologically indistinguishable from its natural counterpart. Site-directed mutagenesis of the SHBG cDNA was used to introduce amino acid substitutions that selectively removed glycosylation sites from SHBG. Analysis of these glycosylation mutants demonstrated that carbohydrates are not involved …

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Transcriptional Regulation Of The Urea Cycle Enzyme Genes In The Liver Of Rana Catesbeiana Tadpoles During Spontaneous And Thyroid Hormone-Induced Metamorphosis, Yuqing Eugene Chen Jan 1995

Transcriptional Regulation Of The Urea Cycle Enzyme Genes In The Liver Of Rana Catesbeiana Tadpoles During Spontaneous And Thyroid Hormone-Induced Metamorphosis, Yuqing Eugene Chen

Digitized Theses

The ornithine urea cycle enzymes, carbamyl phosphate synthetase (CPS-1), ornithine transcarbamylase (OTC) and arginase, are liver-specific proteins. Their expression is coordinately activated during the metamorphosis of the Rana catesbeiana tadpole by thyroid hormone (TH), and their presence is critical for the shift of this amphibian from an aquatic, ammonotelic larva into a terrestrial, ureotelic adult. My studies were focused on analyzing the transcriptional regulation of the genes encoding these urea cycle enzymes and determining whether these genes were upregulated directly or indirectly by TH. With this thought in mind, I isolated and characterized the sequences in the promoter regions of …

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The Function Of Sarcoplasmic Reticulum In The Aged Rat Heart, Ming Tao Jiang Jan 1995

The Function Of Sarcoplasmic Reticulum In The Aged Rat Heart, Ming Tao Jiang

Digitized Theses

The purpose of this project was to study the effect of aging on the regulation of Ca{dollar}\sp{lcub}2+{rcub}{dollar} by cardiac sarcoplasmic reticulum (SR) and its potential contribution to the age-related alterations in myocardial contractile performance in Fischer 344 rats.;In cardiac membranes enriched in SR (MSR) and its light (LSR) and heavy (HSR) subfractions fractionated by a sucrose density gradient, the rate of ATP-supported and oxalate-facilitated Ca{dollar}\sp{lcub}2+{rcub}{dollar} uptake was significantly reduced (24-50%) in the aged (26-30 months old) compared with that of the adult rats (6-8 months old). With aging, the Ca{dollar}\sp{lcub}2+{rcub}{dollar}-stimulated phosphoenzyme of the Ca{dollar}\sp{lcub}2+{rcub}{dollar} pumps was reduced in MSR, LSR …

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Neurotransmission Of Visceral Information In The Parabrachial Nucleus Of The Rat, Tarek Saleh Jan 1995

Neurotransmission Of Visceral Information In The Parabrachial Nucleus Of The Rat, Tarek Saleh

Digitized Theses

The parabrachial nucleus (PB) has been shown to be a major relay site for visceral afferents ascending through the ventrobasal thalamus and terminating in the insular cortex. The purpose of these investigations was to determine the neurotransmitter mechanisms in the PB involved in relaying visceral sensory information to the thalamus in the rat. Using electrophysiological techniques in the cloral hydrate anesthetised male Wistar rat, our results show that the visceral pathway from the PB to the thalamus appears to use two neuronal systems, one mediating the relay of specific visceral information via glutamatergic N-methyl D-aspartate (NMDA) receptors in the PB, …

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The Interaction Of Thyroid Stimulating Hormone (Tsh), Insulin-Like Growth Factors (Igfs), And Insulin-Like Growth Factor Binding Proteins (Igfpbs) In The Regulation Of The Synthesis And Secretion Of Thyroid Hormones By Cultured Sheep Thyroid Cells, Jia Fang Wang Jan 1995

The Interaction Of Thyroid Stimulating Hormone (Tsh), Insulin-Like Growth Factors (Igfs), And Insulin-Like Growth Factor Binding Proteins (Igfpbs) In The Regulation Of The Synthesis And Secretion Of Thyroid Hormones By Cultured Sheep Thyroid Cells, Jia Fang Wang

Digitized Theses

Thyroid growth and function are regulated by TSH in synergy with other hormones, growth factors, and neurotransmitters. Insulin-like growth factors (IGFs), which have insulin-like effects on metabolism and regulate cell growth and function, are synthesized and secreted by thyroid cells. IGFs are associated with their specific binding proteins (IGFBPs), which not only carry and store IGFs in body fluids but also modulate the biological function of IGFs. Previous studies found that both IGFs and IGFBPs participated in the regulation of the growth of thyroid cells.;This study has further examined the biological function of IGFs and IGFBPs in the regulation of …

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