Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Theses and Dissertations

Discipline
Institution
Keyword
Publication Year
File Type

Articles 4231 - 4260 of 5010

Full-Text Articles in Life Sciences

Determination Of The Primary Levels Of The Residues Of The Seeds Of Wheat, Maize, And Barley For The Elaboration Of The Food Mixture For Rabbits, Aida Esperanza Morejon Jacome Jan 2006

Determination Of The Primary Levels Of The Residues Of The Seeds Of Wheat, Maize, And Barley For The Elaboration Of The Food Mixture For Rabbits, Aida Esperanza Morejon Jacome

Theses and Dissertations

The present investigation was done in the parish of Chaltura, Granja "La Pradera" which belongs to the University Técnica del Norte. The main objective of this investigation was to determine the primary levels of the residues of the seeds of wheat, maize, barley for the elaboration of the food mixture for rabbits. The evaluated variables, food consumed, weight gain, food value, protein percentage, production cost per treatment. Previously to the initiation of the field phase bromatological analysis were done on the three food mixtures in the National Institute of Farming Investigation, Quality and Nutrition Area. The treatments were four: TI …


Energy Value In Llamas (Lama Glama) Fed With Alfalfa Hay (Modicago Sativa) And Barley (Hordeum Vulgare) For Apparent Digestibility In Vivo In The National Camelid Germplasm Bank (Ceac), Edwin Gonzalo Ugarte Huanca Jan 2006

Energy Value In Llamas (Lama Glama) Fed With Alfalfa Hay (Modicago Sativa) And Barley (Hordeum Vulgare) For Apparent Digestibility In Vivo In The National Camelid Germplasm Bank (Ceac), Edwin Gonzalo Ugarte Huanca

Theses and Dissertations

In this experiment, we used four male llamas that were three to four years of age from the Khara race. They were divided into two ad libitum feeding groups. The digestible energy (ED) was determined using samples that were sent to the laboratory. These samples were derived from a conventional in vivo assay using the method of total fecal collection in order to determine the difference between energy consumed and energy excreted. Metabolizable energy was calculated by deducting digestible energy, energy loss in the urine and energy loss in the gases (methane). Urinary energy was determined through the measurement of …


Monocyte Modulation Of Disease Pathogenesis And Progression In Localized Aggressive Periodontitis, Chu Ri Shin Jan 2006

Monocyte Modulation Of Disease Pathogenesis And Progression In Localized Aggressive Periodontitis, Chu Ri Shin

Theses and Dissertations

Localized Aggressive Periodontitis (LAgP) is an aggressive, early onset form of periodontitis characterized by a unique myeloid cell phenotype. In addition to its bacterial origin, the unique phenotype of the myeloid cell contributes to disease pathogenesis and progression through mechanisms mediating host inflammatory and immune responses. LAgP monocytes synthesize increased levels of the potent proinflammatory lipid mediator, Prostaglandin E2 (PGE2), preferentially differentiate into dendritic cells, and lead to increased IgG2 production. In addition, levels of Platelet Activating Factor (PAF) have shown to be elevated in the gingival tissue and gingival crevicular fluid of subjects with periodontitis. The aim of this …


Phylogeography Of Marine Meiofaunal Nemerteans Of The Ototyphlonemertes Fila Species Complex, Alexander Tulchinsky Jan 2006

Phylogeography Of Marine Meiofaunal Nemerteans Of The Ototyphlonemertes Fila Species Complex, Alexander Tulchinsky

Theses and Dissertations

Morphological conservatism combined with intraspecific variability has obstructed studies of speciation and species boundaries among marine meiofauna. Ototyphlonemertes is a genus of meiofaunal nemerteans inhabiting the interstitial spaces of marine sediments. Its members lack pelagic larvae and dispersal potential is believed to be poor. A phylogeographic study of Ototyphlonemertes fila is presented using mitochondrial (cox3) and nuclear (ISSR) molecular markers. Deep genetic divergence (approximately 18% in cox3) was observed between sympatric mitochondrial lineages in Florida. This divergence was reflected in the nuclear marker as well, suggesting the presence of two cryptic species. The first contains Florida and New England populations …


Early Mediators Of Cutaneous Ischemia Reperfusion Injury: A Mouse Model, Christopher Rogers Pruitt Jan 2006

Early Mediators Of Cutaneous Ischemia Reperfusion Injury: A Mouse Model, Christopher Rogers Pruitt

Theses and Dissertations

Chronic tissue injuries present an enormous problem to both patients and healthcare professionals, and yet little is definitively known as to the underlying pathophysiology. While there are numerous comorbidities associated with these wounds, a unifying theme has been proposed to be the repetitive incidence of ischemia reperfusion injury.A mouse model of cyclic ischemia reperfusion was employed to examine the initiation events in the pathology of chronic wounds. Mice were subjected to eight hours of magnetic skin compression via four cycles of two-hours ischemia and thirty minutes of reperfusion. The presence of neutrophil markers of oxidative stress and inflammation such as …


Stretch-Dependant Tonic Force Maintenance In Rabbit Epigastric Artery, Krystina Michelle Berg Jan 2006

Stretch-Dependant Tonic Force Maintenance In Rabbit Epigastric Artery, Krystina Michelle Berg

Theses and Dissertations

The contractile state of vascular smooth muscle (VSM) plays a key role in blood pressure regulation. Abnormal VSM contractility characterizes hypertension and understanding the regulatory mechanisms of VSM may provide some insights to specific treatment of hypertension. Upon muscle stimulation, Ca2+, myosin light chain (MLC) phosphorylation, crossbridge cycling rates and force increase to high levels, but with time, force is maintained while all other parameters of muscle activation fall to low levels. Thus, contraction is divided temporally into early (phasic) and late (tonic) phases, as determined by the underlying regulatory mechanism. Muscles with more phasic characteristics have a higher peak …


Inhibition Of Margination And Diapedesis Of Neutrophils By Protein Synthesis Blockade, Phyllis V. Acquah Jan 2006

Inhibition Of Margination And Diapedesis Of Neutrophils By Protein Synthesis Blockade, Phyllis V. Acquah

Theses and Dissertations

Acute Respiratory Distress Syndrome (ARDS), an age-old clinical problem facing the Emergency Department and Intensive Care Units of all health systems, is a common debilitating lung condition consequent upon severe systemic inflammation. Although several studies have gone into understanding the epidemiology and pathogenesis of the disease thus making way for new advances in treatment strategies, there seems to be no known study tailored to its prevention. Neutrophil extravasation within the tissues during inflammation is the hallmark of this syndrome. Our study sought to block excessive neutrophil infiltration by inhibiting the biosynthesis of some essential proteins necessary for the process. In …


Characterization Of The Rank Ligand Positive Giant Cell Found In The Interfacial Membrane, Patrick Emerson Jones Jan 2006

Characterization Of The Rank Ligand Positive Giant Cell Found In The Interfacial Membrane, Patrick Emerson Jones

Theses and Dissertations

Aseptic osteolysis is a major complication to total joint arthroplasty requiring several thousand people a year to have to undergo revisions of their joint prosthesis. The formation of the interfacial membrane has been associated with aseptic osteolysis leading to the failure of all types of total joints. Recent evidence suggests that RANKL, a potent activator of bone reabsorption, is present in the interfacial membrane. Prior research in this laboratory to determine the source of RANKL in the interfacial membrane has revealed the presence of intense areas of RANKL concentration in the membrane. These areas of RANKL concentration correspond to multiple …


The Effects Of Hemoglobin-Based Oxygen Carriers On Mean Arterial Pressure, Arteriolar Diameter, And Nitric Oxide In The Microcirculation, Veronique C. Hionis Jan 2006

The Effects Of Hemoglobin-Based Oxygen Carriers On Mean Arterial Pressure, Arteriolar Diameter, And Nitric Oxide In The Microcirculation, Veronique C. Hionis

Theses and Dissertations

In the US today, blood transfusion is safer than ever. Nevertheless, the century-old quest for a suitable blood substitute persists. The elimination of unwanted side effects, especially transfusion-transmitted diseases, the problems and high cost factor involved in collecting and storing human blood, the pending worldwide shortages, and the need for compatibility testing are the driving forces contributing towards the development of blood substitutes. The leading research is focusing on hemoglobin-based oxygen carriers (HBOCs), which are limited in clinical application due to the pressor effect they induce. In this study, the mechanisms through which HBOCs affect mean arterial pressure (MAP), arteriolar …


Calcium/Calmodulin Dependent Protein Kinase Type-Ii Associates With Flightless-I To Influence Its Nuclear Localization, Matthew Edward Seward Jan 2006

Calcium/Calmodulin Dependent Protein Kinase Type-Ii Associates With Flightless-I To Influence Its Nuclear Localization, Matthew Edward Seward

Theses and Dissertations

Ca2+/calmodulin-dependent protein kinase type-II (CaMK-II) is a Ser/Thr protein kinase regulated by Ca2+ and Calmodulin. It is a highly conserved and broadly expressed enzyme and has a unique structure and dynamic regulation. It has the ability to remain active in the absence of Ca 2+ as a result of Ca2+ dependent autophosphorylation. CaMK-II phospliorylates proteins involved in neurotransmitter secretion, long term potentiation, cytoskeletal dynamics, gene transcription, and cell motility. To support existing and identify new intracellular roles of CaMK-II, potential binding partners were identified. This was accomplished by transfecting and purifying "FLAG-tagged" CaMK-II's (α, βE, δC, and δE). CaMK-II associated …


The Effect Of Adding Drag-Reducing Polymers To Resuscitation Fluid During Hemorrhagic Shock On Skeletal Muscle Microcirculation, Geoffrey C. Alexander Jan 2006

The Effect Of Adding Drag-Reducing Polymers To Resuscitation Fluid During Hemorrhagic Shock On Skeletal Muscle Microcirculation, Geoffrey C. Alexander

Theses and Dissertations

Previous studies have shown an increase in survival when a minute amount of drag-reducing polymers were added to a resuscitation fluid. The purpose of this investigation was to examine the effect of adding a minute amount of the drag-reducing polymer polyethylene glycol to a resuscitation fluid, on the microcirculation of skeletal muscle during a volume-controlled hemorrhage model. The spinotrapezius muscle in twelve male Sprague Dawley rats was exteriorized for microvascular measurements of the arterioles. The diameters of the three levels of arterioles, interstitial fluid PO2, and RBC velocity in the feed arteriole were measured. Flow in the feed arteriole was …


Transforming Growth Factor-Β1 (Tgf-Β1) Induces Mast Cell Apoptosis, Farnaz Norozian Jan 2006

Transforming Growth Factor-Β1 (Tgf-Β1) Induces Mast Cell Apoptosis, Farnaz Norozian

Theses and Dissertations

Mast cells are potent effectors of the inflammatory response, playing an important role in atopy, bacterial immunity, and animal models of arthritis, multiple sclerosis, and heart disease. Hence controlling mast cell numbers and responsiveness is essential for preventing inflammatory disease. This work demonstrated that the cytokine TGF-β1 is a potent inducer of mast cell apoptosis, a finding that was consistent for cultured mouse bone marrow-derived mast cells, peritoneal mast cells, and human mast cells. Cell death appeared to be the result of TGF-mediated repression of IL-3 receptor expression and function, leading to mitochondria1 damage and activation of an apoptotic cascade …


Genetic Variation Among Geographically Disparate Yellow Perch Broodstock Populations, Chandler Brooke Givens Jan 2006

Genetic Variation Among Geographically Disparate Yellow Perch Broodstock Populations, Chandler Brooke Givens

Theses and Dissertations

As a prelude to strain selection for domestication and future marker assisted selection, genetic variation revealed by microsatellite DNA was evaluated in yellow perch, Perca flavescens, from four wild North American populations collected in 2003-2004 (Maine, ME; New York, NY; North Carolina, NC; and Pennsylvania, PA), and two captive populations (Michigan, MI; Ohio, OH). For the loci examined, levels of heterozygosity ranged from He = 0.04 to 0.88, genetic differentiation was highly significant among all population pairs, and effective migration ranged from low (Nem = 0.3) to high (Nem = 4.5). Deviation from Hardy-Weinberg 1equilibrium was regularly observed indicating significant …


Isolation Of Mesenchymal Stem Cells Derived From Adult Bone Marrow And Umbilical Cord Blood And Their Potential To Differentiate Into Osteoblasts, Andrew P. Pacitti Jan 2006

Isolation Of Mesenchymal Stem Cells Derived From Adult Bone Marrow And Umbilical Cord Blood And Their Potential To Differentiate Into Osteoblasts, Andrew P. Pacitti

Theses and Dissertations

The demand for treatment strategies of musculoskeletal tissues is continuously growing, especially considering the increasing number of elderly people with degenerative diseases of the skeletal system. Despite major strides in the field of bone regenerative medicine during the years, current therapies, such as bone grafts, still have several limitations. Multipotent stem cells, such as mesenchymal stem cells (MSCs) are promising candidates for tissue repair because of their differentiation potential and their capacity to undergo extensive replication. However, isolating a homogeneous population of MSCs from multiple sources is an area that needs to be addressed. Also, the knowledge regarding the mechanisms …


Atm-Dependent Erk Signaling In Response To Dna Double Strand Breaks, Ashraf Khalil Jan 2006

Atm-Dependent Erk Signaling In Response To Dna Double Strand Breaks, Ashraf Khalil

Theses and Dissertations

Ionizing radiation (IR) triggers many signaling pathways stemming from DNA damage, and, independently, from extra-nuclear events. To generate radio-mimetic DNA double-strand breaks (DSBs) without and minimizing the effects on extra-nuclear radiation targets, human (p53+) glioma and carcinoma cells containing bromodeoxyuridine (BrdU)- substituted DNA were treated with Hoechst 33258 followed by long wave-length UV (UV-A) (BrdU photolysis). BrdU photolysis resulted in well-controlled, dose-dependent generation of DSBs equivalent to 0.2 - 20 Gy of IR, as detected by pulse-field gel electrophoresis, accompanied by dose-dependent H2AX phosphorylation at ser-139 and ATM phosphorylation at ser-1981, indicating ATM activation. Furthermore, BrdU photolysis increased phosphorylation of …


Phospholipase A2 Induced Monocyte Chemotaxis To Apoptotic Cells, Kwasi Karikari Jan 2006

Phospholipase A2 Induced Monocyte Chemotaxis To Apoptotic Cells, Kwasi Karikari

Theses and Dissertations

Apoptosis is a form of programmed cell death that is essential in such processes as organ and tissue remodeling and maturation of hematopoietic cells. The clearance of apoptotic cells is essential to prevent autoimmune responses to sequestered antigens. This process is mediated by phagocytes of the monocyte lineage. Before phagocytosis can occur, macrophages must be recruited to the apoptotic cells through chemotaxis. Products of the reaction catalyzed by the phospholipases A2 (PLA2) have been shown to induce monocyte chemotaxis either directly or indirectly. Some investigators have implicated a cytosolic calcium-independent PLA2 (iPLA2) in the production of these products during apoptosis. …


Novel Characteristics Of Murine Bone Marrow-Derived Macrophages And Human Macrophage-Like Cells, George Tharwat Georges Jan 2006

Novel Characteristics Of Murine Bone Marrow-Derived Macrophages And Human Macrophage-Like Cells, George Tharwat Georges

Theses and Dissertations

These studies provide evidence for novel properties of macrophages derived from bone marrow stem cells. In study 1, treatment of activated mouse bone marrow-derived macrophages (BMM) with either catecholamine synthesis inhibitors (α-methyl-para-tyrosine and fusaric acid) or the β2 adrenergic receptor antagonist ICI 118,551 demonstrated that BMM produce catecholamines. The catecholamines modulated macrophage cytokine production through autocrine actions on adrenergic receptors. In study II, undifferentiated human bone marrow cells were incubated in 30% mouse L929 fibroblast conditioned medium and generated adherent cells within three days. The cells were clearly identifiable as macrophages based on surface proteins and phagocytic activity but produced …


Comparison Of Leukocyte Classes Most Likely To Cause Vascular Dysfunction In Preeclampsia, Kristen Anne Cadden Jan 2006

Comparison Of Leukocyte Classes Most Likely To Cause Vascular Dysfunction In Preeclampsia, Kristen Anne Cadden

Theses and Dissertations

Leukocytes are activated in women with preeclampsia, but the class of leukocyte most likely to cause vascular dysfunction is not known. We hypothesized that neutrophils may be the class of leukocyte most involved in causing this dysfunction because neutrophils are the most abundant of the leukocytes and their numbers increase during pregnancy. In this study we compared vascular infiltration of neutrophils (CD66b) with monocytes/macrophages (CD14) and lymphocytes (CD99) in normal non-pregnant women (NNP), normal pregnant women (NP), and preeclamptic women (PE). There was no significant difference in the infiltration of lymphocytes into the maternal vasculature in PE as compared to …


Effect Of Nitric Oxide On Oxygen Consumption Of Skeletal Muscle, Christina Lyn Cox Jan 2006

Effect Of Nitric Oxide On Oxygen Consumption Of Skeletal Muscle, Christina Lyn Cox

Theses and Dissertations

Mammalian cells require a continuous and sufficient supply of oxygen to carry out their functions. The oxygen pathway has an overall direction taking O2 from the air to the mitochondria, which is a result of the mitochondrial O2 consumption (VO2) NO various effects on the mitochondria: at low concentrations for short periods NO specifically and irreversibly inhibits cytochrome c and reversibly inhibits cytochrome c oxidase, to decrease VO2. Thus, NO can modulate VO2 of skeletal muscle. The purpose of the present study was to measure VO2 of the rat spinotrapezius muscle under conditions of altered NO. The methods used provide …


Characterization Of The Ftf/Hnf-4 Sites Within The 7alpha- And The 12alpha-Hydroxylase Promoters Involved In The Bile Acid-Mediated Transcription Of Their Regulation, Preeti Pramanik Jan 2006

Characterization Of The Ftf/Hnf-4 Sites Within The 7alpha- And The 12alpha-Hydroxylase Promoters Involved In The Bile Acid-Mediated Transcription Of Their Regulation, Preeti Pramanik

Theses and Dissertations

Bile acids regulate their own synthesis through a feedback regulatory mechanism of mainly two enzymes in the classic pathway, the 7α-hydroxylase and the 12α-hydroxylase. In the early 1990's it was shown that the regulatory responses of 7α-hydroxylase are mediated at the transcriptional level and since then many positive and negative transcription factors that mediate regulatory response have been identified. An important finding was that the transcription factors regulating the expression of 7α- and 12α-hydroxylase genes are nuclear receptors.One of the first nuclear receptors identified to play a role in the transcription of the 7α-hydroxylase gene was HNF-4 since then many …


Autocrine Effects Of Catecholamines On Macrophage Release Of Interleukin-6 (Il-6), Shaunta D. Poe Jan 2006

Autocrine Effects Of Catecholamines On Macrophage Release Of Interleukin-6 (Il-6), Shaunta D. Poe

Theses and Dissertations

Effects of norepinephrine (NE) on macrophage cytokine release are complex because the cells have both α2 and β2 adrenergic receptors, which mediate opposing actions. Furthermore, β2-adrenergic agonists are reported to have both stimulatory and inhibitory effects on interleukin-6 (IL-6). This study was designed to clarify the autocrine role of macrophage-derived NE on IL-6 production in activated peritoneal macrophages. Effects of NE on IL-6 production in the RAW264.7 macrophage cell-line also were investigated. Treatment of activated peritoneal macrophages with endotoxin, the α2-adrenergic antagonists yohimbine or RS79948 revealed that the α2-adrenergic receptor mediates a stimulatory autocrine action of catecholamines on IL-6 production. …


Anatomical Bases For Auditory Projections To Suprasylvian Visual Areas In The Cat Cerebral Cortex, Giriaj K. Sharma Jan 2006

Anatomical Bases For Auditory Projections To Suprasylvian Visual Areas In The Cat Cerebral Cortex, Giriaj K. Sharma

Theses and Dissertations

How the neural representations of different sensory modalities transition from one to another is an unexplored issue of cortical organization. The present experiments addressed this problem by examining auditory projections to the lateral suprasylvian visual area (LSS) of the cat using neuroanatomical tract tracing methods. Injections of tracer (Biotinylated Dextran Amine, BDA) were made into defined areas of the cat auditory cortex. Following transport and tissue processing, a light microscope with a digitizing stage was used to visualize and plot labeled auditory projections to the LSS. The results showed that all auditory cortices tested demonstrated projections to a restricted portion …


Assessment Of Chenopodium Quinoa Willd. Genetic Diversity In The Usda And Cip-Fao Collections Using Ssr?S And Snp?S, Shawn A. Christensen Nov 2005

Assessment Of Chenopodium Quinoa Willd. Genetic Diversity In The Usda And Cip-Fao Collections Using Ssr?S And Snp?S, Shawn A. Christensen

Theses and Dissertations

Quinoa (Chenopodium quinoa Willd.) is a staple grain for the indigenous people of the Andean region of South America with excellent nutritional qualities, including protein content. The objective of this study is to report on the development of fluorescence-tagged simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) to (1) genetically characterize the inherent diversity of 152 accessions of C. quinoa; (2) determine to what degree the CIP-FAO collection represents the range of genetic diversity in quinoa; and (3) test four hypotheses regarding quinoa?s center of diversity, Highland and Lowland clustering patterns, origin of Lowland varieties, and the …


The Role Of Phosducin-Like Protein And The Cytosolic Chaperonin Cct In G Beta Gamma Dimer Assembly, Ting Hu Nov 2005

The Role Of Phosducin-Like Protein And The Cytosolic Chaperonin Cct In G Beta Gamma Dimer Assembly, Ting Hu

Theses and Dissertations

Phosducin-like protein (PhLP), a G protein beta gamma subunit dimer binder and G protein signaling regulator, was suggested to regulate the activity of cytosolic chaperonin CCT by their high affinity interaction. In the present study, the three-dimensional structure of PhLP:CCT complex has been solved by cryoelectron microscopy. PhLP was found to bind only one of the chaperonin rings with both N- and C-terminal domains. It spans the central folding cavity of CCT and interacts with two opposite sides of the top apical region, inducing the constraining of the entry of the folding cavity. These findings support a putative role of …


Palladium-Imidazolium Carbene Catalyzed Heck Coupling Reactions And Synthesis Of A Novel Class Of Fluoroanthracenylmethyl Ptc Catalysts, Jiuqing Zhang Nov 2005

Palladium-Imidazolium Carbene Catalyzed Heck Coupling Reactions And Synthesis Of A Novel Class Of Fluoroanthracenylmethyl Ptc Catalysts, Jiuqing Zhang

Theses and Dissertations

Palladium catalyzed Heck coupling with aryl and alkenyl halides has become a powerful means of carbon-carbon bond formation. This standard synthetic method has been developed to a high level of utility using various catalysts, conditions and substrates. Yet significant drawbacks remain, including poor reactivity, the need for high temperatures and base, limited substrate generality, and selectivity. Mixed products often suffer from olefin migration following insertion. N-Heterocyclic carbenes (NHC) have proven to be electron-rich donors which provide higher stability and reactivity than phosphines. In a previous paper reported by our research group the imidazolium-palladium carbene has proven to be highly efficient …


Total Syntheses Of (+)-Geldanamycin, (-)-Ragaglitazar, And (+)-Kurasoin A And Phase-Transfer-Catalyzed Asymmetric Alkylation, Erik J. Hicken Nov 2005

Total Syntheses Of (+)-Geldanamycin, (-)-Ragaglitazar, And (+)-Kurasoin A And Phase-Transfer-Catalyzed Asymmetric Alkylation, Erik J. Hicken

Theses and Dissertations

Geldanamycin possesses various biological activities as seen in the NCI 60 cell line panel (13 nM avg., 70 nM SKBr-3 cells). The predominant mode of action providing these unique results arises from the ability of geldanamycin (GA) to bind to the chaperone heat shock protein 90 (Hsp90). Despite its complicated functionality, the first total synthesis of GA was accomplished, which included two new reactions developed specifically to address the stereochemical features. The final step in the synthesis of GA was a demethylation-oxidation sequence to generate the desired para-quinone. This step could only be accomplished with HNO3/AcOH, producing GA in …


Development Of Biological Reference Conditions Of Wadeable Streams In The Major Ecoregions And Subecoregions Of Georgia, Duncan L. Hughes Nov 2005

Development Of Biological Reference Conditions Of Wadeable Streams In The Major Ecoregions And Subecoregions Of Georgia, Duncan L. Hughes

Theses and Dissertations

One bioassessment tool available to resource managers to indicate NPS impairment of wadeable streams and rivers are multi-metric invertebrate indices. Such indices are assembled from metrics in broad categories that represent different aspects of community structure and function (e.g. richness, composition, tolerance/intolerance, feeding group, and habit). Indices must incorporate suites of metrics that are ecologically relevant, quantifiable, non-redundant, and that best individually discriminate between reference sites and impaired sites. More than 240 wadeable streams in Georgia were sampled during the September thru February index period using RBP protocols during three successive sample seasons (1999-2003). Ecoregional reference (minimally impaired) sites, as …


Specific Heat And Thermodynamic Properties Of Metallic Systems: Instrumentation And Analysis, Brian E. Lang Oct 2005

Specific Heat And Thermodynamic Properties Of Metallic Systems: Instrumentation And Analysis, Brian E. Lang

Theses and Dissertations

A small-scale adiabatic calorimeter has been constructed as part of a larger project to study nano-particles and to facilitate specific heat measurements on samples where it is difficult to obtain enough material to run on the current large-scale adiabatic apparatus. This calorimeter is designed to measure sample sizes of less than 0.8 cc over a temperature range from 13 K to 350 K. Specific heat results on copper, sapphire, and benzoic acid show the accuracy of the measurements to be better than ±0.4% for temperatures higher than 50 K. The reproducibility of these measurements is generally better than ±0.25%. Experimental …


Polymer Microchips For Capillary Electrophoresis And Electric Field Gradient Focusing Of Biomolecules, Ryan Thomas Kelly Sep 2005

Polymer Microchips For Capillary Electrophoresis And Electric Field Gradient Focusing Of Biomolecules, Ryan Thomas Kelly

Theses and Dissertations

Polymeric materials have seen increasing use as microfluidic device substrates due to their low cost and the simplicity of templated fabrication procedures. I showed that poly(methyl methacrylate) (PMMA) microdevices could be enclosed in a boiling water bath, which allowed the seal to form more quickly than in conventional approaches, and enabled microchannels to remain hydrated throughout the bonding process. Microchip capillary electrophoresis (µ-CE) devices were fabricated using water-based enclosure, and a mixture of fluorescently labeled amino acids was separated in 30 s in these microchips. To create more robust capillary electrophoresis (CE) microdevices with improved separation performance, phase-changing sacrificial materials …


Structure Elucidation Of Bioactive Compounds Isolated From Endophytes Of Alstonia Scholaris And Acmena Graveolens, Nicholas James Hundley Sep 2005

Structure Elucidation Of Bioactive Compounds Isolated From Endophytes Of Alstonia Scholaris And Acmena Graveolens, Nicholas James Hundley

Theses and Dissertations

Alstonia scholaris is an evergreen tree native to Southeast Asia and Australia. It is commonly used as a medicinal plant throughout these regions. In the present study, an endophyte of the genus Xylaria was isolated from a stem of Alstonia scholaris, its mycelia and exudate extracted, and the extract assayed for growth inhibition of HeLa cancer cells in vitro. Several known compounds were isolated and identified based on NMR, infrared, and mass spectral data. The compounds identified are 19,20-epoxycytochalasin C; 19,20epoxycytochalasin D; and xylobovide. Two other compounds, fusaric acid and dehydrofusaric acid, were discovered in an endophyte of the Hypocreales …