View All Items

Title: An ultrastructural investigation of spermatogenesis in the holopelagic polychaetes Vanadis formosa and Krohnia lepidota (Polychaeta: Alciopidae).
Creator: Rice, Stanley A., Eckelbarger, Kevin J., Harbor Branch Oceanographic Institute
Date Issued: 1989
PURL: http://purl.flvc.org/FCLA/DT/3171559
Subject Headings: Spermatogenesis, Cell membranes, Cell division, Chromosomes, Oceanographic submersibles
Format: Document (PDF)

Title: Construction of mitochondrion-targeted telomerase for analysis in Saccharomyces cerevisiae.
Creator: Martin, Ricardo., Harriet L. Wilkes Honors College
Abstract/Description: Telomerase is associated with telomere production and nDNA protection. However, studies by Santos et al. have demonstrated that human telomerase has a mitochondrial entry sequence and in the presence of hydrogen peroxide it has been found inside the mitochondrion and may cause mitochondrial DNA mutations. Saccharomyces cerevisiae contains telomerase, but it does not have the mitochondrial entry sequence. To determine if the presence of telomerase in the mitochondria can induce mutations an...
Show moreTelomerase is associated with telomere production and nDNA protection. However, studies by Santos et al. have demonstrated that human telomerase has a mitochondrial entry sequence and in the presence of hydrogen peroxide it has been found inside the mitochondrion and may cause mitochondrial DNA mutations. Saccharomyces cerevisiae contains telomerase, but it does not have the mitochondrial entry sequence. To determine if the presence of telomerase in the mitochondria can induce mutations an experiment was developed in which a mitochondrion entry sequence would be fused to the S. cerevisiae telomerase enzyme. This fusion could then be screened in S. cerevisiae with an ade2 mutation for a simple color assay of mitochondrial activity. To date, no successful transformant has been identified. The frequency of incorrect ligations has been recognized and may indicate that the desired fusion is lethal to E. coli cells.
Show less
Date Issued: 2009
PURL: http://purl.flvc.org/FAU/209994
Subject Headings: Cell membranes, Formation, Mitochondrial DNA, Mutation (Biology), Cell metabolism
Format: Document (PDF)

Title: Investigation of talin head-tail interactions.
Creator: Butyn, Amber., Harriet L. Wilkes Honors College
Abstract/Description: Talin is a ubiquitous, high-molecular-weight, flexible protein that plays a critical role in focal adhesions by activating, as well as connecting, integrins to the actin cytoskeleton. Talin's inactive auto-inhibitory state is speculated to be one of its modes of regulation inside the cell and is achieved through its head-tail interactions. In order to decipher the stability of this interaction, the head domain (residues 206-405) was cloned into a modified pET28m vector while the tail domains ...
Show moreTalin is a ubiquitous, high-molecular-weight, flexible protein that plays a critical role in focal adhesions by activating, as well as connecting, integrins to the actin cytoskeleton. Talin's inactive auto-inhibitory state is speculated to be one of its modes of regulation inside the cell and is achieved through its head-tail interactions. In order to decipher the stability of this interaction, the head domain (residues 206-405) was cloned into a modified pET28m vector while the tail domains (residues 1654-2344 and 2225-2344) were cloned into the pET32a vector to obtain octa-histidine tagged and un-tagged peptide, respectively. Neither co-expression nor pull-down using the His-tagged head domain was successful in purifying a stable head-tail complex. Our results indicate rather weak interactions between the talin head and rod domains and hence, under our experimental conditions, do not lead to a stable auto-inhibitory complex that can be purified for further studies.
Show less
Date Issued: 2009
PURL: http://purl.flvc.org/FAU/209984
Subject Headings: Membrane proteins, Structure-activity relationships, Cell membranes, Physiology, Molecular biology, Cell interaction, Developmental cytology
Format: Document (PDF)

Title: STUDIES ON POLYETHYLENE GLYCOL-MEDIATED AGGREGATION AND FUSION OF AVIAN ERYTHROCYTES.
Creator: BATCHELOR, ROGER ALLEN., Florida Atlantic University
Abstract/Description: Polyethylene glycol (PEG)-induced aggregation, hemolysis and fusion of chicken red blood ceils (CRBC's) was studied in relation to the following parameters: osmotic pressure, polymer concentration, ionic strength, electrolyte species, surface charge removal and glutaraldehyde fixation. Indirect evidence indicated that osmotic pressure does not play a primary role in aggregation and fusion of red blood cells. Maximum aggregation and fusion was obtained in solutions of 20 and 40% PEG,...
Show morePolyethylene glycol (PEG)-induced aggregation, hemolysis and fusion of chicken red blood ceils (CRBC's) was studied in relation to the following parameters: osmotic pressure, polymer concentration, ionic strength, electrolyte species, surface charge removal and glutaraldehyde fixation. Indirect evidence indicated that osmotic pressure does not play a primary role in aggregation and fusion of red blood cells. Maximum aggregation and fusion was obtained in solutions of 20 and 40% PEG, respectively. In contrast, hemolysis increased almost linearily with PEG concentration. The negative electrostatic charge due to the presence of sialic acid on the membrane surface was found to be the primary factor affecting aggregation, hemolysis and fusion. Removal of the charge by neuraminidase or screening with cations enhanced aggregation and fusion while inhibiting hemolysis. The inhibition of aggregation by glutaraldehyde fixation, and hemolysis and fusion results not attributed to surface charges, are discussed in terms of intramembrane interactions with PEG.
Show less
Date Issued: 1977
PURL: http://purl.flvc.org/fcla/dt/13893
Subject Headings: Cell hybridization, Erythrocytes, Hemolysis and hemolysins, Membrane fusion
Format: Document (PDF)

Title: Study of pulsing flow of reactants in a proton exchange membrane fuel cell (PEMFC).
Creator: Perez, Aquiles., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Pulsing the flow of reactants in proton exchange membrane fuel cells (PEMFC) is a new frontier in the area of fuel cell research. Although power performance losses resulting from water accumulation also referred to as flooding, and power performance recovery resulting from water removal or purging, have been studied and monitored, the nexus between pulsing of reactants and power performance has yet to be established. This study introduces pulsing of reactants as a method of improving power...
Show morePulsing the flow of reactants in proton exchange membrane fuel cells (PEMFC) is a new frontier in the area of fuel cell research. Although power performance losses resulting from water accumulation also referred to as flooding, and power performance recovery resulting from water removal or purging, have been studied and monitored, the nexus between pulsing of reactants and power performance has yet to be established. This study introduces pulsing of reactants as a method of improving power performance. This study investigates how under continuous supply of reactants, pressure increase due to water accumulation, and power performance decay in PEMFCs. Furthermore, this study shows that power performance can be optimized through pulsing of reactants, and it investigates several variables affecting the power production under these conditions. Specifically, changes in frequency, duty cycle, and shifting of reactants as they affect performance are monitored and analyzed. Advanced data acquisition and control software allow multi-input monitoring of thermo-fluid and electrical data, while analog and digital controllers make it possible to implement optimization techniques for both discrete and continuous modes.
Show less
Date Issued: 2009
PURL: http://purl.flvc.org/FAU/367764
Subject Headings: Proton exchange membrane fuel cells, Reliability, Fuel cells, Reliability, Renewable energy sources
Format: Document (PDF)

Title: Modeling and Control of Proton Exchange Membrane (PEM) Fuel Cell System.
Creator: Saengrung, Anucha, Zilouchian, Ali, Abtahi, Amir, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This dissertation presents the design, implementation and application of soft computing methodologies to Proton Exchange Membrane (PEM) Fuel Cell systems. In the first part of the research work, two distinct approaches for the modeling and prediction of a commercial PEM fuel cell system are presented. Several Simulink models are constructed from the electrochemical models of the PEM fuel cells. The models have been simulated in three dimension (3-D) space to provide the visual understanding...
Show moreThis dissertation presents the design, implementation and application of soft computing methodologies to Proton Exchange Membrane (PEM) Fuel Cell systems. In the first part of the research work, two distinct approaches for the modeling and prediction of a commercial PEM fuel cell system are presented. Several Simulink models are constructed from the electrochemical models of the PEM fuel cells. The models have been simulated in three dimension (3-D) space to provide the visual understanding of fuel cell behaviors. In addition, two optimal predictive models, based on back-propagation (BP) and radial basis function (RBF) neural networks are developed. Experimental data as well as pre-processing data are utilized to determine the accuracy and speed of the proposed prediction algorithms. Extensive simulation results are presented to demonstrate the effectiveness of the proposed method on prediction of nonlinear input-output linear input-output mapping. In the second part of the study, the design and implementation of several fuzzy logic controllers (FLCs) as well as classical controllers are carried out. The proposed real-time controller design is based on the integration of sensory information, Labview programming, mathematical calculation, and expert knowledge of the process to yield optimum output power performance under variable load condition. The implementations of the proposed controllers are carried out for a commercial PEM fuel system at FA U Fuel Cell Laboratory. The performance of the proposed controllers pertaining to the oxygen (02) flow rate optimization as well as the actual fuel cell output power under a variable load bank are compared and investigated. It was found the Fuzzy Logic Controller design provide a simple and effective approach for the implementation of the fuel cell systems.
Show less
Date Issued: 2008
PURL: http://purl.flvc.org/fau/fd/FA00012577
Subject Headings: Proton exchange membrane fuel cells--Design and construction, Proton exchange membrane fuel cells--Computer simulation, Fuel cells--Design and construction
Format: Document (PDF)

Title: The effects of Toll-like receptor (TLR) agonists on human nicDC-NK mediated memory/effector T-cell development.
Creator: Tamjidi, Saba, Nouri-Shirazi, Mahyar, Florida Atlantic University, Charles E. Schmidt College of Medicine, Department of Biomedical Science
Abstract/Description: There is compelling evidence that smokers are less responsive to vaccination. We reported that both therapeutic and prophylactic vaccines fail to protect and cure animals from disease due to negative effects of nicotine on DCs’ ability to generate effector T cells. We have been investigating whether vaccine formulated with TLR agonist(s) could potentially overcome the immunosuppressive effects of nicotine on human DC-NK cross-talk essential for effector T cell generation. Monocyte-derived DCs...
Show moreThere is compelling evidence that smokers are less responsive to vaccination. We reported that both therapeutic and prophylactic vaccines fail to protect and cure animals from disease due to negative effects of nicotine on DCs’ ability to generate effector T cells. We have been investigating whether vaccine formulated with TLR agonist(s) could potentially overcome the immunosuppressive effects of nicotine on human DC-NK cross-talk essential for effector T cell generation. Monocyte-derived DCs and nicDCs were stimulated with individual and combined TLR agonists prior to co-culture with purified T cells. The phenotypes and cytokine profiles of T cell were assessed using Flow Cytometry and ELISA, respectively. We found nicDCs cultured with TLR-8/7 alone or in combination with TLR-3 produce quantitatively and qualitatively similar IFN-γ producing effector T cells when compared to control DCs. Our data suggest that the addition of appropriate TLR agonist to vaccine formulation could potentially overcome the immunosuppression seen in smokers, thereby containing the spread of infectious disease to vulnerable population
Show less
Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004469, http://purl.flvc.org/fau/fd/FA00004469
Subject Headings: Cell membranes, Cell receptors, Evidence based medicine, Immune system, Molecular biology, T cells -- Receptors, Tobacco -- Physiological effects
Format: Document (PDF)

Title: Study of high temperature PEM fuel cell (HT-PEMFC) waste heat recovery through ejector based refrigeration.
Creator: Fuchs, Michel., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The incorporation of an ejector refrigeration cycle with a high temperature PEM fuel cell (HT-PEMFC) presents a novel approach to combined heat and power (CHP) applications. An ejector refrigeration system (ERS) can enhance the flexibility of a CHP system by providing an additional means of utilizing the fuel cell waste heat besides domestic hot water (DHW) heating. This study looks into the performance gains that can be attained by incorporating ejector refrigeration with HT-PEMFC micro-CHP ...
Show moreThe incorporation of an ejector refrigeration cycle with a high temperature PEM fuel cell (HT-PEMFC) presents a novel approach to combined heat and power (CHP) applications. An ejector refrigeration system (ERS) can enhance the flexibility of a CHP system by providing an additional means of utilizing the fuel cell waste heat besides domestic hot water (DHW) heating. This study looks into the performance gains that can be attained by incorporating ejector refrigeration with HT-PEMFC micro-CHP (mCHP) systems (1 to 5kWe). The effectiveness of the ERS in utilizing fuel cell waste heat is studied as is the relulting enhancement to overall system efficiency. A test rig specially constructed to evaluate an ERS under simulated HT-PEMFC conditions is used to test the concept and verify modeling predictions. In addition, two separate analytical models were constructed to simulate the ERS test rig and a HT-PEMFC/ERS mCHP system. The ERS test rig was simulated using a Matlab based model, while two residential sized HT-PEMFC/ERS mCHP systems were simulated using a Simulink model. Using U.S. Energy Information Administration (EIA) air conditioning and DHW load profiles, as well as data collected from a large residential monitoring study in Florida, the Simulink model provides the results in system efficiency gain associated with supporting residential space cooling and water heating loads. It was found that incorporation of an ERS increased the efficiency of a HT-PEMFC mCHP system by 8 t0 10 percentage points over just using the fuel cell waste heat for DHW. In addition, results from the Matlab ERS test rig model were shown to match well with experimental results.
Show less
Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3355557
Subject Headings: Proton exchange membrane fuel cells, Fuel cells, Mathematical models, Heat exchangers, Design and construction, Renewable energy sources
Format: Document (PDF)

Title: Characterization of RNase in Mycoplasma genitalium and study of its possible role in tRNA processing.
Creator: Lalonde, Maureen S., Florida Atlantic University, Li, Zhongwei, Charles E. Schmidt College of Medicine, Department of Biomedical Science
Abstract/Description: Exoribonucleases degrade RNA and are important in RNA metabolism and gene expression. Mycoplasma genitalium, a bacterium with the smallest genome known, has only one identified exoribonuclease, RNase R (MgR). In this work RNA degradation properties of purified MgR were examined. As observed in Escherichia coli RNase R (EcR) studies, MgR degrades poly(A), rRNA, and oligoribonucleotides in 3'--->5' direction, though its substrate specificity and optimal activity requirements vary. Interestingly...
Show moreExoribonucleases degrade RNA and are important in RNA metabolism and gene expression. Mycoplasma genitalium, a bacterium with the smallest genome known, has only one identified exoribonuclease, RNase R (MgR). In this work RNA degradation properties of purified MgR were examined. As observed in Escherichia coli RNase R (EcR) studies, MgR degrades poly(A), rRNA, and oligoribonucleotides in 3'--->5' direction, though its substrate specificity and optimal activity requirements vary. Interestingly, MgR is sensitive to 2-O-methylation stopping downstream of such modifications in native rRNA and synthetic oligoribonucleotides. MgR removes the 3' trailer sequence from a tRNA precursor of M. genitalium and generates products equal to the mature tRNA, demonstrating a role of MgR in tRNA maturation. The 3' terminal CCA sequence and the acceptor stem of tRNA play a role in determining the formation of such products by MgR. These results suggest multiple functions of RNase R in RNA metabolism in Mycoplasma.
Show less
Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13317
Subject Headings: Gene expression, RNA-protein interactions, Cellular control mechanisms, Ribonucleases--Analysis, Cell membranes
Format: Document (PDF)

Title: Purification and characterization of two members of the protein tyrosine phosphatase family: dual specificity phosphatase PVP and low molecular weight phosphatase WZB.
Creator: Livingston, Paula A., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: Two protein tyrosine phosphatases, dual specificity phosphatase PVP and low molecular weight phosphatase WZB were purified and characterized. PVP was expressed as inclusion bodies and a suitable purification and refolding method was devised. Enzyme kinetics revealed that p-nitrophenylphosphate and (Sb(B-naphthyl phosphate were substrates with KM of 4.0mM and 8.1mM respectively. PVP showed no reactivity towards phosphoserine. Kinetic characterization of WZB showed that only...
Show moreTwo protein tyrosine phosphatases, dual specificity phosphatase PVP and low molecular weight phosphatase WZB were purified and characterized. PVP was expressed as inclusion bodies and a suitable purification and refolding method was devised. Enzyme kinetics revealed that p-nitrophenylphosphate and (Sb(B-naphthyl phosphate were substrates with KM of 4.0mM and 8.1mM respectively. PVP showed no reactivity towards phosphoserine. Kinetic characterization of WZB showed that only pnitrophenylphosphate was a substrate with no affinity for Ç-naphthyl phosphate and phosphoserine. Optimal conditions for activity with PNPP were found at a pH of 5 with a KM of 1.1mM, kcat of 35.4s-1 and kcat/KM of 32.2s-1mM-1. Inhibition studies showed that phosphate, fluoride, and molybdate were competitive inhibitors with Ki of 3.2mM, 71.7mM, and 50.4(So(BM respectively and hydrogen peroxide abolished activity. Active site mutants of WZB Cys9Ser and Asp115Asn showed no activity.
Show less
Date Issued: 2009
PURL: http://purl.flvc.org/FAU/332911
Subject Headings: Protein-tyrosine phosphatase, Cellular signal transduction, Cell cycle, Regulation, Membrane proteins, Structure-activity relationships, Protein kinases
Format: Document (PDF)

Title: Reciprocal regulation between taurine and glutamate response via Ca2+ - dependent pathways in retinal third-order neurons.
Creator: Bulley, Simon, Shen, Wen
Date Issued: 2010-08-24
PURL: http://purl.flvc.org/fcla/dt/3327274
Subject Headings: Amacrine Cells*/cytology, Amacrine Cells*/drug effects, Amacrine Cells*/metabolism, Ambystoma, Calcium/metabolism, Calcium Channels/metabolism, Cells, Cultured, Enzyme Inhibitors/metabolism, Excitatory Amino Acid Agonists/pharmacology, GABA Antagonists/pharmacology, Glutamic Acid/metabolism, Glycine Agents/pharmacology, Kainic Acid/pharmacology, Membrane Glycoproteins, Membrane Potentials, Neurotransmitter Agents, Retinal Ganglion Cells, Signal Transduction, Synaptic Transmission
Format: Document (PDF)

Search In

Sort Results By:

Narrow results by:

Collection

Topical Subject

Genre

Type of Resource

Language

Creator

Format

Owner