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Organismal Biological Physiology Commons

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The Mycoplasma Genitalium Mg_454 Gene Product Resists Killing By Organic Hydroperoxides, Sankaralingam Saikolappan, Smitha Sasindran, Hongwei Yu, Joel Basema, Subramanian Dhandayuthapani 2012 Marshall University

The Mycoplasma Genitalium Mg_454 Gene Product Resists Killing By Organic Hydroperoxides, Sankaralingam Saikolappan, Smitha Sasindran, Hongwei Yu, Joel Basema, Subramanian Dhandayuthapani

Hongwei Yu

Mycoplasma genitalium is the smallest self-replicating organism and a successful human pathogen associated with a range of genitourinary maladies. As a consequence of its restricted genome size, genes that are highly conserved in other bacteria are absent in M. genitalium. Significantly, genes that encode antioxidants like superoxide dismutase and catalase-peroxidase are lacking. Nevertheless, comparative genomics has revealed that MG_454 of M. genitalium encodes a protein with putative function as an organic hydroperoxide reductase (Ohr). In this study, we found that an M. genitalium transposon mutant that lacks expression of MG_454 was sensitive to killing by t-butyl hydroperoxide and cumene hydroperoxide ...


Lipotoxin F Of Pseudomonas Aeruginosa Is An Algu-Dependent And Alginate-Independent Outer Membrane Protein Involved In Resistance To Oxidative Stress And Adhesion To A549 Human Lung Epithelia, F. Damron, Jennifer Napper, M. Teter, Hongwei Yu 2012 Marshall University

Lipotoxin F Of Pseudomonas Aeruginosa Is An Algu-Dependent And Alginate-Independent Outer Membrane Protein Involved In Resistance To Oxidative Stress And Adhesion To A549 Human Lung Epithelia, F. Damron, Jennifer Napper, M. Teter, Hongwei Yu

Hongwei Yu

Chronic lung infection with P. aeruginosa and excessive neutrophil-associated inflammation are major causes of morbidity and mortality in patients with cystic fibrosis (CF). Overproduction of an exopolysaccharide known as alginate leads to the formation of mucoid biofilms that are resistant to antibiotics and host defences. Alginate overproduction or mucoidy is controlled by a stress-related ECF sigma factor AlgU/T. Mutation in the anti-sigma factor MucA is a known mechanism for conversion to mucoidy. Recently, we showed that inactivation of a kinase (KinB) in nonmucoid strain PAO1 results in overproduction of alginate. Here, we report the initial characterization of lipotoxin F ...


Characterization Of Chemosensing In The Alphaproteobacterium Azospirillum Brasilense , Matthew Hamilton Russell 2012 University of Tennessee - Knoxville

Characterization Of Chemosensing In The Alphaproteobacterium Azospirillum Brasilense , Matthew Hamilton Russell

Doctoral Dissertations

Motile bacteria must navigate their environment in constant search of nutrients to sustain life. Thus they have evolved precise and adaptable sensory systems to achieve this goal, making the navigation system of the model bacterium Escherichia coli the best characterized signal transduction pathway in Biology. However, many bacteria have evolved more sophisticated arsenals for sensing and responding to their environment including chemoreceptors to identify novel attractants in the microenvironment. The diazotrophic alphaproteobacterium Azospirillum brasilense inhabits the soil and colonizes the roots of cereals like rice, corn, and wheat. Like most proteobacterial, A. brasilense encodes multiple chemotaxis-like pathways, 4, of which ...


Cell Bioenergetics In Leghorn Male Hepatoma Cells And Immortalized Chicken Liver Cells In Response To 4-Hydroxynonenal Induced Oxidative Stress, Alissa Laura Piekarski 2012 University of Arkansas, Fayetteville

Cell Bioenergetics In Leghorn Male Hepatoma Cells And Immortalized Chicken Liver Cells In Response To 4-Hydroxynonenal Induced Oxidative Stress, Alissa Laura Piekarski

Theses and Dissertations

Bioenergetic mechanisms responsible for ATP production are essential in carrying out maintenance and cell-specific functions. In this study, hepatocytes (liver cells) were used to test both endogenous and exogenous stress on cellular respiration. The secondary lipid peroxide, 4-hydroxynonenal (HNE), was used because it alters bioenergetics by increasing mitochondrial proton leak that attenuates mitochondrial radical production and, therefore, endogenous oxidative stress. The major objective of this study was to demonstrate effects of HNE-induced oxidative stress on avian hepatocyte bioenergetics. Various chemical which help enable the determination of oxygen (O2) consumption linked to ATP synthesis (oligomycin), maximal O2 consumption (FCCP), and proton ...


Sea Slug—Algal Chloroplast Symbiosis: Towards An Integrated Understanding Of Long-Term Chloroplast Functioning In An Animal, Mary E. Rumpho 2012 Principal Investigator; University of Maine, Orono

Sea Slug—Algal Chloroplast Symbiosis: Towards An Integrated Understanding Of Long-Term Chloroplast Functioning In An Animal, Mary E. Rumpho

University of Maine Office of Research Administration: Grant Reports

Photosynthesis plays a fundamental role in understanding plant growth and productivity. The chloroplast, the organelle of photosynthesis, evolved following the endosymbiotic uptake of a cyanobacterium and massive gene transfer. As a result, the chloroplast is highly dependent upon nuclear genes to provide essential chloroplast proteins. A special form of endosymbiosis, kleptoplasty, has evolved in the marine mollusc Elysia chlorotica. This green, leaf-like animal carries out photosynthesis for its entire ten month life-cycle, as if it were a plant, by using chloroplasts it steals and retains from the alga Vaucheria litorea. It is highly likely that horizontal gene transfer (HGT) has ...


Links From Mantle To Microbe At The Lau Integrated Study Site: Insights From A Back-Arc Spreading Center, Margaret K. Tivey, Erin Becker, Roxanne Beinart, Charles R. Fisher, Peter Girguis, Charles H. Langmuir, Peter J. Michael, Anna-Louise Reysenbach 2012 Woods Hole Oceanographic Institution

Links From Mantle To Microbe At The Lau Integrated Study Site: Insights From A Back-Arc Spreading Center, Margaret K. Tivey, Erin Becker, Roxanne Beinart, Charles R. Fisher, Peter Girguis, Charles H. Langmuir, Peter J. Michael, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

The Lau Integrated Study Site (ISS) has provided unique opportunities for study of ridge processes because of its back-arc setting in the southwestern Pacific. Its location allows study of a biogeographical province distinct from those of eastern Pacific and mid-Atlantic ridges, and crustal compositions along the ridge lie outside the range of mid-ocean ridge crustal compositions. The Lau ISS is located above a subduction zone, at an oblique angle. The underlying mantle receives water and other elements derived from the downgoing lithospheric slab, with an increase in slab influence from north to south. Water lowers the mantle melting temperature and ...


Thoughts On Quorum Sensing And Fungal Dimorphism, Kenneth W. Nickerson, Audrey L. Atkin, Jessica C. Hargarten, Ruvini U. Pathirana, Sahar Hasim 2012 University of Nebraska-Lincoln

Thoughts On Quorum Sensing And Fungal Dimorphism, Kenneth W. Nickerson, Audrey L. Atkin, Jessica C. Hargarten, Ruvini U. Pathirana, Sahar Hasim

Papers in Microbiology

Farnesol has been best studied for its role in regulating fungal dimorphism. However, farnesol is also a lipid and in this review we analyze data relevant to farnesol’s function and synthesis from the perspective of farnesol and bacterial endotoxins acting as membrane active compounds. This analysis implicates the possible roles of: (1) endotoxins in the regulation of farnesol production by C. albicans; (2) farnesol in the interactions between C. albicans and the host during disseminated infections; and (3) ubiquinones in the mechanisms for unusually high resistance to farnesol by some C. albicans cell types. Finally we discuss the implications ...


Parasites Of Civets (Mammalia, Viverridae) In Sabah, Borneo: A Coprological Survey, Christina P. Colon, Sharon Patton 2012 Kingsborough Community College

Parasites Of Civets (Mammalia, Viverridae) In Sabah, Borneo: A Coprological Survey, Christina P. Colon, Sharon Patton

Publications and Research

Parasite data were collected from unlogged and selectively logged lowland rain forests in Borneo. Scat from a female Viverra tangalunga (Malay civet) in the unlogged forest contained eggs of Capillaria spp., Trichuris sp., Mamomoganomus sp., and nematode larvae. Scat attributed to V. tangalunga contained reproductive products (eggs/oocysts/cysts/larvae) of Capillaria sp., Toxocara sp., Ancylostoma sp. (probably A. ceylanicum), Isospora spp., strongylate-type eggs (probably Ancylostoma spp.), Paragoni­ mus sp. and other Trematoda eggs, Monocystis sp. cysts, Gnathostoma sp. (probably G. spinigerum), the lungworm Viverrostrongylus brauni, pinworm-type eggs, Eimeria spp., Sarcocystis-type sporocyst, dermanysid mites and mesostigmatid mites. Parasites from gut ...


Potential For Nitrogen Fixation And Nitrification In The Granite-Hosted Subsurface At Henderson Mine, Co, Elizabeth D. Swanner, Alexis S. Templeton 2011 University of Colorado Boulder

Potential For Nitrogen Fixation And Nitrification In The Granite-Hosted Subsurface At Henderson Mine, Co, Elizabeth D. Swanner, Alexis S. Templeton

Elizabeth D. Swanner

The existence of life in the deep terrestrial subsurface is established, yet few studies have investigated the origin of nitrogen that supports deep life. Previously, 16S rRNA gene surveys cataloged a diverse microbial community in subsurface fluids draining from boreholes 3000 feet deep at Henderson Mine, CO, USA (Sahl et al., 2008). The prior characterization of the fluid chemistry and microbial community forms the basis for the further investigation here of the source of NH4+. The reported fluid chemistry included N2, NH4+ (5–112 μM), NO2− (27–48 μM), and NO3− (17–72 μM). In this study, the correlation between ...


Systematics Of Protosteloid Amoebae, Lora Lindley Shadwick 2011 University of Arkansas

Systematics Of Protosteloid Amoebae, Lora Lindley Shadwick

Theses and Dissertations

Because of their simple fruiting bodies consisting of one to a few spores atop a finely tapering stalk, protosteloid amoebae, previously called protostelids, were thought of as primitive members of the Eumycetozoa sensu Olive 1975. The studies presented here have precipitated a change in the way protosteloid amoebae are perceived in two ways: (1) by expanding their known habitat range and (2) by forcing us to think of them as amoebae that occasionally form fruiting bodies rather than as primitive fungus-like organisms. Prior to this work protosteloid amoebae were thought of as terrestrial organisms. Collection of substrates from aquatic habitats ...


Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley 2011 Western Washington University

Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley

STAR Program Research Presentations

Salmonids, such as Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss), are a staple economic, recreational, tribal, and environmental resource, yet many populations are unsustainable. This study was part of a broad scale effort to monitor the impact of downstream migration obstacles on juvenile salmonid health and survival, which is an essential step towards increasing Smolt-to-Adult Return ratios (SARs). The objective of this study was to determine if juvenile Chinook salmon and steelhead exhibit differing quantities of alphaII-Spectrin Breakdown Products (SBDPs) over two consecutive spring migration periods, indicative of neurogenesis rate and/or biological response to head injury. AlphaII-Spectrin is ...


Evidence Of A Rudimentary Colon In Leucoraja Erinacea, Alyssa M. Simeone 2011 Union College - Schenectady, NY

Evidence Of A Rudimentary Colon In Leucoraja Erinacea, Alyssa M. Simeone

Honors Theses

During the transition of animals from water onto land, the colon is believed to have evolved as an essential water-absorbing organ in terrestrial vertebrates to prevent desiccation. The class Chondrichthyes, comprised of sharks, rays, and skates, are isotonic to their marine environment, and thus do not require a functional colon. The Chondrichthyes are an excellent organism for developmental and physiological studies in evolutionary context because they have undergone little evolutionary change since their appearance 450 million years ago. Previous histochemical studies demonstrate potential water absorbing properties in the digestive tract of the little skate, Leucoraja erinacea (Theodosiou et al., 2007 ...


Archaeoparasitology Of Chaco Canyon, Rachel Paseka 2011 University of Nebraska-Lincoln

Archaeoparasitology Of Chaco Canyon, Rachel Paseka

Environmental Studies Undergraduate Student Theses

Ancient cultures of the Colorado Plateau have been a focus of archaeoparasitology since its inception, and a vast parasitological history is recorded in coprolites preserved in this arid region. The inhabitants of Chaco Canyon dominated Ancestral Puebloan culture between 1050 and 1120 AD and were responsible for the construction of great towns, road systems, and early agriculture. Analysis of the parasites preserved in fecal remains contributes to an increased knowledge of ancient Chacoan health and culture. Nineteen coprolites from four sites in Chaco Canyon were rehydrated and analyzed microscopically for parasite remains. Rhabditiform and filariform nematode larvae were found from ...


Structured Multiple Endosymbiosis Of Bacteria And Archaea In A Ciliate From Marine Sulfidic Sediments: A Survival Mechanism In Low Oxygen, Sulfidic Sediments?, Virginia P. Edgcomb, Edward R. Leadbetter, William A. Bourland, David Beaudoin, Joan M. Bernhard 2011 Boise State University

Structured Multiple Endosymbiosis Of Bacteria And Archaea In A Ciliate From Marine Sulfidic Sediments: A Survival Mechanism In Low Oxygen, Sulfidic Sediments?, Virginia P. Edgcomb, Edward R. Leadbetter, William A. Bourland, David Beaudoin, Joan M. Bernhard

William Bourland

Marine micro-oxic to sulfidic environments are sites of intensive biogeochemical cycling and elemental sequestration, where prokaryotes are major driving forces mediating carbon, nitrogen, sulfur, phosphorus, and metal cycles, important from both biogeochemical and evolutionary perspectives. Associations between single-celled eukaryotes and bacteria and/or archaea are common in such habitats. Here we describe a ciliate common in the micro-oxic to anoxic, typically sulfidic, sediments of Santa Barbara Basin (CA, USA). The ciliate is 95% similar to Parduzcia orbis (18S rRNA). Transmission electron micrographs reveal clusters of at least three different endobiont types organized within membrane-bound sub-cellular regions. Catalyzed reporter deposition–fluorescent ...


Effects Of Land Use In The Ohio River Basin On The Distribution Of Coliform And Antibiotic Resistant Bacteria In The Ohio River, Gene Chou 2011 Marshall University

Effects Of Land Use In The Ohio River Basin On The Distribution Of Coliform And Antibiotic Resistant Bacteria In The Ohio River, Gene Chou

Theses, Dissertations and Capstones

Recent studies indicate that antibiotic resistant bacteria can be useful as indicators of water quality (1, 2, 5, 7, 8, 9, 10). Studies in our laboratory have shown that fecal pollution did not fully explain the distribution or the frequency of antibiotic resistant bacteria in the Ohio River (27, 28). Therefore, it is important to understand the factors that affect the distribution of antibiotic resistant bacteria in aquatic habitat. The purpose of this study was to examine the correlations between land use, water quality, and concentration of antibiotic resistant bacteria in the Ohio River. Mid-channel water samples were collected at ...


Performance Screening Of Chemostat Adapted Recombinant Zymomonas Mobilis Strains, Deirdre M. Beard, Nancy Dowe 2011 University of Colorado-Boulder

Performance Screening Of Chemostat Adapted Recombinant Zymomonas Mobilis Strains, Deirdre M. Beard, Nancy Dowe

STAR Program Research Presentations

Corn stover biomass can be pretreaed and hydrolyzed into soluble sugars to be fermented by microorganisms to ethanol. NREL has developed a recombinant bacteria Zymomonas mobilis 8b that metabolizes both five and six carbon sugars. During pretreatment, toxic inhibitors such as furfural and acetate are produced. NREL has made an attempt to adapt two sub-strains of Z. mobilis 8b to acetate and furfural by using a chemostat method. During the chemostat process, cultures were frozen back in glycerol and saved. In this study, those frozen cultures were revived and analyzed for performance in environments with varying concentrations of furfural and ...


A Messenger Molecule Governs Interdependency In An Evolved Pseudomonas Aeruginosa Biofilm Community, Thomas MacElliott Johnson 2011 University of New Hampshire

A Messenger Molecule Governs Interdependency In An Evolved Pseudomonas Aeruginosa Biofilm Community, Thomas Macelliott Johnson

Honors Theses and Capstones

Biofilm populations are known to harbor great diversity, but the importance of this diversity is not fully understood. A likely contributor to this variation is the second messenger molecule cyclic-di-GMP: low levels associate with a planktonic lifestyle while high levels favor biofilm formation. In ongoing studies of an evolving biofilm population of Pseudomonas aeruginosa (PA), we observed extensive ecological diversification that may relate to this lifestyle switch. In PA, the gene bifA encodes a phosphodiesterase that is known to degrade cyclic-di-GMP and reduce biofilm. This gene was cloned onto a plasmid under control of an inducible promoter and the plasmid ...


Dorsal Eye Selector Pannier (Pnr) Suppresses The Eye Fate To Define Dorsal Margin Of The Drosophila Eye, Sarah M. Oros, Meghana Tare, Madhuri Kango-Singh, Amit Singh 2010 University of Dayton

Dorsal Eye Selector Pannier (Pnr) Suppresses The Eye Fate To Define Dorsal Margin Of The Drosophila Eye, Sarah M. Oros, Meghana Tare, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Axial patterning is crucial for organogenesis. During Drosophila eye development, dorso-ventral (DV) axis determination is the first lineage restriction event. The eye primordium begins with a default ventral fate, on which the dorsal eye fate is established by expression of the GATA-1 transcription factor pannier (pnr). Earlier, it was suggested that loss of pnr function induces enlargement in the dorsal eye due to ectopic equator formation. Interestingly, we found that in addition to regulating DV patterning, pnr suppresses the eye fate by downregulating the core retinal determination genes eyes absent (eya), sine oculis (so) and dacshund (dac) to define the ...


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