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Microbiology Commons

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2009

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Articles 151 - 161 of 161

Full-Text Articles in Microbiology

Microbiology Of Oil Fly Larvae, Kenneth Nickerson, Bradley A. Plantz Jan 2009

Microbiology Of Oil Fly Larvae, Kenneth Nickerson, Bradley A. Plantz

Kenneth Nickerson Papers

One animal beautifully adapted to the viscous asphalt of the La Brea tar pits is the oil fly Helaeomyia petrolei (Syn. Psilopa). As a normal part of its carnivorous existence the oil fly larval guts are filled with tar, with no adverse effects. Surface sterilized larvae 5 contained ca. 2 x 10 heterotrophic bacteria per larva. These bacteria have been identified as a mixture of enteric bacteria, most commonly Providencia rettgeri, and Acinetobacter spp. These bacteria were clearly growing because their numbers in the larval guts were 100 to 1,000 times greater than in free oil/asphalt. There is …


Characterization Of Aerobic Respiration In Great Basin Hot Springs, Caitlin N. Murphy Jan 2009

Characterization Of Aerobic Respiration In Great Basin Hot Springs, Caitlin N. Murphy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Despite a wide diversity of possible electron donors available to fuel chemolithotrophy, it has been proposed that hydrogen is the single most important electron donor in geothermal ecosystems. To directly test this hypothesis, a simple system was devised to determine whether microorganisms in hot spring water and sediment are capable of using hydrogen and other electron donors for aerobic respiration using microrespirometry. The protocol for these experiments was developed using pure cultures of Thermocrinis ruber to determine the effect of growth conditions on the rate of oxygen consumption following the addition of electron donors. For field experiments, samples were collected …


Peptide Hydrolysis And The Uptake Of Dipeptides By Phytoplankton, Margaret R. Mulholland, Cindy Lee Jan 2009

Peptide Hydrolysis And The Uptake Of Dipeptides By Phytoplankton, Margaret R. Mulholland, Cindy Lee

OES Faculty Publications

Rates of peptide hydrolysis (using the fluorescent substrate, lucifer yellow anhydride-labeled tetra-alanine) and dipeptide uptake (using dually labeled, 15N and 13C, dialanine) were measured in phytoplankton cultures and in natural populations during algal blooms dominated by one or two taxa. During most sampling events, both peptide hydrolysis and dipeptide uptake were greatest in the size fraction containing the dominant phytoplankter, suggesting that phytoplankton contribute substantially to or may even dominate observed extracellular peptide hydrolysis and dipeptide uptake in the environment. These are the first data suggesting that dipeptides may be taken up directly by phytoplankton and this may …


Reelin Signaling Promotes Radial Glia Maturation And Neurogenesis, Serene Keilani Jan 2009

Reelin Signaling Promotes Radial Glia Maturation And Neurogenesis, Serene Keilani

Electronic Theses and Dissertations

The end of neurogenesis in the human brain is marked by the transformation of the neural progenitors, the radial glial cells, into astrocytes. This event coincides with the reduction of Reelin expression, a glycoprotein that regulates neuronal migration in the cerebral cortex and cerebellum. A recent study showed that the dentate gyrus of the adult reeler mice, with homozygous mutation in the RELIN gene, have reduced neurogenesis relative to the wild type. Based on the above findings, our first hypothesis states that Reelin expression is important for the formation of radial glia and the generation of neurons from the neural …


Vesicle Targeting In Plasmodium Falciparum: The Identification And Molecular Characterization Of Plasmodium Falciparum Family Of Of Snare Proteins, Lawrence Sumanjah Ayong Jan 2009

Vesicle Targeting In Plasmodium Falciparum: The Identification And Molecular Characterization Of Plasmodium Falciparum Family Of Of Snare Proteins, Lawrence Sumanjah Ayong

Electronic Theses and Dissertations

Proteins of the SNARE (Soluble N-ethylmaleimide sensitive factor attachment protein receptor) super-family have been characterized as playing an essential role in vesicle targeting and fusion in all eukaryotes. The intracellular malaria parasite Plasmodium falciparum exhibits an unusual endomembrane system that is characterized by an unstacked Golgi apparatus, a developmentally induced apical complex, and various organellar structures of parasite origin in the infected host cells. How malaria parasites target nuclear-encoded proteins to these novel compartments is a central question in Plasmodium cell biology. Ultrastructural studies elsewhere have implicated the participation of specialized vesicular elements in transport of virulence proteins, including various …


Interaction Between Bacteriophage Dms3 And Host Crispr Region Inhibits Group Behaviors Of Pseudomonas Aeruginosa, Michael E. Zegans, Jeffrey C. Wagner, Kyle C. Cady, Daniel M. Murphy, John H. Hammond, George A. O'Toole Jan 2009

Interaction Between Bacteriophage Dms3 And Host Crispr Region Inhibits Group Behaviors Of Pseudomonas Aeruginosa, Michael E. Zegans, Jeffrey C. Wagner, Kyle C. Cady, Daniel M. Murphy, John H. Hammond, George A. O'Toole

Dartmouth Scholarship

Bacteriophage infection has profound effects on bacterial biology. Clustered regular interspaced short palindromic repeats (CRISPRs) and cas (CRISPR-associated) genes are found in most archaea and many bacteria and have been reported to play a role in resistance to bacteriophage infection. We observed that lysogenic infection of Pseudomonas aeruginosa PA14 with bacteriophage DMS3 inhibits biofilm formation and swarming motility, both important bacterial group behaviors. This inhibition requires the CRISPR region in the host. Mutation or deletion of five of the six cas genes and one of the two CRISPRs in this region restored biofilm formation and swarming …


An Algorithm For Identifying Novel Targets Of Transcription Factor Families: Application To Hypoxia-Inducible Factor 1 Targets, Yue Jiang, Bojan Cukic, Donald A. Adjeroh, Heath D. Skinner, Jie Lin, Qingxi J. Shen, Bing-Hua Jiang Jan 2009

An Algorithm For Identifying Novel Targets Of Transcription Factor Families: Application To Hypoxia-Inducible Factor 1 Targets, Yue Jiang, Bojan Cukic, Donald A. Adjeroh, Heath D. Skinner, Jie Lin, Qingxi J. Shen, Bing-Hua Jiang

Electrical & Computer Engineering Faculty Research

Efficient and effective analysis of the growing genomic databases requires the development of adequate computational tools. We introduce a fast method based on the suffix tree data structure for predicting novel targets of hypoxia-inducible factor 1 (HIF-1) from huge genome databases. The suffix tree data structure has two powerful applications here: one is to extract unknown patterns from multiple strings/sequences in linear time; the other is to search multiple strings/sequences using multiple patterns in linear time. Using 15 known HIF-1 target gene sequences as a training set, we extracted 105 common patterns that all occur in the 15 training genes …


Results From A Mathematical Model For Human Monocytic Ehrlichiosis, H. Gaff, L. Gross, E. Schaefer Jan 2009

Results From A Mathematical Model For Human Monocytic Ehrlichiosis, H. Gaff, L. Gross, E. Schaefer

Biological Sciences Faculty Publications

Human monocytic ehrlichiosis (Ehrlichia chaffeensis), HME, is a tick-transmitted, rickettsial disease that has recently increased substantially in the USA from 142 reported cases in 2001 to 506 reported cases in 2005 [1,2]. There have been increasing surveys of tick populations over the past 10 years that have in turn supported the development of models for tick-borne disease transmission. Resulting HME models [3] suggest the importance of metapopulation structures, landscape environment parameters and periodic climatic effects in predicting the dynamics of HME transmission and the efficacy of control efforts, such as the reduction of the tick population through acaricide …


Relating Fractal Dimension To Branching Behaviour In Filamentous Microorganisms, David Barry, Onwuarolu Ifeyinwa, Shauna Mcgee, Raymond Ryan, Gwilym Williams, Jonathan Blackledge Jan 2009

Relating Fractal Dimension To Branching Behaviour In Filamentous Microorganisms, David Barry, Onwuarolu Ifeyinwa, Shauna Mcgee, Raymond Ryan, Gwilym Williams, Jonathan Blackledge

Articles

The productivity of an industrial fermentation process involving a filamentous microbe is heavily dependent on the morphological form adopted by the organism. The development of systems capable of rapidly and accurately characterising morphology within a given process represents a significant challenge to biotechnologists, as the complex phenotypes that are manifested are often not easily quantified. Conventional parameters employed in these analyses are of limited value, as they reveal little about the specific branching behaviour of the organism, which is an important consideration given the demonstrated link between branching frequency and metabolite production. More recently, fractal geometry has been employed in …


Cd20 Positivity In Classical Hodgkin's Lymphoma: Diagnostic Challenge Or Targeting Opportunity., Muhammad Abrar Barakzai, Shahid Ahmed Jan 2009

Cd20 Positivity In Classical Hodgkin's Lymphoma: Diagnostic Challenge Or Targeting Opportunity., Muhammad Abrar Barakzai, Shahid Ahmed

Department of Pathology and Laboratory Medicine

BACKGROUND:It is now well established that Hodgkin cells are clonal B cells with a CD30 and CD15 phenotype. However, on immunohistochemistry, in our experience and the experience of others, CD20 positivity in an otherwise typical classical Hodgkin's Lymphoma is not uncommon and if associated with CD15 negativity poses a potential diagnostic trap and is likely to be called B-NHL.
OBJECTIVE:To assess the frequency of B-cell related antigens CD20 and CD79a in classical Hodgkin's Lymphoma.
MATERIALS AND METHODS:A total of 91 consecutive cases of classical Hodgkin's Lymphoma were analyzed for co-expression of CD20 and CD79a. Both males and …


Controlled Evaluation Of Bactec Peds Plus/F And Bactec Lytic/10 Anaerobic/F Media For Isolation Of Salmonella Enterica Serovars Typhi And Paratyphi A From Blood, Megan E. Reller, Anita K. M. Zaidi, Shazia Sultana, Shazia Azeem, Beenish Hanif, Shahida Qureshi, Rumina Hasan, Zulfiqar Ahmed Bhutta, Rehana Akhter, Donald A. Goldmann Jan 2009

Controlled Evaluation Of Bactec Peds Plus/F And Bactec Lytic/10 Anaerobic/F Media For Isolation Of Salmonella Enterica Serovars Typhi And Paratyphi A From Blood, Megan E. Reller, Anita K. M. Zaidi, Shazia Sultana, Shazia Azeem, Beenish Hanif, Shahida Qureshi, Rumina Hasan, Zulfiqar Ahmed Bhutta, Rehana Akhter, Donald A. Goldmann

Department of Paediatrics and Child Health

We compared anaerobic lytic (AL) and pediatric aerobic resin-containing (Peds Plus/F) blood culture media for the isolation of Salmonella enterica serotype Typhi or Paratyphi A from children. The yields from AL and Peds Plus/F media were the same with equal volumes of blood, but recovery was faster from AL medium than Peds Plus/F medium (10.7 and 16.4 h, respectively) (P < 0.001).