Organismal Biological Physiology Commons^™

Gut Symbiont Viability In Honey Bees Exposed To Agrochemical Stressors, Bryant Justin Gabriel

Dissertations and Student Research in Entomology

The honey bee gut microbiome is essential for protecting this pollinator against abiotic and biotic stressors, including the prevention of harmful gut parasites and pathogens. Previous studies have not only demonstrated a linkage of bee gut dysbiosis to increased immunodeficiencies and pathogen sensitivities, but also report the maladaptation of the gut microbiome in bees exposed to agricultural and apicultural chemistries. There are few techniques available that allow for a simple and reliable analysis of the relative proportions of live and dead gut microbes in bees exposed to these chemistries. Previous techniques for measuring gut symbiont dysbiosis are temporally limited by ...

The Effect Of Alcohol On Pfk1 Gene Expression And Feeding Activity In Tetrahymena Thermophila, Evelyn Sowers, Alex Skoulis

Carroll College Student Undergraduate Research Festival

The purpose of this experiment was to test whether alcohol induces starvation conditions in Tetrahymena thermophila. Prior research has shown that exposure to alcohol results in decreases in both the frequency of feeding and overall growth. For this experiment, it was hypothesized that these effects are due to a lack of energy available in the organism for feeding. This hypothesis was tested by monitoring food vacuole formation and expression of the PFK-1 gene in Tetrahymena that were exposed to alcohol. The PFK-1 gene was chosen because its encoded protein plays an essential role in cellular metabolism. For the experiment, control ...

Synthesis And Kinetic Studies Of High-Valent Metal-Oxo Species Generated By Photochemical And Chemical Methods, Haiyan Liu

Masters Theses & Specialist Projects

Highly reactive iron-oxo intermediates play important roles as active oxidants in enzymatic and synthetic catalytic oxidation. Many transition metal catalysts are designed for biomimetic studies of the predominant oxidation catalysts in Nature, namely cytochrome P450 enzymes. In this work, a series of iron(IV)-oxo porphyrins [Fe^IV(Por)O] and manganese(IV)-oxo porphyrins [Mn^IV(Por)O] have been successfully produced in two electron-deficient ligands by photochemical and chemical methods, and spectroscopically characterized by UV-vis, and ¹H-NMR.

With iodobenzene diacetate [PhI(OAc)₂] as the oxygen source, iron(III) porphyrin and manganese(III) porphyrin complexes converted to ...

Identifying Mechanisms Of Host Plant Specialization In Aphis Craccivora And Its Bacterial Symbionts, Thorsten Hansen

Theses and Dissertations--Entomology

Many insects form close relationships with microbial symbionts. Insect symbionts can provide novel phenotypes to their hosts, including influencing dietary breadth. In the polyphagous cowpea aphid, Aphis craccivora, the facultative symbiont Arsenophonus improves aphid performance on one host plant (locust), but decreases performance on other plants. The goal of my thesis was to investigate the mechanism by which Arsenophonus facilitates use of locust. First, I assembled an Aphis craccivora-Arsenophonus-Buchnera reference transcriptome to conduct RNAseq analysis, comparing gene expression in aphids feeding on locust and fava, with and without Arsenophonus infection. Overall, few transcripts were differentially expressed. However, genes ...

The Bi-Directional Relationship Between Gut Microbiota And Autoimmunity, Trevor O. Kirby

EWU Masters Thesis Collection

Humans serve as a major reservoir for a vast number of microbiota. These microbes have evolved symbiotic relationships with humans due to their close proximity with their host. As a result, the immune system adapts to the microbiota thus modulating immunological function. Autoimmunity is a state in which there are aberrant immune responses produced against host tissue. Intestinal bacteria are directly impacted by instances of inflammation brought on by autoimmunity. The complicated nature between autoimmunity and bacterial modulation demonstrates a bi-directional relationship. Here, we utilize experimental autoimmune encephalomyelitis, a model for multiple sclerosis, to explore the bi-directional relationship that disease ...

Emergence Of New Metabolic Pathways In Escherichia Coli, Michael Kristofich

Undergraduate Honors Theses

Catalytic promiscuity provides a starting point for the evolution of new enzymes. Taking this concept further, a series of promiscuous enzymes may assemble to form the basis of a new metabolic pathway (termed “serendipitous pathway”) that may emerge and become more efficient in adapting bacterial cells that require it to grow. The Copley lab at the University of Colorado at Boulder has been observing genetic changes that improve growth of Escherichia coli cells that lack the essential gene pdxB. These genetic changes are believed to improve the flux of metabolites through one or more serendipitous pathways that make up for ...

Balance And Trade: Charting The Course Of Fungal Symbiosis In Sugarcane Root Systems, Anders Christian Claassens

Theses

The root systems of sugarcane (Saccharum L. spp. hybrids) host a variety of symbiotic fungal organisms including arbuscular mycorrhizae (AM) fungi and dark septate endophytes (DSE). AM/DSE symbioses are widely reported to influence the productive capacity of a range of agricultural crops via enhanced nutrient assimilation and plant stress tolerance. Presently, the biological and functional characteristics AM/DSE in sugarcane have only been examined superficially and remain poorly understood. Before the potential benefits of AM/DSE symbioses can be exploited through management strategies, characterisation of the temporal changes in AM/DSE colonisation over the sugarcane crop cycle is required ...

Evidence For The Priming Effect In Single Strain And Simplified Communities Of Estuarine Bacteria, Abigail Amina Edwards

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Through their transformation of naturally occurring organic matter, coastal marine bacteria play an essential role in carbon cycling. A phenomenon termed the priming effect (PE) occurs when microbial communities remineralize recalcitrant organic matter faster in the presence of labile organic matter and may be prevalent in coastal systems. To understand how microbial community members interact to induce PE, it is essential to first understand the mechanisms underlying PE in single strains and simplified bacterial communities. The effect to which different concentrations and sources of labile carbon stimulated the production of bacterial biomass from riverine organic matter by two marine bacteria ...

The Effect Of Diet On Midgut And Resulting Changes In Infectiousness Of Acmnpv Baculovirus In Trichoplusia Ni, Elizabeth Chen

Electronic Thesis and Dissertation Repository

The cabbage looper, Trichoplusia ni, a global generalist lepidopteran pest, has developed resistance to many synthetic and biological insecticides, requiring effective and environmentally acceptable alternatives. One possibility is the Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). This baculovirus is highly infectious for T. ni, with potential as a biocontrol agent, however, its effectiveness is strongly influenced by dietary context. In this study, microscopy and transcriptomics were used to examine how the efficacy of this virus was affected when T. ni larvae were raised on different diets. Larvae raised on potato host plants had lower chitinase and chitin deacetylase transcript levels and thickened ...

Functional Analysis Of Microrna Pathway Genes In The Somatic Gonad And Germ Cells During Ovulation In C. Elegans, Carmela Rios

Dissertations (2009 -)

MicroRNAs (miRNAs) are post-­transcriptional regulators of gene expression that play critical roles in animal development and physiology, though functions for most miRNAs remain unknown. Worms with reduced miRNA biogenesis due to loss of Drosha or Pasha/DGCR8 activity are sterile and fail to ovulate, indicating that miRNAs are required for the process of oocyte maturation and ovulation. Starting with this penetrant sterile phenotype and using new strains created to perform tissue-­specific RNAi, we characterize the roles of the C. elegans Pasha, pash-­1, and two miRNA-­specific Argonautes, alg-­1 and alg-­2, in somatic gonad cells and ...

Characterization Of Neuronal Nicotinic Acetylcholine Receptors And Their Positive Allosteric Modulators, Doris Clark Jackson

All Theses and Dissertations

Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that are necessary in memory and cognition. They are pentameric and consist of α and β subunits. They are most commonly heteromeric but, can sometimes be homomeric. nAChRs are activated by many ligands including nicotine (exogenous) and acetylcholine (endogenous).nAChRs are located on hippocampal interneurons. The interneurons, although sparse, control the synchronous firing of the pyramidal cells. However, the hippocampal interneuron structure and function is quite diverse and not fully characterized. Therefore, we sought to quantify nAChR subunit mRNA levels using real-time PCR of CA1 hippocampal interneurons.Surprisingly we found that ...

Elucidating The Interplay Between Sodium Selenite On The Tick Amblyomma Maculatum Selenoprotein Gene Expression, Afnan M. Beauti

Honors Theses

Selenium (Se) is an element recognized as an essential micronutrient in eukaryote organisms. Selenoproteins contain selenium as selenocysteine, the 21st amino acid. Selenium plays a role in cell growth and functioning. At low concentrations, it can induce growth and at high concentrations, it can cause a cell to stop growing and potentially have toxic effects on the cell and organism. When selenium levels are high, oxidative stress results by the production of reactive oxidative species. Selenoproteins, however, can aid the antioxidant response in the cell. Ticks are arthropods of interest, as they are one of few that contain many selenogenes ...

Antimicrobial Properties Of S-Benzofuran-2-Yl Ethanol Produced By Biotransformation, Nick Cheatwood, Ann Davis, Elizabeth Schabeck, Kelsi Hooker, Michele Harris

Undergraduate Research Conference

All living organisms contain enzymes to carry out biological reactions, which produce substances with a specific three dimensional shape. Enantiomers are two molecules that are mirror images of each other just as hands are mirror images of each other. It is well known in the pharmaceutical world that one of the enantiomers (one of the mirrorimage molecules) has a positive biological effect while the other can be harmful or have no effect. Currently, any potential pharmaceutical that could exist as enantiomers must have each enantiomer tested for biological activity prior to FDA approval. In our laboratory, we have focused on ...

Bioethics In The Work Of Ernest Everett Just: + Missing - Some 400 Pages, Theodore Walker

Perkins Faculty Research and Special Events

Biology + ethics = bioethics. Here we see that Howard University biologist Ernest Everett Just (born 1883, died 1941) connected biology to ethics.

According to Just, various forms of specific biology (including especially cell biology) plus “general biology” are necessary for explaining adequately the origin of ethical behaviors. Social ethical behaviors, especially mutual aid and cooperative interactions with others and the environment, are essential to evolutionary advances among living creatures, ranging from humans to cells. Accordingly, theory of ethics (moral theory) should have roots in biology.

Also, Just wrote an unpublished book-length manuscript—“some 400 typed pages” (Just 1940)—on seeking the ...

Using Artificial Selection To Understand Orientation Behavior In Drosophila, Mariah M. Mckechnie, Rachel L. Mendazona, Secilia Torrez, Natalie E. Wallace, Michael J. Baltzley, Kristin L. Latham

Student Theses, Papers and Projects (Biology)

Several studies suggest that the fruit fly Drosophila melanogaster can use magnetic fields for orientation1-4; however, the responses to magnetic fields are not consistent across studies and experiments investigating the mechanism of magnetoreception rely on magnetic fields that are at least 10 times stronger than the magnetic field of the Earth5-6. We are attempting to determine whether Drosophila have the ability to detect Earth-strength magnetic fields by running flies through a progressive Y-maze and then selectively breeding the flies based on their choices in the maze. There are two main hypotheses about the mechanism of magnetoreception in animals. The first ...

Determining Whether Drosophila Melanogaster Have An Innate Directional Preference Based On The Ambient Magnetic Field Of The Earth, Rachel L. Mendazona, Marian Mckechnie, Natalie Wallace, Stephanie Torrez, Michael Baltzley, Kristin Latham

Student Theses, Papers and Projects (Biology)

The status of the fruit fly Drosophila melanogaster as a model organism for behavioral and genetic research makes it an attractive candidate for investigations of the genetic basis of magnetoreception. There are two main hypotheses for how animals detect Earth-strength magnetic fields. One hypothesis is that animals use magnetite, which forms long chains and serves as a magnetic dipole, while the other hypothesis is that animals have a light-dependent magnetic response utilizing cryptochrome. Several studies have found that Drosophila can orient to Earth-strength magnetic fields using a mechanism consistent with a cryptochrome-based magnetoreceptor, but the specifics of the findings have ...

Identification And Characterization Of Fungal Isolates From Land-Applied Sewage Sludge, Vaille Swenson, Hope L. Juntunen, R Honour, R C. Hale, Michael Gaylor, Patrick Videau

Faculty Research & Publications

Approximately eight million dry tons of sewage sludge is generated in the U.S. each year, with more than half of that now land-applied as the primary method of disposal. Despite the proliferation of this practice, little is known about the microbial constituents of these noxious materials. To address this knowledge gap, we isolated and characterized fungi present in archived samples of land-disposed sewage sludge collected from the Snoqualmie National Forest (Washington State). Sludge samples were resuspended in sterile water and 15 fungal isolates were selected and purified on sabouraud dextrose agar plates supplemented with 50 mg/L of chloramphenicol ...

Biomarkers Of Sepsis: A Retrospective Approach, Jose M. Roberts

Honors Research Projects

Background: Biomarkers are taking the spotlight in becoming the norm for early diagnoses. Sepsis is an inflammatory disease that increases metabolic rate in children. The first biomarker is hyponatremia. Hyponatremia is a frequent electrolyte imbalance in clinical practice, often observed in children with inflammatory disease and infection. Presence of hyponatremia is associated with electrical signaling imbalances, inflammation and renal dysfunction. The clinical value of hyponatremia in pediatric patients is unknown. The C-reactive protein is a second biomarker. Its presence signifies that necrotic cells and inflammation are present.

Objectives: To evaluate the use of biomarkers in children seen in the Emergency ...

Letter From The Dean, Lona Robertson

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Trophic Roles Of Tadpoles In Tropical Australian Streams, Katrin Schmidt, Melanie L. Blanchette, Richard G. Pearson, Ross A. Alford, Aaron M. Davis

ECU Publications Post 2013

Tadpoles can be abundant consumers in stream ecosystems, and may influence the structure and function of streams through their feeding activities and interactions with other organisms. To understand the contribution of tadpoles to stream functioning, and the potential impact of their loss, it is necessary to determine their diets and how they might influence food-web structure. Using gut-content analysis and stable-isotope analysis of N and C, we determined the main food sources and trophic positions of tadpoles of five native frog species, invertebrates, and fish in upland and lowland Australian Wet Tropics streams. Omnivory was prevalent among the tadpoles and ...