Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Animal Sciences (3953)
- Ecology and Evolutionary Biology (3449)
- Physical Sciences and Mathematics (2743)
- Medicine and Health Sciences (2216)
- Zoology (2192)
-
- Genetics and Genomics (1679)
- Plant Sciences (1675)
- Cell and Developmental Biology (1528)
- Biochemistry, Biophysics, and Structural Biology (1465)
- Microbiology (1306)
- Social and Behavioral Sciences (1125)
- Marine Biology (993)
- Chemistry (972)
- Terrestrial and Aquatic Ecology (966)
- Environmental Sciences (957)
- Education (938)
- Integrative Biology (920)
- Biodiversity (871)
- Genetics (801)
- Cell Biology (742)
- Population Biology (630)
- Physics (619)
- Physiology (615)
- Aquaculture and Fisheries (607)
- Entomology (607)
- Molecular Biology (598)
- Medical Sciences (593)
- Biochemistry (588)
- Institution
-
- Utah State University (2711)
- TÜBİTAK (1681)
- Morehead State University (1585)
- Washington University in St. Louis (1127)
- Raynor Library Marquette University (1001)
-
- University of Nebraska - Lincoln (932)
- University of New Mexico (792)
- University of South Carolina (732)
- California Polytechnic State University, San Luis Obispo (715)
- Portland State University (688)
- University of Texas Rio Grande Valley (614)
- University of Montana (602)
- City University of New York (CUNY) (575)
- Nova Southeastern University (558)
- Brigham Young University (553)
- Old Dominion University (531)
- Eastern Illinois University (506)
- Wright State University (471)
- Western Kentucky University (434)
- Loyola University Chicago (414)
- University of Richmond (404)
- Missouri University of Science and Technology (395)
- Boise State University (389)
- University of Kentucky (388)
- University of Central Florida (382)
- Montclair State University (371)
- University of South Florida (371)
- University of Arkansas, Fayetteville (347)
- Smith College (341)
- Virginia Commonwealth University (323)
- Keyword
-
- Biology (1042)
- Ecology (358)
- Evolution (355)
- Climate change (329)
- Biological Sciences (300)
-
- Department of Biological Sciences (271)
- Conservation (259)
- Scanning electron microscopy (257)
- Cancer (255)
- Genetics (235)
- Animals (207)
- Bacteria (206)
- Biodiversity (202)
- Metabolism (190)
- Gene expression (182)
- Apoptosis (180)
- Morphology (172)
- Behavior (170)
- Fish (165)
- Genomics (160)
- Phylogeny (159)
- Bioinformatics (158)
- Invasive species (158)
- Drosophila (157)
- Biological sciences (156)
- Mitochondria (144)
- Development (143)
- Temperature (143)
- Physiology (136)
- Taxonomy (134)
- Publication Year
- Publication
-
- Turkish Journal of Biology (1681)
- Roger W. Barbour Slide Collection (1387)
- Biology Faculty Publications (1366)
- Biological Sciences Faculty Publications (1157)
- Scanning Microscopy (1089)
-
- Theses and Dissertations (876)
- Arts & Sciences Graduate Student Theses and Dissertations (839)
- Biological Sciences Faculty Research and Publications (758)
- Faculty Publications (748)
- Biology Faculty Publications and Presentations (664)
- School of Biological Sciences: Faculty Publications (649)
- Biology ETDs (639)
- Electronic Theses and Dissertations (632)
- Biological Sciences (627)
- Master's Theses (520)
- Honors Theses (498)
- Masters Theses (498)
- Biology Faculty Works (397)
- Biology Faculty Research (396)
- Biology (377)
- School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology) (368)
- Dissertations and Theses (367)
- Faculty Research & Creative Activity (337)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (332)
- Biological Sciences: Faculty Publications (317)
- Scanning Electron Microscopy (289)
- Journal of Undergraduate Research (283)
- Dissertations (273)
- Karbala International Journal of Modern Science (264)
- Tanzania Journal of Science (249)
- Publication Type
Articles 5131 - 5160 of 39159
Full-Text Articles in Biology
Cyclic-Di-Gmp Regulates Salmonella Typhimurium Infection Of Epithelial Cells And Macrophages, Abdulafiz Musa
Cyclic-Di-Gmp Regulates Salmonella Typhimurium Infection Of Epithelial Cells And Macrophages, Abdulafiz Musa
Electronic Theses and Dissertations
Regulation of the bacterial second messenger cyclic-di-GMP in Salmonella Typhimurium allows it to delicately alter phenotypes to optimize invasion and survive intracellularly in epithelial cells and macrophages to become virulent and cause infection. Cyclic-di-GMP concentration is regulated by the presence of external stimuli, sensory diguanylate cyclases (DGCs) and phosphodiesterases (PDEs), and cyclic-di-GMP binding effectors. Previous studies established that maintenance of low cyclic-di-GMP concentrations is required for survival in macrophages, and that deletion of 3 active PDEs reduces this survival. Here I showed that these 3 PDEs also influenced the infection of epithelial cells. Further studies re-established the decreased survival in …
The Emerging Oral Pathogen, Filifactor Alocis, Modulates Antimicrobial Responses In Primed Human Neutrophils., Ian J. Snider
The Emerging Oral Pathogen, Filifactor Alocis, Modulates Antimicrobial Responses In Primed Human Neutrophils., Ian J. Snider
College of Arts & Sciences Senior Theses
Periodontitis is an irreversible, chronic inflammatory, infectious disease of the oral cavity that affects approximately half of all adults 30 years or older in the USA. The oral cavity is under high immune surveillance because of its constant exposure to microbes in the environment. The primary immune cell responsible for this surveillance is the neutrophil. Pathogens associated with periodontitis possess virulence factors and have evolved strategies to evade neutrophil antimicrobial responses to survive. One such pathogen is Filifactor alocis, whose presence is associated with the progression of periodontitis. F. alocis manipulates several neutrophil antimicrobial functional responses to avoid killing, an …
Impacts Of Dietary Restriction On A Drosophila Model Of Werner Syndrome, Eileen Sember
Impacts Of Dietary Restriction On A Drosophila Model Of Werner Syndrome, Eileen Sember
College of Arts & Sciences Senior Theses
Werner syndrome (WS) is an autosomal recessive disorder that results in premature aging and occurs in 1 in 1,000,0000 to 1 in 10,000,000 people. In humans, WS is the result of mutations that render the WRN gene, that contains a helicase and an exonuclease domain, non-functional. Currently, there is no cure for WS in humans, making dietary and lifestyle interventions attractive for increasing the quality and longevity of lives. Diet restriction (DR) has been shown to extend the lifespan of several model organisms, including Drosophila melanogaster, making it a strong candidate for WS treatment. In this thesis, mutant flies …
Impact Of Lyophilization On Porcine Hemoglobin Properties., Mustafa Almosawi
Impact Of Lyophilization On Porcine Hemoglobin Properties., Mustafa Almosawi
College of Arts & Sciences Senior Theses
Blood transfusion is the single most often performed lifesaving procedure in hospitals worldwide. Unfortunately, packed red blood cells (RBCs) used for transfusion can only be stored for 42 days at 4 °C before being discarded due to irreversible damage that occurs during storage. Any reduction in available RBCs for an extended period can lead to blood shortages. To increase the shelf-life of RBCs, we investigated freeze-drying (lyophilizing) in the presence of the non-toxic sugar trehalose as a method for long-term preservation. However, the oxidative stress of the lyophilization and storage processes can compromise the functionality of these cells, and the …
A Field‐Capable Rapid Plant Dna Extraction Protocol Using Microneedle Patches For Botanical Surveying And Monitoring, Jonathan Selz, Nicolas R. Adam, Céline E. M. Magrini, Fulvia Malvido Montandon, Sven Buerki, Sebastian J. Maerkl
A Field‐Capable Rapid Plant Dna Extraction Protocol Using Microneedle Patches For Botanical Surveying And Monitoring, Jonathan Selz, Nicolas R. Adam, Céline E. M. Magrini, Fulvia Malvido Montandon, Sven Buerki, Sebastian J. Maerkl
Biology Faculty Publications and Presentations
Premise: A novel protocol for rapid plant DNA extraction using microneedles is proposed, which supports botanic surveys, taxonomy, and systematics. This protocol can be conducted in the field with limited laboratory skills and equipment. The protocol is validated by sequencing and comparing the results with QIAGEN spin-column DNA extractions using BLAST analyses.
Methods and Results: Two sets of DNA extractions were conducted on 13 species spanning various leaf anatomies and phylogenetic lineages: (i) fresh leaves were punched with custom polymeric microneedle patches to recover genomic DNA, or (ii) QIAGEN DNA extractions. Three plastid (matK, rbcL, and trnH-psbA …
Use Of Space And Foraging Behavior Of Loggerhead Shrikes In Urban Areas, Katie Anne Maddox
Use Of Space And Foraging Behavior Of Loggerhead Shrikes In Urban Areas, Katie Anne Maddox
Electronic Theses and Dissertations
Loggerhead shrikes, Lanius ludovicianus, are a declining grassland songbird native to North America. Land-use change has been associated with the decline of grassland bird species. However, the process of urbanization creates novel short-grass habitats reminiscent of shrikes’ natural habitats. Loggerhead shrikes have been observed living in developed areas, particularly in Southeastern coastal states. Understanding the long-term impacts of urban-dwelling on loggerhead shrike populations is vital to identifying whether urban areas offer refuge or act as an ecological sink for shrike populations.
In chapter one, I quantified the use of space by shrikes in urban habitats within Horry County, South …
Deterrent Effects Of The Select Magnetic And Repellent Treated (Smarttm) Hooks And The Recently Developed "Smarter" Hooks On Sharks In Recreational Hook-And-Line And Longline Trials, Ryan Lowndes
Electronic Theses and Dissertations
As bycatch continues to impact global shark populations, there is a continuing need for effective bycatch reduction devices. Prior research has shown promise in exploiting sharks' electrosensory ability to this end. We tested the deterrent efficacy of the Select Magnetic and Repellant Treated (SMARTTM) and the newly developed "SMARTER" hooks in experimental longline and hook-and-line trials. Both are magnetized and contain an electropositive metal component made of magnesium (SMART) and a magnesium alloy designed to extend longevity (SMARTER). We deployed 127 longlines with SMART hooks, SMARTER hooks, controls, and procedural controls from 2021-2022 in Winyah Bay, South Carolina, and caught …
Importance Of Pelvic Floor Education And Rehabilitation Techniques For Adolescents And Young Adults: A Review, Katherine Laura Schmidt
Importance Of Pelvic Floor Education And Rehabilitation Techniques For Adolescents And Young Adults: A Review, Katherine Laura Schmidt
Honors Program: Senior Projects (Public)
The pelvic floor is the collection of many muscles forming what is often called the pelvic girdle. Understanding the different muscles and their roles is an important part of pelvic floor education. Although both males and females have pelvic floors, there is a lack of knowledge of basic anatomy seen in adolescents and young adults. This review analyzes the importance of providing more education for students about the pelvic floor, gives examples of common pelvic disorders for young adults, and provides details on the physical therapy rehabilitation techniques offered today to treat these conditions.
Extranodal Tumors And Chromosomal Abnormalities Associated With Non-Hodgkin Lymphoma In T(14;18)-Positive Patients, Alexis Finch
Extranodal Tumors And Chromosomal Abnormalities Associated With Non-Hodgkin Lymphoma In T(14;18)-Positive Patients, Alexis Finch
Honors Program: Senior Projects (Public)
Nebraska is mostly an agricultural state with a non-Hodgkin lymphoma (NHL) incidence rate of 20.1 per 100,000 individuals, which is greater than the US incidence rate of 19 per 100,000 individuals. It is possible that the higher incidence rate in Nebraska is due to an increase in pesticide usage. Pesticide exposure is linked to t(14;18), a genetic translocation involving the BCL2 gene that regulates apoptosis. The dysregulation of apoptosis could contribute to the proliferation of NHL. This exploratory study utilized the Nebraska Lymphoma Study Group, which consists of patients with non-Hodgkin lymphoma, Hodgkin disease, or some other neoplastic hematologic disorder …
Education, Beliefs, And Health Literacy Of Care Providers On Mouth Care Of Older Adults, Molly Lakin
Education, Beliefs, And Health Literacy Of Care Providers On Mouth Care Of Older Adults, Molly Lakin
Honors Program: Senior Projects (Public)
Oral health is important to one’s overall health and quality of life as it can lead to chronic illnesses such as cardiovascular disease, stroke, and neurodegenerative disorders (Haumschild et al. 2021). In long-term care facilities, it is important that dependent older adults are provided mouth care to maintain their oral health and decrease their chances of developing a chronic illness; however, there are barriers affecting the level, quality, and quantity of mouth care being provided in these facilities. A survey was developed to look at the education, beliefs, and health literacy of care providers on providing mouth care in hopes …
Development Of A Computational Model To Investigate Pathways And The Effects Of Treatment In Fanconi Anemia, Sabrina Kellett
Development Of A Computational Model To Investigate Pathways And The Effects Of Treatment In Fanconi Anemia, Sabrina Kellett
Biological Sciences Undergraduate Honors Theses
Fanconi Anemia (FA) is a rare type of anemia that is not easily studied and can have very detrimental effects. This disease compromises the bone marrow, resulting in decreased hemopoiesis. Symptoms of FA also include abnormalities in the brain and spinal cord, incorrect formation of the kidneys, abnormal formation of the heart and lungs, and a dramatically increased risk of developing cancer. FA can be caused by various mutations in any of the 22 genes that encode for proteins involved in what is called the FA DNA repair pathway. In healthy individuals, this pathway specifically repairs interstrand cross-links (ICLs) recognized …
Sequence Analysis Of Herbicide Target Genes In Herbicide-Tolerant Rice, Jonathan Kearney, Nilda R. Burgos, Gulab D. Rangani
Sequence Analysis Of Herbicide Target Genes In Herbicide-Tolerant Rice, Jonathan Kearney, Nilda R. Burgos, Gulab D. Rangani
Biological Sciences Undergraduate Honors Theses
The tolerance of mutagenized rice (Oryza sativa) lines to selector herbicides was investigated and the sequence of ALS gene was analyzed in plants that survived treatment with 4x the label rate of imazethapyr herbicide. This was done to determine if insensitivity to imazethapyr is due to mutation(s) in the herbicide binding site. Seedlots previously treated with ethyl-methyl sulfonate were planted in the field and 3-leaf seedlings were treated with various herbicides to screen for herbicide-tolerant mutants. Seeds from survivors composed the rice lines tested in the current research. Seeds were planted in the greenhouse and 3-leaf seedlings were …
Interactive Map Code (R And Rstudio), Peter G. Butterfield
Interactive Map Code (R And Rstudio), Peter G. Butterfield
Data Files: White Oaks in Vinton Furnace Experimental Forest
Interactive map code puts data and coordinates into readable table format and creates data visualizations.
Effects Of Maternal Disease History On Provisioning, Brooding, And Offspring Outcomes, Sakura Roberts
Effects Of Maternal Disease History On Provisioning, Brooding, And Offspring Outcomes, Sakura Roberts
Biological Sciences Undergraduate Honors Theses
Disease within a population has the ability to shape the development, evolution, and general performance of a species. Pathogen exposure to hosts can influence their physiology and behavioral patterns to further shape offspring immunity. Parental conditions experienced by offspring during early development can benefit survival and fitness (e.g. increasing provisioning rates), as well as help deter against similar diseases experienced by parents. By testing if parental behavior changes can better prepare offspring outcomes for disease exposure, such as disease severity or duration of infection, we can see the beneficial impacts it has on disease dynamics and host-pathogen processes. Incubation temperature, …
Computational Modeling Of The Fanconi Anemia Gene Network And Its Connection To Cancer, Alyssa Warren-Belford
Computational Modeling Of The Fanconi Anemia Gene Network And Its Connection To Cancer, Alyssa Warren-Belford
Biological Sciences Undergraduate Honors Theses
Fanconi anemia (FA) is a rare genetic condition in which the cell’s DNA repair machinery is dysregulated, significantly increasing the chances of tumorigenesis. Further research is being done in order to improve patient outcomes and incidences of cancer. Our group created a computational model of the FA DNA repair gene network, which removes interstrand crosslinks found in damaged DNA and repairs it so DNA synthesis can continue. Computer simulations show the number of DNA damage indicators decreased as the pathway continued. This was expected as the FA pathway repairs DNA damage. The goal of this project was to provide further …
Identifying Nocturnal Pollinator Diversity In Apple Orchards In Northwest Arkansas, Emily Brown
Identifying Nocturnal Pollinator Diversity In Apple Orchards In Northwest Arkansas, Emily Brown
Biological Sciences Undergraduate Honors Theses
Insects have an essential role in nature, largely in part to pollination. These animals allow for many plants to reproduce and are directly involved in many of the earth’s fruit and vegetable supply. Bees, along with many other diurnal pollinators have gained the attention of the public, which has sparked debates and change to protect them. Many nocturnal species have previously been disregarded due to the assumption that diurnal pollinators provide the only significant pollinations, although recent studies show otherwise. For example, a recent study in apples suggests that nocturnal insects increase fruit production and flower cluster pollination at comparable …
Involvement Of Chromosome Remodeling Complexes On Chromosome Segregation, Adelle Warford
Involvement Of Chromosome Remodeling Complexes On Chromosome Segregation, Adelle Warford
Biological Sciences Undergraduate Honors Theses
Errors in chromosome segregation during cell replication are detrimental to the health of living cells. These errors cause aneuploidy: daughter cells with an incorrect number of chromosomes, as well as polyploidy: the complete duplication of a genome. In humans, these segregation errors are responsible for many harmful diseases and disorders. Using the model organism S. cerevisiae, a double mutant was created by removing two key chromosome remodeling complexes, SWR1 and INO80, both known to independently cause aneuploidy, decreased fitness, and damages the sensitivity of a cell's DNA (Andalis et al. 2004). By creating a double mutant strain, genetic cell …
Assessing Illegal Shooting Of Birds Along Power Lines, Eve C. Thomason
Assessing Illegal Shooting Of Birds Along Power Lines, Eve C. Thomason
Boise State University Theses and Dissertations
Birds found dead near power lines typically are assumed to have died from electrocution. However, birds die from many causes, and inaccurate diagnosis of cause of death undermines law enforcement, management, threat assessment, and mitigation. We used field and necropsy data from dead birds collected along 196 km of power lines in four western USA states in 2019 – 2022 to test the assumption that electrocution is the leading cause of death of birds on power lines. Of 175 birds with a known cause of death, 66% died from gunshot, whereas only 17% died from electrocution or by trauma. To …
Automating Pharmacokinetic Predictions In Artemisia, Celin Younan
Automating Pharmacokinetic Predictions In Artemisia, Celin Younan
Boise State University Theses and Dissertations
Pharmacokinetics (PK) is the time course of a compound in the body that is dependent on mechanisms of absorption, distribution, metabolism, and excretion or ADME. A thorough understanding of PK is essential to predict the consequences of organisms exposed to chemicals. In medicine, predictions of PK of drugs allows us to properly prescribe drug treatments. In toxicology, PK allows us to predict the potential exposure of environmental contaminants and how they may affect organisms at the time of exposure or in the future. Chemical ecology could benefit from computational predictions of PK to better understand which plants are consumed or …
Determining The Effect Of Absorbents And Soybean Systems On Pfas Precursor Transformation, Tamia Wellington
Determining The Effect Of Absorbents And Soybean Systems On Pfas Precursor Transformation, Tamia Wellington
Biological Sciences
PFAS (Per- and polyfluoroalkyl substances) refers to a class of chemicals that consist of long-chains of carbon bonded to fluorine. These are chemicals that have many industrial uses, from cosmetics to industrial fire-fighting foam. Since PFAS is so widely used and available, it has become increasingly present in water and soil, resulting in its uptake and bioaccumulation in plants. This study focused on the impacts of powdered activated carbon (PAC) and montmorillonite on the PFOS precursor N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA), in soil, and in plants grown in that soil. This study focused on spiking soil with PFAS chemicals, …
Quantification Of Fibrosis And Infiltrates In The Salivary Gland, Nikhita Kumar
Quantification Of Fibrosis And Infiltrates In The Salivary Gland, Nikhita Kumar
Biological Sciences
Fibrosis is characterized by the excessive buildup of extracellular matrix components (ECM) in tissues and organs in response to injury, chronic inflammation, auto immune disorders, and genetic alterations. Non-obese diabetic mice (NOD) are a model for Sjögren’s Syndrome. We hypothesize that NOD mice, which start to develop Sjögren’s-like disease at approximately 12 weeks of age are suffering from hyposalivation at least in part due to fibrosis of the submandibular salivary glands (SMGs). Fibrosis refers to the over-production of extracellular matrix proteins in the connective tissue compartment. To test this hypothesis 16-week-old mice were treated with either the fibrosis inhibitor Nintedanib …
Improvement Of Depressive-Like Behaviors In Hemi-Parkinsonian Rats With Non-Invasive Peripheral Focused Ultrasound Modulation, Hudy Berger
Biological Sciences
Parkinson’s disease (PD) is a chronic and progressive neurodegenerative disease with marked loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). In PD, there are motor and non-motor symptoms. Depression, a non-motor symptom, is seen in 40% of the patients with PD which decreases their quality of life. For treatment-resistant depression, vagus nerve stimulation (VNS) has been shown to improve depression. Here, non-invasive focused ultrasound (FUS) is investigated as a therapeutic to improve depression-like behavior by targeting the celiac plexus since it is innervated by the vagus nerve. FUS was chosen due to its parallel mechanism to VNS. …
Progress Towards Peptide And Protein Synthesis Involving Thiol Moieties, Ryan Lo Chen
Progress Towards Peptide And Protein Synthesis Involving Thiol Moieties, Ryan Lo Chen
Biological Sciences
Polypeptides and proteins play crucial roles in biological systems, including enzymatic activity regulation, molecule transport, and cell and tissue structural support. Amino acids are the building blocks of peptides and proteins, and peptides can act as hormones, neurotransmitters, and enzymes. Proteins are made up of one or more polypeptide chains and have diverse functions such as catalyzing chemical reactions, transporting molecules, and providing structural support. Protein preparation can be done biologically by expression systems or isolation and purification from natural sources. While these methods have their advantages, they also have their shortcomings. Chemical synthesis is an alternative method that allows …
Assessing Stream Ecosystem Structure And Function In An Urban Canal And Logan River In Logan, Utah, Ellie Smith-Eskridge
Assessing Stream Ecosystem Structure And Function In An Urban Canal And Logan River In Logan, Utah, Ellie Smith-Eskridge
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Humans have constructed canals to support agriculture, to mitigate flooding, and to discharge stormwater, especially in the Intermountain West. These canals are common in Cache Valley, where they receive flows from the Logan River during summer months. However, the ecological structure (e.g., water quality, freshwater invertebrates) and function (e.g., leaf decomposition) of these canals remains largely unknown. Studying ecosystem structure and function of these urban waterways is important because it can inform us of the health of these waterways.
My research had three objectives. First, I compared water chemistry, invertebrate assemblages, and leaf decomposition in an urban canal and the …
Thermal Tolerance, Physiology, And Microhabitat Use Of Eleutherodactylus Coqui Across An Elevational Gradient In Hawai‘I, Jack Marchetti
Thermal Tolerance, Physiology, And Microhabitat Use Of Eleutherodactylus Coqui Across An Elevational Gradient In Hawai‘I, Jack Marchetti
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The coqui frog (Eleutherodactylus coqui) is an invasive species in Hawai‘i, and has spread across much of the island. While elevational temperature differences are thought to restrict the coqui’s spread, it is unclear if they have resulted in changes to the coqui’s physiology and microhabitat use as it has expanded into higher elevations.
We first sought to determine if the coqui’s substrate use and baseline physiology differs between elevations. We found that frogs at high elevation were found closer to the forest floor and used different substrates than frogs from low and mid-elevations. This change in microhabitat use …
Consequences Of Host Life Cycles For Symbiont Genome Evolution, Ashley Elizabeth Dederich
Consequences Of Host Life Cycles For Symbiont Genome Evolution, Ashley Elizabeth Dederich
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Aphids are small insects that feed exclusively on plant sap, a notoriously low source of nutrients due to the high sugar content and low amino acid content. To make up for these deficiencies in nutrition, aphids harbor Buchnera aphidicola, a bacterial endosymbiont that resides in a specialized organ called the bacteriome. B. aphidicola provides essential amino acids and vitamins for the aphid in exchange for a safe place to live. Over the course of the symbiosis (established 160 million years ago), B. aphidicola has lost much of its genome, including essential genes for cell envelope synthesis, DNA replication and …
The Effects Of Habitat Isolation On Fine-Scale Genetic And Geographic Structure Of Populations Of Two Threatened Endemic Insects In Southern Nevada, Pseudocotalpa Giulianii And Icaricia Shasta Charlestonensis, Kristen Tovar
UNLV Theses, Dissertations, Professional Papers, and Capstones
Assessing the role geographic isolation and ecological specialization have on phylogeographic patterns contributes to our understanding of the evolutionary history of a species and the processes that erode genetic diversity. I used mitochondrial and nuclear genomic sequences to assess whether habitat isolation has shaped the fine-scale patterns of present-day genetic structure and diversity in two threatened insect species endemic to southern Nevada. Pseudocotalpa giulianii (Coleoptera; Scarabaeidae) is a dune obligate scarab beetle endemic to only two small, isolated sand dunes in Nye County, Nevada, with a usable habitat of less than 4.2 km sq that is impacted by on-going degradation. …
Biochemical Characterization Of Fsa1572 From Fervidibacter Sacchari, The First Hyperthermophilic Gh50 With Β-1, 4-Glucanase Activity, Jonathan Covington
Biochemical Characterization Of Fsa1572 From Fervidibacter Sacchari, The First Hyperthermophilic Gh50 With Β-1, 4-Glucanase Activity, Jonathan Covington
UNLV Theses, Dissertations, Professional Papers, and Capstones
The bacterium Fervidibacter sacchari is an aerobic hyperthermophile that catabolizes various polysaccharides and is the only cultivated member of the class Fervidibacteria within the phylum Armatimonadota. Among its glycoside hydrolase (GH) cache is an enzyme from GH family 50 (GH50), an understudied family with only 25 characterized representatives and two known activities from 1,518 predicted members in the Carbohydrate-Active EnZyme (CAZy) Database. Here, we expressed, purified, and functionally characterized an extracellular GH50 from F. sacchari called Fsa1572. Using colorimetric assays, we show it has novel β-1,4-glucanase activity and only weak agarose activity that is typical for GH50 enzymes. The purified …
Long-Range Regulation By The Shigella Virulence Gene Regulator, Virb, Cody Cris
Long-Range Regulation By The Shigella Virulence Gene Regulator, Virb, Cody Cris
UNLV Theses, Dissertations, Professional Papers, and Capstones
Nucleoid-structuring proteins (NSPs) in bacterial cells can exert gene regulatory effects over great distances on DNA. This contrasts with the traditional view of bacterial transcriptional regulation, where transcription factors bind cis-acting regulatory sites proximal (<250 bp) to promoters to influence gene expression. In Shigella species, the histone-like nucleoid-structuring protein (H-NS) transcriptionally silences many genes on the large (~220 kb) virulence plasmid. During host colonization, however, silencing by H-NS is alleviated by the anti-silencer protein, VirB, which remodels the H-NS:DNA complex. This transcriptional anti-silencing is mediated by VirB:DNA interactions and the modulation of DNA supercoiling, which lead to the up-regulation of virulence genes. VirB is a central regulator of Shigella virulence, but the mechanistic basis for transcriptional regulation is incompletely characterized. Here, I focus on the potential for VirB to regulate transcription from remotely located DNA binding sites. Employing complementary in vivo approaches, I assessed the spatial stringency of the VirB binding site and elucidated how varying cellular VirB levels impacts regulation over different distances. I also evaluated how a molecular roadblock on DNA influences remote regulation by VirB. Additionally, I developed control tools to validate the ability of VirB to spread along DNA, an activity of VirB that putatively drives transcriptional regulation. These data are consistent with transcriptional anti-silencing being driven by VirB spreading along DNA. Overall, these findings highlight how VirB is not a conventional transcriptional regulator and broaden our perspective on transcriptional control in bacteria. Furthermore, this work contributes to our understanding of long-range gene regulatory effects, which are frequently overlooked and poorly characterized in bacteria.
Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel
Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel
UNLV Theses, Dissertations, Professional Papers, and Capstones
Desert springs are aquatic oases, being considered among the most diverse and imperiled ecosystems on Earth. Despite the ecological significance and threatened status of desert springs, few studies have surveyed the microorganisms in these systems or their interactions with other community members. The primary goal of this dissertation was to describe the major controls influencing the community ecology of prokaryotic and BMI communities in cold- and moderate-temperature desert springs of the southern hydrographic Great Basin. Chapter 1 provides a broad overview of spring ecosystems and of each chapter included in this dissertation. Chapter 2 documents the first-ever, regional-scale survey of …