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Full-Text Articles in Life Sciences

Genetic Analysis Of A Novel Ftsk Homolog, Hfka, In Streptomyces Coelicolor Development-Associated Chromosome Segregation, Sumedha Sethi Dec 2019

Genetic Analysis Of A Novel Ftsk Homolog, Hfka, In Streptomyces Coelicolor Development-Associated Chromosome Segregation, Sumedha Sethi

Electronic Theses and Dissertations

A quintessential phenomenon occurring during prokaryotic development is accurate segregation of the replicated genomes into the daughter cells. Key energy-dependent processes like chromosome condensation and subcellular partitioning of the genomes are driven by conserved proteins like SMC, ParB, FtsK. During its complex developmental cycle, Streptomyces coelicolor segregates its genomes into chains of unicellular spores when its multigenomic syncytial aerial hyphae undergo division.

A novel ftsK-like gene, hfkA (Homolog of FtsK protein A), was examined for function and localization during development-associated chromosome segregation. Individual deletions did not affect segregation, but a ΔhfkA ΔftsK mutant exhibited 8% anucleate spores ...


The Role Of Xenopus Laevis Reck In Ecm Remodeling And Tissue Patterning, Jessica Willson Nov 2019

The Role Of Xenopus Laevis Reck In Ecm Remodeling And Tissue Patterning, Jessica Willson

Electronic Thesis and Dissertation Repository

Proper cell-cell and cell-extracellular matrix (ECM) interactions are vital for cell migration and patterning of the vertebrate embryo. Matrix metalloproteinases (MMPs) and their inhibitors, reversion-inducing cysteine-rich proteins with Kazal motifs (RECK) and tissue inhibitors of metalloproteinases (TIMPs), are all differentially expressed during embryogenesis to regulate such ECM remodeling events and cell interactions. While TIMPs are a family of 4 secreted proteins that share overlapping substrate specificities of MMPs, RECK is unique in that it is a membrane-anchored MMP inhibitor that is embryonic lethal in mice. I used Xenopus laevis as a model organism to investigate the role of RECK as ...


How Does The Brain Represent Digits? Investigating The Neural Correlates Of Symbolic Number Representation Using Fmri-Adaptation, Celia Goffin Oct 2019

How Does The Brain Represent Digits? Investigating The Neural Correlates Of Symbolic Number Representation Using Fmri-Adaptation, Celia Goffin

Electronic Thesis and Dissertation Repository

How does the brain represent numerical symbols (e.g., Arabic digits)? Activity in left parietal regions correlates with symbolic number processing. Research with functional resonance imaging adaptation (fMRI-A) indicates that the intraparietal sulcus (IPS) exhibits a rebound (increase in activation) effect when a repeatedly presented number is followed by a new number. Importantly, this rebound effect is modulated by numerical ratio as well as the difference between presented numbers (distance). This ratio-dependent rebound effect could reflect a link between symbolic numerical representation and an approximate number system (ANS). In this doctoral dissertation, fMRI-A is used to investigate mechanisms underlying symbolic ...


The Origins And Development Of Visual Categorization, Laura Cabral Jun 2019

The Origins And Development Of Visual Categorization, Laura Cabral

Electronic Thesis and Dissertation Repository

Forming categories is a core part of human cognition, allowing us to make quickly make inferences about our environment. This thesis investigated some of the major theoretical interpretations surrounding the neural basis of visual category development. In adults, there are category-selective regions (e.g. in ventral temporal cortex) and networks (which include regions outside traditional visual regions—e.g. the amygdala) that support visual categorization. While there has been extensive behavioural work investigating visual categorization in infants, the neural sequence of development remains poorly understood. Based on behavioral experiments, one view holds that infants are initially using subcortical structures to ...


Investigation Of Even-Skipped, A Developmentally-Regulated Gene Controlling Neural Segmentation In Dragonflies, Kathryn Bangser Jun 2019

Investigation Of Even-Skipped, A Developmentally-Regulated Gene Controlling Neural Segmentation In Dragonflies, Kathryn Bangser

Honors Theses

A comprehensive understanding of the genetic mechanisms underlying pattern formation and neurogenesis is necessary in order to trace the evolutionary history of insect embryogenesis.

One of the most important processes of embryogenesis is the organized pattern formation that allows for proper body segmentation and neural development. Proper segmentation, which relies on a series of specific gene expressions, is necessary for the development of an operational nervous system. Even-skipped (eve), one such regulatory gene, has been studied extensively in certain model organisms, and theories regarding the evolution of its functional role could be further elucidated by visualizing its expression in adult ...


Characterization Of Pth Type-2 Receptor (Pth2rb) And Its Endogenous Ligand Pth2 In Zebrafish Development, Nicholas Seitz May 2019

Characterization Of Pth Type-2 Receptor (Pth2rb) And Its Endogenous Ligand Pth2 In Zebrafish Development, Nicholas Seitz

Theses and Dissertations

Members of the parathyroid hormone family of ligands, PTH (parathyroid hormone), PTH2, and PTHLH (parathyroid hormone-like hormone). These hormones interact with the class B GCPRs parathyroid hormone receptors PTH1R, PTH2R, and PTH3R to regulate a variety of biological processes. In mammals, PTH and PTHLH activate PTH1R and PTH3R to mediate serum calcium homeostasis, chondrogenesis, and bone maintenance. PTH2R activation by PTH2 has been studied primarily in regard to its neuroendocrine roles but is also found in the skin where it contributes to wound healing and keratinocyte differentiation. Still, little is known about the impacts of PTH2R signaling relative to PTH1R ...


Play Behavior And The Development Of Boldness And Caution In Juvenile Belding’S Ground Squirrels (Urocitellus Beldingi), Madelene Shehan May 2019

Play Behavior And The Development Of Boldness And Caution In Juvenile Belding’S Ground Squirrels (Urocitellus Beldingi), Madelene Shehan

Master's Theses

The ubiquity of play among juvenile mammals suggests it provides adaptive benefits, potentially through influences on the development of temperament in young animals. Juvenile Belding’s ground squirrels (Urocitellus beldingi) must balance competing demands for boldness and caution imposed by the fundamental trade-off between their short active season and their vulnerability to predation. In this study, I evaluated whether play helps to facilitate the development of an appropriate balance between boldness and caution in juvenile U. beldingi.I observed the play behavior of juvenile U. beldingiand conducted flight-initiation distance tests to measure boldness-caution at the beginning and toward the ...


The Battle Of The Powers: Newly Obtained Benefits From The Revitilised Trans-Pacific Partnership Agreement, Scott Halsted May 2019

The Battle Of The Powers: Newly Obtained Benefits From The Revitilised Trans-Pacific Partnership Agreement, Scott Halsted

Master's Projects and Capstones

The Trans Pacific Partnership (TPP) agreement would have been the most sizeable free trade agreement in history. The agreement was set up by the Obama administration as an economic benefactor plus geopolitical tool to maintain the balance of power in the Asia Pacific region, rivaling the power of China. However, numerous politicians within the Trump administration, plus multiple political opposers including Hillary Clinton and Sen. Bernie Sanders, were major advocates for the U.S. removal after realistically adjusted estimates of the TPP showed economic benefits not equating to original estimates. However, the United States withdrawal raises significant successes that can ...


Effects Of Herbicides On Zebrafish Embryo Development And Viability, Kayla Ray King May 2019

Effects Of Herbicides On Zebrafish Embryo Development And Viability, Kayla Ray King

MSU Graduate Theses

Environmental contaminants are chemicals of anthropogenic origin that are found in water, soil, and air, and are harmful to a wide variety of organisms (ORD US EPA, 2018-a). One common group of contaminants are herbicides. Though herbicides are used to control unwanted vegetation in agriculture, aquatic organisms and humans may be exposed to these herbicides through run off into streams and rivers, by drinking contaminated water, by consuming treated crops, by direct exposure, or through bioaccumulation. Thus the effect of these herbicides on animals needs further investigation. In this study, I sought to determine whether six different herbicides, which have ...


Partial Characterization Of Putative Cyp86a Genes From Soybean, Trish Tully Mar 2019

Partial Characterization Of Putative Cyp86a Genes From Soybean, Trish Tully

Electronic Thesis and Dissertation Repository

Soybean (Glycine max [L.] Merr.) is a globally cultivated crop that is important to the sustainability of many industries. However, like all plants, optimal cultivation of soybean is threatened by detrimental environmental factors. For example, high yield of soybean is threatened by soil-borne pathogens like Phytophthora sojae. Resistance against P. sojae was previously positively correlated with aliphatic suberin deposition in soybean. As such, a deeper understanding of the biosynthesis of suberin may assist in engineering a resistant form of soybean, based on enhanced suberin content. In soybean, the ω-OH fatty acid monomers are predominant and most strongly correlated with resistance ...


Examining The Effects Of Fadrozole, An Aromatase Inhibitor, On Testosterone And Estrogen Production Of Domestic Chicken Embryos (Gallus Gallus), Abby E. Joseph Jan 2019

Examining The Effects Of Fadrozole, An Aromatase Inhibitor, On Testosterone And Estrogen Production Of Domestic Chicken Embryos (Gallus Gallus), Abby E. Joseph

Honors Theses

The hypothalamic-pituitary-gonadal (HPG) axis is responsible for the production of the hormones testosterone and estradiol, and testosterone is thought to contribute to regulation of the axis through a negative feedback mechanism. Regulation by negative feedback involves the product of a pathway turning off that pathway when enough product is made. However, because the enzyme P450 aromatase converts testosterone to estradiol, estradiol may also contribute to regulation of the HPG axis and other phenomena that have been attributed to testosterone, like the inhibition of immune function. Previous studies have injected birds with an aromatase inhibitor (presumably reducing estradiol production) and shown ...


A Trio Of Sigma Factors Control Hormogonium Development In Nostoc Punctiforme, Alfonso Gonzalez Jr. Jan 2019

A Trio Of Sigma Factors Control Hormogonium Development In Nostoc Punctiforme, Alfonso Gonzalez Jr.

University of the Pacific Theses and Dissertations

Cyanobacteria are prokaryotes capable of oxygenic photosynthesis, and for many species, nitrogen fixation, giving cyanobacteria an important role in global carbon and nitrogen cycles. Furthermore, multicellular filamentous cyanobacteria are developmentally complex, capable of differentiation into different cell types, including cells capable of nitrogen fixation and cells for motility, making them an ideal platform for studying development, as well as for practical use in biotechnology. Understanding how developmental programmes are activated require an understanding of the role of alternative sigma factors, which are required for transcriptional activation in bacteria. In order to investigate the gene regulatory network and to determine the ...


Rates Of Water Loss And Metabolism In The Eggs Of Stick Insect Eurycantha Calcarata, Garret K. Jolma Jan 2019

Rates Of Water Loss And Metabolism In The Eggs Of Stick Insect Eurycantha Calcarata, Garret K. Jolma

Undergraduate Theses and Professional Papers

The thorny devil stick insect (Eurycantha calcarata) of New Guinea has eggs that take four months or more to develop—incredibly long for an insect. Long development times can be a challenge for eggs because of their finite resources, including nutrients, energy to support development, and water. I investigated the physiological mechanisms underlying long development times in stick insect eggs.

The first experiment examined rates of water loss and survival of eggs held in different experimental humidities (0, 75, or 100% RH). Eggs dried quickly in the 0% humidity “dry” container; and more slowly in the 75% humidity “intermediate” container ...


Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel Jan 2019

Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel

Masters Theses

In order to ascertain the degree of compatibility in developmental restructuring and behavioral plasticity between two fish species frequently made subject of laboratory research (Metriaclima zebra & Danio rerio), alternative trophic niche exposure experiments utilizing novel three-prong feeding treatments were conducted to obtain morphometric data, which demonstrated both species do bear some degree of plasticity. The results are somewhat complicated by differences in locality of detectable restructuring, which may be due to disparity in the form-function relationship for each species’ lineage. Each is notable in the manner of respective species’ jaw protrusion, as it is driven by anterior kinethmoid rotation in ...


The Effects Of Bisphenol F On Embryonic Cardiac Output In Zebrafish, Kyle Monnot Jan 2019

The Effects Of Bisphenol F On Embryonic Cardiac Output In Zebrafish, Kyle Monnot

Williams Honors College, Honors Research Projects

Bisphenol F (BPF) is an analog compound of the xenoestrogen bisphenol A (BPA). BPA utilization has decreased dramatically due to its detrimental effects as an endocrine disrupter. In place of BPA, BPF is growing to be a ubiquitous chemical in epoxy resin manufacturing. Recent research has begun to investigate the possible endocrinal effects of BPF as an analog of BPA. This study was performed to examine the potential effects of BPF exposure on cardiac parameters of zebrafish (Danio rerio) embryos. Embryos were exposed to 50 µg/L BPF for 48 hours, and cardiac parameters (stroke volume, heart rate, and cardiac ...


Determining Kinetic Parameters Of Thiamine Degradation In Three Nasa Spaceflight Foods In Thermal Processing And Long-Term Storage And Methods For Analyzing Microstructure And Precipitant Development In Real And Model Wines, Timothy R. Goulette Jan 2019

Determining Kinetic Parameters Of Thiamine Degradation In Three Nasa Spaceflight Foods In Thermal Processing And Long-Term Storage And Methods For Analyzing Microstructure And Precipitant Development In Real And Model Wines, Timothy R. Goulette

Doctoral Dissertations

The current NASA spaceflight food program encompasses a wide variety of commercial and custom-made edible products. These foods are designed to ensure each crewmember receives the Recommended Dietary Allowance (RDA) of vitamins and minerals to maintain adequate health during the entire spaceflight mission. With the desire for long-duration and exploration-class missions, such as the impending mission to Mars, the retention of important nutrients such as labile vitamins in spaceflight foods is critically important. For this reason, multiple studies were conducted to determine the vitamin degradation behavior of thiamine (vitamin B1) within three spaceflight foods which demonstrated both significant presence ...


Analysis Of Brevundimonas Subvibrioides Developmental Signaling Systems Reveals Unexpected Differences Between Phenotypes And C-Di-Gmp Levels, Lauryn Anne Sperling Jan 2019

Analysis Of Brevundimonas Subvibrioides Developmental Signaling Systems Reveals Unexpected Differences Between Phenotypes And C-Di-Gmp Levels, Lauryn Anne Sperling

Electronic Theses and Dissertations

The DivJ-DivK-PleC signaling system of Caulobacter crescentus is a signaling network that regulates polar development and the cell cycle. This system is conserved in closely related bacteria, including the sister genus Brevundimonas. Previous studies had shown unexpected phenotypic differences between the C. crescentus divK mutant and the analogous mutant of Brevundimonas subvibrioides, but further characterization was not performed. Here, phenotypic assays analyzing motility, adhesion, and pilus production (the latter characterized by a newly discovered bacteriophage) revealed that divJ and pleC mutants have mostly similar phenotypes as their C. crescentus homologs, but divK mutants maintain largely opposite phenotypes than expected. Suppressor ...


Identifying And Assessing Conflicts Between Future Development And Current Migratory Bird Habitat Around Farmington Bay, Utah, Aubin A. Douglas Dec 2018

Identifying And Assessing Conflicts Between Future Development And Current Migratory Bird Habitat Around Farmington Bay, Utah, Aubin A. Douglas

All Graduate Plan B and other Reports

Every year, the Great Salt Lake (GSL) and its associated wetlands provide critical habitat for over 250 migratory bird species from both the Pacific and Central Flyways. The GSL borders the Wasatch Front, which is the fastest growing and most populous region in Utah. To support the ever-increasing working population, the government of Utah aspires to increase the robust economic growth of the region through economic incentives and development of infrastructure. As this area continues to develop, greater pressure will be placed on the surrounding natural resources, including the GSL, its wetlands, and the open space and agricultural land that ...


A Comprehensive Catalog Of Post-Translational Modifications Of Drosophila Melanogaster Hox Protein, Sex Combs Reduced, Anirban Banerjee Oct 2018

A Comprehensive Catalog Of Post-Translational Modifications Of Drosophila Melanogaster Hox Protein, Sex Combs Reduced, Anirban Banerjee

Electronic Thesis and Dissertation Repository

During formation of the anterior-posterior axis, Homeotic selector (HOX) proteins determine the identity of Drosophila body segments. HOX proteins are transcription factors that regulate gene expression during development. Besides a highly conserved DNA-binding homeodomain (HD), HOX proteins also contain functionally important, evolutionarily conserved small motifs. These short motifs found in HOX proteins may be Short Linear Motifs (SLiMs). SLiMs are proposed to be sites of phosphorylation and this may regulate the activity of HOX proteins. The primary aim of this work was to develop a comprehensive catalogue of the sites of phosphorylation and other post-translational modifications (PTMs) for Fushi tarazu ...


Histone Deacetylase 3 (Hdac3) Regulates Lymphatic Vascular Development, Harish P. Palleti Janardhan Sep 2018

Histone Deacetylase 3 (Hdac3) Regulates Lymphatic Vascular Development, Harish P. Palleti Janardhan

GSBS Dissertations and Theses

Cardiovascular disease continues to be the leading cause of morbidity and mortality worldwide with an estimated 17 million annual deaths. A majority of cases are attributed to disease affecting the vascular system including arterial, venous and lymphatic vessels. Despite progress in understanding the molecular bases of vascular development and disease, the role of chromatin modifying enzymes in vascular processes remains ill defined. Here we show that the histone-modifying enzyme Hdac3 is a critical regulator of lymphatic vascular development. Endothelial specific loss of Hdac3 in mice affects the development of lymphovenous and lymphatic valves resulting in aberrant blood lymph separation, lymphedema ...


The Inter-Subject Correlation Of Eeg In Response To Naturalistic Stimuli, Samantha S. Cohen Sep 2018

The Inter-Subject Correlation Of Eeg In Response To Naturalistic Stimuli, Samantha S. Cohen

All Dissertations, Theses, and Capstone Projects

Inter-subject correlation is a measure of the similarity of the brain activity of a group of people as they respond to the same naturalistic stimulus, typically a story or video, meant to simulate a real world experience. This thesis tests the hypothesis that the correlation of the brain responses of a group of people is indicative of stimulus engagement. The rationale is that the content of the stimulus drives brain activity in a consistent manner, while internal thoughts are divergent and result in uncorrelated activity. The inter-subject correlation (ISC) of neural responses have previously been assessed with fMRI, EEG, and ...


Association Of P53 Polymorphisms, Pah-Like Fluorescence, And Developmental Trends In Caught Gulf Menhaden To Crude Oil Exposure Post-Deepwater Horizon Oil Spill: A Holistic Approach, Kevin Luiz Frisina May 2018

Association Of P53 Polymorphisms, Pah-Like Fluorescence, And Developmental Trends In Caught Gulf Menhaden To Crude Oil Exposure Post-Deepwater Horizon Oil Spill: A Holistic Approach, Kevin Luiz Frisina

Undergraduate Honors Theses

Environmental pollution is of great concern in the United States. Of special concern is the chronic effects from the exposure to potentially carcinogenic compounds released from episodic environmental disasters (e.g. 911 twin-towers, oil spills). Disasters like the British Petroleum (BP) Deepwater Horizon oil spill in the Gulf of Mexico (GOM), affected many marine organisms, exposing them to crude oil polycyclic aromatic hydrocarbons (PAHs), some of which are known carcinogenic. Despite many marine-based consumer products (e.g. fish oil, animal feed, fertilizer) were known affected by the BP oil spill, bioaccumulation and chronic toxicity of the crude oil PAHs into ...


Stimulating Canonical Wnt Signaling In Pituitary Progenitors Inhibits Differentiation Of Hormone Cell Types, Tanner F. Coleman Apr 2018

Stimulating Canonical Wnt Signaling In Pituitary Progenitors Inhibits Differentiation Of Hormone Cell Types, Tanner F. Coleman

Senior Theses

The mouse pituitary gland secretes hormones that regulate many physiological processes including growth, stress response, and reproduction. The canonical WNT signaling pathway, activation of which results in nuclear accumulation of β-CATENIN and transcription of target genes including LEF1, is crucial for proper development of the pituitary gland. Pituitary progenitors that lack β-CATENIN at embryonic day of development 8.5 (E8.5) cannot form three of the six cell types of the anterior pituitary that produce growth hormone (GH), thyroid stimulating hormone (TSH), and prolactin (PRL). Additionally, stimulating canonical WNT signaling through creation of degradation-resistant β-CATENIN at E9.5 causes pituitary ...


The Developmental Implications Of The Regulatory Relationship Between Cjun And Oct4 In Murine Embryonic Stem Cells, Rachel E. Brewer Jan 2018

The Developmental Implications Of The Regulatory Relationship Between Cjun And Oct4 In Murine Embryonic Stem Cells, Rachel E. Brewer

Theses and projects

As cells transition from the point of fertilization through the process of embryonic development, many molecular changes occur that affect cell fate. At the blastocyst stage, the earliest distinction, two separate cell populations arise. The trophectoderm cells will generate all of the extraembryonic tissues while the inner cell mass will yield all of the embryonic tissues. These cells, which generate the organism, are termed pluripotent at this stage and found within the inner cell mass (ICM). A variety of genetic mechanisms that regulate this event have been characterized. Here, we examined the effect of cJun expression in regulating Oct4, a ...


Mechanosensing By The Nuclear Lamina: From Embryonic Development To Aging, Sangkyun Cho Jan 2018

Mechanosensing By The Nuclear Lamina: From Embryonic Development To Aging, Sangkyun Cho

Publicly Accessible Penn Dissertations

‘Nuclear mechanosensing’ encompasses a wide range of biophysical pathways that are emerging as key processes in the regulation of cell function and fate. Many of these mechanisms involve the main structural protein of the nucleus, lamin-A, which is abundant in stiff and mechanically stressed tissues such as striated muscle, but is comparatively low in soft tissues such as the brain. Lamin-A’s increase with tissue stiffness correlates strongly with elevated levels of collagen-I fibers in the extracellular matrix (ECM), but mechanisms and functional consequences of any matrix-nucleus interplay remain unclear. Here, in the first set of studies, we show that ...


Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho Jan 2018

Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho

Doctoral Dissertations

Mammalian development involves remarkable changes, starting from a single-cell, totipotent zygote and ending with a developed organism comprised of diverse cells types with distinct morphologies, structures, and functions. Within three days of murine development, the two parental genomes merge into a single nucleus, begin zygotic gene expression, undergo epigenetic remodeling, and make the first lineage decisions. Diversity in cell-types is possible even though cells share the same genome. This diversity is achieved by the tight regulation of differential transcriptional programs. There are many ways these transcriptional programs can be initiated. Epigenetic alterations to the genome can drive transcriptional changes.

Epigenetic ...


Disc1 Knockout Rats Reveal Sexually Dimorphic Patterns Of Impairment Across Development, Stephanie S. Desrochers Jan 2018

Disc1 Knockout Rats Reveal Sexually Dimorphic Patterns Of Impairment Across Development, Stephanie S. Desrochers

Honors Theses

Schizophrenia is a chronic disorder characterized by three symptom categories: positive (hallucinations, delusions), negative (anhedonia, anxiety), and cognitive (sensory processing and memory deficits). We worked with a biallelic deletion of the Disrupted-in-schizophrenia-1 (DISC1) gene in Sprague-Dawley rats to facilitate our understanding of the biological bases of schizophrenia. Mutations of DISC1 are associated with a higher prevalence of schizophrenia. Adult DISC1 knockout, compared to wildtype, rats display features of schizophrenia-like outcomes in rodent models. The present study investigated the progression of the cognitive symptom deficits in prepulse inhibition (PPI), assessing animals at postnatal days 17 (pre-weaning), 26 (post-weaning), 39 (adolescent), and ...


Khana Khanu Bhayo (Have You Eaten)? Traditional Rice Varieties, Land Tenure, And Social Structure In Nepal’S Mid-Hills, Marie Louise Ryan Jan 2018

Khana Khanu Bhayo (Have You Eaten)? Traditional Rice Varieties, Land Tenure, And Social Structure In Nepal’S Mid-Hills, Marie Louise Ryan

Graduate Theses and Dissertations

Drawing on research conducted in two villages of Lamjung District in the mid-hills of Nepal, this thesis examines how social structures of caste, ethnicity, and gender, as well as land tenure affect the conservation of traditional rice varieties. Resource-poor farmers in Nepal possess a great wealth of traditional rice varieties. While subsistence farmers continue to maintain a large portion of Nepal’s rice varieties, these individuals represent poor, marginalized members of society. As populations flee rural areas for urban conveniences and economic opportunities abroad, the social dynamics of subsistence farming are shifting. The agricultural landscape of Lamjung has traditionally been ...


Polarity And Competition In The Development Of The Calyx Of Held Terminal In The Medial Nucleus Of The Trapezoid Body In The Mouse, Paul Steven Holcomb Jan 2018

Polarity And Competition In The Development Of The Calyx Of Held Terminal In The Medial Nucleus Of The Trapezoid Body In The Mouse, Paul Steven Holcomb

Graduate Theses, Dissertations, and Problem Reports

In the auditory brainstem, the connection between globular bushy cells of the anteroventral cochlear nucleus and principal cells (PCs) of the medial nucleus of the trapezoid body (MNTB) is created by one of the largest nerve terminals in the central nervous system, the calyx of Held (CH). The characteristics of the CH:MNTB connection—a short developmental period (48-72 hours), accessibility for recording from pre- and postsynaptic components, and clear monoinnervated end point—make this system an ideal model system for studying nervous system development. Model systems undergo stereotyped stages of development, including exuberant overinnervation, competition between terminals, and a ...


Effects Of Ocean Warming And Acidification On Fertilization Success And Early Larval Development In The Green Sea Urchin, Lytechinus Variegatus, Brittney L. Lenz Dec 2017

Effects Of Ocean Warming And Acidification On Fertilization Success And Early Larval Development In The Green Sea Urchin, Lytechinus Variegatus, Brittney L. Lenz

HCNSO Student Theses and Dissertations

Climate change is predicted to affect the larval stages of many marine organisms. Ocean warming can reduce larval survival and hasten larval development, whereas ocean acidification can delay larval development. Ocean acidification is especially concerning for marine organisms that develop and grow calcified shells or skeletons in an environment undersaturated with calcium carbonate minerals. This study assessed the effects of ocean warming and acidification on the fertilization and larval development of the green sea urchin, Lytechinus variegatus, a tropical species common in Florida and the Caribbean. After spawning, gametes were fertilized and embryos/larvae were reared at: 1) 28°C ...