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Articles 1591 - 1620 of 2465

Full-Text Articles in Life Sciences

The Potential Of Forest Biomass Inversion Based On Vegetation Indices Using Multi-Angle Chris/Proba Data, Qiang Wang, Yong Pang, Zengyuan Li, Guoqing Sun, Erxue Chen, Wenge Ni-Meister Oct 2016

The Potential Of Forest Biomass Inversion Based On Vegetation Indices Using Multi-Angle Chris/Proba Data, Qiang Wang, Yong Pang, Zengyuan Li, Guoqing Sun, Erxue Chen, Wenge Ni-Meister

Publications and Research

Multi-angle remote sensing can either be regarded as an added source of uncertainty for variable retrieval, or as a source of additional information, which enhances variable retrieval compared to traditional single-angle observation. However, the magnitude of these angular and band effects for forest structure parameters is difficult to quantify. We used the Discrete Anisotropic Radiative Transfer (DART) model and the Zelig model to simulate the forest canopy Bidirectional Reflectance Distribution Factor (BRDF) in order to build a look-up table, and eight vegetation indices were used to assess the relationship between BRDF and forest biomass in order to find the sensitive …


Improved Parental Dietary Quality Is Associated With Children’S Dietary Intake Through The Home Environment, Karen R. Flórez, A. S. Richardson, M. B. Ghosh-Dastidar, R. Beckman, C. Huang, L. Wagner, T. Dubowitz Oct 2016

Improved Parental Dietary Quality Is Associated With Children’S Dietary Intake Through The Home Environment, Karen R. Flórez, A. S. Richardson, M. B. Ghosh-Dastidar, R. Beckman, C. Huang, L. Wagner, T. Dubowitz

Publications and Research

Background Improving access to supermarkets has been shown to improve some dietary outcomes, yet there is little evidence for such effects on children. Relatedly, there is a dearth of research assessing the impact of a structural change (i.e. supermarket in a former food desert) on the home environment and its relationship with children’s diet.

Objective Assess the relative impact of the home environment on children’s diet after the introduction of a new supermarket in a food desert.

Methods Among a randomly selected cohort of households living in a food desert, parental diet was assessed before and after the opening of …


Sex And Seasonal Differences In Diet And Nutrient Intake In Verreaux's Sifakas (Propithecus Verreauxi), Flávia Koch, Joerg U. Ganzhorn, Jessica M. Rothman, Colin A. Chapman, Claudia Fichtel Oct 2016

Sex And Seasonal Differences In Diet And Nutrient Intake In Verreaux's Sifakas (Propithecus Verreauxi), Flávia Koch, Joerg U. Ganzhorn, Jessica M. Rothman, Colin A. Chapman, Claudia Fichtel

Publications and Research

Fluctuations in food availability are a major challenge faced by primates living in seasonal climates. Variation in food availability can be especially challenging for females, because of the high energetic costs of reproduction. Therefore, females must adapt the particular demands of the different reproductive stages to the seasonal availability of resources. Madagascar has a highly seasonal climate, where food availability can be extremely variable. We investigated the seasonal changes in diet composition, nutrient and energy intake of female and male sifakas (Propithecus verreauxi) in a dry deciduous forest in western Madagascar. We examined how females adjust their diet to different …


Airborne Infectious Agents And Other Pollutants In Automobiles For Domestic Use: Potential Health Impacts And Approaches To Risk Mitigation, Syed A. Sattar, Kathryn E. Wright, Bahram Zargar, Joseph R. Rubino, M. Khalid Ijaz Oct 2016

Airborne Infectious Agents And Other Pollutants In Automobiles For Domestic Use: Potential Health Impacts And Approaches To Risk Mitigation, Syed A. Sattar, Kathryn E. Wright, Bahram Zargar, Joseph R. Rubino, M. Khalid Ijaz

Publications and Research

Theworld total of passenger cars is expected to go fromthe current one billion to >2.5 billion by 2050. Cars for domestic use account for ∼74% of the world’s yearly production ofmotorized vehicles. In North America, ∼80% of the commuters use their own car with another 5.6% travelling as passengers.With the current life-expectancy of 78.6 years, the average North American spends 4.3 years driving a car! This equates to driving 101 minutes/day with a lifetime driving distance of nearly 1.3 million km inside the confined and often shared space of the car with exposure to a mix of potentially harmful pathogens, …


Cooperative Stimulation Of Megakaryocytic Differentiation By Gfi1b Gene Targets Kindlin3 And Talin1, Divya Singh, Ghanshyam Upadhyay, Ananya Sengupta, Mohammed A. Biplob, Shaleen Chakyayil, Tiji George, Shireen Saleque Oct 2016

Cooperative Stimulation Of Megakaryocytic Differentiation By Gfi1b Gene Targets Kindlin3 And Talin1, Divya Singh, Ghanshyam Upadhyay, Ananya Sengupta, Mohammed A. Biplob, Shaleen Chakyayil, Tiji George, Shireen Saleque

Publications and Research

Understanding the production and differentiation of megakaryocytes from progenitors is crucial for realizing the biology and functions of these vital cells. Previous gene ablation studies demonstrated the essential role of the transcriptional repressor Gfi1b (growth factor independence 1b) in the generation of both erythroid and megakaryocytic cells. However, our recent work has demonstrated the down-regulation of this factor during megakaryocytic differentiation. In this study we identify two new gene targets of Gfi1b, the cytoskeletal proteins Kindlin3 and Talin1, and demonstrate the inverse expression and functions of these cytoskeletal targets relative to Gfi1b, during megakaryocytic differentiation. Both kindlin3 and talin1 promoters …


Molecular Mechanisms Of Stress-Induced Increases In Fear Memory Consolidation Within The Amygdala, Antonio V. Aubry, Peter A. Serrano, Nesha S. Burghardt Oct 2016

Molecular Mechanisms Of Stress-Induced Increases In Fear Memory Consolidation Within The Amygdala, Antonio V. Aubry, Peter A. Serrano, Nesha S. Burghardt

Publications and Research

Stress can significantly impact brain function and increase the risk for developing various psychiatric disorders. Many of the brain regions that are implicated in psychiatric disorders and are vulnerable to the effects of stress are also involved in mediating emotional learning. Emotional learning has been a subject of intense investigation for the past 30 years, with the vast majority of studies focusing on the amygdala and its role in associative fear learning. However, the mechanisms by which stress affects the amygdala and amygdala-dependent fear memories remain unclear. Here we review the literature on the enhancing effects of acute and chronic …


The Evolution Of Line-1 In Vertebrates, Stephane Boissinot, Akash Sookdeo Oct 2016

The Evolution Of Line-1 In Vertebrates, Stephane Boissinot, Akash Sookdeo

Publications and Research

The abundance and diversity of the LINE-1 (L1) retrotransposon differ greatly among vertebrates. Mammalian genomes contain hundreds of thousands L1s that have accumulated since the origin of mammals. A single group of very similar elements is active at a time in mammals, thus a single lineage of active families has evolved in this group. In contrast, non-mammalian genomes (fish, amphibians, reptiles) harbor a large diversity of concurrently transposing families, which are all represented by very small number of recently inserted copies. Why the pattern of diversity and abundance of L1 is so different among vertebrates remains unknown. To address this …


Novel Adaptive Photosynthetic Characteristics Of Mesophotic Symbiotic Microalgae Within The Reef-Building Coral, Stylophora Pistillata, Shai Einbinder, David F. Gruber, Eitan Salomon, Oded Liran, Nir Keren, Dan Tchernov Oct 2016

Novel Adaptive Photosynthetic Characteristics Of Mesophotic Symbiotic Microalgae Within The Reef-Building Coral, Stylophora Pistillata, Shai Einbinder, David F. Gruber, Eitan Salomon, Oded Liran, Nir Keren, Dan Tchernov

Publications and Research

Photosynthetic coral reef structures extend from the shallow sundrenched waters to the dimly lit, “twilight” mesophotic depths. For their resident endosymbiotic dinoflagellates, primarily from the genus Symbiodinium spp., this represents a photic environment that varies ~15-fold in intensity and also differs in spectral composition. We examined photosynthesis in the scleractinian coral Stylophora pistillata in shallow (3 m) and mesophotic settings (65 m) in the northern Red Sea. Symbiodinium spp. in corals originating from the mesophotic environment consistently performed below their photosynthetic compensation point and also exhibited distinct light harvesting antenna organization. In addition, the non-photochemical quenching activity of Symbiodinium spp. …


Rapid And Objective Assessment Of Neural Function In Autism Spectrum Disorder Using Transient Visual Evoked Potentials, Paige M. Siper, Vance Zemon, James Gordon, Julia George-Jones, Stacey Lurie, Jessica Zweifach, Teresa Tavassoli, A. Ting Wang, Jesslyn Jamison, Joseph D. Buxbaum, Alexander Kolevzon Oct 2016

Rapid And Objective Assessment Of Neural Function In Autism Spectrum Disorder Using Transient Visual Evoked Potentials, Paige M. Siper, Vance Zemon, James Gordon, Julia George-Jones, Stacey Lurie, Jessica Zweifach, Teresa Tavassoli, A. Ting Wang, Jesslyn Jamison, Joseph D. Buxbaum, Alexander Kolevzon

Publications and Research

Objective There is a critical need to identify biomarkers and objective outcome measures that can be used to understand underlying neural mechanisms in autism spectrum disorder (ASD). Visual evoked potentials (VEPs) offer a noninvasive technique to evaluate the functional integrity of neural mechanisms, specifically visual pathways, while probing for disease pathophysiology.

Methods Transient VEPs (tVEPs) were obtained from 96 unmedicated children, including 37 children with ASD, 36 typically developing (TD) children, and 23 unaffected siblings (SIBS). A conventional contrast-reversing checkerboard condition was compared to a novel short-duration condition, which was developed to enable objective data collection from severely affected populations …


Large-Scale Off-Target Identification Using Fast And Accurate Dual Regularized One- Class Collaborative Filtering And Its Application To Drug Repurposing, Hansaim Lim, Aleksandar Poleksic, Yuan Yao, Hanghang Tong, Di He, Luke Zhuang, Patrick Meng, Lei Xie Oct 2016

Large-Scale Off-Target Identification Using Fast And Accurate Dual Regularized One- Class Collaborative Filtering And Its Application To Drug Repurposing, Hansaim Lim, Aleksandar Poleksic, Yuan Yao, Hanghang Tong, Di He, Luke Zhuang, Patrick Meng, Lei Xie

Publications and Research

Target-based screening is one of the major approaches in drug discovery. Besides the intended target, unexpected drug off-target interactions often occur, and many of them have not been recognized and characterized. The off-target interactions can be responsible for either therapeutic or side effects. Thus, identifying the genome-wide off-targets of lead compounds or existing drugs will be critical for designing effective and safe drugs, and providing new opportunities for drug repurposing. Although many computational methods have been developed to predict drug-target interactions, they are either less accurate than the one that we are proposing here or computationally too intensive, thereby limiting …


Electro-Chemotactic Fields Induce Cooperative Movement Of Cns Cells, Shawn Mishra, Stephen Redenti, Maribel Vazquez Oct 2016

Electro-Chemotactic Fields Induce Cooperative Movement Of Cns Cells, Shawn Mishra, Stephen Redenti, Maribel Vazquez

Publications and Research

Vision loss in adults with Age Related Macular Degeneration (AMD) is attributed to damage of retinal photoreceptor cells that initiate vision by absorbing light. Mouse models have suggested that transplantation of precursor cells may be a novel approach to restore vision. This project uses a combination of electrotactic and chemotactic stimuli to promote and guide CNS cell migration within a microdevice model.


In-Vivo Imaging Of Magnetic Fields Induced By Transcranial Direct Current Stimulation (Tdcs) In Human Brain Using Mri, Mayank V. Jog, Robert X. Smith, Kay Jann, Walter Dunn, Belen Lafon, Dennis Truong, Allan Wu, Lucas C. Parra, Marom Bikson, Danny J. J. Wang Oct 2016

In-Vivo Imaging Of Magnetic Fields Induced By Transcranial Direct Current Stimulation (Tdcs) In Human Brain Using Mri, Mayank V. Jog, Robert X. Smith, Kay Jann, Walter Dunn, Belen Lafon, Dennis Truong, Allan Wu, Lucas C. Parra, Marom Bikson, Danny J. J. Wang

Publications and Research

Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique that applies mA currents at the scalp to modulate cortical excitability. Here, we present a novel magnetic resonance imaging (MRI) technique, which detects magnetic fields induced by tDCS currents. This technique is based on Ampere’s law and exploits the linear relationship between direct current and induced magnetic fields. Following validation on a phantom with a known path of electric current and induced magnetic field, the proposed MRI technique was applied to a human limb (to demonstrate invivo feasibility using simple biological tissue) and human heads (to demonstrate feasibility in …


The Effect Of Protein Import On Membrane Potential, Ruth Hartke Oct 2016

The Effect Of Protein Import On Membrane Potential, Ruth Hartke

Student Theses and Dissertations

Mitochondria are essential organelles often referred to as the “power plants” of eukaryotic cells. Energy conversion in mitochondria relies on oxidation of metabolite intermediates by protein components of the electron transport chain and establishment of an electrochemical gradient across the inner membrane. Some of the proteins involved are encoded by mitochondrial DNA, but the vast majority, over 98%, has to be imported from the cytosol. Protein import complexes form pores in the outer and inner membranes to mediate the process. However, opening of these pores would in theory jeopardize formation of the electrochemical gradient. In this study we examined this …


Laboratory Exercises In Microbiology: Discovering The Unseen World Through Hands-On Investigation, Joan Petersen, Susan Mclaughlin Oct 2016

Laboratory Exercises In Microbiology: Discovering The Unseen World Through Hands-On Investigation, Joan Petersen, Susan Mclaughlin

Open Educational Resources

The exercises in this laboratory manual are designed to engage students in hand-on activities that reinforce their understanding of the microbial world. Topics covered include: staining and microscopy, metabolic testing, physical and chemical control of microorganisms, and immunology. The target audience is primarily students preparing for a career in the health sciences, however many of the topics would be appropriate for a general microbiology course as well.


Evolutionary Interpretations Of Mycobacteriophage Biodiversity And Host-Range Through The Analysis Of Codon Usage Bias, Laura A. Esposito, Swati Gupta, Fraida Streiter, Ashley Prasad, John J. Dennehy Oct 2016

Evolutionary Interpretations Of Mycobacteriophage Biodiversity And Host-Range Through The Analysis Of Codon Usage Bias, Laura A. Esposito, Swati Gupta, Fraida Streiter, Ashley Prasad, John J. Dennehy

Publications and Research

In an genomics course sponsored by the Howard Hughes Medical Institute (HHMI), undergraduate students have isolated and sequenced the genomes of more than 1,150 mycobacteriophages, creating the largest database of sequenced bacteriophages able to infect a single host, Mycobacterium smegmatis, a soil bacterium. Genomic analysis indicates that these mycobacteriophages can be grouped into 26 clusters based on genetic similarity. These clusters span a continuum of genetic diversity, with extensive genomic mosaicism among phages in different clusters. However, little is known regarding the primary hosts of these mycobacteriophages in their natural habitats, nor of their broader host ranges. As such, it …


Ben Domain Protein Elba2 Can Functionally Substitute For Linker Histone H1 In Drosophila In Vivo, Na Xu, Xingwu Lu, Harsh Kavi, Alexander V. Emelyanov, Travis J. Bernardo, Elena Vershilova, Arthur I. Skoultchi, Dmitry V. Fyodorov Sep 2016

Ben Domain Protein Elba2 Can Functionally Substitute For Linker Histone H1 In Drosophila In Vivo, Na Xu, Xingwu Lu, Harsh Kavi, Alexander V. Emelyanov, Travis J. Bernardo, Elena Vershilova, Arthur I. Skoultchi, Dmitry V. Fyodorov

Publications and Research

Metazoan linker histones are essential for development and play crucial roles in organization of chromatin, modification of epigenetic states and regulation of genetic activity. Vertebrates express multiple linker histone H1 isoforms, which may function redundantly. In contrast, H1 isoforms are not present in Dipterans, including D. melanogaster, except for an embryo-specific, distantly related dBigH1. Here we show that Drosophila BEN domain protein Elba2, which is expressed in early embryos and was hypothesized to have insulator-specific functions, can compensate for the loss of H1 in vivo. Although the Elba2 gene is not essential, its mutation causes a disruption of normal internucleosomal …


Examining Relationships Between Basic Emotion Perception And Musical Training In The Prosodic, Facial, And Lexical Channels Of Communication And In Music, Jamie Twaite Sep 2016

Examining Relationships Between Basic Emotion Perception And Musical Training In The Prosodic, Facial, And Lexical Channels Of Communication And In Music, Jamie Twaite

Dissertations, Theses, and Capstone Projects

Research has suggested that intensive musical training may result in transfer effects from musical to non-musical domains. There is considerable research on perceptual and cognitive transfer effects associated with music, but, comparatively, fewer studies examined relationships between musical training and emotion processing. Preliminary findings, though equivocal, suggested that musical training is associated with enhanced perception of emotional prosody, consistent with a growing body of research demonstrating relationships between music and speech. In addition, few studies directly examined the relationship between musical training and the perception of emotions expressed in music, and no studies directly evaluated this relationship in the facial …


Phylogeny, Systematics And Biogeography Of Short-Tailed Opossums (Didelphidae: Monodelphis), Silvia E. Pavan Sep 2016

Phylogeny, Systematics And Biogeography Of Short-Tailed Opossums (Didelphidae: Monodelphis), Silvia E. Pavan

Dissertations, Theses, and Capstone Projects

Short-tailed opossums (genus Monodelphis) comprise the most species-rich genus of New World marsupials, with 25 currently recognized species. Monodelphis comprise small, terrestrial species collectively widespread in South America, which makes the group potentially informative about biogeographic processes that have shaped the continental fauna. The genus exhibits striking variation in several phenotypic characters, notably pelage coloration, behavior, and reproductive strategies. This diversity is unique among Neotropical marsupials, and makes the group particularly interesting to investigate the evolution and the adaptive significance of phenotypic trait variation. Despite this potential, missing knowledge on phylogeny and basic taxonomy precludes broader studies on evolution …


Specific Binding Affinity Of The Non-Catalytic Domain Of Eukaryotic Like Type Ib Topoisomerase Of Vaccinia Virus, Benjamin R. Reed Sep 2016

Specific Binding Affinity Of The Non-Catalytic Domain Of Eukaryotic Like Type Ib Topoisomerase Of Vaccinia Virus, Benjamin R. Reed

Dissertations, Theses, and Capstone Projects

Topoisomerases are ubiquitous proteins that alter supercoiling in double stranded DNA (dsDNA) during transcription and replication and. vaccinia and the closely related poxvirus variola virus, at 314 amino acids in length, encode the smallest of the type I topoisomerases(TopIB). TopIB is a two domain protein that recognizes the sequence 5’-T/CCCTT, cleaves at the 3’-end and relaxes supercoiling through rotation. The C-terminal domain (CTD) alone contains the catalytic activity and specificity. Deletion of the N-terminal domain results in a greatly reduced rate of relaxation and rapid dissociation. Biochemical data suggests that the N-terminal domain (NTD) is important for pre-cleavage binding and …


Molecular Analysis Of Ftsz-Ring Assembly In E. Coli Cytokinesis, Kuo-Hsiang Huang Sep 2016

Molecular Analysis Of Ftsz-Ring Assembly In E. Coli Cytokinesis, Kuo-Hsiang Huang

Dissertations, Theses, and Capstone Projects

An essential first step in bacterial division is the assembly of a cytokinetic ring (Z-ring) formed by the tubulin-like FtsZ at midcell. The highly conserved core domain of FtsZ has been reported to mediate assembly of FtsZ polymers in vivo and in vitro. Species-specific differences in the FtsZ C-terminal domain such as the FtsZ CTV region and interactions with several modulatory proteins such as ZapC and ZapD, restricted to certain bacterial classes, also serve as key determinants of FtsZ protofilament bundling. Here, we characterize (i) the roles of the FtsZ CTV region in mediating both longitudinal and lateral interactions …


Models And Methods In Cultural And Social Evolution, Elliot G. Aguilar Sep 2016

Models And Methods In Cultural And Social Evolution, Elliot G. Aguilar

Dissertations, Theses, and Capstone Projects

Chapter 1 The mathematical study of genealogies has yielded important insights in population biology, such as the ability to estimate the time to the most recent common ancestor (MRCA) of a sample of genetic sequences or of a group of individuals. Here we introduce a model of cultural genealogies that is a step toward answering similar questions for cultural traits. In our model individuals can inherit from a variable, potentially large number of ancestors, rather than from a fixed, small number of ancestors (one or two) as is typical of genetic evolution. We first show that, given a sample of …


Metabolic Profiling Of Genetically Modified Potato Periderm Tissues, Liqing Jin Sep 2016

Metabolic Profiling Of Genetically Modified Potato Periderm Tissues, Liqing Jin

Dissertations, Theses, and Capstone Projects

Potato tubers are protected from dehydration and pathogens by a covering peel (periderm) impregnated with suberin, a complex cross-linked biopolymer that contains both polyaliphatic and lignin-like aromatic domains. Current models describing the macromolecular structure of suberin assume that ferulic acid cross-links both domains as it may form carboxyl ester bonds with aliphatic monomers and non-ester radical-coupled bonds with phenolics. Ferulic acid also links by ester bonds to glycans and acts in cross-linking polysaccharides and lignin. Fatty alcohol/ω-hydroxyacid hydroxycinnamoyl transferase (FHT) is a BADH acyltransferase responsible for the synthesis of akyl-ferulates that is necessary for suberin biosynthesis. Periderm from FHT-RNAi …


The Role Of Individual Cognitive And Behavioral Ontogeny In Organization And Evolution Of Social Systems, Andrew G. Fulmer Sep 2016

The Role Of Individual Cognitive And Behavioral Ontogeny In Organization And Evolution Of Social Systems, Andrew G. Fulmer

Dissertations, Theses, and Capstone Projects

Exploration and explanation of the relationship between individual variation in behavior and the composition and adaptive success of social groups or populations are crucial problems in the fields of behavioral ecology, ethology, and comparative psychology. These questions have been the subject of a longstanding discussion at both the proximate and ultimate levels of inquiry. Adaptive mechanisms explaining social decision making, both in terms of affiliative and competitive partner choices, are at the center of such discussions. Inclusive fitness, kin-selection, handicap or prestige, risk seeking and risk avoiding strategies, pay-to-stay/reward principles, as well as other theories have been proposed and supported …


Therapeutic Targets For Alzheimer's Disease: Insights From In Vitro And In Vivo Models Of Inflammation, Magdalena J. Kiprowska Sep 2016

Therapeutic Targets For Alzheimer's Disease: Insights From In Vitro And In Vivo Models Of Inflammation, Magdalena J. Kiprowska

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive neuronal loss that over the years spreads from the hippocampus to the neural cortex and impairs memory and cognitive functions. At the cellular level AD is linked to the presence of β-amyloid plaques and neurofibrillary tangles but despite decades of research little is known about their contribution to neurodegeneration and whether they are a cause or rather a result of the disease. It is well established that proteasome activity is impaired in AD brains and some studies suggest that this could be one of the initial factors leading to development …


Role Of Hnrnp A1 In The Regulation Of Hdm2 Gene Expression, Heriberto Moran Sep 2016

Role Of Hnrnp A1 In The Regulation Of Hdm2 Gene Expression, Heriberto Moran

Dissertations, Theses, and Capstone Projects

hnRNP A1 is one of the most abundant and ubiquitously expressed member of hnRNPs (Heterogenous Nuclear Ribonucleoproteins) family of proteins that play multiple roles in gene expression by participating in major steps in the processing of nascent RNA transcripts 1. It is involved in mRNA biogenesis mechanisms such as the transcription, splicing, stability, export and translation of cellular and viral transcripts. The functions of hnRNP A1 extend to the processing of microRNAs, telomere maintenance and DNA repair 1. Our previous studies have shown that hnRNPA1 had reduced protein level and increased cytoplasmic accumulation in senescent human diploid fibroblasts 2,10. Our …


Comparative Population Genomics And Speciation Of Snakes Across The North American Deserts, Edward A. Myers Sep 2016

Comparative Population Genomics And Speciation Of Snakes Across The North American Deserts, Edward A. Myers

Dissertations, Theses, and Capstone Projects

Understanding the process of speciation is of central interest to evolutionary biologists. Speciation can be studied using a phylogeographic approach, by identifying regions that promote lineage divergence, addressing whether speciation has occurred with gene flow, and when extended to multiple taxa, addressing if the same patterns of speciation are shared across codistributed groups with different ecologies. Here I examine the comparative phylogeographic histories and population genomics of thirteen snake taxa that are widely distributed and co-occur across the arid southwest of North America. I first quantify the degree to which these species groups have a shared history of population divergence …


Tuning Into Toxins And Channels: The Characterizations Of Tv1 And A Human Cardiac Sodium Channel Voltage-Sensor Domain, Mohammed H. Bhuiyan Sep 2016

Tuning Into Toxins And Channels: The Characterizations Of Tv1 And A Human Cardiac Sodium Channel Voltage-Sensor Domain, Mohammed H. Bhuiyan

Dissertations, Theses, and Capstone Projects

In nature, peptide toxins are an abundant resource, produced both by marine and terrestrial organisms. A major target of these peptide toxins is the group of the highly important voltage-gated ion channels. Due to their high specificity and affinity, peptide toxins have been used for over a decade in discovery and characterization of voltage-gated ion channels. Although peptide toxins have been extensively characterized structurally, the structural characterization of eukaryotic voltage-gated sodium channels has seen much less progress, due to their large size and high hydrophobicity. Voltage-gated sodium channels play crucial roles in many physiological processes, and when these processes are …


Computerized Classification Of Surface Spikes In Three-Dimensional Electron Microscopic Reconstructions Of Viruses, Younes Benkarroum Sep 2016

Computerized Classification Of Surface Spikes In Three-Dimensional Electron Microscopic Reconstructions Of Viruses, Younes Benkarroum

Dissertations, Theses, and Capstone Projects

The purpose of this research is to develop computer techniques for improved three-dimensional (3D) reconstruction of viruses from electron microscopic images of them and for the subsequent improved classification of the surface spikes in the resulting reconstruction. The broader impact of such work is the following.

Influenza is an infectious disease caused by rapidly-changing viruses that appear seasonally in the human population. New strains of influenza viruses appear every year, with the potential to cause a serious global pandemic. Two kinds of spikes – hemagglutinin (HA) and neuraminidase (NA) – decorate the surface of the virus particles and these proteins …


Metabolic Profiling And Polymer Formation Of Gene Silenced Potato Periderms, Qing Cai Sep 2016

Metabolic Profiling And Polymer Formation Of Gene Silenced Potato Periderms, Qing Cai

Dissertations, Theses, and Capstone Projects

Suberin is a biopolyester constituent of specialized plant periderm tissues formed within the phellem cell walls. Suberin and waxes of the periderm layer act to prevent water diffusion, mechanical breakdown and pathogenic invasion in plants. Ferulic esters, ω-hydroxyacids and α,ω-fatty diacids are considered to be the most important linkage between aliphatic and aromatic suberin domains and also linked with cell-wall polysaccharides. The potato gene FHT (fatty ω- hydroxyacid/fatty alcohol hydroxycinnamoyl transferase) esterifies ferulic acid to suberin. Diminished levels of feruloyl transferase activity have been associated with lowered amounts of feruloyl esters of fatty acids in both suberin-associated waxes and suberin …


The Regulation Of The Phosphatidate Phosphatase Gene Pah1 And Its Regulatory Role On Cell Homeostasis, Goldie Libby Sherr Sep 2016

The Regulation Of The Phosphatidate Phosphatase Gene Pah1 And Its Regulatory Role On Cell Homeostasis, Goldie Libby Sherr

Dissertations, Theses, and Capstone Projects

The Saccharomyces cerevisiae gene, PAH1, encodes a phosphatidate (PA) phosphatase that plays a fundamental role in lipid metabolism. PA phosphatases are key enzymes that catalyze the PA dephosphorylation reaction to form diacylglycerides, the first step in the synthesis of triacylglycerols. Pah1p, one of the main PA phosphatases in yeast, has not only emerged as a key player in lipid biosynthetic pathways, but also acts as an important regulator of nuclear membrane biogenesis, the transcriptional regulation of many inositol-sensitive upstream activating sequence (UASINO)containing genes needed for phospholipid synthesis, vacuole homeostasis, and lipid droplet formation. Due to its …