Open Access. Powered by Scholars. Published by Universities.®

Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

2014

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 211 - 240 of 1587

Full-Text Articles in Biology

Quantitative Modeling Of Spatiotemporal Systems: Simulation Of Biological Systems And Analysis Of Error Metric Effects On Model Fitting, James Hengenius Oct 2014

Quantitative Modeling Of Spatiotemporal Systems: Simulation Of Biological Systems And Analysis Of Error Metric Effects On Model Fitting, James Hengenius

Open Access Dissertations

Understanding the biophysical processes underlying biological and biotechnological processes is a prerequisite for therapeutic treatments and technological innovation. With the exponential growth of computational processing speed, experimental findings in these fields have been complemented by dynamic simulations of developmental signaling and genetic interactions. Models provide means to evaluate "emergent" properties of systems sometimes inaccessible by reductionist approaches, making them test beds for biological inference and technological refinement.^ The complexity and interconnectedness of biological processes pose special challenges to modelers; biological models typically possess a large number of unknown parameters relative to their counterparts in other physical sciences. Estimating these parameter …

Go to article

Intranuclear Strain Measured By Iterative Warping In Cells Under Mechanical And Osmotic Stress, Jonathan T Henderson Oct 2014

Intranuclear Strain Measured By Iterative Warping In Cells Under Mechanical And Osmotic Stress, Jonathan T Henderson

Open Access Dissertations

The nucleus is a membrane bound organelle and regulation center for gene expression in the cell. Mechanical forces transfer to the nucleus directly and indirectly through specific cellular cytoskeletal structures and pathways. There is increasing evidence that the transferred forces to the nucleus orchestrate gene expression activity. Methods to characterize nuclear mechanics typically study isolated cells or cells embedded in 3D gel matrices. Often report only aspect ratio and volume changes, measures that oversimplify the inherent complexity of internal strain patterns. This presents technical challenges to simultaneously observe small scale nuclear mechanics and gene expression levels inside the nuclei of …

Go to article

Towards A Paradigm Shift In The Modeling Of Soil Organic Carbon Decomposition For Earth System Models, Yujie He Oct 2014

Towards A Paradigm Shift In The Modeling Of Soil Organic Carbon Decomposition For Earth System Models, Yujie He

Open Access Dissertations

Soils are the largest terrestrial carbon pools and contain approximately 2200 Pg of carbon. Thus, the dynamics of soil carbon plays an important role in the global carbon cycle and climate system. Earth System Models are used to project future interactions between terrestrial ecosystem carbon dynamics and climate. However, these models often predict a wide range of soil carbon responses and their formulations have lagged behind recent soil science advances, omitting key biogeochemical mechanisms. In contrast, recent mechanistically-based biogeochemical models that explicitly account for microbial biomass pools and enzyme kinetics that catalyze soil carbon decomposition produce notably different results and …

Go to article

Identification And Characterization Of Signal Components In Early Aba Signaling In Arabidopsis, Yueh-Ju Hou Oct 2014

Identification And Characterization Of Signal Components In Early Aba Signaling In Arabidopsis, Yueh-Ju Hou

Open Access Dissertations

The phytohormone abscisic acid (ABA) regulates growth, development, and response to abiotic stress in plants. The core ABA signaling has three key components: ABA receptors PYRABACTIN RESISTANCE 1 and PYR1-Like protein (PYR1/PYLs), type 2C protein phosphatases (PP2Cs) and SNF1- related protein Kinase 2s (SnRK2s). In the presence of ABA, PYR1/PYLs bind to and inhibit PP2Cs, leading to the release of SnRK2s from suppression, to activate downstream events such as ABA-responsive gene expression. To identify new components in the ABA signaling pathway, we performed a yeast two-hybrid screen for PYLs and SnRK2s interactors. We identified two proteins that interact with PYLs …

Go to article

Identification And Characterization Of Factors Involved In Dna Demethylation And Anti-Silencing In Arabidopsis, Zhaobo Lang Oct 2014

Identification And Characterization Of Factors Involved In Dna Demethylation And Anti-Silencing In Arabidopsis, Zhaobo Lang

Open Access Dissertations

DNA methylation is a key epigenetic mark for transcriptional gene silencing in many eukaryotes. DNA methylation status can be dynamically controlled by methylation and active demethylation processes. Compared to the well-known mechanisms of DNA methylation, the mechanisms of DNA demethylation and its regulation are poorly understood. In order to better understand the DNA demethylation pathway, we developed two genetic screening systems in Arabidopsis to identify new components involved in the DNA demethylation. In the first system, which is based on 35S promoter driven SUC2 (sucrose transporter 2) transgene, a mutant (91-1) was isolated and map-based cloning identified the …

Go to article

Multidimensional Approach To Comparative Avian Visual Systems, Bret Alan Moore Oct 2014

Multidimensional Approach To Comparative Avian Visual Systems, Bret Alan Moore

Open Access Dissertations

Since the birth of visual ecology, comparative studies on how birds see their world have been limited to a small number of species and tended to focus on a single visual trait. This approach has constrained our ability to understand the diversity and evolution of the avian visual system. The goal of this dissertation was to characterize multiple visual dimensions on bird groups that are highly speciouse (e.g., Passeriformes), and test some hypotheses and predictions, using modern comparative tools, on the relationship between different visual traits and their association with visual information sampling behaviors. First, I developed a novel method …

Go to article

Acrolein As A Novel Therapeutic Target For Spinal Cord Injury Induced Neuropathic Pain, Jonghyuck Park Oct 2014

Acrolein As A Novel Therapeutic Target For Spinal Cord Injury Induced Neuropathic Pain, Jonghyuck Park

Open Access Dissertations

Despite years of research, post-spinal cord injury (SCI) chronic neuropathic pain remains refractory to treatment and drastically impairs quality of life for SCI victims beyond paralysis. Although inflammation and free radicals contribute to neuropathic pain in SCI, the mechanism is not completely clear. We have recently demonstrated that acrolein, a product and catalyst of lipid peroxidation, induces a vicious cycle of oxidative stress, amplifying its effects and perpetuating oxidative stress and inflammation. In the current study, we have confirmed that acrolein is elevated significantly at least two weeks post-SCI which coincides with the emergence of hyperalgesia (mechanical, cold and thermal). …

Go to article

Modulation Of Host Phosphatidylinositol Phosphates By Salmonella Effector Protein Sopb, Heather L. Piscatelli Oct 2014

Modulation Of Host Phosphatidylinositol Phosphates By Salmonella Effector Protein Sopb, Heather L. Piscatelli

Open Access Dissertations

Salmonella spp. are gram negative bacteria capable of infecting a number of eukaryotic hosts. In humans, Salmonella infection can range anywhere from acute gastroenteritis to typhoid fever which can oftentimes be fatal.Salmonella are facultative intracellular pathogens that have acquired the ability to enter non-phagocytic cells such as those lining the intestinal epithelium. Uptake into epithelial cells is mediated by the Salmonellapathogenicity island 1 (SPI1) encoded type III secretion system (T3SS), a needle-like complex composed of over 20 proteins that translocates effector proteins directly into the host cell cytosol. Salmonella possess a second type III secretion system encoded on …

Go to article

Migratory Ecology Of Sea Turtles, Nathan Jack Robinson Oct 2014

Migratory Ecology Of Sea Turtles, Nathan Jack Robinson

Open Access Dissertations

Establishing the movement patterns of free-ranging animals is imperative to understanding their behavior and ecology, and is often necessary for designing effective conservation-strategies. This is especially true for migratory species, such as sea turtles, whose long-distance movements form a major component of their life history. In this thesis, I investigated which factors are driving the migratory behavior of the leatherback turtleDermochelys coriacea. Firstly, I examined whether the timing of the nesting season (nesting phenology) is influenced by oceanographic conditions along the pre-nesting migratory route or by variation in population structure. The discovery that nesting phenology appears more influenced by …

Go to article

Morphometric Characterization Of Individual Sympathetic Postganglionic Axons Innervating The Muscle Layers Of The Gastrointestinal Tract Of The Rat: A Complex Effector Model, Gary C. Walter Oct 2014

Morphometric Characterization Of Individual Sympathetic Postganglionic Axons Innervating The Muscle Layers Of The Gastrointestinal Tract Of The Rat: A Complex Effector Model, Gary C. Walter

Open Access Dissertations

A full description of the terminal morphology of sympathetic postganglionic axons innervating the musculature of the gastrointestinal (GI) tract has not been available. Furthermore, common assumptions about the morphology and distribution of catecholaminergic terminal fields have been strongly shaped by the limitations of the techniques employed to distinguish the fibers and complicated by inconsistent findings generated with various methodologies. Thus, the present experiment used modern neural tracer techniques to provide high-resolution labeling of sympathetic fibers projecting to the smooth muscle wall of the GI tract. Fischer 344 rats (N = 50) received injections of dextran biotin into the left …

Go to article

Role Of Group Ii Metabotropic Glutamate Receptor Subtype 2 (Mglur2) In Appetitive And Consummatory Aspects Of Ethanol Reinforcement, Kyle Allyson Windisch Oct 2014

Role Of Group Ii Metabotropic Glutamate Receptor Subtype 2 (Mglur2) In Appetitive And Consummatory Aspects Of Ethanol Reinforcement, Kyle Allyson Windisch

Open Access Dissertations

Background: Group II metabotropic glutamate receptors (mGluR2/3) are predominately presynaptically located Gi/o coupled receptors that are highly expressed in the cortex, nucleus accumbens, amygdala, and hippocampus. Previous studies suggest that group II mGluRs are involved in regulating ethanol (EtOH) consumption and seeking following extinction (Backstrom and Hyytia, 2005; Kufahl, et al., 2011). The sipper tube model, which allows for procedural separation of seeking and consumption, was used to further clarify the role of mGluR2/3 in EtOH-seeking and consumption. The non-selective group II mGluR agonist LY379268 (LY37) and selective mGluR2 positive allosteric modulator (PAM) BINA were used to determine the …

Go to article

Host Cell Death In Legionella Pneumophila Pathogenesis And Immunity, Wenhan Zhu Oct 2014

Host Cell Death In Legionella Pneumophila Pathogenesis And Immunity, Wenhan Zhu

Open Access Dissertations

Legionella pneumophila is an intracellular pathogen that causes a severe, atypical pneumonia termed Legionnaires' disease. Upon entering the host cell, L. pneumophila resides in a membrane-bound vacuole, in which the bacterium evades lysosomal fusion and replicates. The establishment of the vacuole requires the Dot/Icm (Defect in organelle trafficking/ intracellular multiplication) transport system, which translocates a large number of substrates into host cells to re-orchestrate various cellular processes, such as intracellular trafficking, protein synthesis and host cell death pathways. Therefore, a key step in understanding the biology of Legionella is to dissect the mechanisms of action of the Dot/Icm substrates. By …

Go to article

Nano-Engineered Polymers In Drug Delivery: Potential Approaches For Attenuation Of Secondary Injury After Spinal Cord Trauma, Wen Gao Oct 2014

Nano-Engineered Polymers In Drug Delivery: Potential Approaches For Attenuation Of Secondary Injury After Spinal Cord Trauma, Wen Gao

Open Access Dissertations

Secondary injury elicits a complex series of pathophysiological events after the primary spinal cord trauma and even after its implantation treatment for neural functional recovery. These secondary injuries include an up-regulation of glial cells associated reactive oxygen species, nitrogen species, and reactive astrogliosis, and they can result in various levels of cellular and tissue damage. The inhibition of them has been proved to lead to functional recovery of the spinal cord. In this study, we concentrated on developing polymers and nano-techniques based drug delivery strategies to eliminate these secondary injuries. ^ To maintain and improve the performance of the implants …

Go to article

Associated Behavioral, Genetic, And Gene Expression Variation With Alternative Life History Tactics In Salmonid Fishes, Ashley Chin-Baarstad Oct 2014

Associated Behavioral, Genetic, And Gene Expression Variation With Alternative Life History Tactics In Salmonid Fishes, Ashley Chin-Baarstad

Open Access Dissertations

Individual differences in behavior can have potential fitness consequences and often reflect underlying genetic variation. My research focuses on three objectives related to individual level variation: 1) evaluating the innate behavioral variation within and between individuals, families, and progeny of different life-history types across time; 2) testing for differences in gene expression within the brain associated with this behavioral variation; and 3) using genetic polymorphisms to test for associations with ecotype, as well as population structure, in polymorphic populations. First, we evaluated the variation in a suite of ecologically relevant behaviors across time in juvenile progeny produced from crosses within …

Go to article

Molecular Variation In Avp And Avpr1a In New World Monkeys (Primates, Platyrrhini): Evolution And Implications For Social Monogamy, Dongren Ren, Kelvin R. Chin, Jeffrey French Oct 2014

Molecular Variation In Avp And Avpr1a In New World Monkeys (Primates, Platyrrhini): Evolution And Implications For Social Monogamy, Dongren Ren, Kelvin R. Chin, Jeffrey French

Biology Faculty Publications

The neurohypophysial hormone arginine vasopressin (AVP) plays important roles in fluid regulation and vascular resistance. Differences in AVP receptor expression, particularly mediated through variation in the noncoding promoter region of the primary receptor for AVP (AVPR1a), may play a role in social phenotypes, particularly social monogamy, in rodents and humans. Among primates, social monogamy is rare, but is common among New World monkeys (NWM). AVP is a nonapeptide and generally conserved among eutherian mammals, although a recent paper demonstrated that some NWM species possess a novel form of the related neuropeptide hormone, oxytocin. We therefore characterized variation in the AVP …

Go to article

Hypogammaglobulinemia In Blt Humanized Mice – An Animal Model Of Primary Antibody Deficiency, Francisco Martinez-Torres, Tomonori Nochi, Angela Wahl, J. Victor Garcia, Paul W. Denton Oct 2014

Hypogammaglobulinemia In Blt Humanized Mice – An Animal Model Of Primary Antibody Deficiency, Francisco Martinez-Torres, Tomonori Nochi, Angela Wahl, J. Victor Garcia, Paul W. Denton

Biology Faculty Publications

Primary antibody deficiencies present clinically as reduced or absent plasma antibodies without another identified disorder that could explain the low immunoglobulin levels. Bone marrow-liver-thymus (BLT) humanized mice also exhibit primary antibody deficiency or hypogammaglobulinemia. Comprehensive characterization of B cell development and differentiation in BLT mice revealed other key parallels with primary immunodeficiency patients. We found that B cell ontogeny was normal in the bone marrow of BLT mice but observed an absence of switched memory B cells in the periphery. PC-KLH immunizations led to the presence of switched memory B cells in immunized BLT mice although plasma cells producing PCor …

Go to article

Parental Care In The Cuatro Ciénegas Cichlid, Herichthys Minckleyi (Teleostei: Cichlidae), Ronald G. Oldfield, M. Xavier Nieves Oct 2014

Parental Care In The Cuatro Ciénegas Cichlid, Herichthys Minckleyi (Teleostei: Cichlidae), Ronald G. Oldfield, M. Xavier Nieves

Faculty Scholarship

Behavioral studies have often examined parental care by measuring phenotypic plasticity of behavior within a species. Phylogenetic studies have compared parental care among species, but only at broad categories (e.g., care vs. no care). Here we provide a detailed account that integrates phylogenetic analysis with quantitative behavioral data to better understand parental care behavior in the Cuatro Ciénegas cichlid, Herichthys minckleyi. We found that H. minckleyi occurs in a clade of sexually monochromatic or weakly dichromatic monogamous species, but that male and female H. minckleyi have dramatically different reproductive coloration patterns, likely as a result of sexual selection. Furthermore, we …

Go to article

How Discordant Morphological And Molecular Evolution Among Microorganisms Can Revise Our Notions Of Biodiversity On Earth, Daniel J.G. Lahr, Haywood Dail Laughinghouse, Angela M. Oliverio, Feng Gao, Laura A. Katz Oct 2014

How Discordant Morphological And Molecular Evolution Among Microorganisms Can Revise Our Notions Of Biodiversity On Earth, Daniel J.G. Lahr, Haywood Dail Laughinghouse, Angela M. Oliverio, Feng Gao, Laura A. Katz

Biological Sciences: Faculty Publications

Microscopy has revealed tremendous diversity of bacterial and eukaryotic forms. Recent molecular analyses show discordance in estimates of biodiversity between morphological and molecular analyses. Moreover, phylogenetic analyses of the diversity of microbial forms reveal evidence of convergence at scales as deep as interdomain: morphologies shared between bacteria and eukaryotes. Here, we highlight examples of such discordance, focusing on exemplary lineages such as testate amoebae, ciliates, and cyanobacteria. These have long histories of morphological study, enabling deeper analyses on both the molecular and morphological sides. We discuss examples in two main categories: (i) morphologically identical (or highly similar) individuals that are …

Go to article

An Rnai-Based Suppressor Screen Identifies Interactors Of The Myt1 Ortholog Of Caenorhabditis Elegans, Anna Allen, Jessica Nesmith, Andy Golden Oct 2014

An Rnai-Based Suppressor Screen Identifies Interactors Of The Myt1 Ortholog Of Caenorhabditis Elegans, Anna Allen, Jessica Nesmith, Andy Golden

Department of Biology Faculty Publications

Oocyte maturation in all species is controlled by a protein complex termed the maturation promoting factor (MPF). MPF is comprised of a cyclin-dependent kinase (CDK) and its partner cyclin, and is regulated by dueling regulatory phosphorylation events on the CDK. In Caenorhabditis elegans, the Wee1/Myt1 ortholog WEE-1.3 provides the inhibitory phosphorylations on CDK-1 that keep MPF inactive and halts meiosis. Prior work has shown that depletion of WEE-1.3 in C. elegans results in precocious oocyte maturation in vivo and a highly penetrant infertility phenotype. This study sought to further define the precocious maturation phenotype and to identify novel interactors with …

Go to article

Nectar Yeasts In The Tall Larkspur Delphinium Barbeyi (Ranunculaceae) And Effects On Components Of Pollinator Foraging Behavior, Robert N. Schaeffer, Cody R. Phillips, M. Catherine Duryea, Jonathan Andicoechea, Rebecca E. Irwin Oct 2014

Nectar Yeasts In The Tall Larkspur Delphinium Barbeyi (Ranunculaceae) And Effects On Components Of Pollinator Foraging Behavior, Robert N. Schaeffer, Cody R. Phillips, M. Catherine Duryea, Jonathan Andicoechea, Rebecca E. Irwin

Dartmouth Scholarship

Microorganisms frequently colonize the nectar of angiosperm species. Though capable of altering a suite of traits important for pollinator attraction, few studies exist that test the degree to which they mediate pollinator foraging behavior. The objective of our study was to fill this gap by assessing the abundance and diversity of yeasts associated with the perennial larkspur Delphinium barbeyi (Ranunculaceae) and testing whether their presence affected components of pollinator foraging behavior. Yeasts frequently colonized D. barbeyi nectar, populating 54–77% of flowers examined depending on site. Though common, the yeast community was species-poor, represented by a single species, Metschnikowia reukaufii. …

Go to article

The Ecology Of Infancy And Early Childhood In Rural Senegal; A Five Year Old Can Boot But Not Foot, An Exploration Of Where Biology Meets Culture, Heather Mills Oct 2014

The Ecology Of Infancy And Early Childhood In Rural Senegal; A Five Year Old Can Boot But Not Foot, An Exploration Of Where Biology Meets Culture, Heather Mills

Independent Study Project (ISP) Collection

This research project explores the life stages of infancy and early childhood in the village of Ndiane in the Thies region of Senegal. I will discuss how biology meets culture to influence children, parenting styles, and expectations of the life stage. How does ecology, the interaction of physical, biological and cultural landscapes, characterize childhood and the intertwined belief systems that influence parenting? The information was gathered using a combination of participant observation and free list interviews.

Go to article

Structural And Biochemical Studies Of The Carboxyltransferase Domain From Pyruvate Carboxylase, Adam David Lietzan Oct 2014

Structural And Biochemical Studies Of The Carboxyltransferase Domain From Pyruvate Carboxylase, Adam David Lietzan

Dissertations (1934 -)

Pyruvate carboxylase (PC; E.C. 6.4.1.1), a multifunctional biotin-dependent enzyme, catalyzes the bicarbonate- and MgATP-dependent carboxylation of pyruvate to oxaloacetate. To complete the overall reaction, the tethered biotin prosthetic group must first gain access to the biotin carboxylase domain and become carboxylated, and then translocate to the carboxyltransferase (CT) domain where the carboxyl group is transferred from biotin to pyruvate. Kinetic analyses of PC have suggested that the spatially distinct reactions, which occur in the active sites of the BC and CT domains, are well coordinated. To gain insights into the molecular events necessary for coordinating catalysis in the CT domain, …

Go to article

Impact Of Mtr4 Structural Domains On Its Enzymatic Activities, In The Regulation Of Nuclear Rna Turnover, Li Yan Oct 2014

Impact Of Mtr4 Structural Domains On Its Enzymatic Activities, In The Regulation Of Nuclear Rna Turnover, Li Yan

Dissertations (1934 -)

RNA processing and turnover plays an important role in RNA maturation, metabolism and quality control, which contribute to gene regulation and cell health. The TRAMP complex, composed of an RNA binding protein Air2p, a poly-A polymerase Trf4p, and a RNA helicase Mtr4p, assist nuclear exosome-dependent RNA processing and degradation in Saccharomyces cerevisiae, like tRNAiMet turnover, 5'ETS degradation and rRNA processing. Mtr4p structure reveals a novel protruding arch domain, which contains the recognizable KOW domain and a stalk domain. Except for the two conserved RecA-like helicase domains, the helicase core contains two other structural domains, a winged helix that connects arch …

Go to article

Multimodal Sensory Reliance In The Nocturnal Homing Of The Amblypygid Phrynus Pseudoparvulus (Class Arachnida, Order Amblypygi)?, Eileen A. Hebets, Alfonso Aceves-Aparicio, Samuel Aguilar-Argüello, Verner P. Bingman, Ignacio Escalante, Eben J. Gering, David R. Nelson, Jennifer Rivera, José Ángel Sánchez-Ruiz, Laura Segura-Hernández, Virginia Settepani, Daniel D. Wiegmann, Jay A. Stafstrom Oct 2014

Multimodal Sensory Reliance In The Nocturnal Homing Of The Amblypygid Phrynus Pseudoparvulus (Class Arachnida, Order Amblypygi)?, Eileen A. Hebets, Alfonso Aceves-Aparicio, Samuel Aguilar-Argüello, Verner P. Bingman, Ignacio Escalante, Eben J. Gering, David R. Nelson, Jennifer Rivera, José Ángel Sánchez-Ruiz, Laura Segura-Hernández, Virginia Settepani, Daniel D. Wiegmann, Jay A. Stafstrom

Eileen Hebets Publications

Like many other nocturnal arthropods, the amblypygid Phrynus pseudoparvulus is capable of homing. The environment through which these predators navigate is a dense and heterogeneous tropical forest understory and the mechanism(s) underlying their putatively complex navigational abilities are presently unknown. This study explores the sensory inputs that might facilitate nocturnal navigation in the amblypygid P. pseudoparvulus. Specifically, we use sensory system manipulations in conjunction with field displacements to examine the potential involvement of multimodal—olfactory and visual—stimuli in P. pseudoparvulus’ homing behavior. In a first experiment, we deprived individuals of their olfactory capacity and displaced them to the opposite side of …

Go to article

A Comparison Of The Caulobacter Na1000 And K31 Genomes Reveals Extensive Genome Rearrangements And Differences In Metabolic Potential, Kurt Ash, Theta Brown, Tynetta Watford, Latia E. Scott, Craig Stephens, Bert Ely Oct 2014

A Comparison Of The Caulobacter Na1000 And K31 Genomes Reveals Extensive Genome Rearrangements And Differences In Metabolic Potential, Kurt Ash, Theta Brown, Tynetta Watford, Latia E. Scott, Craig Stephens, Bert Ely

Faculty Publications

The genus Caulobacter is found in a variety of habitats and is known for its ability to thrive in low-nutrient conditions. K31 is a novel Caulobacter isolate that has the ability to tolerate copper and chlorophenols, and can grow at 4°C with a doubling time of 40 h. K31 contains a 5.5 Mb chromosome that codes for more than 5500 proteins and two large plasmids (234 and 178 kb) that code for 438 additional proteins. A comparison of the K31 and the Caulobacter crescentus NA1000 genomes revealed extensive rearrangements of gene order, suggesting that the genomes had been randomly scrambled. …

Go to article

Recruitment Patterns Of Juvenile Fish At An Artificial Reef In The Gulf Of Mexico, Rachel Noel Arney Oct 2014

Recruitment Patterns Of Juvenile Fish At An Artificial Reef In The Gulf Of Mexico, Rachel Noel Arney

Theses and Dissertations - UTB/UTPA

In 2011, the Texas Parks and Wildlife Department deployed 4,000 culverts as an artificial reef off Port Mansfield, TX to serve as habitat for sport fish species in the Gulf of Mexico. The aim of this study was to assess juvenile fish recruitment at particular culvert densities among the reef. Standard monitoring units for the recruitment of reef fish (SMURFs) were used in this study and acted as sampling devices. SMURFs were placed at thirteen sampling stations among four different reef patch densities and sampled repeatedly from 2013-2014. Culvert densities included stations with: zero culverts, 1-50 culverts, 51-100 culverts, and …

Go to article

Learning From Conservation Planning For The U.S. National Wildlife Refuges, Robert L. Fischman, Vicky J. Meretsky Oct 2014

Learning From Conservation Planning For The U.S. National Wildlife Refuges, Robert L. Fischman, Vicky J. Meretsky

Articles by Maurer Faculty

The U.S. National Wildlife Refuge System has nearly completed its first round of unit-level, comprehensive conservation plans (CCPs) and will soon begin required revisions. Laws and policies governing refuge planning emphasize ecological integrity, landscape-scale conservation, and adaptive management. We evaluated 185 CCPs completed during 2005–2011, which cover 324 of 555 national wildlife refuges. We reviewed CCP prescriptions addressing 5 common conservation issues (habitat and game, nongame, imperiled, and invasive species) and 3 specialized topics (landscape-scale conservation, climate change, and environmental quality). Common conservation issues received prescriptions in >90% of CCPs. Specialized topics received more variable treatment. Prescriptions for aquatic connectivity, …

Go to article

Investigating The Role Of Micrornas In The Response To Nitrogen Deprivation In The Green Alga Chlamydomonas Reinhardtii, Adam Voshall Oct 2014

Investigating The Role Of Micrornas In The Response To Nitrogen Deprivation In The Green Alga Chlamydomonas Reinhardtii, Adam Voshall

School of Biological Sciences: Dissertations, Theses, and Student Research

Microalgae are gaining attention as a potential feedstock for the production of biodiesel, mainly derived from triacylglycerols (TAG). In many algae, TAG synthesis increases dramatically upon certain stresses but this is often accompanied by growth retardation. Rational improvements to strain productivity are limited by the scant knowledge on algal lipid metabolism and gene regulatory mechanisms. In this context, systems-level approaches aimed at understanding and modeling metabolic and regulatory networks may enable hypothesis-driven genetic engineering strategies. The green microalga Chlamydomonas reinhardtii accumulates significant amounts of TAGs under nutrient starvation and provides a genetically tractable model for manipulating biosynthetic pathways. In order …

Go to article

Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands, Mariano Soley Oct 2014

Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands, Mariano Soley

Dissertations, Theses, and Capstone Projects

This dissertation focused on the methodological and theoretical improvement of correlative ecological niche models (ENMs) to better understand the processes governing species distributions and associated evolutionary divergence in rodents inhabiting mesic conditions in the Neotropics. Focusing on a widespread rodent from northern South America (Heteromys anomalus), in the first chapter I proposed and tested a methodological approach to surmount the challenge of incorporating environmental information from the margins of species geographic ranges into ENMs. In so doing, I argue how populations that exist on the borders of species' local ranges (spatial margins) can lead to exaggerated estimates of their niches …

Go to article

Foraging Ecology Of Shorebirds At A Stopover Site: Niche Dynamics, Aggression And Resource Use In Delaware Bay, Ivana Novcic Oct 2014

Foraging Ecology Of Shorebirds At A Stopover Site: Niche Dynamics, Aggression And Resource Use In Delaware Bay, Ivana Novcic

Dissertations, Theses, and Capstone Projects

Classical ecological theory predicts that generally similar species ought to partition resources in order to minimize competition amongst themselves. This basic idea becomes complex when one is dealing with species that migrate over thousands of miles and forage in a broad diversity of habitats and geographical locations. I studied a suite of migratory sandpipers, and asked whether they partitioned niches at a major migratory stopover in Delaware Bay. During migration, shorebirds form large, usually mixed-species flocks, which forage on marshes, mudflats, beaches or similar two-dimensional habitats where all individuals are distributed on the same horizontal plane. These habitats are often …

Go to article

First Prev Next Last