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2015

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Articles 931 - 960 of 1751

Full-Text Articles in Biology

Transfer Of Heavy Metals Through Terrestrial Food Webs: A Review, Jillian E. Gall, Robert Boyd, Nishanta Rajakaruna Apr 2015

Transfer Of Heavy Metals Through Terrestrial Food Webs: A Review, Jillian E. Gall, Robert Boyd, Nishanta Rajakaruna

Biological Sciences

Heavy metals are released into the environment by both anthropogenic and natural sources. Highly reactive and often toxic at low concentrations, they may enter soils and groundwater, bioaccumulate in food webs, and adversely affect biota. Heavy metals also may remain in the environment for years, posing long-term risks to life well after point sources of heavy metal pollution have been removed. In this review, we compile studies of the community-level effects of heavy metal pollution, including heavy metal transfer from soils to plants, microbes, invertebrates, and to both small and large mammals (including humans). Many factors contribute to heavy metal …


A Preliminary Survey Of The Diversity Of Soil Algae And Cyanoprokaryotes On Mafic And Ultramafic Substrates In South Africa, Arthurita Venter, Anatoliy Levanets, Stefan Siebert, Nishanta Rajakaruna Apr 2015

A Preliminary Survey Of The Diversity Of Soil Algae And Cyanoprokaryotes On Mafic And Ultramafic Substrates In South Africa, Arthurita Venter, Anatoliy Levanets, Stefan Siebert, Nishanta Rajakaruna

Biological Sciences

Despite a large body of work on the serpentine-substrate effect on vascular plants, little work has been undertaken to describe algal communities found on serpentine soils derived from peridotite and other ultramafic rocks. We report a preliminary study describing the occurrence of algae and cyanoprokaryotes on mafic and ultramafic substrates from South Africa. Results suggest that slope and aspect play a key role in species diversity and community composition and, although low pH, nutrients and metal content do not reduce species richness, these edaphic features also influence species composition. Further, typical soil genera such as Leptolyngbya, Microcoleus, Phormidium …


Growth And Nickel Uptake By Serpentine And Non-Serpentine Populations Of Fimbristylis Ovata (Cyperaceae) From Sri Lanka, P. K. D. Chathuranga, S. K. A. T. Dharmasena, Nishanta Rajakaruna, M.C.M. Iqbal Apr 2015

Growth And Nickel Uptake By Serpentine And Non-Serpentine Populations Of Fimbristylis Ovata (Cyperaceae) From Sri Lanka, P. K. D. Chathuranga, S. K. A. T. Dharmasena, Nishanta Rajakaruna, M.C.M. Iqbal

Biological Sciences

Compared with serpentine floras of Southeast Asia, the serpentine vegetation of Sri Lanka is impoverished in regard to serpentine endemics and nickel hyperaccumulators. All species so far documented from the serpentine outcrops of Sri Lanka also have non-serpentine populations; it is unclear whether the serpentine populations are physiologically distinct and deserve ecotypic recognition. We conducted a preliminary study to examine whether serpentine and non-serpentine populations of Fimbristylis ovata represent locally adapted ecotypes by investigating their growth and potential for nickel uptake and tolerance under greenhouse conditions. Although both populations of F. ovata showed a similar growth pattern in serpentine soil …


Vegetation Dynamics And Mesophication In Response To Conifer Encroachment Within An Ultramafic System, J. Burgess, K. Szlavecz, N. Rajakaruna, S. Lev, C. Swan Apr 2015

Vegetation Dynamics And Mesophication In Response To Conifer Encroachment Within An Ultramafic System, J. Burgess, K. Szlavecz, N. Rajakaruna, S. Lev, C. Swan

Biological Sciences

The biological, ecological, and evolutionary significance of serpentine habitats has long been recognised. We used an integrated physiochemical dataset combining plot spatial data with temporal data from tree cores to evaluate changes in soils and vegetation. Data suggest that this unique habitat is undergoing a transition, endangering local biodiversity and endemic plant species. The objective of this work was to analyse the vegetation dynamics of a xeric serpentine savanna located in the Mid-Atlantic, USA. We employed vegetation surveys of 32 10 × 15 m quadrats to obtain woody species composition, density, basal area, and developed a spatial physiochemical dataset of …


Is Green Tea The Panacea We’Ve Been Searching For? A Review Of The Scientific Literature On Green Tea And Human Health, Eleanor L. Axson Apr 2015

Is Green Tea The Panacea We’Ve Been Searching For? A Review Of The Scientific Literature On Green Tea And Human Health, Eleanor L. Axson

Senior Honors Projects

There are many claims surrounding the health benefits of consuming green tea, some of which involve its use in the treatment of medical conditions as wide ranging as cancer, diabetes, and neuro-degenerative disorders. The desire for the use of non-toxic and natural drugs to treat various diseases makes any health-benefitting claims about green tea and its components important to investigate for their potential public health benefits. I conducted a critical review of the research literature on green tea and its effects on human health and synthesized the results. There is convincing epidemiological evidence pointing to the health benefits derived from …


Alkaloid-Based Chemical Defenses In The Brazilian Poison Frog Melanophryniscus Simplex Inhibit Mycobacterial Growth, Megan A. Boyk Apr 2015

Alkaloid-Based Chemical Defenses In The Brazilian Poison Frog Melanophryniscus Simplex Inhibit Mycobacterial Growth, Megan A. Boyk

Senior Honors Projects

This study investigated the antimycobacterial properties of M. simplex alkaloids from geographically isolated populations against two species of mycobacteria, M. smegmatis, a soil-dwelling species, and M. phlei, a saprophytic species (Berney et al. 2014; Egamberdieva 2011). Both of these species are fast-growing, commonly found in the environment, and typically nonpathogenic in healthy animals (Balazova et al. 2014, Berney et al. 2014, Egamberdieva 2011). Both M. smegmatis and M. phlei are commonly used as model strains for the study of antimycobacterial agents (Zhang et al. 2014, Bruce-Micah et al. 2009). Optical density and colony-forming unit assays were used to evaluate …


Age-Dependent Modifications Of Axons, Mitochondrial Dynamics, And Ca2+ Homeostasis Underlie The Vulnerability Of Aging White Matter To Ischemia, Katharine E. Stahon Apr 2015

Age-Dependent Modifications Of Axons, Mitochondrial Dynamics, And Ca2+ Homeostasis Underlie The Vulnerability Of Aging White Matter To Ischemia, Katharine E. Stahon

Senior Honors Projects

Aging white matter (WM) is increasingly susceptible to neurodegenerative diseases and stroke. Among others, changes in ATP production, mitochondrial dynamics, and Ca2+ homeostasis contribute to increased susceptibility of aging WM to stroke. We utilized a pure white matter tract, mouse optic nerve (MON), obtained from 2- and 12-month old mice to quantify axon structure and function using electrophysiology, 3D-EM, immunoblots, and ATP assays. Functionally, aging axons did not recover as well after ischemia compared to young axons. Structurally, aging axons became thicker with lower G ratios, indicating increased myelin thickness, as well as increased internodal distances and nodal lengths. …


Fisheries Management Paper No.273 - Blue Swimmer Crab Resource Of The Peel-Harvey Estuary Harvest Strategy, 2015-2020. Version 1.0, Department Of Fisheries, Western Australia Apr 2015

Fisheries Management Paper No.273 - Blue Swimmer Crab Resource Of The Peel-Harvey Estuary Harvest Strategy, 2015-2020. Version 1.0, Department Of Fisheries, Western Australia

Fisheries Management Papers

Harvest strategies for aquatic resources managed by the Western Australian Department of Fisheries (the Department) are formal documents prepared to support the decision-making processes required to ensure the management of these resources are consistent with the principles of Ecologically Sustainable Development (ESD). The objectives of ESD are reflected in the objects of the Fish Resources Management Act 1994 (FRMA), Section 3, and the draft Aquatic Resources Management Bill 2013 (ARMB), Clause 9, which will replace the FRMA once enacted.

The publication of these strategies is intended to make the decision-making considerations and processes for the management of specified aquatic resources …


Plant-Soil Relations On Gypsum And Non-Gypsum Soils Of The Chihuahuan Desert, Clare Muller Apr 2015

Plant-Soil Relations On Gypsum And Non-Gypsum Soils Of The Chihuahuan Desert, Clare Muller

Senior Honors Projects

No abstract provided.


Is Green Tea The Panacea We’Ve Been Searching For? A Review Of The Scientific Literature On Green Tea In Health, Eleanor L. Axson Apr 2015

Is Green Tea The Panacea We’Ve Been Searching For? A Review Of The Scientific Literature On Green Tea In Health, Eleanor L. Axson

Celebration of Scholarship 2012-2017

No abstract provided.


Clonal Integration In Ludwigia Hexapetala Under Different Light Regimes, Rebecca E. Drenovsky, R. E. Glover, C. J. Futrell, Brenda J. Grewell Apr 2015

Clonal Integration In Ludwigia Hexapetala Under Different Light Regimes, Rebecca E. Drenovsky, R. E. Glover, C. J. Futrell, Brenda J. Grewell

Biology

Physiological integration among ramets of invasive plant species may support their colonization and spread in novel aquatic environments where growth-limiting resources are spatially heterogeneous. Under contrasting light conditions, we investigated how clonal integration influences growth, biomass allocation and morphology of Ludwigia hexapetala, an emergent floating-leaved macrophyte that is highly invasive in a range of wetland habitat types. In aquatic mesocosms, stolons of offspring ramets were either connected or severed from parent plants, with the pairs exposed to homogenous or heterogeneous combinations of sun or 85% shade. Morphological traits of all ramets were strongly influenced by light environment, and low …


Specification Of Select Hypothalamic Circuits And Innate Behaviors By The Embryonic Patterning Gene Dbx1, Kevin Jones Apr 2015

Specification Of Select Hypothalamic Circuits And Innate Behaviors By The Embryonic Patterning Gene Dbx1, Kevin Jones

Department of Biology Faculty Publications

The hypothalamus integrates information required for the production of a variety of innate behaviors such as feeding, mating, aggression, and predator avoidance. Despite an extensive knowledge of hypothalamic function, how embryonic genetic programs specify circuits that regulate these behaviors remains unknown. Here, we find that in the hypothalamus the developmentally regulated homeodomain-containing transcription factor Dbx1 is required for the generation of specific subclasses of neurons within the lateral hypothalamic area/zona incerta (LH) and the arcuate (Arc) nucleus. Consistent with this specific developmental role, Dbx1 hypothalamic-specific conditional-knockout mice display attenuated responses to predator odor and feeding stressors but do not display …


Distinguishing The Neches River Rose Mallow, Hibiscus Dasycalyx, From Its Congeners Using Dna Sequence Data And Niche Modeling Methods, Melody P. Sain Apr 2015

Distinguishing The Neches River Rose Mallow, Hibiscus Dasycalyx, From Its Congeners Using Dna Sequence Data And Niche Modeling Methods, Melody P. Sain

Biology Theses

The accurate identification of species that are in need of protection is one of the most essential challenges of conservation biology (Lovich and Gibbons, 1997). When deciding if a species needs conservation protection, there are two main scientific concerns that must be addressed: (1) determining if the taxonomic standing of the target species is upheld (i.e., if it is a real, rare species) and (2) deciding where the target species occurs or is likely to occur. In this study we used an integrative approach combining ecological niche modeling and molecular genetics to understand the taxonomy of a federally threatened Hibiscus …


The Molecular Biology Capstone Assessment: A Concept Assessment For Upper-Division Molecular Biology Students, Brian A. Couch, William B. Wood, Jennifer K. Knight Apr 2015

The Molecular Biology Capstone Assessment: A Concept Assessment For Upper-Division Molecular Biology Students, Brian A. Couch, William B. Wood, Jennifer K. Knight

School of Biological Sciences: Faculty Publications

Measuring students’ conceptual understandings has become increasingly important to biology faculty members involved in evaluating and improving departmental programs. We developed the Molecular Biology Capstone Assessment (MBCA) to gauge comprehension of fundamental concepts in molecular and cell biology and the ability to apply these concepts in novel scenarios. Targeted at graduating students, the MBCA consists of 18 multiple-true/false (T/F) questions. Each question consists of a narrative stem followed by four T/F statements, which allows a more detailed assessment of student understanding than the traditional multiple-choice format. Questions were iteratively developed with extensive faculty and student feedback, including validation through faculty …


Female Mate Choice In A Mainland Population Of The Strawberry Poison Frog, Oophaga Pumilio, Meaghan Gade Apr 2015

Female Mate Choice In A Mainland Population Of The Strawberry Poison Frog, Oophaga Pumilio, Meaghan Gade

Masters Theses

Sexual selection and female mate choice are driving forces in the evolution and maintenance of biological diversity, and may function in the evolution of many secondary sexual characteristics throughout multiple taxa. Female mate selection has been experimentally shown to drive the evolution of color between the polytypic populations of the dendrobatid frog, Oophaga pumilio, in the Bocas del Toro archipelago in Panama. However, limited studies exist examining biologically relevant female mate choices within a single population. Using analogous experimental arenas from previous studies, females were presented with two males exhibiting phenotypic extremes from within the same population at La Selva …


Volume 07, Rachel C. Lombardi, Ben Osterhout, Lindsay Graybill, Rebecca E. Dey, Skyler T. Carpenter, Emma Beckett, Jason Ware, Mollie Andrews, James Bates, Landon Cooper, Tiffani Jeffries, Maria Wheaton, Dallas Price, Laura Kahler, Sarah Charlton, Anna Bultrowicz, Emily Spittle, Erin Godwin, Eamon Brokenbrough Apr 2015

Volume 07, Rachel C. Lombardi, Ben Osterhout, Lindsay Graybill, Rebecca E. Dey, Skyler T. Carpenter, Emma Beckett, Jason Ware, Mollie Andrews, James Bates, Landon Cooper, Tiffani Jeffries, Maria Wheaton, Dallas Price, Laura Kahler, Sarah Charlton, Anna Bultrowicz, Emily Spittle, Erin Godwin, Eamon Brokenbrough

Incite: The Journal of Undergraduate Scholarship

Introduction from Interim Dean Dr. Jennifer Apperson

Spatial Analysis of Potential Risk Factors Associated with Addition of Atlantic Coast Pipeline Through Virginia by Rachel C. Lombardi

"Delicate Matters with No Speaking," "Hope and Nothing," "Mono Duality" by Ben Osterhout

"Connect" Graphic Design Senior Project by Lindsay Graybill

Phenolic Acids in Brassicaceae Plants: Ovipositional Stimulants or Deterrents for Cabbage White Butterfly, Pieris Rapae? by Rebecca E. Dey And Skyler T. Carpenter

"Abecedarian Cards" by Emma Beckett, Jason Ware, And Mollie Andrews

Helvetica: A Type Specimen Book by James Bates, Landon Cooper, Tiffani Jeffries, And Maria Wheaton

“Things Left Behind” by Dallas …


Ph Dependence Of Dna Binding Of Dna Polymerase 1klenow-Like Fragments From D. Radiodurans, T. Aquaticus,And .E Coli, Katelyn Jackson Apr 2015

Ph Dependence Of Dna Binding Of Dna Polymerase 1klenow-Like Fragments From D. Radiodurans, T. Aquaticus,And .E Coli, Katelyn Jackson

Honors Capstones

No abstract provided.


Shell Matrix Protein Gene Composition In Two Marine Bivalve Species, Saxidomus Gigantea And Mytilus Trossulus., Katie Benson Apr 2015

Shell Matrix Protein Gene Composition In Two Marine Bivalve Species, Saxidomus Gigantea And Mytilus Trossulus., Katie Benson

Honors Capstones

No abstract provided.


Characterization Of A Novel Retrotransposon In New World Monkeys, Sreeja Sanampudi Apr 2015

Characterization Of A Novel Retrotransposon In New World Monkeys, Sreeja Sanampudi

Honors Capstones

No abstract provided.


His-Tagged And Myc-Tagged Βca Fusion Genes May Aid In The Characterization Of The Role Of Carbonic Anhydrases In Photosynthesis, Dequantarius Speed Apr 2015

His-Tagged And Myc-Tagged Βca Fusion Genes May Aid In The Characterization Of The Role Of Carbonic Anhydrases In Photosynthesis, Dequantarius Speed

Honors Capstones

No abstract provided.


Identification Of A New Fatty Acid Catabolic Pathway During Heterotrophic Growth In Chlamydomonas Reinhardtii, Clayton Mccuiston Apr 2015

Identification Of A New Fatty Acid Catabolic Pathway During Heterotrophic Growth In Chlamydomonas Reinhardtii, Clayton Mccuiston

Honors Capstones

No abstract provided.


Physical Actvity In Pregnant Rat Dams Reduces Mammary Tumor Formation In Offspring, Leon Clah Apr 2015

Physical Actvity In Pregnant Rat Dams Reduces Mammary Tumor Formation In Offspring, Leon Clah

Open Access Theses

Breast cancer is the most frequently diagnosed cancer and a leading cause of cancer death among women. Lifestyle factors such as physical activity and diet play a role in attenuating the incidence of breast cancer. Current research is beginning to show that exercise during pregnancy can convey long term health benefits to offspring. In light of these studies, the goal of this project was to determine if maternal physical activity during pregnancy could lead to reduced mammary tumor development in female offspring. Towards this goal, female Sprague Dawley rats were divided into two groups, sedentary and exercise, with the exercise …


Mass Transfer Of Large Molecules Through Collagen And Collagen-Silica Hybrid Membranes, Pedro Jofre Lora Apr 2015

Mass Transfer Of Large Molecules Through Collagen And Collagen-Silica Hybrid Membranes, Pedro Jofre Lora

Open Access Theses

Diabetes is a growing concern in the United States and around the world that must be addressed through new treatment options. Current standard treatment options of diabetes are limiting and have tremendous impacts on patient's lives. Emerging therapies, such as the implantation of encapsulated islets, are promising treatment options, but have not yet materialized due to unsolved problems with material properties. Hybrid silica-collagen membranes address some of these unsolved problems and are a promising material for cell encapsulation. However, the mass transfer properties of large molecules, such as insulin, TNF-α, IL1β, and other important proteins in the etiology of diabetes, …


Analysis Of Chd Remodelers During Development: A Tale In Two Organisms, Brett Bishop Apr 2015

Analysis Of Chd Remodelers During Development: A Tale In Two Organisms, Brett Bishop

Open Access Dissertations

The correct development of different organisms requires the precise timing of genes important for development transitions. Organisms have recruited ATP-dependent chromatin remodelers to ensure the correct timing of gene expression during developmental transitions. Here I show how different CHD ATP-dependent chromatin remodelers regulate developmental transitions of different organisms. I show that PICKLE not only promotes H3K27me3 during development to repress developmental genes but also is targeted to these genes. The association of PICKLE to these genes suggests that both repression and H3K27me3 levels is a direct action of PICKLE on these loci. Using zebrafish as a model system, I show …


Monarch Butterfly, Sam Baker Apr 2015

Monarch Butterfly, Sam Baker

Sustainability

No abstract provided.


Investigation Of The Genetic Interactions Between Hippo Signaling Pathway And Drosophila C-Terminal Src Kinase (Dcsk), Hailey Jimin Kwon Apr 2015

Investigation Of The Genetic Interactions Between Hippo Signaling Pathway And Drosophila C-Terminal Src Kinase (Dcsk), Hailey Jimin Kwon

Honors Theses

The focus of my research revolved around the intersection between the Hippo tumor suppressor pathway and the Src oncogenic pathway. Both pathways control tissue and organ size during development by regulating cell proliferation, cell death, cell migration, and cell adhesion. Aberrant functions in either pathway are often detected in human cancers and correlate with poor prognosis. The Drosophila C-terminal Src kinase (dCsk) is a genetic modifier of warts (wts), a tumor-suppressor gene in the Hippo pathway, and interacts with the Src oncogene. Reduction in dCsk expression and the consequent activation of Src are reported in hepatocellular and colorectal tumors. …


Computational Modeling Of Β5-Β6 Carbapenemase Loop In Wild Type And Selected Mutants Of Oxa-24 Class D Β-Lactamase, James Roland Lafleur Apr 2015

Computational Modeling Of Β5-Β6 Carbapenemase Loop In Wild Type And Selected Mutants Of Oxa-24 Class D Β-Lactamase, James Roland Lafleur

Masters Theses

Bacterial resistance to antibiotic therapies, especially to β-lactams, is an increasing problem. β-lactamases are the main source of clinical resistance to these antibiotics, and the class D β-lactamases are one of the most rapidly expanding classes of these enzymes. The emergence of class D enzymes with the ability to hydrolyze the newest family of β-lactams - the carbapenems - is a serious concern for the healthcare system as carbapenems are last resort antibiotics: ideal for severe infections after other therapies have failed. Class D β-lactamases are very diverse in terms of sequence and substrate profile, and it remains unclear what …


Evolution Of Invasive Species In Response To Management: Potential For Herbicide Resistance In Watermilfoil, Lindsey-Ann Louise Schulte Apr 2015

Evolution Of Invasive Species In Response To Management: Potential For Herbicide Resistance In Watermilfoil, Lindsey-Ann Louise Schulte

Masters Theses

Herbicides are commonly used to control invasive plants. While agricultural weed scientists have focused on herbicide resistance, little is known about its importance in nonagricultural settings. Hybrid Eurasian watermilfoil (Myriophyllum spicatum x M. sibiricum) is an invasive aquatic plant that is frequently managed with herbicides throughout the United States. In this thesis, I consider the potential for natural populations of this taxon evolving resistance to 2,4-dichlorophenoxyacetic acid (2,4-D), the most commonly used systemic herbicide. Evolutionary change in a trait between generations as a result of selection requires both genetically based variation of the trait within a generation (heritable …


Photophysiological Studies Of Cyanobacterial Mats In Submerged Sinkholes Of Lake Huron, Michael Snider Apr 2015

Photophysiological Studies Of Cyanobacterial Mats In Submerged Sinkholes Of Lake Huron, Michael Snider

Masters Theses

No abstract provided.


Documenting Annual Differences In Vegetation Cover, Height And Diversity Near Barrow, Alaska, Timothy Frederick Botting Apr 2015

Documenting Annual Differences In Vegetation Cover, Height And Diversity Near Barrow, Alaska, Timothy Frederick Botting

Masters Theses

Vegetation in the Arctic has been shown to respond to climate change. Documented changes have the potential to result in numerous ecosystem consequences. Therefore, understanding vegetation change is of great importance. This study documents changes in tundra vegetation with a focus on understanding the influence of annual differences in weather. Vegetation was sampled using a point frame method on 98 1-m2 plots in 2010 and 2013 near Barrow, Alaska. A subset of 30 of these plots was also sampled in 2012 and 2014. Plant encounters were identified to species and grouped into one of the following functional groups: bryophytes, …