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Articles 481 - 510 of 553

Full-Text Articles in Biology

Utilization Of Phylogenetic Systematics, Molecular Evolution, And Comparative Transcriptomics To Address Aspects Of Nematode And Bacterial Evolution, Scott M. Peat Jun 2010

Utilization Of Phylogenetic Systematics, Molecular Evolution, And Comparative Transcriptomics To Address Aspects Of Nematode And Bacterial Evolution, Scott M. Peat

Theses and Dissertations

Both insect parasitic/entomopathogenic nematodes and plant parasitic nematodes are of great economic importance. Insect parasitic/entomopathogenic nematodes provide an environmentally safe and effective method to control numerous insect pests worldwide. Alternatively, plant parasitic nematodes cause billions of dollars in crop loss worldwide. Because of these impacts, it is important to understand how these nematodes evolve, and, in the case of entomopathogenic nematodes, how their bacterial symbionts evolve. This dissertation contains six chapters. Chapter one is a review of DNA markers and their use in the phylogenetic systematics of entomopathogenic and insect-parasitic nematodes as well as a review of phylogenetic, co-phylogenetic, and …


Infrageneric Relationships Within Collomia (Polemoniaceae), Eric Stewart Green Jun 2010

Infrageneric Relationships Within Collomia (Polemoniaceae), Eric Stewart Green

Theses and Dissertations

Traditional evolutionary models depict evolution as a bifurcating pattern with a single ancestor diverging to form two lineages. However, reticulate species resulting from hybridization and recombination have unique histories shared with two independent lineages, not one. Accounting for the genetic histories of reticulate species increases the power and ability to recover biologically meaningful relationships. The genus Collomia (Polemoniaceae) is used to explore issues of reticulation and the importance of accounting for gene histories in a phylogenetic analysis. The issue of reticulation within species trees is discussed with a multilabeled, network approach being explored to better represent the genus's evolutionary history. …


Investigation Of Science Education Attitudes In Alternative High School Settings, Sarah Jane Rogers May 2010

Investigation Of Science Education Attitudes In Alternative High School Settings, Sarah Jane Rogers

Theses and Dissertations

This study compared the attitudes of administrators, teachers and students in school settings for at-risk students. Students are considered at-risk if they are not academically successful. Teacher and student science education attitudes were analyzed by survey data and categorization of teaching practices. Additionally, data from classroom videotapes and teacher interviews was collected to support and triangulate survey data. Study participants were selected from two school settings for at-risk students 1) public alternative schools (PAS) and 2) private residential treatment centers (RTC). When the survey questions were analyzed by school type and teacher classification several differences were found between 1) teacher …


Student Content Knowledge Increases After Participation In A Hands-On Biotechnology Intervention, Amber L. Bigler May 2010

Student Content Knowledge Increases After Participation In A Hands-On Biotechnology Intervention, Amber L. Bigler

Theses and Dissertations

Hands-on learning is at the heart of science learning. This study examined increased changes of student content knowledge in biology, particularly biotechnology, after a hands-on biotechnology intervention was implemented into a secondary school. A traditional learning school was selected for a control. Both teachers had participated in a biotechnology professional development program called Project Crawfish. Students from both schools took the same assessment before and after their respective units (biotechnology intervention and genetics unit), and the classroom was the unit of analysis (n=5, n=6, respectively). The assessment was compared as a whole and then divided into five components, eight questions …


Assessing Scientific Inquiry: Teacher Beliefs And Practices, Adam James Mitchell May 2010

Assessing Scientific Inquiry: Teacher Beliefs And Practices, Adam James Mitchell

Theses and Dissertations

Science education reform movements have long urged the use of inquiry methods in all science instruction. More recently, standards and accountability reform efforts have emphasized measuring and improving student science achievement. Researchers have questioned the alignment and balance between these reforms (Lane, 2004; Yeh, 2001). This study addresses issues faced by secondary science teachers as they simultaneously meet the goals of these reform movements. Mixed methods were used to answer the questions: 1) Can a teacher's beliefs and practices regarding inquiry teaching methods be correlated with his/her assessment practices?; 2) What item types are most commonly employed by teachers that …


Gene Flow And Dispersal Of The Caddisfly, Neothremma Alicia, In The Rocky Mountains Of Utah: A Multiscale Analysis, Xioben Jiang Apr 2010

Gene Flow And Dispersal Of The Caddisfly, Neothremma Alicia, In The Rocky Mountains Of Utah: A Multiscale Analysis, Xioben Jiang

Theses and Dissertations

We determined genetic variance and gene flow across multiple scales (reaches, tributaries, and catchments) to examine the dispersal ability of the caddisfly, Neothremma alicia in streams along the Wasatch Range in the Rocky Mountains of Utah. Neothremma alicia is one of the most abundant caddisflies in this region. We generated DNA sequence data (mitochondrial COI) from 34 reaches, nested in 15 tributaries distributed across 3 adjacent catchments. We identified 47 haplotypes from a total of 486 individuals. The most abundant haplotype (H1) was found at all sites/reaches and comprised 44% of the total number of individuals sequenced. The remaining rare …


Taxonomy And Applied Biogeography Of Mongolian Stoneflies (Insecta: Plecoptera), Sarah Walker Judson Mar 2010

Taxonomy And Applied Biogeography Of Mongolian Stoneflies (Insecta: Plecoptera), Sarah Walker Judson

Theses and Dissertations

Since the early 1900s, efforts have been made to catalogue the stoneflies of Mongolia. Taxonomic work from 1960 to 1980 greatly expanded basic lists of stoneflies in Mongolia, but no comprehensive survey or synthesis of this dispersed literature has been completed. In conjunction with a modern survey of the aquatic insects of Mongolia, we collected Plecoptera on a series of expeditions to the Selenge (north) and Altai (west) regions of Mongolia. A total of 48 species distributed in 24 genera and 8 families were documented, including 3 of the 5 Mongolian endemics, 2 new species records for Mongolia, and 1 …


Inferring Dispersal Of Aquatic Invertebrates From Genetic Variation: A Comparative Study Of An Amphipod (Talitridae Hyalella Azteca) And Mayfly (Baetidae Callibaetis Americanus) In Great Basin Springs, Heather Lynn Stutz Dec 2009

Inferring Dispersal Of Aquatic Invertebrates From Genetic Variation: A Comparative Study Of An Amphipod (Talitridae Hyalella Azteca) And Mayfly (Baetidae Callibaetis Americanus) In Great Basin Springs, Heather Lynn Stutz

Theses and Dissertations

Whether active or passive, dispersal accompanied by gene flow shapes the population genetics and evolutionary divergence of species. Indirect methods which use genetic markers have the ability to assess effective dispersal—that which resulted in gene flow. My objective was to see if an aquatic insect and an obligate aquatic invertebrate show similar phylogeographic patterns and genetic uniqueness. Hyalella azteca and Callibaetis americanus were collected from 4-5 springs in each of six basins in the Great Basin of western North America. No dispersal or genetic studies of C. americanus have been conducted to date. However, several studies focusing on mtDNA diversity …


Environmental Dna Sequencing Primers For Eutardigrades And Bdelloid Rotifers, Byron J. Adams, Jeremy Whiting, Elizabeth K. Costello, Kristen R. Freeman, Andrew P. Martin, Michael S. Robeson, Steve K. Schmidt Dec 2009

Environmental Dna Sequencing Primers For Eutardigrades And Bdelloid Rotifers, Byron J. Adams, Jeremy Whiting, Elizabeth K. Costello, Kristen R. Freeman, Andrew P. Martin, Michael S. Robeson, Steve K. Schmidt

Faculty Publications

Background: The time it takes to isolate individuals from environmental samples and then extract DNA from each individual is one of the problems with generating molecular data from meiofauna such as eutardigrades and bdelloid rotifers. The lack of consistent morphological information and the extreme abundance of these classes makes morphological identification of rare, or even common cryptic taxa a large and unwieldy task. This limits the ability to perform large-scale surveys of the diversity of these organisms. Here we demonstrate a culture-independent molecular survey approach that enables the generation of large amounts of eutardigrade and bdelloid rotifer sequence data directly …


The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen Dec 2009

The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen

Theses and Dissertations

The movement of individuals is foundational to many ecological processes. For example, the movement of an organism from one place to another alters population density at both sites and has potential for affecting the genetic dynamics within the new population. Individual movement events may be in synchrony with overall trends in populations, e.g. spawning migrations, or may be atypical (asynchronous). This latter movement type can affect population and metapopulation dynamics, depending on its prevalence within a population. Nevertheless, given the complexity of interactions, the causative factors of movement are understood vaguely, much less for aquatic organisms. Drivers of movement are …


Intraspecific Phylogeography Of Cycladenia Humilis (Apocynaceae), Mariana P. Last Nov 2009

Intraspecific Phylogeography Of Cycladenia Humilis (Apocynaceae), Mariana P. Last

Theses and Dissertations

Cycladenia humilis (Apocynaceae) is a rare perennial herb native to western North America and has a fragmented distribution in California, Utah, and Arizona. Populations in Utah and Arizona are federally listed as threatened, while there is no conservation status applied to California populations. Using genetic (three chloroplast and two nuclear DNA loci) and morphological characters, intraspecific variation between populations of C. humilis and current taxonomic conventions were assessed. Nested Clade Phylogeographic Analysis and Bayesian phylogenies were used to assess patterns within C. humilis and supported three main population groupings: a northern California, southern California, and Colorado Plateau group. The northern …


Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega Aug 2009

Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega

Faculty Publications

Life-history theory predicts that populations experiencing different levels of extrinsic mortality will evolve divergent reproductive strategies. Previous work in the live bearing fish Brachyrhaphis rhabdophora shows that individuals from populations that occur with piscivorous fish mature earlier and at smaller sizes and have more and smaller offspring than fish from populations without predators. However, until now, there have been no data to demonstrate that differences in mortality rates actually exist between predator and predator free sites. Here we present the results of a serial mark-recapture field study designed to estimate mortality rates in natural populations of B. rhabodophora from Costa …


The Trouble With Transfer, Kathryn Jane Groneman Jul 2009

The Trouble With Transfer, Kathryn Jane Groneman

Theses and Dissertations

It is hoped that the scientific reasoning skills taught in our biology courses will carry over to be applied in novel settings: to new concepts, future courses, other disciplines, and non-academic pursuits. This is the educational concept of transfer. Efforts over many years in the Cell Biology course at BYU to design effective assessment questions that measure competence in both deep understanding of conceptual principles and the ability to draw valid conclusions from experimental data have had at least one disquieting result. The transfer performance of many otherwise capable students is not very satisfactory. In order to explain this unsatisfactory …


Co-Occurrence With A Congeneric Species Predicts Life History And Morphological Diversification In The Mexican Livebearing Fish Poelicopsis Baenschi, Laura E. Scott Jul 2009

Co-Occurrence With A Congeneric Species Predicts Life History And Morphological Diversification In The Mexican Livebearing Fish Poelicopsis Baenschi, Laura E. Scott

Theses and Dissertations

Understanding why some species coexist and others do not remains one of the fundamental challenges of ecology. While several lines of evidence suggest that closely related species are unlikely to occupy the same habitat because of competitive exclusion, there are many cases where closely related species do co-occur. Research comparing sympatric and allopatric populations of co-occurring species provides a framework to understand the role of phenotypic diversification in species coexistence. In this study I focus on the livebearing fish Poeciliopsis baenschi and ask if differences in phenotypic traits among populations can be explained by the presence or absence of the …


Transcriptomic Analysis Of The Entomopathogenic Nematode Heterorhabditis Bacteriophora Tto1, Byron J. Adams, Xiaodong Bai, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Parwinder S. Grewal, Saskia A. Hogenhout, John Spieth, Paul W. Sternberg, Richard K. Wilson Apr 2009

Transcriptomic Analysis Of The Entomopathogenic Nematode Heterorhabditis Bacteriophora Tto1, Byron J. Adams, Xiaodong Bai, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Parwinder S. Grewal, Saskia A. Hogenhout, John Spieth, Paul W. Sternberg, Richard K. Wilson

Faculty Publications

Background: The entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium, Photorhabdus luminescens, are important biological control agents of insect pests. This nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. Elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. This large-scale expressed sequence tag (EST) analysis effort enables gene discovery and development of microsatellite markers. These ESTs will also aid in the annotation of the upcoming complete genome sequence of H. bacteriophora. Results: A total of 31,485 high quality ESTs were generated …


Molecular Systematics Of Spiny Pocket Mice (Subfamily Heteromyinae) Inferred From Mitochondrial And Nuclear Sequence Data, Melina Crystal Williamson Apr 2009

Molecular Systematics Of Spiny Pocket Mice (Subfamily Heteromyinae) Inferred From Mitochondrial And Nuclear Sequence Data, Melina Crystal Williamson

Theses and Dissertations

This study aims to determine species-level relationships within the genus Heteromys, as well as generic-level relationships among members of the subfamily Heteromyinae using a phylogenetic framework. Molecular sequence data were generated from two mitochondrial genes (cytochrome b and cytochrome oxidase I) and three nuclear gene segments (β-fibrinogen, engrailed protein II, and myosin heavy chain II), and analyzed under maximum parsimony, maximum likelihood, and Bayesian optimality criteria to infer relationships. Chapter 1 focuses on the phylogenetic and taxonomic implications for Heteromys from the analyses of sequence data. Phylogenies also provided a framework for delimiting species boundaries within the wide-ranging Heteromys desmarestianus …


Biogeography Of The Livebearing Fish Poecilia Gillii In Costa Rica: Are Phylogeographic Breaks Congruent With Fish Community Boundaries?, Jared Benjamin Lee Mar 2009

Biogeography Of The Livebearing Fish Poecilia Gillii In Costa Rica: Are Phylogeographic Breaks Congruent With Fish Community Boundaries?, Jared Benjamin Lee

Theses and Dissertations

One of the original goals of phylogeography was to use genetic data to identify historical events that might contribute to breaks among biotic communities. In this study, we examine the phylogeography of a common livebearing fish (Poecilia gillii) from Costa Rica. Our goal was to see if phylogeographic breaks in this species were congruent with previously-defined boundaries among four fish community provinces. We hypothesized that if abiotic factors influence both community boundaries and genetic structuring in P. gillii then we would find four monophyletic clades within our focal species that were geographically separated along community boundary lines. Similarly, we expected …


Small Mammals In Portions Of Great Basin National Park Susceptible To Groundwater Withdrawal: Diversity And Stable Isotope Perspectives, Bryan T. Hamilton Feb 2009

Small Mammals In Portions Of Great Basin National Park Susceptible To Groundwater Withdrawal: Diversity And Stable Isotope Perspectives, Bryan T. Hamilton

Theses and Dissertations

To support population growth in Las Vegas, Nevada, large scale increases in groundwater pumping are planned across the state. This pumping could affect riparian areas in Great Basin National Park by lowering groundwater levels, reducing stream flows, and xerifying riparian vegetation. Great Basin National Park (GBNP) is mandated to manage its resources unimpaired for future generations. Loss of biodiversity is unacceptable under this mandate. If groundwater levels are reduced beyond a threshold, aquatic and riparian diversity would be lost, but the effects on small mammal communities are less clear. To provide baseline information and to consider the effects of groundwater …


Desiccation Survival In An Antarctic Nematode: Molecular Analysis Using Expressed Sequenced Tags, Byron J. Adams, Bishwo N. Adhikari, Diana H. Wall Feb 2009

Desiccation Survival In An Antarctic Nematode: Molecular Analysis Using Expressed Sequenced Tags, Byron J. Adams, Bishwo N. Adhikari, Diana H. Wall

Faculty Publications

Background: Nematodes are the dominant soil animals in Antarctic Dry Valleys and are capable of surviving desiccation and freezing in an anhydrobiotic state. Genes induced by desiccation stress have been successfully enumerated in nematodes; however we have little knowledge of gene regulation by Antarctic nematodes which can survive multiple environmental stresses. To address this problem we investigated the genetic responses of a nematode species, Plectus murrayi, that is capable of tolerating Antarctic environmental extremes, in particular desiccation and freezing. In this study, we provide the first insight into the desiccation induced transcriptome of an Antarctic nematode through cDNA library construction …


Does Shape Predict Performance? An Analysis Of Morphology And Swimming Performance In Great Basin Fishes, John R. Aedo Dec 2008

Does Shape Predict Performance? An Analysis Of Morphology And Swimming Performance In Great Basin Fishes, John R. Aedo

Theses and Dissertations

Swimming performance strongly influences fitness in aquatic organisms and is closely tied to external body morphology. Although this connection has been closely examined at the individual and species level, few studies have focused on this relationship as it pertains to functional group assemblages. Using functional groups based on similarities in habitat use and morphology, I tested the hypothesis that swimming performance can be reliably predicted by functional group composition. I measured swimming performance as burst speed using a simulated predator attack and as prolonged speed using a step-endurance test in a laboratory flume. I measured morphology using geometric morphometric techniques. …


Calculating Expected Dna Remnants From Ancient Founding Events In Human Population Genetics, Nathan C. Sheffield, Keith A. Crandall, Andrew Stacey Oct 2008

Calculating Expected Dna Remnants From Ancient Founding Events In Human Population Genetics, Nathan C. Sheffield, Keith A. Crandall, Andrew Stacey

Faculty Publications

Background- Recent advancements in sequencing and computational technologies have led to rapid generation and analysis of high quality genetic data. Such genetic data have achieved wide acceptance in studies of historic human population origins and admixture. However, in studies relating to small, recent admixture events, genetic factors such as historic population sizes, genetic drift, and mutation can have pronounced effects on data reliability and utility. To address these issues we conducted genetic simulations targeting influential genetic parameters in admixed populations. Results- We performed a series of simulations, adjusting variable values to assess the affect of these genetic parameters on current …


Many Species In One: Dna Barcoding Overestimates The Number Of Species When Nuclear Mitochondrial Pseudogenes Are Coamplified, Michael F. Whiting, Hojun Song, Keith A. Crandall, Jennifer E. Buhay Sep 2008

Many Species In One: Dna Barcoding Overestimates The Number Of Species When Nuclear Mitochondrial Pseudogenes Are Coamplified, Michael F. Whiting, Hojun Song, Keith A. Crandall, Jennifer E. Buhay

Faculty Publications

Nuclear mitochondrial pseudogenes (numts) are nonfunctional copies of mtDNA in the nucleus that have been found in major clades of eukaryotic organisms.


Double-Stranded Rna-Activated Protein Kinase Pkr Of Fishes And Amphibians: Varying The Number Of Double-Stranded Rna Binding Domains And Lineage-Specific Duplications, Loubna Tazi, Stefan Rothenburg, Nikolaus Deigendesch, Madhusudan Dey, Thomas E. Dever Mar 2008

Double-Stranded Rna-Activated Protein Kinase Pkr Of Fishes And Amphibians: Varying The Number Of Double-Stranded Rna Binding Domains And Lineage-Specific Duplications, Loubna Tazi, Stefan Rothenburg, Nikolaus Deigendesch, Madhusudan Dey, Thomas E. Dever

Faculty Publications

Double-stranded (ds) RNA, generated during viral infection, binds and activates the mammalian anti-viral protein kinase PKR, which phosphorylates the translation initiation factor eIF2alpha leading to the general inhibition of protein synthesis. Although PKR-like activity has been described in fish cells, the responsible enzymes eluded molecular characterization until the recent discovery of goldfish and zebrafish PKZ, which contain Z-DNA-binding domains instead of dsRNA-binding domains (dsRBDs). Fish and amphibian PKR genes have not been described so far. Results- Here we report the cloning and identification of 13 PKR genes from 8 teleost fish and amphibian species, including zebrafish, demonstrating the coexistence of …


Phylogeography Of The Livebearer Xenophallus Umbratilis (Teleostei: Poeciliidae): Glacial Cycles And Sea Level Change Predict Diversification Of A Freshwater Tropical Fish, Carissa Poole Jones Dec 2007

Phylogeography Of The Livebearer Xenophallus Umbratilis (Teleostei: Poeciliidae): Glacial Cycles And Sea Level Change Predict Diversification Of A Freshwater Tropical Fish, Carissa Poole Jones

Theses and Dissertations

The biogeography of Central America is considered a classical case study in understanding the impact of vicariant events on patterns of biotic dispersal. While many biogeographers have focused on community composition and geographic limits of species at broad scales across Central America, much less work has focused on post-colonization diversification patterns at finer scales. The livebearing freshwater fish Xenophallus umbratilis presents an ideal system for determining the impact of recent earth history events on biodiversity in northern Costa Rica. Here, we test the hypothesis that marine inundation of the San Carlos and Northern Limón basins during the Miocene has caused …


Niche Separation Along Environmental Gradients As A Mechanism To Promote The Coexistence Of Native And Invasive Species, Edmund R. Priddis Dec 2007

Niche Separation Along Environmental Gradients As A Mechanism To Promote The Coexistence Of Native And Invasive Species, Edmund R. Priddis

Theses and Dissertations

Niche separation may be the key to promoting the long-term coexistence of introduced and native species. Physical alterations to the environment (habitat manipulation) or re-introducing native species to former habitats can exploit the maladapted traits of introduced species to create a refuge for native species. No two species have identical niches because evolutionary constraints differ between species with different evolutionary histories. Our objectives were to determine if cold temperatures could promote coexistence between native least chub and introduced western mosquitofish. We used individual scale and population scale experiments to test four hypotheses: 1) colder temperatures would reduce the aggressive behavior …


Protein Coevolution And Coadaptation In The Vertebrate Bc1 Complex, Kimberly Kay Baer Jul 2007

Protein Coevolution And Coadaptation In The Vertebrate Bc1 Complex, Kimberly Kay Baer

Theses and Dissertations

The cytochrome bc1 complex of the mitochondrial electron transport chain accomplishes the enzymatic reaction known as the modified Q-cycle. In the Q-cycle the bc1 complex transports protons from the matrix to the intermembrane space of the mitochondria, creating the proton gradient used to make ATP. The energy to move these protons is obtained by shuttling electrons from the coenzyme ubiquinol (QH2) to coenzyme ubiquinone (Q) and the mobile cytochrome c. This well studied complex is ideal for examining molecular adaptation because it consists of ten different subunits, it functions as a dimer, and it includes at least five different active …


The Origins, Evolution, And Phylogeny Of The Praying Mantises (Dictyoptera: Mantodea), Gavin John Svenson Jul 2007

The Origins, Evolution, And Phylogeny Of The Praying Mantises (Dictyoptera: Mantodea), Gavin John Svenson

Theses and Dissertations

The relatively small insect order Mantodea (praying mantises) is comprised of approximately 2,366 described species distributed in 436 genera. Members of the group occupy diverse habitats and are distributed across the globe, though their greatest numbers and diversity are concentrated primarily in the tropics. Though continental endemism is common, many groups have a broad global distribution. An immense diversity of morphology is exhibited across the order with adult mantises ranging in size from 2cm to ~25cm, and appearing like a dead leaf, a piece of quartz rock, or a blade of grass. The diversification and specialization of mantises in ecologically …


Bioassessment And The Partitioning Of Community Composition And Diversity Across Spatial Scales In Wetlands Of The Bonneville Basin, Mary Jane Keleher Jul 2007

Bioassessment And The Partitioning Of Community Composition And Diversity Across Spatial Scales In Wetlands Of The Bonneville Basin, Mary Jane Keleher

Theses and Dissertations

The Bonneville Basin encompasses an area that was covered by ancient Lake Bonneville and which today lies within the Great Basin province. The Bonneville Basin is distinguished geologically by its characteristic parallel north-south mountain ranges that are separated by broad, alluviated desert basins and valleys. Benches and other shoreline features of ancient Lake Bonneville prominently mark the steep, gravelly slopes of these ranges. Numerous artesian desert springs are present at the base of the mountains and in the valley floors that form various sizes of both isolated wetlands and wetland complexes. Many these wetlands are some of the most unique …


Distinguishing Importation From Diversification Of Quinolone-Resistant Neisseria Gonorrhoeae By Molecular Evolutionary Analysis, Keith A. Crandall, Marcos Perez-Losada, Margaret C. Bash, Michael Dan, Jonathan Zenilman, Raphael P. Viscidi Jun 2007

Distinguishing Importation From Diversification Of Quinolone-Resistant Neisseria Gonorrhoeae By Molecular Evolutionary Analysis, Keith A. Crandall, Marcos Perez-Losada, Margaret C. Bash, Michael Dan, Jonathan Zenilman, Raphael P. Viscidi

Faculty Publications

Distinguishing the recent introduction of quinolone resistant gonococci into a population from diversification of resistant strains already in the population is important for planning effective infection control strategies. We applied molecular evolutionary analyses to DNA sequences from 9 housekeeping genes and gyrA, parC and porB of 24 quinolone resistant N. gonorrhoeae (QRNG) and 24 quinolone sensitive isolates collected in Israel during 2000-2001. Results- Phylogenetic and eBURST analyses and estimates of divergence time indicated QRNG were introduced on 3 separate occasions and underwent limited diversification by mutation, deletion and horizontal gene transfer. Reconstruction of N. gonorrhoeae demography showed a slowly declining …


Fresh Water Ecology Unit For Secondary Education Science Courses, Eric L. Hyer Mar 2007

Fresh Water Ecology Unit For Secondary Education Science Courses, Eric L. Hyer

Theses and Dissertations

Science means “to know", a process for gaining knowledge and an understanding of the natural world. Students need to be involved in active learning. In other words, they must do science, not just hear about it. Good science encourages students to gain knowledge by doing science: observing, questioning, exploring, making and testing hypotheses, comparing predictions, evaluating data, and communicating conclusions. This unit plan is designed to incorporate the components of fresh water, ecology, water quality, and a class-wide science project. Each lesson addresses selected standards from the state core curriculum and has specific objectives that are tied to the learning …