Biology Commons^™

Mojave Applied Ecology Notes Summer 2010, Scott R. Abella, E. Cayenne Engel

Mojave Applied Ecology Notes

Survey of monitoring and management for conservation of rare plants, Roadside restoration techniques in Joshua Tree NP, and an update on renewable energy developments in the Southwestern deserts

Loss Of Individual Micrornas Causes Mutant Phenotypes In Sensitized Genetic Backgrounds In C. Elegans, John L. Brenner, Kristen L. Jasiewicz, Alisha F. Fahley, Benedict J. Kemp, Allison L. Abbott

Biological Sciences Faculty Research and Publications

MicroRNAs (miRNAs) are small, noncoding RNAs that regulate the translation and/or stability of their mRNA targets. Previous work showed that for most miRNA genes of C. elegans, single-gene knockouts did not result in detectable mutant phenotypes. This may be due, in part, to functional redundancy between miRNAs. However, in most cases, worms carrying deletions of all members of a miRNA family do not display strong mutant phenotypes. They may function together with unrelated miRNAs or with non-miRNA genes in regulatory networks, possibly to ensure the robustness of developmental mechanisms. To test this, we examined worms lacking individual miRNAs in …

Lianas Suppress Tree Regeneration And Diversity In Treefall Gaps, Stefan A. Schnitzer, Walter P. Carson

Biological Sciences Faculty Research and Publications

Treefall gaps are hypothesized to maintain diversity by creating resource‐rich, heterogeneous habitats necessary for species coexistence. This hypothesis, however, is not supported empirically for shade‐tolerant trees, the dominant plant group in tropical forests. The failure of gaps to maintain shade‐tolerant trees remains puzzling, and the hypothesis implicated to date is dispersal limitation. In central Panama, we tested an alternative ‘biotic interference’ hypothesis: that competition between growth forms (lianas vs. trees) constrains shade‐tolerant tree recruitment, survival and diversity in gaps. We experimentally removed lianas from eight gaps and monitored them for 8 years, while also monitoring nine un‐manipulated control gaps. Removing …

Regulation Of The G2/M Transition In Rodent Oocytes, Stephen M. Downs

Biological Sciences Faculty Research and Publications

Regulation of maturation in meiotically competent mammalian oocytes is a complex process involving the carefully coordinated exchange of signals between the somatic and germ cell compartments of the ovarian follicle via paracrine and cell–cell coupling pathways. This review highlights recent advances in our understanding of how such signaling controls both meiotic arrest and gonadotropin-triggered meiotic resumption in competent oocytes and relates them to the historical context. Emphasis will be on rodent systems, where many of these new findings have taken place. A regulatory scheme is then proposed that integrates this information into an overall framework for meiotic regulation that demonstrates …

Diurnal Rhythms Of Behavior And Brain Mrna Expression For Arginine Vasotocin, Isotocin, And Their Receptors In Wild Amargosa Pupfish (Cyprinodon Nevadensis Amargosae), Sean C. Lema, Lauren J. Wagstaff, Nina M. Gardner

Biological Sciences

Amargosa pupfish (Cyprinodon nevadensis amargosae) occupy remote desert habitats that vary widely in environmental conditions from day to night. In this study, die! patterns of behavior were documented for pupfish in their natural habitat, and examined relative to changes in the abundance of mRNAs encoding prepro-arginine vasotocin (pro-VT), prepro-isotocin (pro-IT), three distinct vasotocin receptors (V1a1, V1a2, and V2), and an isotocin receptor (ITR) in the brain. The behavior of wild pupfish varied diurnally, with frequent aggression from 12:00 to 15:00 h and courtship and spawning most common between 15:00 and 19:00h. Transcript abundance for pro-VT in the brain …

Use Of Archive Aerial Photography For Monitoring Black Mangrove Populations, James H. Everitt, C. Yang, Frank W. Judd, Kenneth R. Summy

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

A study was conducted on the South Texas Gulf Coast to evaluate archive aerial color-infrared (CIR) photography combined with supervised image analysis techniques to quantify changes in black mangrove [Avicennia germinans (L.) L.] populations over a 26-year period. Archive CIR film from two study sites (sites 1 and 2) was studied. Photographs of site 1 from 1976,1988, and 2002 showed that black mangrove populations made up 16.2%, 21.1%, and 29.4% of the study site, respectively. Photographs of site 2 from 1976 and 2002 showed that black mangrove populations made up 0.4% and 2.7% of the study site, respectively. Over the …

Weeds In The Flower Garden: An Exploration Of Plagiarism In Graduate Students’ Research Proposals And Its Connection To Enculturation, Esl, And Contextual Factors, Joanna Gilmore, Denise Strickland, Briana Eileen Timmerman, Michelle Maher, David Feldon

Faculty Publications

Existing literature provides insight into the nature and extent of plagiarism amongst undergraduate students (e.g., Ellery, 2008; Parameswaran & Devi, 2006; Selwyn, 2008). Plagiarism amongst graduate students is relatively unstudied, however, and the existing data are largely based on self-reports. This study investigated the rates and potential causes of plagiarism amongst graduate students in master’s and doctoral programmes in science, technology, engineering, mathematics, and science or mathematics education by examining actual research proposals written by graduate students. Results indicate that plagiarism is a prevalent issue at each of the three university sites sampled and across all of the investigated disciplines. …

Pkcα And Cpi-17 Expression And Spatial-Temporal Distribution With Activation In Pig Stomach Antrum And Fundus, Yu Zhang

Master's Theses (2009 -)

Smooth muscle contraction is a complicated process coordinated by contractile, regulatory and cytoskeletal proteins. The force generation depends on the phosphorylation of Myosin Regulatory Light Chain (MLC20). Myosin Light Chain Kinase (MLCK) and Myosin Light Chain Phosphatase (MLCP) are the two main regulators of the MLC20 phosphorylation level. MLCP is further controlled by two known pathways including the G protein coupled receptors (GPCRs)/ phospholipase C (PLC)/ diacylglycerol (DAG)/ protein kinase C (PKC)/ PKC-potentiated inhibitory protein for heterotrimeric myosin light chain phosphatase of 17 kDa (CPI-17) pathway. While messengers involved in this pathway have been proposed, studies on the details of …

Physiological Studies On Candida Albicans, Swetha Tati

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

Candida albicans is a common opportunistic, dimorphic human fungal pathogen. One of its virulence factors is the morphological switch between yeasts and hyphal or pseudohyphal forms, which can invade tissues and cause damage. Our studies focus on factors regulating pseudohyphae and epigenetic modifications of C. albicans. Regulating factors of pseudohyphae are aromatic alcohols and high phosphate. At low concentrations, exogenous aromatic alcohols induced pseudohyphae, as did high phosphate. For addressing the pathways involved in inducing pseudohyphae by aromatic alcohols or high phosphate, we used mutants defective in cAMP dependent PKA pathway (efg1/efg1), MAP kinase pathway (cph1/cph1), or both (cph1/cph1/efg1/efg1). …

Getting Up To Speed: Acceleration Strategies In The Florida Scrub Lizard, Sceloporus Woodi, Eric J. Mcelroy, Lance D. Mcbrayer

Biology: Faculty Publications

Small animals typically rely on quick bursts and intermittent pauses when moving in the wild. Hence, the study of acceleration capacity is important for understanding the ecology and evolution of locomotor performance. In this study, we investigate intraspecific variation in the acceleration capacity of a small lizard (Sceloporus woodi). To quantify animal acceleration performance, the momentum‐impulse theorem is applied to data collected from high‐speed video recordings of individuals accelerating from a standstill and over a subsequent distance of 0.4 m. Unlike earlier studies, the momentum‐impulse approach allows one to directly and precisely quantify the per step contribution to …

Husbandry Of Monodelphis Domestica In The Study Of Mammalian Embryogenesis, Holly Rousmaniere, Rachel Silverman, Rachel A. White, Mark M. Sasaki, Siobhan D. Wilson, Jeremy T. Morrison, Yolanda P. Cruz

Faculty & Staff Scholarship

Monodelphis domestica, commonly called the laboratory opossum, is a useful laboratory animal for studying marsupial embryogenesis and mammalian development. Females breed year-round and the animals can be sustainably bred indoors. The authors draw on their own laboratory's experience to supplement previously published research on laboratory opossums. They describe a breeding protocol that reliably produces timed-pregnant M. domestica. Additionally, the authors discuss general laboratory opossum husbandry techniques and describe how to collect, handle and culture embryos.

Lps-Induced Production Of Inflammatory Mediators In The Liver Of Postnatal Animals, Valerie P. Le Rouzic

Seton Hall University Dissertations and Theses (ETDs)

Lipopolysaccharide (LPS) is the primary component of the outer membrane of Gram-negative bacteria and is responsible for the majority of inflammatory effects of infections from Gram-negative bacteria. To gain better understanding of the effects that postnatal age has on the inflammatory response, pups were randomly assigned to be treated with 250 µg/kg of LPS or saline at postnatal day (P) 1, P21, and P70. Two hours post stimulation, the pups were sacrificed and their livers were harvested for total RN A extraction. Relative mRNA levels of inflammatory genes and �-actin were determined using RT-PCR analysis with appropriate rat sense and …

Histone H2a And H2b Are Monoubiquitinated At Aid-Targeted Loci, Glen M. Borchert, Nathaniel W. Holton, Kevin A. Edwards, Laura A. Vogel, Erik D. Larson

Faculty Publications – Biological Sciences

Background: Somatic hypermutation introduces base substitutions into the rearranged and expressed immunoglobulin (Ig) variable regions to promote immunity. This pathway requires and is initiated by the Activation Induced Deaminase (AID) protein, which deaminates cytidine to produce uracils and UG mismatches at the Ig genes. Subsequent processing of uracil by mismatch repair and base excision repair factors contributes to mutagenesis. While selective for certain genomic targets, the chromatin modifications which distinguish hypermutating from non-hypermutating loci are not defined. Methodology/Principal Findings: Here, we show that AID-targeted loci in mammalian B cells contain ubiquitinated chromatin. Chromatin immunoprecipitation (ChIP) analysis of a constitutively hypermutating …

Community Structure And Dynamics Of Monogenea And Trematoda In Three North American Cyprinid Species In The Salt Valley Watershed, Nebraska, Alaine Kathryn Knipes

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

An investigation was made of the communities of gill monogene genus Dactylogyrus (Platyhelminthes, Monogenea) and the populations of blackspot parasite (Platyhelminthes, Trematoda) of Pimephales promelas, Notropis stramineus, and Semotilus atromaculatus in 3 distinct sites along the 3 converging tributaries in southeastern Nebraska from 2004 to 2006. This work constitutes the first multi-site, multi-year study of a complex community of Dactylogyrus spp. and their reproductive activities on native North American cyprinid species. The biological hypothesis that closely related species with direct lifecycles respond differently to shared environmental conditions was tested. It was revealed that in this system that, Cyprinid …

Increased Abundance And First Breeding Record Of The Neotropic Cormorant (Phalacrocorax Brasilianus) On The Alluvial Plain Of Mississippi, Katie C. Hanson, Travis L. Devault, Stephen J. Dinsmore

United States Department of Agriculture Wildlife Services: Staff Publications

Phalacrocorax brasilianus (Neotropic Cormorant) has been observed with increasing frequency in the alluvial plain (Delta region) of Mississippi. In the past 6 years, 22 individuals have been observed in 20 separate sightings during spring and summer. These sightings have occurred at breeding colonies of other colonial waterbirds and commercial aquaculture facilities of Ictalurus punctatus (Channel Catfish). Two sexually mature Neotropic Cormorants have been collected at a colonial waterbird breeding colony near the Mississippi River in the western Delta region among flocks of Phalacrocorax auritus (Double-crested Cormorants). Twice during the summer of 2008, confirmed nesting of Neotropic Cormorants were documented in …

The Impact Of Lianas On 10 Years Of Tree Growth And Mortality On Barro Colorado Island, Panama, Laura L. Ingwell, S. Joseph Wright, Kristen K. Becklund, Stephen P. Hubbell, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

1. Lianas compete intensely with trees, but few studies have examined long‐term effects of liana infestation on tree growth and mortality. We quantified the effects of lianas in tree crowns (n = 2907) and rooted within 2 m of trees (n = 1086) on growth and mortality of 30 tree species from 1995 to 2005 on Barro Colorado Island (BCI), Panama, documented liana infestation in tree crowns in 1996 and 2007 to determine the dynamics of liana infestation, and quantified liana infestation in the crowns of 3231 additional canopy trees (d.b.h. ≥20 cm) in 2007 to compare with …

Always Read The Introduction: Integrating Regulatory And Coding Sequence Evolution In Yeast, Annette M. Evangelisti

Biology ETDs

We analyze duplicate genes in a yeast, Saccharomyces cerevisiae with the aim of determining a genes history and to observe that gene in its genomic context. In Chapter 2 we show that the fate of a duplicate gene pair is in part determined by its genome location. Moreover, we show that for two classes of duplicate genes, resulting from either small-scale duplication or whole-genome duplication, this fate can often be assessed by measuring the patterns of asymmetry in the sequence divergence of the genes in question. In Chapter 3 we study duplicate genes in the context of their local environments …

High-Throughput Genomic/Proteomic Studies: Finding Structure And Meaning By Similarity, George Sidney Davidson

Biology ETDs

The post-genomic challenge was to develop high-throughput technologies for measuring genome scale mRNA expression levels. Analyses of these data rely on computers in an unprecedented way to make the results accessible to researchers. My research in this area enabled the first compendium of microarray experiments for a multi-cellular eukaryote, Caenorhabditis elegans. Prior to this research approximately 6% of the C. elegans genome had been studied, and little was known about global expression patterns in this organism. Here I cluster data from 553 different microarray experiments and show that the results are stable, statistically significant and highly enriched for specific biological …

Female Perception Of Testeronized Male Facial Images: Evidence Of A Co-Evolutionary Tradeoff Responsive To Conditions For Both Competition And Cooperation, Melissa L. Franklin

Biology ETDs

Theorists and researchers who examine the evolutionary ecology of mating dynamics consider two primary forces, intrasexual and intersexual, as important pressures of selection. Bilateral symmetry and, more controversially, hormone markers in many species, impart information that has been found to influence some aspects of intersexual selection. Both symmetry, as a sign of developmental stability, and hormone markers (i.e., testosteronized traits as cues of immunocompetence) have been classically treated as signals of genetic fitness (Moller & Swaddle, 1997; Hamilton & Zuk, 1982), although neither are consistently shown to correlate with increased mating success. Indeed, results between studies on either trait independently …

Genome Architecture In The Fungal Kingdom, Diego Antonio Martinez

Biology ETDs

Previous studies have suggested that the location of genes in genomes is not random; instead they may be organized in a way that is beneficial to cellular processes and the organism. While a few studies have investigated the organization of genes on a whole genome scale, they were limited in the functions of genes used in the search and in the number and type of genomes searched. With the recent explosion of available fungal genomes and tools to automatically annotate many genes in a short period of time, it is now possible to obtain a global view of the level …

Temporal Dynamics And Spatial Analysis Of Competing Dengue 2 Virus Strains In The Americas, Stacy O'Neil Scholle

Biology ETDs

The dengue virus is the causative agent of an important re-emerging infectious disease that has become increasingly significant in tropical America and the Caribbean due to the infiltration of a more pathogenic Asian/American strain of dengue serotype 2 into the population. This invading strain is responsible for epidemics of dengue hemorrhagic fever, a life-threatening disease that was not previously a large public health concern in the region. Here, I create a historical map of the invasion and replacement of the endemic American strain of dengue 2 by the Asian/American strain, showing that the timing of invasion spans 25 years, and …

Comparison Of Microbial Communities On Roots, Ceilings And Floors Of Two Lava Tube Caves In New Mexico, Jessica R. Snider

Biology ETDs

Lava tube caves possess a rich and patchy mosaic of nutrients and water that fosters a wide variety of microbial life. Water percolating past vegetation and through surface soils introduces dissolved carbon and nitrogen into caves. Roots provide even higher levels of carbon, nitrogen and microorganisms as they grow into the cave environment from surface vegetation. I hypothesized that this mosaic of nutrients and energy resources has a direct effect on the distribution and composition of microbial communities within caves. To test this hypothesis, I selected two lava tube caves in New Mexico, USA and identified six zones consisting of …

Upper Thermal Tolerances Of Early Life Stages Of Freshwater Mussels, Tamara J. Pandolfo, W. Gregory Cope, Consuelo Arellano, Robert B. Bringolf, M. Christopher Barnhart

College of Natural and Applied Sciences

Freshwater mussels (order Unioniformes) fulfill an essential role in benthic aquatic communities, but also are among the most sensitive and rapidly declining faunal groups in North America. Rising water temperatures, caused by global climate change, industrial discharges, drought, or land development, could further challenge imperiled unionid communities. The aim of our study was to determine the upper thermal tolerances of the larval (glochidia) and juvenile life stages of freshwater mussels. Glochidia of 8 species of mussels were tested: Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata, Lasmigona complanata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis. Seven of these species also …

Microarray Analysis Of A Salamander Hopeful Monster Reveals Transcriptional Signatures Of Paedomorphic Brain Development, Robert B. Page, Meredith A. Boley, Jeramiah J. Smith, Srikrishna Putta, Stephen R. Voss

Biology Faculty Publications

Background

The Mexican axolotl (Ambystoma mexicanum) is considered a hopeful monster because it exhibits an adaptive and derived mode of development - paedomorphosis - that has evolved rapidly and independently among tiger salamanders. Unlike related tiger salamanders that undergo metamorphosis, axolotls retain larval morphological traits into adulthood and thus present an adult body plan that differs dramatically from the ancestral (metamorphic) form. The basis of paedomorphic development was investigated by comparing temporal patterns of gene transcription between axolotl and tiger salamander larvae (Ambystoma tigrinum tigrinum) that typically undergo a metamorphosis.

Results

Transcript abundances from whole brain …

Probiotic Therapy - Recruiting Old Friends To Fight New Foes, Roy D. Sleator

Department of Biological Sciences Publications

Against a backdrop of increasing antibiotic resistance, and the emergence of new and evolving pathogens, clinicians are increasingly forced to consider alternative therapies - probiotics are one such alternative.

Negative Plant–Soil Feedback Predicts Tree-Species Relative Abundance In A Tropical Forest, Scott A. Mangan, Stefan A. Schnitzer, Edward A. Herre, Keenan M.L. Mack, Mariana C. Valencia, Evelyn I. Sanchez, James D. Bever

Biological Sciences Faculty Research and Publications

The accumulation of species-specific enemies around adults is hypothesized to maintain plant diversity by limiting the recruitment of conspecific seedlings relative to heterospecific seedlings^1,2,3,4,5,6. Although previous studies in forested ecosystems have documented patterns consistent with the process of negative feedback^{7,8,9,10,11,12,13,14,15,16}, these studies are unable to address which classes of enemies (for example, pathogens, invertebrates, mammals) exhibit species-specific effects strong enough to generate negative feedback¹⁷, and whether …

The Interpretation Of Habitat Preference Metrics Under Use–Availability Designs, Hawthorne L. Beyer, Daniel T. Haydon, Juan M. Morales, Jacqueline L. Frair, Mark Hebblewhite, Michael Mitchell, Jason Matthiopoulos

Biological Sciences Faculty Publications

Models of habitat preference are widely used to quantify animal–habitat relationships, to describe and predict differential space use by animals, and to identify habitat that is important to an animal (i.e. that is assumed to influence fitness). Quantifying habitat preference involves the statistical comparison of samples of habitat use and availability. Preference is therefore contingent upon both of these samples. The inferences that can be made from use versus availability designs are influenced by subjectivity in defining what is available to the animal, the problem of quantifying the accessibility of available resources and the framework in which preference is modelled. …

Resolving Issues Of Imprecise And Habitat-Biased Locations In Ecological Analyses Using Gps Telemetry Data, Jacqueline L. Frair, John Fieberg, Mark Hebblewhite, Francesca Cagnacci, Nicholas J. Decesare, Luca Pedrotti

Biological Sciences Faculty Publications

Global positioning system (GPS) technologies collect unprecedented volumes of animal location data, providing ever greater insight into animal behaviour. Despite a certain degree of inherent imprecision and bias in GPS locations, little synthesis regarding the predominant causes of these errors, their implications for ecological analysis or solutions exists. Terrestrial deployments report 37 per cent or less non-random data loss and location precision 30 m or less on average, with canopy closure having the predominant effect, and animal behaviour interacting with local habitat conditions to affect errors in unpredictable ways. Home-range estimates appear generally robust to contemporary levels of location imprecision …

Distinguishing Technology From Biology: A Critical Review Of The Use Of Gps Telemetry Data In Ecology, Mark Hebblewhite, Daniel T. Haydon

Biological Sciences Faculty Publications

In the past decade, ecologists have witnessed vast improvements in our ability to collect animal movement data through animal-borne technology, such as through GPS or ARGOS systems. However, more data does not necessarily yield greater knowledge in understanding animal ecology and conservation. In this paper, we provide a review of the major benefits, problems and potential misuses of GPS/Argos technology to animal ecology and conservation. Benefits are obvious, and include the ability to collect fine-scale spatio-temporal location data on many previously impossible to study animals, such as ocean-going fish, migratory songbirds and long-distance migratory mammals. These benefits come with significant …

Correlation And Studies Of Habitat Selection: Problem, Red Herring Or Opportunity?, John Fieberg, Jason Matthiopoulos, Mark Hebblewhite, Mark S. Boyce, Jacqueline L. Frair

Biological Sciences Faculty Publications

With the advent of new technologies, animal locations are being collected at ever finer spatio-temporal scales. We review analytical methods for dealing with correlated data in the context of resource selection, including post hoc variance inflation techniques, ‘two-stage’ approaches based on models fit to each individual, generalized estimating equations and hierarchical mixed-effects models. These methods are applicable to a wide range of correlated data problems, but can be difficult to apply and remain especially challenging for use–availability sampling designs because the correlation structure for combinations of used and available points are not likely to follow common parametric forms. We also …