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Sirnas Compete With Mirnas For Methylation By Hen1 In Arabidopsis, Bin Yu, Liu Bi, Jixian Zhai, Manu Agarwal, Shengben Li, Qingfa Wu, Shou-Wei Ding, Blake C. Meyers, Hervé Vaucheret, Xuemei Chen

Bin Yu Publications

Plant microRNAs (miRNAs) and small interfering RNAs (siRNAs) bear a 2'-O-methyl group on the 3'-terminal nucleotide. This methyl group is post-synthetically added by the methyltransferase protein HEN1 and protects small RNAs from enzymatic activities that target the 3'-OH. A mutagenesis screen for suppressors of the partial loss-offunction hen1-2 allele in Arabidopsis identified second-site mutations that restore miRNA methylation. These mutations affect two subunits of the DNA-dependent RNA polymerase IV (Pol IV), which is essential for the biogenesis of 24 nt endogenous siRNAs. A mutation in RNA-dependent RNA polymerase 2, another essential gene for the biogenesis of endogenous 24-nt …

What Scatter-Hoarding Animals Have Taught Us About Small-Scale Navigation, Kristy L. Gould, Debbie M. Kelly, Alan Kamil

Avian Cognition Papers

Many animals use cues for small-scale navigation, including beacons, landmarks, compasses and geometric properties. Scatter-hoarding animals are a unique system to study small-scale navigation. They have to remember and relocate many individual spatial locations, be fairly accurate in their searching and have to remember these locations for long stretches of time. In this article, we review what is known about cue use in both scatter-hoarding birds and rodents. We discuss the importance of local versus global cues, the encoding of bearings and geometric rules, the use of external compasses such as the Sun and the influence of the shape of …

Landmark Use By Clark’S Nutcrackers (Nucifraga Columbiana): Influence Of Disorientation And Cue Rotation On Distance And Direction Estimates, Debbie M. Kelly, Alan Kamil, Ken Cheng

Papers in Behavior in Biological Sciences

Many species have been shown to encode multiple sources of information to orient. To examine what kinds of information animals use to locate a goal we manipulated cue rotation, cue availability, and inertial orientation when the food-storing Clark’s nutcracker (Nucifraga columbiana) was searching for a hidden goal in a circular arena. Three groups of birds were used, each with a different goal–landmark distance. As the distance between the goal and the landmark increased, nutcrackers were less accurate in finding the correct direction to the goal than they were at estimating the distance (Experiment 1). To further examine what …

Contributions Of Demography And Dispersal Parameters To The Spatial Spread Of A Stage-Structured Insect Invasion, Tom E. X. Miller, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Stage-structured models that integrate demography and dispersal can be used to identify points in the life cycle with large effects on rates of population spatial spread, information that is vital in the development of containment strategies for invasive species. Current challenges in the application of these tools include: (1) accounting for large uncertainty in model parameters, which may violate assumptions of ‘‘local’’ perturbation metrics such as sensitivities and elasticities, and (2) forecasting not only asymptotic rates of spatial spread, as is usually done, but also transient spatial dynamics in the early stages of invasion. We developed an invasion model for …

Environmentally Sensitive Life-Cycle Traits Have Low Elasticity: Implications For Theory And Practice, Valery E. Forbes, Mette Olsen, Annemette Palmqvist, Peter Calow

Valery Forbes Publications

The relationships between population growth rate and the life-cycle traits contributing to it are nonlinear and variable. This has made it difficult for ecologists to consistently predict changes in population dynamics from observations on changes in life-cycle traits. We show that traits having a high sensitivity to chemical toxicants tend to have a low elasticity, meaning that changes in them have a relatively low impact on population growth rate, compared to other life-cycle traits. This makes evolutionary sense in that there should be selection against variability in population growth rate. In particular, we found that fecundity was generally more sensitive …

Investigation Of The Fate And Effects Of Acetyl Cedrene On Capitella Teleta And Sediment Bacterial Community, Lea Ellegaard-Petersen, Henriette Selck, Anders Priemé, Daniel Salvito, Valery E. Forbes

Valery Forbes Publications

The fate of the fragrance material, acetyl cedrene (AC), in sediment was examined in a 16 day laboratory experiment using the sediment microbial community subjected to the following treatments: AC (nominal concentration; 0 and 50 μg g−1 dw sediment) and macrofaunal worms (with/without Capitella teleta (formerly Capitella sp. I)). Furthermore effects of AC on microbial respiration in the system were determined by examining CO₂ flux. T-RFLP (terminal restriction fragment length polymorphism) was used to analyze PCR (polymerase chain reaction) amplified 16S DNA gene fragments from the sediments to detect changes in the structure and diversity of the bacterial community. …

No Interaction Between Competition And Herbivory In Limiting Introduced Cirsium Vulgare Rosette Growth And Reproduction, Tomomi  Suwa, Svata M. Louda, F. Leland Russell

Svata M. Louda Publications

Both competition and herbivory have been shown to reduce plant survival, growth, and reproduction. Much less is known about whether competition and herbivory interact in determining plant performance, especially for introduced, weedy plant species in the invaded habitat. We simultaneously evaluated both the main and interactive effects of plant neighbors and insect herbivory on rosette growth and seed reproduction in the year of flowering for Cirsium vulgare (bull thistle, spear thistle), an introduced Eurasian species, in tallgrass prairie in 2 years. Effects of insect herbivory were strong and consistent in both years, causing reduced plant growth and seed production, whereas …

A Signal-Substrate Match In The Substrate-Borne Component Of A Multimodal Courtship Display, Damian O. Elias, Andrew C. Mason, Eileen Hebets

Eileen Hebets Publications

The environment can impose strong limitations on the efficacy of signal transmission. In particular, for vibratory communication, the signaling environment is often extremely heterogeneous at small scales. Nevertheless, natural selection is expected to select for signals well-suited for effective transmission. Here, we test for substrate-dependent signal efficacy in the wolf spider Schizocosa stridulans Stratton 1991. We first explore the transmission characteristics of this important signaling modality by playing recorded substrate-borne signals through three different substrates (leaf litter, pine litter, and red clay) and measuring the propagated signal. We found that the substrate-borne signal of S. stridulans attenuates the least on …

Multimodal Courtship Efficacy Of Schizocosa Retrorsa Wolf Spiders: Implications Of An Additional Signal Modality, Aaron S. Rundus, Roger D. Santer, Eileen Hebets

Eileen Hebets Publications

Here, we simultaneously examine both content and efficacy-based sources of selection on the visual and seismic multimodal courtship display of the wolf spider Schizocosa retrorsa. Immature field-collected S. retrorsa were reared in the laboratory on either high-quantity diet (HD) or low-quantity diet (LD) treatments. On maturation, females of each diet treatment were run in simultaneous mate choice trials with both a HD and an LD male (content-based selection). Simultaneous mate choice trials were conducted across different signaling environments (efficacy-based selection) in a fully crossed 2 × 2 design with visual treatments of light/dark (visual signal present/absent) and seismic treatments …

Failing The Bay: Clean Water Act Enforcement In Maryland Falling Short, Robert L. Glicksman, Yee Huang

GW Law Faculty Publications & Other Works

The Maryland Department of the Environment (MDE) is responsible for enforcing Clean Water Act (CWA) requirements in Maryland. This report evaluates MDE's enforcement of the CWA and draws three significant conclusions: (1) MDE is drastically underfunded; (2) MDE has not designed its enforcement program to effectively deter dischargers from violating CWA and state water quality laws; and (3) MDE fails to take advantage of citizen suits to supplement its own enforcement actions and to maximize its limited resources.

Between 2000 and 2009, MDE's enforcement budget declined in real terms by 25 percent, which coincides with a doubling of the number …

Diversity Of Protein And Mrna Forms Of Mammalian Methionine Sulfoxide Reductase B1 Due To Intronization And Protein Processing, Xinwen Liang, Dmitri E. Fomenko, Deame Hua, Alaattin Kaya, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Background: Methionine sulfoxide reductases (Msrs) are repair enzymes that protect proteins from oxidative stress by catalyzing stereospecific reduction of oxidized methionine residues. MsrB1 is a selenocysteine-containing cytosolic/nuclear Msr with high expression in liver and kidney.

Principal Findings: Here, we identified differences in MsrB1 gene structure among mammals. Human MsrB1 gene consists of four, whereas the corresponding mouse gene of five exons, due to occurrence of an additional intron that flanks the stop signal and covers a large part of the 39-UTR. This intron evolved in a subset of rodents through intronization of exonic sequences, whereas the human gene structure represents …

Cug Start Codon Generates Thioredoxin/Glutathione Reductase Isoforms In Mouse Testes, Maxim Gerashchenko, Dan Su, Vadim Gladyshev

Department of Biochemistry: Faculty Publications

Mammalian cytosolic and mitochondrial thioredoxin reductases are essential selenocysteine-containing enzymes that control thioredoxin functions. Thioredoxin/glutathione reductase (TGR) is a third member of this enzyme family. It has an additional glutaredoxin domain and shows highest expression in testes. Herein, we found that human and several other mammalian TGR genes lack any AUG codons that could function in translation initiation. Although mouse and rat TGRs have such codons, we detected protein sequences upstream of them by immunoblot assays and direct proteomic analyses. Further gene engineering and expression analyses demonstrated that a CUG codon, located upstream of the sequences previously thought to initiate …

Identification And Characterization Of Oxalate Oxidoreductase, A Novel Thiamine Pyrophosphate-Dependent 2-Oxoacid Oxidoreductase That Enables Anaerobic Growth On Oxalate, Elizabeth Pierce, Donald F. Becker, Stephen W. Ragsdale

Department of Biochemistry: Faculty Publications

Moorella thermoacetica is an anaerobic acetogen, a class of bacteria that is found in the soil, the animal gastrointestinal tract, and the rumen. This organism engages the Wood-Ljungdahl pathway of anaerobic CO₂ fixation for heterotrophic or autotrophic growth. This paper describes a novel enzyme, oxalate oxidoreductase (OOR), that enables M. thermoacetica to grow on oxalate, which is produced in soil and is a common component of kidney stones. Exposure to oxalate leads to the induction of three proteins that are subunits of OOR, which oxidizes oxalate coupled to the production of two electrons and CO₂ or bicarbonate. Like …

Genetic Conflict And Sex Chromosome Evolution, Colin D. Meiklejohn, Yun Tao

School of Biological Sciences: Faculty Publications

Chromosomal sex determination systems create the opportunity for the evolution of selfish genetic elements that increase the transmission of one sex chromosome at the expense of its homolog. Because such selfish elements on sex chromosomes can reduce fertility and distort the sex ratio of progeny, unlinked suppressors are expected to evolve, bringing different regions of the genome into conflict over the meiotic transmission of the sex chromosomes. Here we argue that recurrent genetic conflict over sex chromosome transmission is an important evolutionary force that has shaped a wide range of seemingly disparate phenomena including the epigenetic regulation of genes expressed …

Purification And Characterization Of Cytoplasmic Nadp+- Isocitrate Dehydrogenase, And Amplification Of The Nadp+-Idh Gene From The Wing-Dimorphic Sand Field Cricket, Gryllus Firmus, Anthony J. Zera, Susan Newman, David Berkheim, Christine Black, Lindsay Klug, Erica Crone

School of Biological Sciences: Faculty Publications

Cytoplasmic NADP+-isocitrate dehydrogenase (NADP+-IDH) has been purified and characterized, and its gene sequenced in many animal, plant, and yeast species. However, much less information is available on this enzyme-gene in insects. As a first step in investigating the biochemical and molecular mechanisms by which NADP+-IDH contributes to adaptations for flight vs. reproduction in insects, the enzyme was purified to homogeneity in the wing-dimorphic cricket, Gryllus firmus, characterized, and its corresponding gene sequenced. Using a combination of polyethylene glycol precipitation, Cibacron-Blue affinity chromatography, and hydrophobic interaction chromatography the enzyme was purified 291-fold (7% yield; specific activity = 15.8 μmol NADPH/min/mg …

Seed Availability And Insect Herbivory Limit Recruitment And Adult Density Of Native Tall Thistle, F. Leland Russell, Karen E. Rose, Svata M. Louda

School of Biological Sciences: Faculty Publications

Understanding spatial and temporal variation in factors influencing plant regeneration is critical to predicting plant population growth. We experimentally evaluated seed limitation, insect herbivory, and their interaction in the regeneration and density of tall thistle (Cirsium altissimum) across a topographic ecosystem productivity gradient in tallgrass prairie over two years. On ridges and in valleys, we used a factorial experiment manipulating seed availability and insect herbivory to quantify effects of: seed input on seedling density, insect herbivory on juvenile density, and cumulative impacts of both seed input and herbivory on reproductive adult density. Seed addition increased seedling densities at …

Gardner-Webb, The Magazine 2010, Winter (Volume 44 No. 1), Noel T. Manning Ii

Gardner-Webb, The Magazine

Gardner-Webb, The Magazine, previously titled The Webb Magazine, focuses on alumni news and campus events from Gardner-Webb College; now Gardner-Webb University.This issue begins by looking back on a survivor's story on U.S. Airways flight 1549. The magazine then moves on to recognize the new opening of an apartment style residence hall and the new distinguished alumni. One of the big stories in this issue is the one entitled "Drivers Education" and how alternative ideas fueled a class project. GWU also honors Jordan Boyd Traylor, a fallen soccer player by retiring his jersey.

International Law And African Judiciaries: The Example Of South Africa, Erika George

Faculty Scholarship

In recent years, commentators have questioned the extent to which African courts would rely upon foreign law or resort to rules of international law in their domestic decision making. I Comparatively, the African continent offers an interesting and important point of departure for exploring the influence of international law on domestic legal systems. While Africa boasts a number of new constitutional democracies, Africa is also home to a number of countries that remain burdened by colonial legacies and conflict.

It would not be unreasonable to expect international and foreign law to meet with considerable resistance or to be rejected as …

A Study Of Perceived Leadership Styles Of Seven Jesuit University Presidents In México, Rubén Arceo

Doctoral Dissertations

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Eliminating Suffering Through The Birth Of Metta : A Critical Hermeneutic Inquiry Of The Identity And Ethical Intention Of Selected Monks Of Burma, Beryl Banks

Doctoral Dissertations

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Chosen Traditions Influencing Tourism, Policy-Making, And Curriculum In Lao People's Democratic Republic : A Critical Hermeneutic Study In Development, Laura Nelsen

Doctoral Dissertations

NA

At The Crossroads Of Learning And Culture : Identifying A Construct For Effective Computer-Assisted Language Learning For English Language Learners, Yun Shaw

Doctoral Dissertations

NA

The Role Of Spanglish In The Social And Academic Lives Of Second Generation Latino Students : Students' And Parents' Perspectives, Araceli Osorio

Doctoral Dissertations

NA

A Critical Hermeneutic Approach To Hmong Leadership In The Lao Pdr : Horizons Of Forgiveness And Action Through Imagination In Community Development, Chai Xiong

Doctoral Dissertations

NA

Go West Young Woman!: The Mercer Girls And Legal Historiography, Kristin Collins

Faculty Scholarship

This essay is a response to Professor Kerry Abrams’s article The Hidden Dimension of Nineteenth-Century Immigration Law, published in Vanderbilt Law Review. The Hidden Dimension tells the story of Washington Territory’s entrepreneurial Asa Shinn Mercer, who endeavored to bring hundreds of young women from the East Coast to the tiny frontier town of Seattle as prospective brides for white men who had settled there. Abrams locates the story of the Mercer Girls, as they were called, in the history of American immigration law. My response locates The Hidden Dimension in American legal historiography, both that branch of American legal historiography …

Justice And Elegance For Hedgehogs - In Life, Law, And Literature, Linda C. Mcclain

Faculty Scholarship

At a time when value pluralism and even value polarization seem to be undeniable facts of contemporary life, Ronald Dworkin unrepentantly defends the unity of value. His point of departure is the Greek poet Archilochus’s saying, “The fox knows many things, but the hedgehog knows one big thing,” made famous in liberal philosopher Isaiah Berlin’s essay, The Hedgehog and the Fox. In his forthcoming book, Justice for Hedgehogs, Dworkin argues for the integration of ethics, personal morality, and political morality and contends that law is a branch of political morality that in turn is a branch of morality, broadly understood. …

Nmr Investigations Of Biomass-To-Fuel Conversions By Hydrothermal Processes, Wenjia Zhang

Doctoral Dissertations

"Biofuels have gained significant attention as the most promising alternative energy and fuel supply for the near future because of two dominant reasons: first, biofuels are environmentally friendly; and second, they afford a sustainable technology. Biofuels can be synthesized from biomass by several different processes, among which, hydrothermal conversion is considered to be more energy efficient. However, scientific efforts to improve hydrothermal biomass-to-fuel (HT-BTF) conversion efficiencies are severely limited because little is known about the salient reaction mechanisms and intermediates. This study is aimed at a better understanding of the hydrothermal biomass degradation kinetics by advanced NMR spectroscopy and, accordingly, …

Trademark Remedies And Online Intermediaries, Stacey Dogan

Faculty Scholarship

For several years now, courts and commentators have tussled over the question of whether online intermediaries can face liability under trademark law. Because both case law and commentary have largely focused on the threshold question of "trademark use, " we know little about what specific behavior will subject intermediaries to liability and what remedies might follow. This Essay takes some preliminary steps toward addressing those questions.

Absence Of Predation Eliminates Coexistence: Experience From The Fish-Zooplankton Interface, Z. M. Gilwicz, Wayne A. Wurtsbaugh, E. Szymansk

Watershed Sciences Faculty Publications

Examples from fishless aquatic habitats show that competition among zooplankton for resources instigates rapid exclusion of competitively inferior species in the absence of fish predation, and leads to resource monopolization by the superior competitor. This may be a single species or a few clones with large body size: a cladoceran such as Daphnia pulicaria, or a branchiopod such as Artemia franciscana, each building its population to a density far higher than those found in habitats with fish. The example of zooplankton from two different fish-free habitats demonstrates the overpowering force of fish predation by highlighting the consequences of its absence. …

The Sagebrush Steppe Treatment Evaluation Project (Sagestep): A Test Of State-And Transition Theory., J. D. Mciver, Mark W. Brunson, S. Buntin, J. Chambers, N. Devoe, P. Doescher, J. Grace, D. Johnson, S. Knick, R. Miller

Environment and Society Faculty Publications

No abstract provided.