Digital Commons Network^™

The Conflicts In Yemen And U.S. National Security, W. Andrew Terrill Dr.

Books, Monographs & Collaborative Studies

Yemen is not currently a failed state, but it is experiencing huge political and economic problems that can have a direct impact on U.S. interests in the region. It has a rapidly expanding population with a resource base that is limited and already leaves much of the current population in poverty. The government obtains around a third of its budget revenue from sales of its limited and declining oil stocks, which most economists state will be exhausted by 2017. Yemen also has critical water shortages and a variety of interrelated security problems. In Sa’ada province in Yemen’s northern mountainous region, …

Civil-Military Relations In Medvedev's Russia, Stephen J. Blank Dr.

Books, Monographs & Collaborative Studies

The best recent scholarship on Russian civil-military relations explicitly addresses this issue’s importance for both domestic and external security. An inquiry into the present state of those relations under conditions of defense reform and the current international situation is of immense analytical and policy relevance for both domestic and external security in Russia. While the Russian regime is serious about military reform, it is encountering severe objections from the uniformed military, and the military has successfully persuaded the government to accept its expansive concept of the threats to Russia, i.e., its threat assessment. Therefore, we must closely follow those developments …

The Law And Politics Of Embryo Research In America, O. Carter Snead

Journal Articles

The moral, legal, and public policy dispute over embryonic stem cell research (and related matters, such as human cloning) is the most prominent issue in American public bioethics of the past decade. The primary moral question raised by the practice of embryonic stem cell research is whether it is defensible to disaggregate (and thus destroy) living human embryos in order to derive pluripotent cells (stem cells) for purposes of basic research that may someday yield regenerative therapies. This essay will explain the legal and political dimensions of the embryonic stem cell debate as it has unfolded at the national level …

Child Support Guidelines: The Good, The Bad, And The Ugly, Margaret F. Brinig, Douglas W. Allen

Journal Articles

Child support guideline systems do more than simply determine the amount of income to be transferred from the noncustodial to the custodial household. They create incentives, one way or another, for spouses to divorce and seek custody and support payments. We examine three cases found in North America, and find that the common method of income shares provides a decent guideline that does not create any perverse incentives for divorce. Percentage-of-obligor-income methods do worse than other systems, and can cause increases in divorce rates for families in which one spouse earns a high income. Finally, the Canadian system, which is …

Morally Hazardous Chemical Regulations: Why Effective Reform Of The Tsca Requires Reduction Of The Toxic Data Gap, John Kvinge

Minnesota Journal of Law, Science & Technology

No abstract provided.

Comparative Susceptibility Of Ostrinia Furnacalis, Ostrinia Nubilalis, And Diatraea Saccharalis (Lepidoptera: Crambidae) To Bacillus Thuringiensis Cry1 Toxins, S. Y. Tan, B. F. Cayabyab, E. P. Alcantara, Y. B. Ibrahim, Fangneng Huang, Erin E. Blankenship, Blair D. Siegfried

Department of Entomology: Faculty Publications

Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) are highly effective against the European corn borer, Ostrinia nubilalis (Hübner), and the closely related Asian corn borer, Ostrinia furnacalis (Guenée). Since the registration of Bt corn hybrids in the U.S. in 1996, there has been a great deal of information generated on O. nubilalis. However, relatively little information exists for O. furnacalis. To help determine whether the information generated for O. nubilalis can be leveraged for decisions regarding the use of transgenic Bt corn against O. furnacalis, experiments were designed to determine whether the pattern of sensitivity …

Characterization Of Olfactory Sensilla Of Stomoxys Calcitrans And Electrophysiological Responses To Odorant Compounds Associated With Hosts And Oviposition Media, K. Tangtrakulwanich, Han Chen, Frederick P. Baxendale, Gary J. Brewer, J. J. Zhu

Department of Entomology: Faculty Publications

Stable flies, Stomoxys calcitrans L. (Diptera: Muscidae), are economically important biting flies that have caused billions of dollars in losses in the livestock industry. Field monitoring studies have indicated that olfaction plays an important role in host location. To further our understanding of stable fly olfaction, we examined the antennal morphology of adults using scanning electron microscopy techniques. Four major types of sensillum were found and classified as: (a) basiconic sensilla; (b) trichoid sensilla with three subtypes; (c) clavate sensilla, and (d) coeloconic sensilla. No significant differences between male and female flies in abundances (total numbers) of these sensillum types …

Analysis Of Event Detection Delay In Wireless Sensor Networks, Yunbo Wang, Mehmet C. Vuran, Steve Goddard

School of Computing: Conference and Workshop Papers

Emerging applications of wireless sensor networks (WSNs) require real-time event detection to be provided by the network. In a typical event monitoring WSN, multiple reports are generated by several nodes when a physical event occurs, and are then forwarded through multi-hop communication to a sink that detects the event. To improve the event detection reliability, usually timely delivery of a certain number of packets is required. Traditional timing analysis of WSNs are, however, either focused on individual packets or traffic flows from individual nodes. In this paper, a spatio-temporal fluid model is developed to capture the delay characteristics of event …

A Novel Channel Probing/Scanning Scheme For Secure Fast Handoff In Ieee 802.11-Based Wireless Networks, Ye Yan, Yi Qian, Rose Qingyang Hu

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

With the proliferation of wireless networks for practical deployments in recent years, secure fast handoff has become significantly important to provide secured access while reduce the latency caused by handoff procedure. Channel probing/scanning delay has been a major contribution to the overall latency of handoff in IEEE 802.11 based wireless networks. In this paper, we present a novel secure fast handoff scheme that adopts network-assisted radio statement (NACS) to eliminate lengthy probing/scanning delay by taking advantage of the knowledge of network topology of neighboring nodes in the network. We apply an opportunistic mechanism to retrieve the channel condition from neighboring …

Priority Preemption For Real-Time Application Qos Guarantees In Cooperative Vehicular Networks, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Tao Ma, Pradhumna Shrestha

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Inter-vehicle and roadside-to-vehicle communications can contribute to a safer and more efficient driving experience by providing time-sensitive and location-aware information. However, its performance suffers from vehicle mobility, intermittent user connectivity, and wireless channel unreliability. In this paper, we propose a novel cross-layer optimization approach based on our Adaptive Distributed Cooperative Medium Access Control (ADC-MAC) protocol to guarantee the quality-of-service (QoS) of real-time applications. Markov chain based theoretical analysis show that our proposed priority preemption approach can improve the quality of a real-time application by guaranteeing its bandwidth and reducing its transmission latency.

Evaluation Of Mold And Mycotoxin Contaminations In Hybrid Hazelnuts Grown In Nebraska, Yixiang Xu, Andreia Bianchini, Milford A. Hanna

Department of Food Science and Technology: Faculty Publications

Hybrid hazelnuts are a potential oilseed crop for food and value-added industrial applications, but they are vulnerable to mold contamination. Mold and mycotoxin contamination were investigated in three forms (whole nut, kernel, and ground meal) of Nebraska hybrid hazelnuts. The nut was the most contaminated form, followed by ground meal and kernel. Penicillium was the predominant genus isolated from all three forms, and Alternaria and Cladosporium also were prevalent. In spite of presence of several toxigenic molds, all tested samples were mycotoxin free.

Barcoded Pyrosequencing Reveals That Consumption Of Galactooligosaccharides Results In A Highly Specific Bifidogenic Response In Humans, Lauren M. G. Davis, Ines Martinez, Jens Walter, Caitlin Goin, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

Prebiotics are selectively fermented ingredients that allow specific changes in the gastrointestinal microbiota that confer health benefits to the host. However, the effects of prebiotics on the human gut microbiota are incomplete as most studies have relied on methods that fail to cover the breadth of the bacterial community. The goal of this research was to use high throughput multiplex community sequencing of 16S rDNA tags to gain a community wide perspective of the impact of prebiotic galactooligosaccharide (GOS) on the fecal microbiota of healthy human subjects. Fecal samples from eighteen healthy adults were previously obtained during a feeding trial …

Hiv-1 Clade B And C Isolates Exhibit Differential Replication: Relevance To Macrophage-Mediated Neurotoxicity, Agnes A. Constantino, Yunlong Huang, Hong Zhang, Charles Wood, Jialin C. Zheng

Nebraska Center for Virology: Faculty Publications

HIV-associated neurocognitive disorders (HAND) continue to be a consequence of HIV-1 infection among clade B-infected individuals. In contrast, the incidence of severe neurological impairment is lower among clade C-infected patients in regions of Sub-Saharan Africa and India. Biological aspects such as replication, cytopathicity, inflammatory response, and neurotoxicity unique to each clade influence neuropathogenicity and ultimately affect the clinical outcome of the disease. We hypothesize that productive infection by clade C isolates leads to macrophagemediated neurotoxicity, although to a lesser extent than clade B isolates. Using a panel of primary isolates of clades B and C we demonstrated that clade B …

Control Of Glucosylceramide Production And Morphogenesis By The Bar1 Ceramide Synthase In Fusarium Graminearum, William B. Rittenour, Ming Chen, Edgar B. Cahoon, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The contribution of plasma membrane proteins to the virulence of plant pathogenic fungi is poorly understood. Accordingly, the objective of this study was to characterize the acyl-CoA dependent ceramide synthase Bar1 (previously implicated in plasma membrane organization) in the wheat pathogen Fusarium graminearum. The role of Bar1 in mediating cell membrane organization was confirmed as DBAR1 mutants failed to display a distinct sterol-rich domain at the hyphal tip. The DBAR1 mutants were non-pathogenic when inoculated onto wheat heads, and their in vitro growth also was severely perturbed. DBAR1 mutants were incapable of producing perithecia (sexual fruiting structures) and only produced …

The Sugar Sensor, Trehalose-6-Phosphate Synthase (Tps1), Regulates Primary And Secondary Metabolism During Infection By The Rice Blast Fungus: Will Magnaporthe Oryzae’S “Sweet Tooth” Become Its “Achilles’ Heel”?, Jesse Fernandez, Richard Wilson

Department of Plant Pathology: Faculty Publications

Rice blast disease is considered one of the most serious diseases of cultivated rice and is mediated by the causal agent, Magnaporthe oryzae. During infection, dome-shaped fungal cells, called appressoria, form on the surface of the leaf and generate turgor through the accumulation of glycerol. This enormous pressure is directed down onto a thin penetration hypha emerging from the base of the cell, forcing it through the surface of the rice leaf and allowing fungal colonization of the plant interior. The non-reducing disaccharide, trehalose, is present in conidia of M. oryzae and is mobilized during appressorium formation. The first …

Mechanisms Of Contact-Mediated Killing Of Yeast Cells On Dry Metallic Copper Surfaces, Davide Quaranta, Travis Krans, Christophe Espirito Santo, Christian Elowsky, Dylan W. Domaille, Christopher J. Chang, Gregor Grass

Department of Plant Pathology: Faculty Publications

Surfaces made of copper or its alloys have strong antimicrobial properties against a wide variety of microorganisms. However, the molecular mode of action responsible for the antimicrobial efficacy of metallic copper is not known. Here, we show that dry copper surfaces inactivate Candida albicans and Saccharomyces cerevisiae within minutes in a process called contact-mediated killing. Cellular copper ion homeostasis systems influenced the kinetics of contact-mediated killing in both organisms. Deregulated copper ion uptake through a hyperactive S. cerevisiae Ctr1p (ScCtr1p) copper uptake transporter in Saccharomyces resulted in faster inactivation of mutant cells than of wild-type cells. Similarly, lack of the …

Consensus-Based Reporting Standards For Diagnostic Test Accuracy Studies For Paratuberculosis In Ruminants, Ian A. Gardner, Søren S. Nielsen, Richard J. Wittington, Michael T. Collins, Douwe Bakker, Beth Harris, Srinand Sreevatsan, Jason E. Lombard, Raymond Sweeney, David R. Smith, Jerrie Gavalchin, Shigetoshi Eda

School of Veterinary and Biomedical Sciences: Faculty Publications

The Standards for Reporting of Diagnostic Accuracy (STARD) statement was developed to encourage complete and transparent reporting of key elements of test accuracy studies in human medicine. The statement was motivated by widespread evidence of bias in test accuracy studies and the finding that incomplete or absent reporting of items in the STARD checklist was associated with overly optimistic estimates of test performance characteristics. Although STARD principles apply broadly, specific guidelines do not exist to account for unique considerations in livestock studies such as herd tests, potential use of experimental challenge studies, a more diverse group of testing purposes and …

Are There Superspin Glasses?, Ralph Skomski

Ralph Skomski Publications

The effect of magnetostatic and exchange interactions on the spin structure of interacting nanoparticles and granular nanomagnets is investigated by model calculations. Effective exchange stiffnesses for inhomogeneous media are defined and determined for some geometries and interactions, and it is argued that typical ensembles of interacting small nanoparticles are micromagnetic systems rather than superspin glasses or superferromagnets. The spin structures of granular magnets often have the character of interaction domains, with far-reaching implications for magnetic phenomena such as hysteresis-loop overskewing.

Switchgrass For Forage And Bioenergy: Harvest And Nitrogen Rate Effects On Biomass Yields And Nutrient Composition, John A. Guretzky, Jon T. Biermacher, Billy Cook, Maru K. Kering, Jagadeesh Mosali

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) may have value as forage and a bioenergy feedstock. Our objective was to evaluate how harvest system and N fertilizer rates affected biomass yield and nutrient composition of young stands of switchgrass (cv. Alamo) in the southern Great Plains, USA. Nitrogen fertilization increased biomass yields from 10.4, 10.8, and 12.2 Mg ha⁻¹ at 0 kg N ha⁻¹ to 13.7, 14.6, and 21.0 Mg ha⁻¹ at 225 kg N ha⁻¹ when harvested after seed set (October), after frost (December), and twice per year after boot stage (July) and frost, respectively. Nutrient concentrations …

Switchgrass Contains Two Cinnamyl Alcohol Dehydrogenases Involved In Lignin Formation, Aaron J. Saathoff, Christian M. Tobias, Scott E. Sattler, Eric J. Haas, Paul Twigg, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Lignin content of switchgrass (Panicum virgatum L.), a bioenergy species, is a critical determinant of biomass quality since it can negatively impact conversion of biomass into liquid fuels via biochemical platforms. Cinnamyl alcohol dehydrogenase (CAD) is a key enzyme in lignin biosynthesis. Here, we have shown that cv. Kanlow switchgrass contains at least two closely related CAD genes (PviCAD1 and PviCAD2) that code for proteins containing highly conserved domains and residues that identify them as bona fide CADs. Both recombinant proteins displayed substrate kinetics consistent with their presumed role in cell wall lignification. Proteomic and immunoblotting detected …

Flow And Transport Experiments For A Streambank Seep Originating From A Preferential Flow Pathway, Garey A. Fox, Derek M. Heeren, Ronald B. Miller, Aaron R. Mittelstet, Daniel E. Storm

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Streambank seeps commonly originate from localized heterogeneity or preferential flow pathways (PFPs) in riparian floodplains. However, limited field data have been reported on ground water seep flows and solute transport to seeps from PFPs. The objective of this research was to build upon previous floodplain-scale investigations of PFPs by analyzing seep discharge and transport characteristics through a single PFP. An important research question was whether this PFP could be conceptualized as a homogeneous, one-dimensional flow path. Streambank seep discharge measurements were obtained by inducing a hydraulic head in a trench injection system. Also, co-injection of Rhodamine WT (RhWT) and a …

Evaluation Of Select Sensors For Real-Time Monitoring Of Escherichia Coli In Water Distribution Systems, Syreeta L. Miles, Ryan G. Sinclair, Mark R. Riley, Ian L. Pepper

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study evaluated real-time sensing of Escherichia coli as a microbial contaminant in water distribution systems. Most sensors responded to increased E. coli concentrations, showing that select sensors can detect microbial water quality changes and be utilized as part of a contaminant warning system.

A Case Study Concerning The Effects Of Controller Response And Turning Movements On Application Rate Uniformity With A Self-Propelled Sprayer, Joe D. Luck, A. Sharda, Santosh Pitla, J. P. Fulton, S. A. Shearer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The use of precision agriculture technologies such as automatic boom section control allows producers to reduce off-target application when applying herbicides. While automatic boom section control provides benefits, pressure differences across the spray boom resulting from boom section actuation may lead to off-rate application errors. Off-rate errors may also result from spray rate controller compensation for ground speed changes or velocity variation across the spray boom during turning movements. This project focused on characterizing application rate variation for three fields located in central Kentucky. GPS coordinates, boom control status, and nozzle pressure data (at 15 nozzle locations) were recorded as …

Systems-Scale Analysis Reveals Pathways Involved In Cellular Response To Methamphetamine, Lijie Sun, Hong-Mei Li, Manfredo J. Seufferheld, Kent R. Walters Jr., Venu M. Margam, Amber Jannasch, Naomi Diaz, Catherine P. Riley, Weilin Sun, Yueh-Feng Li, William M. Muir, Jun Xie, Jing Wu, Fan Zhang, Jake Y. Chen, Eric L. Barker, Jiri Adamec, Barry R. Pittendrigh

Department of Biochemistry: Faculty Publications

Background: Methamphetamine (METH), an abused illicit drug, disrupts many cellular processes, including energy metabolism, spermatogenesis, and maintenance of oxidative status. However, many components of the molecular underpinnings of METH toxicity have yet to be established. Network analyses of integrated proteomic, transcriptomic and metabolomic data are particularly well suited for identifying cellular responses to toxins, such as METH, which might otherwise be obscured by the numerous and dynamic changes that are induced.

Methodology/Results: We used network analyses of proteomic and transcriptomic data to evaluate pathways in Drosophila melanogaster that are affected by acute METH toxicity. METH exposure caused changes in the …

Functional Diversification Of Thylakoidal Processing Peptidases In Arabidopsis Thaliana, Shih-Chi Hsu, Joshua K. Endow, Nicholas J. Ruppel, Rebecca Roston, Amy J. Baldwin, Kentaro Inoue

Department of Biochemistry: Faculty Publications

Thylakoidal processing peptidase (TPP) is responsible for removing amino-terminal thylakoid-transfer signals from several proteins in the thylakoid lumen. Three TPP isoforms are encoded by the nuclear genome of Arabidopsis thaliana. Previous studies showed that one of them termed plastidic type I signal peptidase 1 (Plsp1) was necessary for processing three thylakoidal proteins and one protein in the chloroplast envelope in vivo. The lack of Plsp1 resulted in seedling lethality, apparently due to disruption of proper thylakoid development. The physiological roles of the other two TPP homologs remain unknown. Here we show that the three A. thaliana TPP isoforms …

Increased Transsulfuration Mediates Longevity And Dietary Restriction In Drosophila, Hadise Kabil, Omer Kabil, Ruma Banerjee, Lawrence G. Harshman, Scott D. Pletcher

School of Biological Sciences: Faculty Publications

The mechanisms through which dietary restriction enhances health and longevity in diverse species are unclear. The transsulfuration pathway (TSP) is a highly conserved mechanism for metabolizing the sulfur-containing amino acids, methionine and cysteine. Here we show that Drosophila cystathionine β-synthase (dCBS), which catalyzes the rate-determining step in the TSP, is a positive regulator of lifespan in Drosophila and that the pathway is required for the effects of diet restriction on animal physiology and lifespan. dCBS activity was up-regulated in flies exposed to reduced nutrient conditions, and ubiquitous or neuron-specific transgenic overexpression of dCBS enhanced longevity in fully fed animals. Inhibition …

A Cytoplasm-Specific Activity Encoded By The Trithorax-Like Atx1 Gene, Ivan Ndamukong, Hanna Lapko, Ronald L. Cerny, Zoya Avramova

School of Biological Sciences: Faculty Publications

Eukaryotes produce multiple products from a single gene locus by alternative splicing, translation or promoter usage as mechanisms expanding the complexity of their proteome. Trithorax proteins, including the Arabidopsis Trithorax-like protein ATX1, are histone modifiers regulating gene activity. Here, we report that a novel member of the Trithorax family has a role unrelated to chromatin. It is encoded from an internal promoter in the ATX1 locus as an isoform containing only the SET domain (soloSET). It is located exclusively in the cytoplasm and its substrate is the elongation factor 1A (EF1A). Loss of SET, but not of the histone modifying …

Evidence For Air Movement Signals In The Agonistic Behaviour Of A Nocturnal Arachnid (Order Amblypygi), Roger D. Santer, Eileen A. Hebets

School of Biological Sciences: Faculty Publications

Many arthropods possess filiform hair sensilla (termed trichobothria in arachnids), which are extremely sensitive detectors of medium particle displacement. Electrophysiological evidence in some taxa suggests that these sensilla can detect air particle displacements resulting from intraspecific communication signals. However, it has not yet been shown for any species that the air particle displacements detected by the filiform hairs are themselves perceived as a ‘signal’ (i.e. that individuals make behavioural decisions based upon the responses of these organs to the displays of conspecifics). We investigate the agonistic behaviour of the whip spider Phrynus marginemaculatus and the role of its trichobothria in …

Dur3 Is The Major Urea Transporter In Candida Albicans And Is Co-Regulated With The Urea Amidolyase Dur1,2, Dhammika H. M. L. P Navarathna, Aditi Das, Joachim Morschhauser, Kenneth W. Nickerson, David D. Roberts

Kenneth Nickerson Papers

Hemiascomycetes, including the pathogen Candida albicans, acquire nitrogen from urea using the urea amidolyase Dur1,2, whereas all other higher fungi use primarily the nickel-containing urease. Urea metabolism via Dur1,2 is important for resistance to innate host immunity in C. albicans infections. To further characterize urea metabolism in C. albicans we examined the function of seven putative urea transporters. Gene disruption established that Dur3, encoded by orf 19.781, is the predominant transporter. [¹⁴C]Urea uptake was energy-dependent and decreased approximately sevenfold in a dur3D mutant. DUR1,2 and DUR3 expression was strongly induced by urea, whereas the other putative transporter genes …

Arabidopsis G-Protein Interactome Reveals Connections To Cell Wall Carbohydrates And Morphogenesis, Karsten Klopffleisch, Nguyen Phan, Kelsey Augustin, Robert S. Bayne, Katherine S. Booker, Jose R. Botella, Nicholas C. Carpita, Tyrell Carr, Jin-Gui Chen, Thomas Ryan Cooke, Arwen Frick-Cheng, Erin J. Friedman, Brandon Fulk, Michael G. Hahn, Kun Jiang, Lucia Jorda, Lydia Kruppe, Chenggang Liu, Justine Lorek, Maureen C. Mccann, Antonio Molina, Etsuko N. Moriyama, M. Shahid Mukhtar, Yashwanti Mudgil, Sivakumar Pattathil, John Schwarz, Steven Seta, Matthew Tan, Ulrike Temp, Yuri Trusov, Daisuke Urano, Bastian Welter, Jing Yang, Ralph Panstruga, Joachim F. Uhrig, Alan M. Jones

School of Biological Sciences: Faculty Publications

The heterotrimeric G-protein complex is minimally composed of Ga, Gb, and Gc subunits. In the classic scenario, the G-protein complex is the nexus in signaling from the plasma membrane, where the heterotrimeric G-protein associates with heptahelical G-protein-coupled receptors (GPCRs), to cytoplasmic target proteins called effectors. Although a number of effectors are known in metazoans and fungi, none of these are predicted to exist in their canonical forms in plants. To identify ab initio plant G-protein effectors and scaffold proteins, we screened a set of proteins from the G-protein complex using two-hybrid complementation in yeast. After deep and exhaustive interrogation, we …