Digital Commons Network^™

Kinetic And Structural Characterization Of Tunnel-Perturbing Mutants In Bradyrhizobium Japonicum Proline Utilization A, Benjamin W. Arentson, Min Luo, Travis A. Pemberton, John J. Tanner, Donald F. Becker

Department of Biochemistry: Faculty Publications

Proline utilization A from Bradyrhizobium japonicum (BjPutA) is a bifunctional flavoenzyme that catalyzes the oxidation of proline to glutamate using fused proline dehydrogenase (PRODH) and Δ¹-pyrroline-5-carboxylate dehydrogenase (P5CDH) domains. Recent crystal structures and kinetic data suggest an intramolecular channel connects the two active sites, promoting substrate channeling of the intermediate Δ¹-pyrroline-5-carboxylate/glutamate-γ-semialdehyde (P5C/GSA). In this work, the structure of the channel was explored by inserting large side chain residues at four positions along the channel in BjPutA. Kinetic analysis of the different mutants revealed replacement of D779 with Tyr (D779Y) or Trp (D779W) significantly decreased the overall …

Estimating The Frequency Of Cry1f Resistance In Field Populations Of The European Corn Borer (Lepidoptera: Crambidae), Blair D. Siegfried, Murugesan Rangasamy, Haichuan Wang, Terence A. Spencer, Chirakkal V. Haridas, Brigitte Tenhumberg, Douglas V. Sumerford, Nicholas P. Storer

School of Biological Sciences: Faculty Publications

Background: Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) have suppressed European corn borer populations and reduced the pest status of this insect throughout much of the US corn belt. A major assumption of the high-dose/refuge strategy proposed for insect resistance management and Bt corn is that the frequency of resistance alleles is low so that resistant pests surviving exposure to Bt corn will be rare. Results: The frequency of resistance to the Cry1F Bt toxin was estimated using two different screening tools and compared with annual susceptibility monitoring based on diagnostic bioassays and LC_{50 …}

Genome-Wide Gene Expression Effects Of Sex Chromosome Imprinting In Drosophila, Bernardo Lemos, Alan T. Branco, Pan-Pan Jiang, Daniel L. Hartl, Colin D. Meiklejohn

School of Biological Sciences: Faculty Publications

Imprinting is well-documented in both plant and animal species. In Drosophila, the Y chromosome is differently modified when transmitted through the male and female germlines. Here, we report genome-wide gene expression effects resulting from reversed parent-of-origin of the X and Y chromosomes. We found that hundreds of genes are differentially expressed between adult male Drosophila melanogaster that differ in the maternal and paternal origin of the sex chromosomes. Many of the differentially regulated genes are expressed specifically in testis and midgut cells, suggesting that sex chromosome imprinting might globally impact gene expression in these tissues. In contrast, we observed much …

Atx1/Atcompass And The H3k4me3 Marks: How Do They Activate Arabidopsis Genes?, Michael E. Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

Despite the proven correlation between gene transcriptional activity and the levels of tri-methyl marks on histone 3 lysine4 (H3K4me3) of their nucleosomes, whether H3K4me3 contributes to, or “registers,” activated transcription is still controversial. Other questions of broad relevance are whether histone-modifying proteins are involved in the recruitment of Pol II and the general transcription machinery and whether they have roles other than their enzyme activities. We address these questions as well as the roles of the ARABIDOPSIS HOMOLOG OF TRITHORAX1 (ATX1), of the COMPASS-related (AtCOMPASS) protein complex, and of their product, H3K4me3, at ATX1-dependent genes. We suggest that the ambiguity …

Endogenous Aba Extraction And Measurement From Arabidopsis Leaves, Ning Liu, Yong Ding, Michael Fromm, Zoya Avramova

School of Biological Sciences: Faculty Publications

The endogenous messenger, the phytohormone abscisic acid (ABA) plays a major role in plant’s adaption to drought, salinity, cold and other abiotic stresses. In addition to abiotic stress signaling, ABA is involved also in developmental regulation and in responses to diverse biotic stresses. Dehydration stress results in a strong increase in endogenous ABA levels, which can be perceived by RCAR/PYR1/PYL receptors, initiating the ABA signaling pathway to coordinate the genome-wide gene expression, and plants adaptive physiological responses. ABA biosynthesis triggered by environmental cues as well as developmental signals occurs predominantly in vascular parenchyma cells. The measurement of ABA content in …

Aba Signaling Is Necessary But Not Sufficient For Rd29b Transcriptional Memory During Successive Dehydration Stresses In Arabidopsis Thaliana, Laetitia Virlouvet, Yong Ding, Hiroaki Fujii, Zoya Avramova, Michael Fromm

School of Biological Sciences: Faculty Publications

Plants subjected to a prior dehydration stress were seen to have altered transcriptional responses during a subsequent dehydration stress for up to 5 days after the initial stress. The abscisic acid (ABA) inducible RD29B gene of Arabidopsis thaliana was strongly induced after the first stress and displayed transcriptional memory with transcript levels nine-fold higher during the second dehydration stress. These increased transcript levels were due to an increased rate of transcription and are associated with an altered chromatin template during the recovery interval between the dehydration stresses. Here we use a combination of promoter deletion/substitutions, mutants in the trans-acting …

An Assembly Of Proteins And Lipid Domains Regulates Transport Of Phosphatidylserine To Phosphatidylserine Decarboxylase 2 In Saccharomyces Cerevisiae, Wayne R. Riekhof, Wen-I Wu, Jennifer L. Jones, Mrinalini Nikrad, Mallory M. Chan, Christopher J. R. Loewen, Dennis R. Voelker

School of Biological Sciences: Faculty Publications

Background: The machinery for interorganelle phosphatidylserine (PtdSer) transport is poorly defined at the molecular level.

Results: Molecular interaction studies identify specific protein-protein and protein-lipid interactions in PtdSer transport.

Conclusion: A protein and lipid interaction network defines key participants in PS transport to the locus of PtdSer-decarboxylase 2.

Significance: This study identifies important molecular participants involved in non-vesicular phospholipid traffic.

Why American Higher Education Needs Parasitologists, John J. Janovy Jr.

John J. Janovy, Jr. Publications

Addresses four topics that characterize the discipline of parasitology and are largely missing from our national conversation in the United States about education, especially at the college and university level. Those topics are the production of transferable skills; our perceptions of the world, especially the natural world; access to reasonably difficult problems in natural settings; and intellectual epidemiology, or the movement of ideas, innovations, and cultural items through populations. These topics have been a part of the author's discussions with fellow parasitologists for at least half a century, beginning with his choice to pursue a graduate degree under the supervision …

Detection Of Predator Cues Alters Mating Tactics In Male Wolf Spiders, Dustin J. Wilgers, Daniel Wickwire, Eileen Hebets

Eileen Hebets Publications

Males of the wolf spider, Rabidosa punctulata, exhibit condition-dependent alternative mating tactics, whereby small, poor condition males engage in multimodal courtship while large, good condition males adopt a direct mount tactic that forgoes courtship. This study explores the possibility that tactic-specific costs can help explain this unintuitive pattern of mating tactic expression. Specifically, we hypothesize that courtship signaling is costly with respect to eavesdropping by predators and that males can alter their tactic expression based upon the perceived environmental predation risk. We test this by first examining the risk of predation associated with different mating tactics. We use a …

The Roles Of Cis- And Trans-Regulation In The Evolution Of Regulatory Incompatibilities And Sexually Dimorphic Gene Expression, Colin D. Meiklejohn, Joseph D. Coolon, Daniel L. Hartl, Patricia J. Wittkopp

School of Biological Sciences: Faculty Publications

Evolutionary changes in gene expression underlie many aspects of phenotypic diversity within and among species. Understanding the genetic basis for evolved changes in gene expression is therefore an important component of a comprehensive understanding of the genetic basis of phenotypic evolution. Using interspecific introgression hybrids, we examined the genetic basis for divergence in genome-wide patterns of gene expression between Drosophila simulans and Drosophila mauritiana. We find that cis-regulatory and trans-regulatory divergences differ significantly in patterns of genetic architecture and evolution. The effects of cis-regulatory divergence are approximately additive in heterozygotes, quantitatively different between males and females, …

Repeated Evolution Of Chimeric Fusion Genes In The Β-Globin Gene Family Of Laurasiatherian Mammals, Michael J. Gaudry, Jay F. Storz, Gary Tyler Butts, Kevin L. Campbell, Federico G. Hoffmann

Jay F. Storz Publications

The evolutionary fate of chimeric fusion genes may be strongly influenced by their recombinational mode of origin and the nature of functional divergence between the parental genes. In the β-globin gene family of placental mammals, the two postnatally expressed δ- and β-globin genes (HBD and HBB, respectively) have a propensity for recombinational exchange via gene conversion and unequal crossing-over. In the latter case, there are good reasons to expect differences in retention rates for the reciprocal HBB/HBD and HBD/ HBB fusion genes due to thalassemia pathologies associated with the HBD/HBB “Lepore” deletion mutant in humans.Here,were port a comparative …

Native Insect Herbivory Limits Population Growth Rate Of A Non-Native Thistle, James O. Eckberg, Brigitte Tenhumberg, Svata M. Louda

Brigitte Tenhumberg Papers

The influence of native fauna on non-native plant population growth, size, and distribution is not well documented. Previous studies have shown that native insects associated with tall thistle (Cirsium altissimum) also feed on the leaves, stems, and flower heads of the Eurasian congener Cirsium vulgare, thus limiting individual plant performance. In this study, we tested the effects of insect herbivores on the population growth rate of C. vulgare. We experimentally initiated invasions by adding seeds at four unoccupied grassland sites in eastern Nebraska, USA, and recorded plant establishment, survival, and reproduction. Cumulative foliage and floral herbivory …

The Unoccupied Electronic Structure Characterization Of Hydrothermally Grown Tho2 Single Crystals, T D. Kelly, J C. Petrosky, D Turner, J W. Mcclory, J M. Mann, J W. Kolis, Xin Zhang, Peter A. Dowben

Peter Dowben Publications

Single crystals of thorium dioxide ThO₂, grown by the hydrothermal growth technique, have been investigated by ultraviolet photoemission spectroscopy (UPS), inverse photoemission spectroscopy (IPES), and L₃, M₃, M₄, and M₅ X-ray absorption near edge spectroscopy (XANES). The experimental band gap for large single crystals has been determined to be 6 eV to 7 eV, from UPS and IPES, in line with expectations. The combined UPS and IPES, place the Fermi level near the conduction band minimum, making these crystals n-type, with extensive band tailing, suggesting an optical gap in the region …

Varestrongylus Eleguneniensis Sp. N. (Nematoda: Protostrongylidae): A Widespread, Multi-Host Lungworm Of Wild North American Ungulates, With An Emended Diagnosis For The Genus And Explorations Of Biogeography, Guilherme G. Verocai, Susan J. Kutz, Manon Simard, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Background: A putative new species of Varestrongylus has been recently recognized in wild North American ungulates based on the ITS-2 sequences of larvae isolated from feces during a wide geographic survey. No taxonomic description was provided, as adult specimens were not examined. Methods: Lungworm specimens were collected in the terminal bronchioles of muskoxen from Quebec, and a woodland caribou from central Alberta, Canada. The L3 stage was recovered from experimentally infected slugs (Deroceras spp.). Description of specimens was based on comparative morphology and integrated approaches. Molecular identity was determined by PCR and sequencing of the ITS-2 region of …

Air Sac Nematode Monopetalonema Alcedinis In A Belted Kingfisher (Megaceryle Alcyon) In Maryland, Usa, Ellen Bronson, Kathleen Kelly, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Sporadic and geographically widespread reports of parasites affecting the Belted Kingfisher (Megaceryle alcyon) have been published but few have described details of the pathology. A female, adult kingfisher was found dead in a heavily wooded area of a zoo in Maryland, USA. At necropsy, numerous sexually dimorphic, 4.4–40.5-cm adult Monopetalonema alcedinis nematodes were found tightly wound within the coelomic cavity between organs and completely filling the caudal thoracic and abdominal air sacs. Abundant, 30–60-mm diameter, larvated, thick-walled ova were found in the bronchi and parabronchi, within the mesentery, and in the serosa of multiple coelomic organs. Monopetalonema alcedinis …

In Memoriam: Robert Lloyd Rausch—A Life In Nature And Field Biology, 1921–2012, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

During his distinguished career, Robert Rausch, a man of great integrity and principles, served in his lifetime as a singular ambassador for parasitology in a broad international arena. Robert was a friend to many, was honored to be considered an equal among the nomadic bands of Nunamiut traversing the Brooks Range 60 years ago, and will be long remembered for the strength of his science and his perceptive views of the natural world.

Levisunguis Subaequalis N. G., N. Sp., A Tongue Worm (Pentastomida: Porocephalida: Sebekidae) Infecting Softshell Turtles, Apalone Spp. (Testudines: Trionychidae), In The Southeastern United States, Stephen S. Curran, Robin M. Overstreet, David E. Collins, George W. Benz

Harold W. Manter Laboratory of Parasitology: Faculty Publications

A new tongue worm (Pentastomida) belonging to the Sebekidae Sambon, 1922 (Porocephaloidea Sambon, 1922) is described based on exemplars collected from softshell terrapins Apalone spinifera aspera (Agassiz) and Apalone ferox (Schneider) in the southeastern United States; a new genus is erected to accommodate the new species. The new species belongs in the Sebekidae because adults possess four simple hooks arranged in a trapezoid pattern on the ventral surface of the cephalothorax, a mouth opening between the anterior and posterior pairs of hooks, a terminal anus, an elongated uterus with preanal uterine pore, and a Y-shaped seminal vesicle. Nymphs possess geminate …

On The Equality Assumption Of Latent And Sensible Heat Energy Transfer Coefficients Of The Bowen Ratio Theory For Evapotranspiration Estimations: Another Look At The Potential Causes Of Inequalities, Suat Irmak, Ayse Kilic, Sumantra Chatterjee

Department of Civil and Environmental Engineering: Faculty Publications

Evapotranspiration (ET) and sensible heat (H) flux play a critical role in climate change; micrometeorology; atmospheric investigations; and related studies. They are two of the driving variables in climate impact(s) and hydrologic balance dynamics. Therefore, their accurate estimate is important for more robust modeling of the aforementioned relationships. The Bowen ratio energy balance method of estimating ET and H diffusions depends on the assumption that the diffusivities of latent heat (K_V) and sensible heat (K_H) are always equal. This assumption is re-visited and analyzed for a subsurface drip-irrigated field in …

Van Der Waals Trilayers And Superlattices: Modification Of Electronic Structures Of Mos2 By Intercalation, Ning Lu, Hongyan Guo, Lu Wang, Xiaojun Wu, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We perform a comprehensive first-principles study of the electronic properties of van der Waals (vdW) trilayers via intercalating a twodimensional (2D) monolayer (ML = BN, MoSe₂, WS₂, orWSe₂) between a MoS₂ bilayer to form various MoS₂/ML/MoS₂ sandwich trilayers. We find that the BN monolayer is themost effective sheet to decouple the interlayer vdW coupling of the MoS₂ bilayer, and the resulting sandwich trilayer can recover the electronic structures of the MoS₂ monolayer, particularly the direct-gap character. Further study of the MoS₂/BN superlattices confirms the effectiveness of …

[The Development Of Public Relations In] Kenya, Dane M. Kiambi

College of Journalism and Mass Communications: Faculty Publications

This chapter traces the practice of PR from pre-independence Kenya to the 21st century. It emerges that the practice of PR is closely tied to major national events and to social, cultural, political and economic forces. PR roles as understood by the pre-independence colonial government: keeping the public informed on government development projects, assessing public opinion and advising government, endearing government to Kenyans and building the awareness of Kenya abroad have continued to modern-day Kenya.

Ashfall Tephra In The Ogallala Group Of The Great Plains: Characteristics And Significance, Michael E. Perkins, Robert F. Diffendal Jr., Michael R. Voorhies, Barbara P. Nash, Bruce E. Bailey

Robert F. Diffendal, Jr., Publications

The Miocene Ogallala Group blankets the Great Plains east of the Rocky Mountains. This sheet of largely fluvial deposits, lying downwind of major silicic volcanic fields to the west, was ideally located to receive and preserve tephra from these fields. This investigation brings modern methods of tephrochronlogy to bear on the age and identity of Ogallala tephra. Results indicate that ~40 separate tephra layers, ranging in age from ~16.5–5.0 Ma, in the Ogallala. Most tephra came from Yellowstone hotspot sources. The relative frequency of hotspot tephra in the Ogallala matches that in more proximal regions to the west with peak …

Sulfites, Steve L. Taylor, Robert K. Bush, Julie A. Nordlee

Department of Food Science and Technology: Faculty Publications

Key Concepts

Sulfites are frequently used food and drug additives.

Ingestion of sulfite residues has been documented to trigger asthmatic reactions in sensitive individuals.

Sulfite-induced asthma occurs in less than 5% of asthmatic individuals, and those with severe, persistent asthma are at greatest risk.

The diagnosis of sulfite-induced asthma is best made by blinded oral challenge with assessment of lung function.

Labeling regulations in the United States alert sulfite-sensitive individuals to the presence of sulfites in foods, which must then be avoided.

Maternal Perceptions Of Agency In Intergenerational Transmission Of Spanish: The Case Of Latinos In The U.S. Midwest, Isabel Velázquez

Spanish Language and Literature Papers

This article examines the ways in which a group of first-generation Latino immigrants to the U.S. Midwest conceptualized their role in their children’s bilingual development. Respondents were asked to identify the individuals or institutions on which their children’s language and academic development depended, as well as household practices perceived as conducive to Spanish maintenance, and perceived obstacles to their children’s use of Spanish in the domains of home, school, and community. Discussion centers on maternal perceptions of agency because of the centrality of the mother in intergenerational minority language transmission. It is argued here that immigrant mothers’ perceptions of agency …

Transpedicular Intracorporeal Grafting For Patients With Thoracolumbar Burst Fractures, Da-Peng Li, Hui-Lin Yang, Yong-Hui Huang, Xiao-Feng Xu, Tai-Cun Sun, Lang Hu

Saudi Medical Journal

OBJECTIVE: To evaluate the efficacy of reinforcing short-segment fixation with transpedicular intracorporeal grafting in restoring vertebral body height and preventing loss of correction in patients with thoracolumbar burst fractures. METHODS: This retrospective study was carried out from the Affiliated Hospital of Jiangsu University, Jiangsu, China. Forty-six patients with thoracolumbar burst fractures without neurological deficit were operatively treated between July 2008 and June 2011. Patients in group A (n=21) were treated by short-segment fixation with transpedicular intracorporeal grafting, whereas patients in group B (n=25) were treated by short-segment fixation without bone grafting. The preoperative, postoperative, and follow-up radiographs (anterior, middle, posterior …

Quality Of Undergraduate Critical Care Medical Education In The Kingdom Of Saudi Arabia. Where Do We Stand?, Mariam A. Alansari

Saudi Medical Journal

No abstract provided.

Evolution Of Supply Chain Collaboration: Implications For The Role Of Knowledge, Michael Gravier, M. Theodore Farris

Marketing Department Faculty Journal Articles

Increasingly, research across many disciplines has recognized the shortcomings of the traditional “integration prescription” for inter-organizational knowledge management. This research conducts several simulation experiments to study the effects of different rates of product change, different demand environments, and different economies of scale on the level of integration between firms at different levels in the supply chain. The underlying paradigm shifts from a static, steady state view to a dynamic, complex adaptive systems and knowledge-based view of supply chain networks. Several research propositions are presented that use the role of knowledge in the supply chain to provide predictive power for how …

A Systems Engineering Approach To Quantitative Comparison Of Molecular Instruments For Use On The International Space Station, Kimberly Lineberger, Jennifer Levitt, David J. Smith, Troy Van Nguyen, Adrian M. Peter

Mathematics and System Engineering Faculty Publications

The presence of microorganisms on the International Space Station (ISS) poses a threat to the health and safety of the ISS crew Currently the ISS utilizes culture-based methods to detect and identify microorganisms These methods are out dated and time-consuming Molecular methods can deliver accurate results and require less processing time This article details an approach to determine which molecular methods instrument most closely meets the Microbial Monitoring System (MMS) requirements for use on the ISS We utilize the decision-theoretic Analytical Hierarchy Process and Quality Function Deployment while aligning the systems requirements vs instrument capabilities m a Pugh Matrix to …

Environmental And Occupational Factors Associated With Chronic Myeloid Leukemia: A Case-Control Study, R. Kasmani, N.A. Othieno-Abinya, M.T. Singh Riyat, G.W. Kiarie, Peter Wanzala

Pathology, East Africa

Background: The relationship between chronic myeloid leukemia (CML) and a broad range of exposures to occupational and environmental factors known to cause leukemia in general is limited. CML is by and large incurable and treatment is just palliative and life prolonging, with high case fatality rate, even in the best centers. Furthermore treatment is very expensive. Identification of leukemogenic factors is therefore important if this can lead to simple public health interventions.

Objective: The objective was to determine key environmental and occupational exposure factors that may be associated with CML.

Methods: This was a case-control study involving CML …

Low Prevalence Of Methicillin Resistant As Determined By An Automated Identification System In Two Private Hospitals In Nairobi, Kenya: A Cross Sectional Study, Geoffrey Omuse, Beatrice Kabera, Gunturu Revathi

Pathology, East Africa

Background: Staphylococcus aureus (S.aureus) is a major cause of both healthcare and community acquired infections. In developing countries, manual phenotypic tests are the mainstay for the identification of staphylococci with the tube and slide coagulase tests being relied upon as confirmatory tests for S. aureus. The subjectivity associated with interpretation of these tests may result in misidentification of coagulase negative staphylococci as S.aureus. Given that antibiotic resistance is more prevalent in CONS, this may result in over estimation of methicillin resistant S.aureus (MRSA) prevalence.

Methods: A review of susceptibility data from all non-duplicate S.aureus isolates generated between March 2011 and …

Kangaroo Is Kangaroo, I Am I, Jeongrye Choi, Special Collections, Fleet Library

Artists' Books

37 unnumbered pages including 3 folded pages : illustrations (some color). "Designed, illustrated, printed, and bound by steph rue at the university of iowa center for the book in the spring of 2014. text graciously provided by jeongrye choi, who holds the copyright. additional thanks for sang-seok yoon, joung-a park, sara langworthy, and julie leonard."--Colophon Edition of 40 copies. Text in English and Korean. Case binding. Library has copy 33 of 40. Purchased at Codex 2024. SEI