Physical Sciences and Mathematics Commons^™

Regulation Of Polar Peptidoglycan Biosynthesis By Wag31 Phosphorylation In Mycobacteria, C. Jani, H. Eoh, J.J. Lee, K. Hamasha

Physics Publications

Background. Sensing and responding to environmental changes is a central aspect of cell division regulation. Mycobacterium tuberculosis contains eleven Ser/Thr kinases, two of which, PknA and PknB, are key signaling molecules that regulate cell division/morphology. One substrate of these kinases is Wag31, and we previously showed that partial depletion of Wag31 caused morphological changes indicative of cell wall defects, and that the phosphorylation state of Wag31 affected cell growth in mycobacteria. In the present study, we further characterized the role of the Wag31 phosphorylation in polar peptidoglycan biosynthesis. Results. We demonstrate that the differential growth among cells expressing different wag31 …

Towards The Clinical Application Of Laser-Induced Breakdown Spectroscopy For Rapid Pathogen Diagnosis: The Effect Of Mixed Cultures And Sample Dilution On Bacterial Identification, Steven J. Rehse, Q.I. Mohaidat, S. Palchaudhuri

Physics Publications

Laser-induced breakdown spectroscopy has been utilized to classify and identify bacterial specimens on the basis of their atomic composition. We have characterized the effect that the presence of a second bacterial species in the ablated specimen had on the identification of the majority species. Specimens with a reduced number of bacterial cells (approximately 2500) were identified with 100% accuracy when compared to undiluted specimens. In addition, a linear dependence of the total spectral power as a function of cell number was determined. Lastly, a high selectivity was obtained for a LIBS-based analysis of nine separate bacterial strains from four genera.

Isotope Shift Measurements In The 2s1/2 → 2p3/2 Transition Of Be+ And Extraction Of The Nuclear Charge Radii For 7,10,11be, M. Zkova, Z. Andjelkovic, M. L. Bissell, Gordon W. F. Drake

Physics Publications

We have performed isotope shift measurements in the 2s1/2 → 2p3/2 transition of Be+ ions using advanced collinear laser spectroscopy with two counter-propagating laser beams. Measurements involving a frequency comb for laser stabilization and absolute frequency determination allowed us to determine the isotope shifts with an accuracy of 2 MHz. From the isotope shifts between 9Be and 7, 10, 11Be, high-accuracy mass shift calculations and the charge radius of the reference isotope 9Be we determined nuclear charge radii for the isotopes 7, 10Be and the one-neutron halo nucleus 11Be. The results are compared to nuclear-structure calculations using the fermionic molecular …

Editorial: 40th Anniversary Of Physical Review A (July 1, 2010), Gordon W. F. Drake

Physics Publications

No abstract provided.

2010 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Inhibition Of Nonsense-Mediated Mrna Decay By Antisense Morpholino Oligonucleotides Restores Functional Expression Of Herg Nonsense And Frameshift Mutations In Long-Qt Syndrome, Qiuming Gong, Matthew R. Stump, Zhengfeng Zhou

Faculty Publications - Department of Biological & Molecular Science

Mutations in the human ether-a-go-go-related gene (hERG) cause long-QT syndrome type 2 (LQT2). We previously described a homozygous LQT2 nonsense mutation Q1070X in which the mutant mRNA is degraded by nonsense-mediated mRNA decay (NMD) leading to a severe clinical phenotype. The degradation of the Q1070X transcript precludes the expression of truncated but functional mutant channels. In the present study, we tested the hypothesis that inhibition of NMD can restore functional expression of LQT2 mutations that are targeted by NMD. We showed that inhibition of NMD by RNA interference-mediated knockdown of UPF1 increased Q1070X mutant channel protein expression and hERG current …

Ranking Bias In Deep Web Size Estimation Using Capture Recapture Method, Jianguo Lu

Computer Science Publications

Many deep web data sources are ranked data sources, i.e., they rank the matched documents and return at most the top k number of results even though there are more than k documents matching the query. While estimating the size of such ranked deep web data source, it is well known that there is a ranking bias—the traditional methods tend to underestimate the size when queries overflow (match more documents than the return limit). Numerous estimation methods have been proposed to overcome the ranking bias, such as by avoiding overflowing queries during the sampling process, or by adjusting the initial …

Geographic Variation In Sperm Traits Reflects Predation Risk And Natural Rates Of Multiple Paternity In The Guppy, K. E. Elgee, J. P. Evans, I. W. Ramnarine, S. A. Rush, Trevor E. Pitcher

Great Lakes Institute for Environmental Research Publications

Guppies (Poecilia reticulata) are models for understanding the interplay between natural and sexual selection. In particular, predation has been implicated as a major force affecting female sexual preferences, male mating tactics and the level of sperm competition. When predation is high, females typically reduce their preferences for showy males and engage more in antipredator behaviours, whereas males exploit these changes by switching from sexual displays to forced matings. These patterns are thought to account for the relatively high levels of multiple paternity in high-predation populations compared to low-predation populations. Here, we assess the possible evolutionary consequences of these patterns by …

The Role Of An Effective It Intervention For Microenterprises, Changsoo Song, Sajda Qureshi

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

Information technology (IT) interventions for micro-enterprises are fragmented and their approach lacks theoretical foundations. While various researchers have conducted studies on the effects of IT adoption in micro-enterprises, little research has been conducted to explain critical aspects of an effective IT intervention for micro-enterprises from a theoretical perspective. This study aims to fill this gap and empirically investigate how IT interventions can effectively facilitate the process of IT adoption by micro-enterprises. This paper suggests that effective IT interventions may have considerable potential for facilitating IT adoption among micro-enterprises across the United States and the world. Following an analysis of four …

Singular Points Of Real Sextic Curves I, David A. Weinberg, Nicholas J. Willis

Faculty Publications - Department of Mathematics

A complete classification of the individual types of singular points is given for irreducible real sextic curves. This classification is derived by using the computer algebra system Maple. There are 191 types of singular points for real irreducible sextic curves. We clarify that the classification is based on computing just enough of the Puiseux expansion to separate the branches. A significant portion of the proof consists of a sequence of large symbolic computations that can be done nicely using Maple.

Carbon Dynamics In A Phragmites Australis Invaded Riparian Wetland, Steven Walters

School of Natural Resources: Dissertations, Theses, and Student Research

Invasive plant species are widely recognized as a major threat to biodiversity and ecosystem stability. Wetland ecosystems tend to be much more susceptible to invasions because of their location on the landscape where water, nutrients, and the impacts of disturbances accumulate. Invasive plants have the ability to alter ecosystem processes and community/population dynamics. The ability of invasive plants to alter these processes can have profound economic consequences. In the United States, control of invasive wetland species alone costs approximately 155 million dollars annually. The state of Nebraska spends 2 million dollars annually controlling invasive plant species in the Platte River …

Connection To Nature In Park Visitors: A Look At Structured And Unstructured Recreational Activities, Chelsea D. West

School of Natural Resources: Dissertations, Theses, and Student Research

There is evidence that park visitation is on the decline (Pergams & Zaradic, 2008) and if this is the case, and budgets decrease proportionately, there is a chance park land will be lost. Definitive explanations of the decline in park visits and time spent in nature are not available. In addition, there has been some discussion and research pertaining to the possible effects on people of not going into the natural environment and experiencing a connection with nature.

This study represents the first research known to focus on connectedness to nature and its relationship to structured and unstructured recreational activities. …

Retention, Movement, And The Biotic Response To Large Woody Debris In The Channelized Missouri River, Michael W. Archer

School of Natural Resources: Dissertations, Theses, and Student Research

Large woody debris (LWD) is an important component of a healthy aquatic ecosystem. However, little is known about the dynamics of LWD in a large, channelized river such as the Missouri River. My objectives were to first, assess the abundance of LWD found along the channelized portion of the Missouri River. Second, I documented movement of LWD that entered the river. Lastly, using PRIMER software I analyzed what effect, if any, river segments, bend types, and LWD had on the community composition of the macroinvertebrate and fish that inhabit the river. Abundance of LWD was greater along bends that have …

A Metric For Routing In Delay-Sensitive Wireless Sensor Networks, Zhen Jiang, Jie Wu, Risa Ito

Computer Science Faculty Publications

No abstract provided.

Cr: Capability Information For Routing Of Wireless Ad Hoc Networks In The Real Environment, Zhen Jiang, Zhigang Li, Nong Xiao, Jie Wu

Computer Science Faculty Publications

No abstract provided.

Logic Is To The Quantum As Geometry Is To Gravity, Rafael D. Sorkin

Physics - All Scholarship

will propose that the reality to which the quantum formalism implicitly refers is a kind of generalized history, the word history having here the same meaning as in the phrase sum-over-histories. This proposal confers a certain independence on the concept of event, and it modifies the rules of inference concerning events in order to resolve a contradiction between the idea of reality as a single history and the principle that events of zero measure cannot happen (the Kochen-Specker paradox being a classic expression of this contradiction). The so-called measurement problem is then solved if macroscopic events satisfy classical rules of …

Covariant Quantum Fields On Noncommutative Spacetimes, A. P. Balachandran, A. Ibort, G. Marmo, M. Martone

Physics - All Scholarship

A spinless covariant field $\phi$ on Minkowski spacetime $\M^{d+1}$ obeys the relation $U(a,\Lambda)\phi(x)U(a,\Lambda)^{-1}=\phi(\Lambda x+a)$ where $(a,\Lambda)$ is an element of the Poincar\'e group $\Pg$ and $U:(a,\Lambda)\to U(a,\Lambda)$ is its unitary representation on quantum vector states. It expresses the fact that Poincar\'e transformations are being unitary implemented. It has a classical analogy where field covariance shows that Poincar\'e transformations are canonically implemented. Covariance is self-reproducing: products of covariant fields are covariant. We recall these properties and use them to formulate the notion of covariant quantum fields on noncommutative spacetimes. In this way all our earlier results on dressing, statistics, etc. for …

Discreteness And The Transmission Of Light From Distant Sources, Fay Dowker, Joe Henson, Rafael Sorkin

Physics - All Scholarship

We model the classical transmission of a massless scalar field from a source to a detector on a background causal set. The predictions do not differ significantly from those of the continuum. Thus, introducing an intrinsic inexactitude to lengths and durations - or more specifically, replacing the Lorentzian manifold with an underlying discrete structure - need not disrupt the usual dynamics of propagation.

Quantum Geons And Noncommutative Spacetimes, A. P. Balachandran, A. Ibort, G. Marmo, M. Martone

Physics - All Scholarship

Physical considerations strongly indicate that spacetime at Planck scales is noncommutative. A popular model for such a spacetime is the Moyal plane. The Poincare group algebra acts on it with a Drinfel'd-twisted coproduct. But the latter is not appropriate for more complicated spacetimes such as those containing the Friedman-Sorkin (topological) geons. They have rich diffeomorphism groups and in particular mapping class groups, so that the statistics groups for N identical geons is strikingly different from the permutation group SN. We generalise the Drinfel'd twist to (essentially) generic groups including to finite and discrete ones and use it to modify the …

S-Waves And The Extraction Of Beta_S, Sheldon Stone

Physics - All Scholarship

The CP Violating asymmetry in Bs mixing (beta_s) is one of the most promising measurements where physics beyond the Standard Model could be revealed. As such, analyses need to be subjected to great scrutiny. The mode Bs -> J/psi\phi has been used, and the mode Bs -> \phi \phi proposed for future measurements. These modes both have two vector particles in the final state and thus angular analyses must be used to disentangle the contributions from CP+ and CP- configurations. The angular distributions, however, could be distorted by the presence of S-waves masquerading as low mass K+K- pairs, that could …

Vortex Dynamics In Superconducting Channels With Periodic Constrictions, Kang Yu, M.B.S. Hesselberth, P. H. Kes, B.L.T. Plourde

Physics - All Scholarship

Vortices confined to superconducting easy flow channels with periodic constrictions exhibit reversible oscillations in the critical current at which vortices begin moving as the external magnetic field is varied. This commensurability scales with the channel shape and arrangement, although screening effects play an important role. For large magnetic fields, some of the vortices become pinned outside of the channels, leading to magnetic hysteresis in the critical current. Some channel configurations also exhibit a dynamical hysteresis in the flux-flow regime near the matching fields.

Nonperturbative Results For Yang-Mills Theories, Francesco Sannino, Joseph Schechter

Physics - All Scholarship

Some non perturbative aspects of the pure SU(3) Yang-Mills theory are investigated assuming a specific form of the beta function, based on a recent modification by Ryttov and Sannino of the known one for supersymmetric gauge theories. The characteristic feature is a pole at a particular value of the coupling constant, g. First it is noted, using dimensional analysis, that physical quantities behave smoothly as one travels from one side of the pole to the other. Then it is argued that the form of the integrated beta function g(m), where m is the mass scale, determines the mass gap of …

Light Scalar Puzzle In Qcd, Amir H. Fariborz, Renata Jora, Joseph Schechter

Physics - All Scholarship

An approach to understanding the light scalar meson spectroscopy is briefly reviewed

To What Type Of Logic Does The "Tetralemma" Belong?, Rafael D. Sorkin

Physics - All Scholarship

Although the so called "tetralemma" might seem to be incompatible with any recognized scheme of logical inference, its four alternatives arise naturally within the "anhomomorphic" logics proposed recently in order to accommodate certain features of microscopic (i.e. quantum) physics. This suggests that non-classical logics of a similar type might have been known in ancient India.

Plasmonic Light-Trapping And Quantum Efficiency Measurements On Nanocrystalline Silicon Solar Cells And Silicon-On-Insulator Devices, Eric A. Schiff, Hui Zhao, Birol Ozturk, Baojie Yan, Jeff Yang

Physics - All Scholarship

Quantum efficiency measurements in nanocrystalline silicon (nc-Si:H)solar cells deposited onto textured substrates indicate that these cells are close to the "stochastic lighttrapping limit" proposed by Yablonovitch in the 1980s. An interesting alternative to texturing is "plasmonic" light-trapping based on non-textured cells and using an overlayer of metallic nanoparticles to produce light-trapping. While this type of light-trapping has not yet been demonstrated for nc-Si:H solar cells, significant photocurrent enhancements have been reported on silicon-on-insulator devices with similar optical properties to nc-Si:H. Here we report our measurements of quantum efficiencies in nc-Si:H solar cells and normalized photoconductance spectra in SOI photodetectors with …

Technology For The Organic Chemist: Three Exploratory Modules, John J. Esteb, Luanne M. Mcnulty, John Magers, Paul Morgan

Scholarship and Professional Work - LAS

The ability to use computer-based technology is an essential skill set for students majoring in chemistry. This exercise details the introduction of appropriate uses for this technology in the organic chemistry series. The incorporation of chemically appropriate online resources (module 1), scientific databases (module 2), and the use of a chemical drawing program (module 3) are detailed here.

John Borchert’S “American Metropolitan Evolution”, Risa Palm

Geosciences Faculty Publications

The article presents comments on the article "American Metropolitan Evolution," originally published in 1967 by the urban geographer John Borchert. Details are given overviewing the thesis and research of the paper, focusing on its discussion of the organizational structure of the four "epochs" of urban development in U.S. history. Discussion is offered explaining the significance of the 1967 paper. The author also highlights the influence which the article had on his own research and of the field at large over 40 years.

Reclaiming A Sense Of Place: Geospatial Technologies And The Flat Rock Cemetery Project, Jeffrey Glover, Kathryn Jackson, Johnny Waits

Geosciences Faculty Publications

The Flat Rock community in southern DeKalb County, Georgia (just outside Atlanta) is one of the oldest continually-occupied African-American communities in Georgia. Although history shows that many African-American communities in the South were broken apart as former slaves migrated north in search of jobs and a more equitable life, Flat Rock remained an intact community. This was largely due to the efforts of individuals who were able to purchase land and later sell it in small parcels to fellow community members. Proximity—both to ancestors and significant places—is a cross-culturally important component to the creation of a sense of community. Placed …

A Primer On Digital Object Identifiers For Law Librarians, Benjamin J. Keele

Library Staff Publications

No abstract provided.

Selling Location: Illinois Town Advertisements 1835-1837, William D. Walters Jr.

Department Publications – Geography, Geology, and the Environment

This document consists of two parts. Part I is an introduction to Illinois towns and town selling during the boom of 1835-1837 when as many as one thousand new towns were laid out. Part II is a summary, in standard format, of over one hundred advertisements for new towns created during these years. These are followed by Appendix A, which lists the names of all proprietors named in the advertisements, and Appendix B, which is a list of all towns platted during this period in central Illinois.