Physical Sciences and Mathematics Commons^™

Acrb Multidrug Efflux Pump Of Escherichia Coli: Composite Substrate-Binding Cavity Of Exceptional Flexibility Generates Its Extremely Wide Substrate Specificity, Edward Yu, Julio R. Aires, Hiroshi Nikaido

Edward Yu

Gram-negative bacteria have, in general, much higher intrinsic levels of resistance to various antibiotics, antiseptics, dyes, and detergents than do gram-positive bacteria. This is, in part, due to the effectiveness of the outer membrane as a barrier. The porin channels exclude large compounds (for example, vancomycin) and drastically slow down the influx of most antibiotics, which are usually much larger than common nutrients. Most antibiotics and chemotherapeutic agents that act on targets in the cytosol must cross the inner, cytoplasmic membrane, usually by spontaneous diffusion, and this necessitates their being at least moderately lipophilic. These compounds can in principle diffuse …

Sensorimotor Coordination And The Structure Of Space, Gin Mccollum

Gin McCollum

Embedded in neural and behavioral organization is a structure of sensorimotor space. Both this embedded spatial structure and the structure of physical space inform sensorimotor control. This paper reviews studies in which the gravitational vertical and horizontal are crucial. The mathematical expressions of spatial geometry in these studies indicate methods for investigating sensorimotor control in freefall.

In freefall, the spatial structure introduced by gravitation – the distinction between vertical and horizontal – does not exist. However, an astronaut arriving in space carries the physiologically-embedded distinction between horizontal and vertical learned on earth. The physiological organization based on this distinction collapses …

Fractional Bandwidth Reacquisition Algorithms For Vsw-Mcm, Ben Cook, Daniel Marthaler, Chad M. Topaz, Andrea L. Bertozzi, Mathieu Kemp

Chad M. Topaz

Autonomous underwater vehicles are gradually being recognized as key assets in future combat systems. Central to this attitude is the realization that teams of vehicles acting in concerted fashion can accomplish tasks that are either too costly or simply outside the range of capabilities of single vehicles. The VSW-MCM target reacquisition problem is the primary driver of underwater multi-agent research. Because of the VSW's inherent high vehicle attrition rate and unreliable communication, it is felt that vehicle coordination must be done off-site. In this paper, we suggest an alternative to this which permits on-site coordination despite loss of vehicles and …

Infrared-Active Vibron Bands Associated With Substitutional Impurities In Solid Parahydrogen, Robert Hinde

Robert Hinde

We present a model for the line shapes of infrared-active Q₁(0) vibron bands observed in solid parahydrogen doped with low concentrations of spherical substitutional impurities. The line shapes are highly sensitive to the H₂ vibrational dependence of the dopant–H₂ interaction. When this vibrational dependence is strong, the dopant can trap the infrared-active vibron in its first solvation shell; in this case, the trapped vibron manifests itself in the absorption spectrum as a narrow feature to the red of the pure solid’s vibron band.

Rapid Development Of Hindi Named Entity Recognition Using Conditional Random Fields And Feature Induction, Wei Li, Andrew Mccallum

Andrew McCallum

This paper describes our application of Conditional Random Fields (CRFs) with feature induction to a Hindi named entity recognition task. With only five days development time and little knowledge of this language, we automatically discover relevant features by providing a large array of lexical tests and using feature induction to automatically construct the features that most increase conditional likelihood. In an effort to reduce overfitting, we use a combination of a Gaussian prior and early-stopping based on the results of 10-fold cross validation.

Efficiently Inducing Features Of Conditional Random Fields, Andrew Mccallum

Andrew McCallum

Conditional Random Fields (CRFs) are undirected graphical models, a special case of which correspond to conditionally-trained finite state machines. A key advantage of CRFs is their great flexibility to include a wide variety of arbitrary, non-independent features of the input. Faced with this freedom, however, an important question remains: what features should be used? This paper presents an efficient feature induction method for CRFs. The method is founded on the principle of iteratively constructing feature conjunctions that would significantly increase conditional log-likelihood if added to the model. Automated feature induction enables not only improved accuracy and dramatic reduction in parameter …

Perturbation Of Global Solution Curves For Semilinear Problems, Philip Korman, Yi Li, Tiancheng Ouyang

Yi Li

We revisit the question of exact multiplicity of positive solutions for a class of Dirichlet problems for cubic-like nonlinearities, which we studied in 161. Instead of computing the direction of bifurcation as we did in [6], we use an indirect approach, and study the evolution of turning points. We give conditions under which the critical (turning) points continue on smooth curves, which allows us to reduce the problem to the easier case of f (0) = 0. We show that the smallest root of f (u) does not have to be restricted.

Multiple Solutions For An Inhomogeneous Semilinear Elliptic Equation In Rn, Yinbin Deng, Yi Li, Xuejin Zhao

Yi Li

No abstract provided.

Classification With Hybrid Generative/Discriminative Models, Rajat Raina, Yirong Shen, Andrew Y. Ng, Andrew Mccallum

Andrew McCallum

Although discriminatively-trained classifiers are usually more accurate when labeled training data is abundant, previous work has shown that when training data is limited, generative classifiers can out-perform them.This paper describes a hybrid model in which a high-dimensional subset of the parameters are trained to maximize generative likelihood, and another, small, subset of parameters are trained to maximize conditional likelihood. We also give a sample complexity bound showing that in order to fit the discriminative parameters well, the number of training examples required depends only logarithmically on the number of feature occurrences and feature set size. Experimental results show that hybrid …

Table Extraction Using Conditional Random Fields, David Pinto, Andrew Mccallum, Xing Wei, W. Bruce Croft

Andrew McCallum

The ability to find tables and extract information from them is a necessary component of data mining, question answering, and other information retrieval tasks. Documents often contain tables in order to communicate densely packed, multi-dimensional information. Tables do this by employing layout patterns to efficiently indicate fields and records in two-dimensional form. Their rich combination of formatting and content present difficulties for traditional language modeling techniques, however. This paper presents the use of conditional random fields (CRFs) for table extraction, and compares them with hidden Markov models (HMMs). Unlike HMMs, CRFs support the use of many rich and overlapping layout …

On The Location Of Critical Points Of Polynomials, Branko Ćurgus, Vania Mascioni

Mathematics Faculty Publications

Given a polynomial p of degree n ≥ 2 and with at least two distinct roots let Z(p) = { z: p(z) = 0}. For a fixed root α ∈ Z(p) we define the quantities ω(p, α) := min (formula) and (formula). We also define ω (p) and τ (p) to be the corresponding minima of ω (p,α) and τ (p,α) as α runs over Z(p). Our main results show that the ratios τ (p,α)/ω (p,α) and τ (p)/ω (p) are bounded above and below by constants that only depend on the degree of p. In particular, …

Continuous Embeddings, Completions And Complementation In Krein Spaces, Branko Ćurgus, H. Langer

Mathematics Faculty Publications

Let the Krein space (A,[^. , ^. ]_A) be continuously embedded in the Krein space (K,[^.,^.]_K )_^. A unique self-adjoint operator A in K can be associated with(A,[^. , ^. ]_A) via the adjoint of the inclusion mapping of A in K. Then (A,[^. , ^. ]_A) is a Krein space completion of R(A) equipped with an A-inner product. In general this completion is not unique. If, additionally, the embedding of A …

Development Of Dose Coefficients For Radionulides Produced In Spallation Neutron Sources: Annual Report, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The University of Nevada, Las Vegas (UNLV) Transmutation Research Program has been tasked to support U.S. Department of Energy (DOE) efforts to assess the health risks associated with the operation of each of their accelerator-driven nuclear facilities for both NEPA and PSAR development. Quantifying the radiological risks to workers will have to be addressed during the design and siting of each of these facilities. U.S. Environmental Protection Agency (EPA) Federal Guidance Report No. 11 “Limiting Values of Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion”, developed two derived guides, Annual Limit on Intake (ALI) and …

Design And Analysis Of A Process For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Yitung Chen, Darrell Pepper, Randy Clarksean

Fuels Campaign (TRP)

The goal of this project is to investigate the casting processes for metallic fuels to help design a process that minimizes the loss of the volatile actinide elements from the fuel.

The research effort centers on the development of advanced numerical models to assess conditions that significantly impact the transport of volatile actinides during the melt casting process and represents a joint effort between researchers at the University of Nevada, Las Vegas (UNLV) and Argonne National Laboratory (ANL).

Task 1: Geodetic Monitoring Of The Yucca Mountain Region Using Continuous Global Positioning System Measurements, Jonathan Price

Publications (YM)

The principal purpose of the cooperative agreement is to develop and continue providing the public and the Yucca Mountain Site Characterization Office (YMSCO) with an independently derived, unbiased body of scientific and engineering data concerning the study of Yucca Mountain as a potential high level waste repository. Under this agreement, the University and Community College System of Nevada (UCCSN) will perform scientific or engineering research, and develop and foster collaborative working relationships between the Government and academic researchers. The following describes the objectives of Task 1 “Geodetic Monitoring of the Yucca Mountain Region Using Continuous Global Positioning System Measurements” under …

Scientific And Engineering Studies Of Systems, Structures, And Components Important To Safety For A Potential Repository At Yucca Mountain, Nevada, Ian Buckle, E. Manos Maragakis

Publications (YM)

TASK 26: Upgrade of Earthquake Simulation Facilities in the Large-Scale Structures Laboratory at University of Nevada Reno

The objective of this Task was to purchase, install and commission the equipment necessary to upgrade two existing shake tables in the Structures Laboratory at UNR, from uniaxial to biaxial motion.

It was recognized that a parallel effort, funded by NSF and HUD, to add a third biaxial table with identical properties to the upgraded existing tables, would be undertaken at the same time.

Needs Assessment: A Report On Seven Focus Groups In Ohio, Kevin O'Brien, Daniel Baracskay, Wendy A. Kellogg, Michael Mcgoun, Claudette Robey, Michael J. Tevesz, Kirstin S. Toth

All Maxine Goodman Levin School of Urban Affairs Publications

A series of seven focus groups were conducted in various locations throughout northern Ohio to identify and assess coastal resources management training needs across the Ohio Great Lakes basin. The focus groups were comprised of a cross-section of professionals who make decisions affecting watershed areas or Lake Erie coastal areas. Six of the focus groups included decision-makers considered previous and potential users of coastal resources management training (non-providers). A seventh focus group included decision-makers who provide training in coastal resources management (providers).

Bridging The Ict Gap: A Study Of Uk Online Centres, John Cook, Matt Smith

Articles

An initiative to create about 6,000 UK online centres aims to bridge the gap between those in society who have access to and are able to use information and communication technologies competently, and those who do not. UK online centres can be seen as networked community learning entities, playing an expanding role in formal and informal community-based learning.

The study described below provides a detailed snapshot of what was happening in UK online centres in the first nine months of 2002. The goal was to gain an improved understanding of the social context of the centres, and issues around the …

Contents

Journal of Mathematics and Science: Collaborative Explorations

No abstract provided.

Discovery Of Functional And Approximate Functional Dependencies In Relational Databases, Ronald S. King, James J. Legendre

Computer Science Faculty Publications and Presentations

This study develops the foundation for a simple, yet efficient method for uncovering functional and approximate functional dependencies in relational databases. The technique is based upon the mathematical theory of partitions defined over a relation's row identifiers. Using a levelwise algorithm the minimal non-trivial functional dependencies can be found using computations conducted on integers. Therefore, the required operations on partitions are both simple and fast. Additionally, the row identifiers provide the added advantage of nominally identifying the exceptions to approximate functional dependencies, which can be used effectively in practical data mining applications.

Birkhoff-Kellogg Theorems On Invariant Directions For Multimaps, Ravi P. Agarwal, Donal O'Regan

Mathematics and System Engineering Faculty Publications

We establish Birkhoff-Kellogg type theorems on invariant directions for a general class of maps. Our results, in particular, apply to Kakutani, acyclic, O'Neill, approximable, admissible, and script U signCK maps.

Random Fixed Point Theory In Spaces With Two Metrics, Donal O'Regan, Naseer Shahzad, Ravi P. Agarwal

Mathematics and System Engineering Faculty Publications

We present new random fixed point theorems in spaces with two metrics. Our results extend recent results of Tan and Yuan [10] and Xu [11].

Common Fixed Point Theorems For A Pair Of Countably Condensing Mappings In Ordered Banach Spaces, Bapurao C. Dhage, Donal O'Regan, Ravi P. Agarwal

Mathematics and System Engineering Faculty Publications

In this paper some common fixed point theorems for a pair of multivalued weakly isotone mappings on an ordered Banach space are proved.

A Non-Markovian Queueing System With A Variable Number Of Channels, Hong-Tam T. Rosson, Jewgeni H. Dshalalow

Mathematics and System Engineering Faculty Publications

In this paper we study a queueing model of type GI/M/m̃a/∞ with m parallel channels, sonic of which may suspend their service at specified random moments of time. Whether or not this phenomenon occurs depends on the queue length. The queueing process, which we target, turns out to be semi-regenerative, and we fully explore this utilizing semi-regenerative techniques. This is contrary to the more traditional supplementary variable approach and the less popular approach of combination semi-regenerative and supplementary variable technique. We pass to the limiting distribution of the continuous time parameter process through the embedded Markov chain for which we …

Patterns Of Curriculum Design, Doug Blank, Deepak Kumar

Computer Science Faculty Research and Scholarship

We present a perspective on the design of a curriculum for a new computer science program at a women s liberal arts college. The design incorporates lessons learned at the college in its successful implementation of other academic programs, incorporation of best practices in curriculum design at other colleges, results from studies performed on various computer science programs, and a significant number of our own ideas. Several observations and design decisions are presented as curriculum design patterns. The goal of making the design patterns explicit is to encourage a discussion on curriculum design that goes beyond the identification of core …

Python Robotics: An Environment For Exploring Robotics Beyond Legos, Doug Blank, Lisa Meeden, Deepak Kumar

Computer Science Faculty Research and Scholarship

This paper describes Pyro, a robotics programming environment designed to allow inexperienced undergraduates to explore topics in advanced robotics. Pyro, which stands for Python Robotics, runs on a number of advanced robotics platforms. In addition, programs in Pyro can abstract away low-level details such that individual programs can work unchanged across very different robotics hardware. Results of using Pyro in an undergraduate course are discussed.

Mimeomatroids, Vadim Ponomarenko

Mathematics Faculty Research

A mimeomatroid is a matroid union of a matroid with itself. We develop several properties of mimeomatroids, including a generalization of Rado's theorem, and prove a weakened version of a matroid conjecture by Rota[2].

Direct Paths Of Wavelets, Eugen J. Ionascu

Faculty Bibliography

We associate a von Neumann algebra with each pair of complete wandering vectors for a unitary system. When this algebra is nonatomic, there is a norm–continuous path of a simple nature connecting the original pair of wandering vectors. We apply this technique to wavelet theory and compute the above von Neumann algebra in some special cases. Results from selection theory and ergodic theory lead to nontrivial examples where both atomic and nonatomic von Neumann algebras occur.

Phosphoproteomic Studies Of Smooth Muscle Contraction: Investigation Of Differential Phosphorylation In Relaxed/Contracted Rat Aortic Smooth Muscle Tissue Using Maldi-Tof Ms, Tonya M. Pekar

Theses, Dissertations and Capstones

Many human disorders are associated with the malfunction of smooth muscle tissue, or are related to the capabilities of its proper function—asthma, glaucoma, renal inefficiency, hypertension, and cardiovascular disease. Dysfunctional proteins are frequently implicated as the source of such disorders. As the second highest cause of death in the United States, the epidemic of cardiovascular disease makes the study of smooth muscle of utmost concern.

The capabilities of proteomics and mass spectrometry allow the entire proteome complement of a cell or tissue type to be analyzed at once. This investigation employs such techniques in an effort to better understand the …

Investigations Of Supramolecular And Catalytic Properties Of Ppi Dendrimers, Aaron K. Holley

Theses, Dissertations and Capstones

The research reported in this thesis focused on supramolecular and catalytic properties of poly(propylene imine) (PPI) dendrimers. Analytical techniques used in this research included high resolution NMR spectroscopy, as well as UV-vis and fluorescence spectroscopies and scanning electron microscopy. This investigation showed that: (1) PPI dendrimers interact with diacids to form interlock self-assemblies by electrostatic interactions (with an increase in dendrimer generation, smaller diacids are required to form the most efficient self-assembly); (2) PPI/diacid self-assemblies are able to encapsulate fluorescent dyes within the void spaces of the PPI/diacid moieties; (3) PPI-3 can chelate many types of metal cations, and these …