Physical Sciences and Mathematics Commons^™

Optimization Of Breast Cancer Screening Modalities, Yu Shen, Giovanni Parmigiani

Johns Hopkins University, Dept. of Biostatistics Working Papers

Mathematical models and decision analyses based on microsimulations have been shown to be useful in evaluating relative merits of various screening strategies in terms of cost and mortality reduction. Most investigations regarding the balance between mortality reduction and costs have focused on a single modality, mammography. A systematic evaluation of the relative expenses and projected benefit of combining clinical breast examination and mammography is not at present available. The purpose of this report is to provide methodologic details including assumptions and data used in the process of modeling for complex decision analyses, when searching for optimal breast cancer screening strategies …

Modeling The Incubation Period Of Anthrax, Ron Brookmeyer, Elizabeth Johnson, Sarah Barry

Johns Hopkins University, Dept. of Biostatistics Working Papers

Models of the incubation period of anthrax are important to public health planners because they can be used to predict the delay before outbreaks are detected, the size of an outbreak and the duration of time that persons should remain on antibiotics to prevent disease. The difficulty is that there is little direct data about the incubation period in humans. The objective of this paper is to develop and apply models for the incubation period of anthrax. Mechanistic models that account for the biology of spore clearance and germination are developed based on a competing risks formulation. The models predict …

Low Latitude Ionospheric Disturbance Electric Field Effects Duringthe Recovery Phase Of The October 19-21, 1998 Magnetic Storm, Bela G. Fejer, J. T. Emmert

Bela G. Fejer

[1] Low-latitude ionospheric electric fields and currents are often strongly disturbed during periods of enhanced geomagnetic activity. These perturbations can last for several hours after geomagnetic quieting. We use incoherent scatter radar measurements from Jicamarca and Arecibo during 19–21 October 1998 to study, for the first time, the low-latitude disturbance electric fields during the recovery phase of a large magnetic storm. On 19 October the Jicamarca data showed initially large and short-lived (time scale of about 10–20 min) upward and westward drift perturbations in the early afternoon sector, due to the penetration of strong magnetospheric electric fields probably driven by …

The Second Hull Of A Knotted Curve, Jason Cantarella, Greg Kuperberg, Robert B. Kusner, John M. Sullivan

Robert Kusner

The convex hull of a set K in space consists of points which are, in a certain sense, "surrounded" by K. When K is a closed curve, we define its higher hulls, consisting of points which are "multiply surrounded" by the curve. Our main theorem shows that if a curve is knotted then it has a nonempty second hull. This provides a new proof of the Fary/Milnor theorem that every knotted curve has total curvature at least 4pi.

The Recent Evolution Of The Dwarf Starburst Galaxy Ngc 625 From Hubble Space Telescope Imaging, John M. Cannon, R C. Dohm-Palmer, E D. Skillman, D J. Bomans, S Cote, B W. Miller

John Cannon

No abstract provided.

Physica: The Newsletter Of Utep's Department Of Physics, Utep Department Of Physics

The Department of Physics

Electronic newsletter of UTEP's Department of Physics, December 2003.

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix: Quaterly Report September-December 2003, Spencer M. Steinberg

Separations Campaign (TRP)

The recovery of iodine released during the processing of used nuclear fuel poses a significant challenge to the transmutation of radioactive iodine. This proposal will develop and examine the use of Fullerene Containing Carbon (FCC) compounds as potential sorbents for iodine release from the reprocessing of nuclear fuel. This work will also include the development of bench-scale testing capabilities at UNLV to allow the testing of the FCC material in a simulated process off-gas environment. This experimental capability will also be used to test other potential sorption materials and processes, such as natural organic matter (NOM) and other promising alternatives. …

Multi-Phase Homework Assignments In Cs I And Cs Ii, James Huggins

Computer Science Presentations And Conference Materials

ll of the panelists have used small sets of related programming assignments in introductory CS courses. These assignments are essentially larger programs which are developed during several separate phases. This approach has several advantages: • Students are able to develop more realistic and interesting programs. • Students are motivated to write better code as well as documentation. Those who don't are quickly confronted by the implications. • Student interest in completing the projects is better sustained, since there is continuity from one project to the next. • It models desirable techniques such as iterative development and encapsulation. • It demonstrates …

Drill 3.1, Vadim Ponomarenko

Mathematics Faculty Research

Distance learning can offer a solution to a long-standing challenge of undergraduate education: how to assign an appropriate amount of work to each student, and how to assess this work efficiently. In this paper I describe the Depository of Repetitive Internet-based probLems and Lessons (DRILL), an online system for providing education and assessment for precalculus, which can substitute for routine problems given in homework and as exam questions. Its special features include:

• adaptive testing,
• on-the-fly question generation,
• instant assessment,
• context-sensitive help,
• question balancing, and
• two-dimensional test design.

Galaxies At Z = 3 Around Damped Ly-Α Clouds, N. Bouché, James D. Lowenthal

Astronomy: Faculty Publications

We are exploring the connection between Damped Ly-α Absorption systems and Lyman Break Galaxies using deep m (5σ)=26 m - broad band imaging (UBVI) of four wide fields (0.25deg each) obtained at the Kitt Peak 4-m telescope with MOSAIC. Each field contains a DLA at z ∼ 3. We want to address the nature of DLA at high-redshifts: (1) Are the DLAs embedded in much larger systems of galaxies? (2) How does the spatial distribution of emitters in 3D (space and redshift) correlate with the absorber? Contrary to most previous DLA studies, we are not looking for the absorber, and …

Internal Phosphorus Loading In Spring Lake: Year 1, Dr. Alan Steinman, Dr. Rick Rediske

Scientific Technical Reports

The rate of phosphorus release from sediments, and the degree to which alum reduces phosphorus release from sediments, was investigated in Spring Lake during the summer of 2003. Triplicate cores were sampled from 4 sites in the lake, and exposed to one of four treatments in the laboratory: 1) oxygen/alum; 2) oxygen/ no alum; 3) nitrogen/alum; or 4) nitrogen/no alum. Both soluble reactive phosphorus (SRP) and total phosphorus (TP) release rates were virtually undetectable in the alum treatments (both with and without oxygen). Low, but detectable, release rates were measured in the oxygen/no alum treatment. The highest release rates were …

Preliminary Watershed Assessment: Mona Lake Watershed, Alan Steinman, Rick Rediske, Xuefeng Chu, Rod Denning, Lori Nemeth, Don Uzarski, Bopi Biddanda, Mark Luttenton

Scientific Technical Reports

The Mona Lake watershed, located in Muskegon and Newaygo Counties in west Michigan, is relatively small in area (~ 200 km2 or 48,000 acres), but faces a large number of environmental challenges. An ecological assessment of the watershed was conducted to provide a new baseline of information, in the hope that this effort would catalyze actions to improve the health of the watershed.

Buck Creek Watershed Management Plan, Annis Water Resources Institute

Watershed Management Plans and Reports

The water quality goals are based on improving or restoring the designated uses of the Watershed and attaining compliance with the E. coli TMDL established in Buck Creek. The following long-term goals for the Watershed have been determined:

● Improve or restore the coldwater and coolwater fisheries
● Improve and protect the safety and enjoyment of fishing, canoeing, and swimming
● Improve or restore the warmwater fishery
● Improve and protect the habitats for other indigenous aquatic life and wildlife
The short-term objectives to reduce sediment in the Watershed are:

● Stabilize stream flows to moderate hydrology and increase base …

Physics First, Marcelo Alonso

Aerospace, Physics, and Space Science Faculty Publications

It is true that now most biology courses begin with the DNA molecule, and many chemistry courses introduce the notion of electronic orbitals in atoms and molecules, topics for which students are not well prepared, since most of them have not taken physics courses. Physics courses in turn relegate to the end some discussion of the structure of matter and electromagnetic interaction, or do not discuss that at all. Thus, students miss the overall picture.

Forensic Computing, X. Li, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

Technology is rapidly changing the speed and manner in which people interact with each other and with the world. As technology helps criminals to operate more easily and quickly across borders, so law enforcement capability must continuously improve to keep one step ahead. Computer forensics has become a specialized and accepted investigative technique with its own tools and legal precedents that validate the discipline. Specially designed forensic software is also widely used during the whole process of computer forensic investigation. This article introduces computer forensic and computer evidence, introduces and compares some forensic software, and summarizes its likely future development.

Living On The Edge-Plants And Global Change In Continental And Maritime Antarctica, Sharon A. Robinson, J. Wasley, A. K. Tobin

Faculty of Science - Papers (Archive)

Antarctic terrestrial ecosystems experience some of the most extreme growth conditions on Earth and are characterised by extreme aridity and sub-zero temperatures. Antarctic vegetation is therefore at the physiological limits of survival and, as a consequence, even slight changes to growth conditions are likely to have a large impact, rendering Antarctic terrestrial communities sensitive to climate change. Climate change is predicted to affect the high latitude regions first and most severely. In recent decades, the Antarctic has undergone significant environmental change, including the largest increases in ultraviolet B (UV-B; 290-320nm) radiation levels in the world and, in the maritime region …

Rank-Aware Query Optimization, Ihab F. Ilyas, Rahul Shah, Walid G. Aref, Jeffrey S. Vitter, Ahmed K. Almagarmid

Department of Computer Science Technical Reports

No abstract provided.

Efficient Execution Of Sliding-Window Queries Over Data Streams, Moustafa A. Hammad, Walid G. Aref, Michael J. Franklin, Mohammed P. Mokbel, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.

An Approach To Identifying Beneficial Collaboration Securely In Decentralized Logistics Systems, Richard Cho, Chris Clifton, Ananth V. Ilyer, Wei Jiang, Murat Kantarioglu

Department of Computer Science Technical Reports

No abstract provided.

Normal Forms For Nonlinear Discrete Time Control Systems, Boumediene Hamzi, Issa Amadou Tall

Miscellaneous (presentations, translations, interviews, etc)

We study the feedback classification of discrete-time control systems whose linear approximation around an equilibrium is controllable. We provide a normal form for systems under investigation.

Comparisons Of Electron Fluxes Measured In The Crustal Fields At Mars By The Mgs Magnetometer/Electron Reflectometer Instrument With A B Field-Dependent Transport Code, Michael W. Liemohn, David L. Mitchell, Andrew F. Nagy, Jane L. Fox, Tamara W. Reimer, Yingjuan J. Ma

Physics Faculty Publications

We compare Mars Global Surveyor (MGS) magnetometer/electron reflectometer data with results from a B field–dependent kinetic transport code for ‘‘superthermal’’ electrons. The photoelectrons created on crustal field loops, when they are on the dayside, allow for the exploration of the magnetic topology and the upper atmospheric density structure. A case study of a typical orbit of the MGS satellite through the strong crustal field region in the southern hemisphere of Mars is examined. The results indicate that the low solar wind dynamic pressure during the selected orbit allowed for the expansion of the crustal field line to relatively high altitudes. …

Fabrication And Characterization Of N-Zno/P-Algan Heterojunction Light-Emitting Diodes On 6h-Sic Substrates, Ya I. Alivov, E. V. Kalinina, A. E. Cherenkov, David C. Look, B. M. Ataev, A. K. Omaev, M. V. Chukichev, D. M. Bagnall

Physics Faculty Publications

We report on the fabrication of n-ZnO/p-AlGaN heterojunction light-emitting diodes on 6H-SiC substrates. Hydride vapor phase epitaxy was used to grow p-type AlGaN, while chemical vapor deposition was used to produce the n-type ZnO layers. Diode-like, rectifying I-V characteristics, with threshold voltage ~3.2 V and low reverse leakage current ~10^-7 A, are observed at room temperature. Intense ultraviolet emission with a peak wavelength near 389 nm is observed when the diode is forward biased; this emission is found to be stable at temperatures up to 500 K and shown to originate from recombination within the ZnO.

Physics Department News, December 2003, College Of Arts And Sciences

Physics Newsletter

Contents from Volume 2, Issue 2:

• A Note from the Editor
• From the Chair
• What’s New at the University
• Faculty Highlights
• Staff Highlights
• Accelerator Upgrade 5
• PhysTEC
• Distinguished Alumni Award
• Alumni News
• Recent Guest
• Goldwater Scholar
• New Grants
• Student Awards
• Recent Graduates
• Department Roster
• Photo Gallery
• Feedback/Update Reply Form

Evaluation Of 2,2'-Bipyridylpyridinetricarbonylrhenium (I) Triflate Complex As A Luminescent Probe For The Study Of Macromolecular Solution Dynamics, Richard Allen Allston

Seton Hall University Dissertations and Theses (ETDs)

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Case 3270: Isometrinae Clark, 1917 (Ecinodermata, Crinoidea): Proposed Emendation Of Spelling To Isometrainae To Remove Homonymy With Isometrinae Kraepelin, 1891 (Arachnida, Scorpiones), Victor Fet, Charles G. Messing

Marine & Environmental Sciences Faculty Articles

The purpose of this application, under Articles 55 and 29 of the Code, is to remove the homonymy between the crinoid subfamily name ISOMETRINAE Clark, 1917 (type genus Isometra Clark, 1908; family ANTEDONIDAE) and the scorpion subfamily name ISOMETRINAE Kraepelin, 1891 (type genus Isometrus Ehrenberg in Hemprich & Ehrenberg, 1828; family BUTHIDAE). It is proposed that the entire generic name of Isometra should be adopted as the stem, so that the correct spelling of the crinoid subfamily will become ISOMETRAINAE Clark, 1917.

Reviewed Work(S): Electronic Tagging And Tracking In Marine Fisheries., David W. Kerstetter

Marine & Environmental Sciences Faculty Articles

No abstract provided.

Understanding The Impact Of Shill Bidding In Online English Auctions, Bharat Bhargava, Mamata Jenamani, Yuhui Zhong

Department of Computer Science Technical Reports

No abstract provided.

“Don’T Tell Me, I’Ll Find Out”: Robert Karplus—A Science Education Pioneer, Robert Fuller

Robert G. Fuller Publications

Robert Karplus (1927–90), who began his career as a brilliant theoretical physicist, switched to science education in the early 1960s. He made many substantial contributions to this field in addition to developing a complete K–6 hands-on science curriculum. Karplus provided his curriculum with a sound epistemological foundation, based on the work of Piaget. He developed an effective classroom teaching strategy, the learning cycle. He and his team used a scientific approach to curriculum development. They focused on teacher development. Karplus was committed to science for ALL students. Through science activities he sought to share the joy of discovery. A recent …

Software Development Productivity And Cycle Time Reduction, Victor A. Clincy

Faculty Articles

Increasing software developers' productivity and reducing the software development process' cycle time are key goals for organizations responsible for building software applications. This paper proposes four major areas impacting an organization's ability to increase developer productivity and reduce development cycle time. The four areas are (1) organizational structure and climate, (2) reward system, (3) software development process and (4) the use of software design and testing tools.

Lamb Shift Of Laser-Dressed Atomic States, Ulrich D. Jentschura, Jorg Evers, Martin K. Haas, Christoph H. Keitel

Physics Faculty Research & Creative Works

We discuss radiative corrections to an atomic two-level system subject to an intense driving laser field. It is shown that the Lamb shift of the laser-dressed states, which are the natural state basis of the combined atom-laser system, cannot be explained in terms of the Lamb shift received by the atomic bare states which is usually observed in spectroscopic experiments. In the final part, we propose an experimental scheme to measure these corrections based on the incoherent resonance fluorescence spectrum of the driven atom.