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2005

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Articles 121 - 150 of 5641

Full-Text Articles in Physical Sciences and Mathematics

Cloning, Overexpression, Purification And Characterization On N-Terminal Metal Binding Domains 5 And 6 Of Wilsons Disease Protein, David Achila Dec 2005

Cloning, Overexpression, Purification And Characterization On N-Terminal Metal Binding Domains 5 And 6 Of Wilsons Disease Protein, David Achila

Masters Theses

Wilsons disease is an autosomal recessive disorder of copper metabolism which results from mutations in the gene encoding for Wilson disease protein (WDP). The cytosolic N-terminus of WDP comprises six metal binding domains each containing a conserved metal binding motif, GMXCXXC. The contribution of these metal binding domains to copper homeostasis is poorly understood. We have cloned, expressed and purified residues 485 to 633 corresponding to N-terminal metal-binding domains 5 and 6 of WDP (WD5-6). Two of the 3 disease causing mutations in the N-terminal metal binding domains of WDP occur one in each of these domains and the two …


Monthly Variability In Florida Bay Benthic Foraminifera Community Structure, C. Featherstone, Patricia Blackwelder Dec 2005

Monthly Variability In Florida Bay Benthic Foraminifera Community Structure, C. Featherstone, Patricia Blackwelder

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Florida Bay is a shallow subtropical estuary, which experiences highly variable environmental fluctuations due to natural forces (hurricanes, climatic variations and sea level rise) and anthropogenic influences (agricultural activity, water management and urbanization). Study of short time-scale variability in benthic community population structure and synchronous environmental change is essential to understanding forcing relationships between environment and its effects on population. Benthic foraminifera assemblage variability is an excellent indicator of environmental change in estuarine and coastal areas because populations may respond relatively quickly on spatial and temporal scales (Alve, 1995). Temporal resolution is enhanced because foraminifera may reproduce as often as …


Improved Peak Detection And Quantification Of Mass Spectrometry Data Acquired From Surface-Enhanced Laser Desorption And Ionization By Denoising Spectra With The Undecimated Discrete Wavelet Transform, Kevin R. Coombes, Spiros Tsavachidis, Jeffrey S. Morris, Keith A. Baggerly, Henry M. Kuerer Dec 2005

Improved Peak Detection And Quantification Of Mass Spectrometry Data Acquired From Surface-Enhanced Laser Desorption And Ionization By Denoising Spectra With The Undecimated Discrete Wavelet Transform, Kevin R. Coombes, Spiros Tsavachidis, Jeffrey S. Morris, Keith A. Baggerly, Henry M. Kuerer

Jeffrey S. Morris

Background: Mass spectrometry, especially surface enhanced laser desorption and ionization (SELDI) is increasingly being used to find disease-related proteomic patterns in complex mixtures of proteins derived from tissue samples or from easily obtained biological fluids such as serum, urine, or nipple aspirate fluid. Questions have been raised about the reproducibility and reliability of peak quantifications using this technology. For example, Yasui and colleagues opted to replace continuous measures of the size of a peak by a simple binary indicator of its presence or absence in their analysis of a set of spectra from prostate cancer patients.

Methods: We collected nipple …


Pooling Information Across Different Studies And Oligonucleotide Microarray Chip Types To Identify Prognostic Genes For Lung Cancer., Jeffrey S. Morris, Guosheng Yin, Keith A. Baggerly, Chunlei Wu, Li Zhang Dec 2005

Pooling Information Across Different Studies And Oligonucleotide Microarray Chip Types To Identify Prognostic Genes For Lung Cancer., Jeffrey S. Morris, Guosheng Yin, Keith A. Baggerly, Chunlei Wu, Li Zhang

Jeffrey S. Morris

Our goal in this work is to pool information across microarray studies conducted at different institutions using two different versions of Affymetrix chips to identify genes whose expression levels offer information on lung cancer patients’ survival above and beyond the information provided by readily available clinical covariates. We combine information across chip types by identifying “matching probes” present on both chips, and then assembling them into new probesets based on Unigene clusters. This method yields comparable expression level quantifications across chips without sacrificing much precision or significantly altering the relative ordering of the samples. We fit a series of multivariable …


Accounting For Missing Data In End-Of-Life Research, Paula Diehr, Laura Lee Johnson Dec 2005

Accounting For Missing Data In End-Of-Life Research, Paula Diehr, Laura Lee Johnson

Paula Diehr

End-of-life studies are likely to have missing data because sicker persons are less likely to provide information and because measurements cannot be made after death. Ignoring missing data may result in data that are too favorable, because the sickest persons are effectively dropped from the analysis. In a comparison of two groups, the group with the most deaths and missing data will tend to have the most favorable data, which is not desirable. Results based on only the available data may not be generalizable to the original study population. If most of the missing data are absent because of death, …


Kinetic Theory Of Random Graphs: From Paths To Cycles, E. Ben-Naim, P.L. Krapivsky Dec 2005

Kinetic Theory Of Random Graphs: From Paths To Cycles, E. Ben-Naim, P.L. Krapivsky

Eli Ben-Naim

Structural properties of evolving random graphs are investigated. Treating linking as a dynamic aggregation process, rate equations for the distribution of node to node distances (paths) and of cycles are formulated and solved analytically. At the gelation point, the typical length of paths and cycles, l, scales with the component size k as l ~ k^{1/2}. Dynamic and finite-size scaling laws for the behavior at and near the gelation point are obtained. Finite-size scaling laws are verified using numerical simulations.


Gradient Directed Regularization For Sparse Gaussian Concentration Graphs, With Applications To Inference Of Genetic Networks, Hongzhe Li, Jiang Gui Dec 2005

Gradient Directed Regularization For Sparse Gaussian Concentration Graphs, With Applications To Inference Of Genetic Networks, Hongzhe Li, Jiang Gui

UPenn Biostatistics Working Papers

Large-scale microarray gene expression data provide the possibility of constructing genetic networks or biological pathways. Gaussian graphical models have been suggested to provide an effective method for constructing such genetic networks. However, most of the available methods for constructing Gaussian graphs do not account for the sparsity of the networks and are computationally more demanding or infeasible, especially in the settings of high-dimension and low sample size. We introduce a threshold gradient descent regularization procedure for estimating the sparse precision matrix in the setting of Gaussian graphical models and demonstrate its application to identifying genetic networks. Such a procedure is …


11,12-Bis(2,2-Dimethyl­Prop­Yl)-9,10-Dihydro-9,10-Ethenoanthracene, Joseph P. Herres, Mark A. Forman, Kraig A. Wheeler Dec 2005

11,12-Bis(2,2-Dimethyl­Prop­Yl)-9,10-Dihydro-9,10-Ethenoanthracene, Joseph P. Herres, Mark A. Forman, Kraig A. Wheeler

Kraig A. Wheeler

The title compound, C26H32, was retrieved as one of three products from the reaction of tert-butyl­lithium with 11,12-dimethyl­ene-9,10-dihydro­ethenoanthracene and 4,5-diiodo­penta­cyclo­[4.3.0.02,4.03,8.05,7]nonane. The structure shows the expected ethenoanthracene geometry with mol­ecules arranged via van der Waals surfaces.


Climatology Of F Region Zonalplasma Drifts Over Jicamarca, Bela G. Fejer, J. R. Souza, A. S. Santos, A. E. Costa Pereira Dec 2005

Climatology Of F Region Zonalplasma Drifts Over Jicamarca, Bela G. Fejer, J. R. Souza, A. S. Santos, A. E. Costa Pereira

Bela G. Fejer

[1] We use extensive incoherent scatter radar observations made at the Jicamarca Radio Observatory between 1970 and 2003 to study and model empirically the equatorial zonal plasma drifts near the F region peak using Bernstein polynomials as base functions. Our quiet-time model results confirm that the daytime drifts are westward and are nearly season and solar cycle independent. The nighttime drifts are eastward, have larger magnitudes, and increase strongly with solar flux, particularly near equinox and December solstice. Enhanced geomagnetic activity drives small eastward perturbation drifts during the day and much larger westward disturbance drifts at night. The nighttime drift …


From Tapes To Bits: The Changing Landscape Of Broadcasting, Veronika M. Megler, Luis Estrada Dec 2005

From Tapes To Bits: The Changing Landscape Of Broadcasting, Veronika M. Megler, Luis Estrada

Veronika M. Megler

For more than a decade, IBM has been a leader in digital media technology, helping broadcast companies worldwide transition from analog to digital environments with a full slate of end-to-end solutions and services. This white paper discusses the evolution of the digital production environment in broadcasting, why the central storage-based model is outperforming other business models as the option of choice, and how to design and implement a scalable digital media infrastructure using IBM technology that simplifies digital video sharing and management. The IT-based infrastructure for broadcast production is particularly valuable as broadcasters transition to high-definition video production, where their …


54th Spsj Annual Meeting Yokohama, Japan, May 25-27, 2005, Jane C. Vogl, Hiroyuki Ohno Dec 2005

54th Spsj Annual Meeting Yokohama, Japan, May 25-27, 2005, Jane C. Vogl, Hiroyuki Ohno

Otto Vogl

No abstract provided.


Triangle Grouping And Structure Recovery For 3d Building Modelling And Visualization, Joe Hegarty, James Carswell Dec 2005

Triangle Grouping And Structure Recovery For 3d Building Modelling And Visualization, Joe Hegarty, James Carswell

Conference papers

Location based and spatial technologies research for the web has endless application for mobile/position content delivery (m-commerce or pcommerce). By exploiting the inherent location-based intelligence of the underling spatial component, relevant examples can include geometrically accurate and photo realistic virtual representations for: property assessments; land/marine information systems; routing information; on-line shopping; cultural heritage/tourist information/sites; etc. A major challenge for this technology is its reliance on professional developers when creating the virtual worlds used for web-based navigation of these services. This paper describes SAMATS, a Semi-Automated Modeling And Texturing System, which has the capability of producing geometrically accurate and photorealistic VR …


On The Existence Of Multiple Periodic Solutions For The Vector P-Laplacian Via Critical Point Theory, Haishen Lu, Donal O'Regan, Ravi P. Agarwal Dec 2005

On The Existence Of Multiple Periodic Solutions For The Vector P-Laplacian Via Critical Point Theory, Haishen Lu, Donal O'Regan, Ravi P. Agarwal

Mathematics and System Engineering Faculty Publications

We study the vector p-Laplacian (∗){−(|u′|p−2u′)′=∇F(t,u)a.e.t∈[0,T],u(0)=u(T),u′(0)=u′(T),1


Investigation Of Egocentric And Exocentric Distance Perception In Virtual Environments: Application To Enhance Transfer Of Training In Multi-Model Ves, Cali Fidopiastis Dec 2005

Investigation Of Egocentric And Exocentric Distance Perception In Virtual Environments: Application To Enhance Transfer Of Training In Multi-Model Ves, Cali Fidopiastis

Link Foundation Modeling, Simulation and Training Fellowship Reports

In this report we summarize the results for three experiments completed during the Link Fellowship period. The aim of the first and second experiments were to test the efficacy of a novel assessment procedure for determining visual acuity and quantifying depth errors of observers wearing an optical see-t1u·ough prototype head-mounted display. If successful, the assessments could provide an optimization procedure capable of discerning limitations attributed to separate components of the VE system or to the system as a whole. The second experiment explored the feasibility of utilizing mixed reality (a mix of real and virtual items) environments for the study …


The Relationship Between The Number Of Shots And The Quality Of Gamma Knife Radiosurgeries, D Cheek, Allen G. Holder, M Fuss, B Salter Dec 2005

The Relationship Between The Number Of Shots And The Quality Of Gamma Knife Radiosurgeries, D Cheek, Allen G. Holder, M Fuss, B Salter

Mathematics Faculty Research

Radiosurgery is a non-invasive alternative to brain surgery that uses a single focused application of high radiation to destroy intracerebral target tissues. A Gamma Knife delivers such treatments by using 201 cylindrically collimated cobalt-60 sources that are arranged in a hemispherical pattern and aimed to a common focal point. The accumulation of radiation at the focal point, called a \shot" due to the spherical nature of the dose distribution, is used to ablate (or destroy) target tissue in the brain. If the target is small and spherical, it is easily treated by choosing one of four available collimators (4, 8, …


Loss Aware Rate Allocations In H.263 Coded Video Transmissions, Xiao Su, Benjamin Wah Dec 2005

Loss Aware Rate Allocations In H.263 Coded Video Transmissions, Xiao Su, Benjamin Wah

Faculty Publications

For packet video, information loss and bandwidth limitation are two factors that affect video playback quality. Traditional rate allocation approaches have focused on optimizing video quality under bandwidth constraint alone. However, in the best-effort Internet, packets carrying video data are susceptible to losses, which need to be reconstructed at the receiver side. In this paper, we propose loss aware rate allocations in both group-of-block (GOB) level and macroblock level, given that certain packets are lost during transmissions and reconstructed using simple interpolation methods at the receiver side. Experimental results show that our proposed algorithms can produce videos of higher quality …


Enterprise Systems Manager, Edward Aractingi Dec 2005

Enterprise Systems Manager, Edward Aractingi

IT Research

Presentation on the need of remote systems administration.


On Sequential And Fixed Designs For Estimation With Comparisons And Applications, Mekki Terbeche, Broderick O. Oluyede, Ahmed Barbour Dec 2005

On Sequential And Fixed Designs For Estimation With Comparisons And Applications, Mekki Terbeche, Broderick O. Oluyede, Ahmed Barbour

Department of Mathematical Sciences Faculty Publications

A fully sequential approach to the estimation of the difference of two population means for distributions belonging to the exponential family of distributions is adopted and compared with the best fixed design. Results on the lower bound for the Bayes risk due to estimation and expected cost are presented and shown to be of first order efficiency. Applications involving the Poisson and exponential distributions with gamma priors as well as the Bernoulli distribution with beta priors are given. Finally, some numerical results are presented.


Isobaric Analog States As A Tool For Spectroscopy Of Exotic Nuclei, G. V. Rogachev, A. A. Aprahamian, F. D. Becchetti, P. Boutachkov, Y. Chen, G. Chubarian, P. A. Deyoung, A. Fomichev, V. Z. Goldberg, M. S. Golovkov, J. J. Kolata, Yu. Ts. Oganessian, Graham F. Peaslee, M. Quinn, A. Rodin, B. B. Skorodumov, R. S. Slepnev, G. Ter-Akopian, W. H. Trzaska, A. Wohr, R. Wolski Dec 2005

Isobaric Analog States As A Tool For Spectroscopy Of Exotic Nuclei, G. V. Rogachev, A. A. Aprahamian, F. D. Becchetti, P. Boutachkov, Y. Chen, G. Chubarian, P. A. Deyoung, A. Fomichev, V. Z. Goldberg, M. S. Golovkov, J. J. Kolata, Yu. Ts. Oganessian, Graham F. Peaslee, M. Quinn, A. Rodin, B. B. Skorodumov, R. S. Slepnev, G. Ter-Akopian, W. H. Trzaska, A. Wohr, R. Wolski

Faculty Publications

Spectroscopy of neutron rich exotic isotopes via their isobaric analog states (IAS) in less exotic nuclei is discussed. Several different experimental techniques, which can be applied to search for IAS of exotic isotopes, are described. Successful application of these techniques to the studies of heavy helium isotopes7He and 9He led to the observation of unknown IAS in 7Li and 9Li. Spectroscopic information for these states were obtained, and implication of these findings to the structure of 7,9He is considered.


A Combined Routing Method For Ad Hoc Wireless Networks, Zhenhui Jiang Dec 2005

A Combined Routing Method For Ad Hoc Wireless Networks, Zhenhui Jiang

Dartmouth College Master’s Theses

To make ad hoc wireless networks adaptive to different mobility and traffic patterns, we studied in this thesis an approach to swap from one protocol to another protocol dynamically, while routing continues. By the insertion of a new layer, we were able to make each node in the ad hoc wireless network notify each other about the protocol swap. To ensure that routing works efficiently after the protocol swap, we initialized the destination routing protocol's data structures and reused the previous routing information to build the new routing table. We also tested our approach under different network topologies and traffic …


A Steerable, Untethered, 250x60 Micron Mems Mobile Micro-Robot, Bruce R. Donald, Christopher G. Levey, Craig D. Mcgray, Igor Paprotny, Daniela Rus Dec 2005

A Steerable, Untethered, 250x60 Micron Mems Mobile Micro-Robot, Bruce R. Donald, Christopher G. Levey, Craig D. Mcgray, Igor Paprotny, Daniela Rus

Computer Science Technical Reports

We present a steerable, electrostatic, untethered, MEMS micro-robot, with dimensions of 60 µm by 250 µm by 10 µm. This micro-robot is 1 to 2 orders of magnitude smaller in size than previous micro-robotic systems. The device consists of a curved, cantilevered steering arm, mounted on an untethered scratch drive actuator. These two components are fabricated monolithically from the same sheet of conductive polysilicon, and receive a common power and control signal through a capacitive coupling with an underlying electrical grid. All locations on the grid receive the same power and control signal, so that the devices can be operated …


How Hard Is It To Cheat In The Gale-Shapley Stable Matching Algorithm, Chien-Chung Huang Dec 2005

How Hard Is It To Cheat In The Gale-Shapley Stable Matching Algorithm, Chien-Chung Huang

Computer Science Technical Reports

We study strategy issues surrounding the stable marriage problem. Under the Gale-Shapley algorithm (with men proposing), a classical theorem says that it is impossible for every liar to get a better partner. We try to challenge this theorem. First, observing a loophole in the statement of the theorem, we devise a coalition strategy in which a non-empty subset of the liars gets a better partner and no man is worse off than before. This strategy is restricted in that not everyone has the incentive to cheat. We attack the classical theorem further by means of randomization. However, this theorem shows …


Crawdad: A Community Resource For Archiving Wireless Data At Dartmouth, David Kotz, Tristan Henderson Dec 2005

Crawdad: A Community Resource For Archiving Wireless Data At Dartmouth, David Kotz, Tristan Henderson

Dartmouth Scholarship

Wireless network researchers are seriously starved for data about how real users, applications, and devices use real networks under real network conditions. CRAWDAD (Community Resource for Archiving Wireless Data at Dartmouth) is a new National Science Foundation-funded project to build a wireless-network data archive for the research community. It will host wireless data and provide tools and documents to make collecting and using the data easy. This resource should help researchers identify and evaluate real and interesting problems in mobile and pervasive computing. To learn more about CRAWDAD and discuss its direction, about 30 interested people gathered at a workshop …


When A Mechanical Model Goes Nonlinear, Lisa D. Humphreys, P. J. Mckenna Dec 2005

When A Mechanical Model Goes Nonlinear, Lisa D. Humphreys, P. J. Mckenna

Faculty Publications

This paper had its origin in a curious discovery by the first author in research performed with an undergraduate student. The following odd fact was noticed: when a mechanical model of a suspension bridge (linear near equilibrium but allowed to slacken at large distance in one direction) is shaken with a low-frequency periodic force, several different periodic responses can result, many with high-frequency components.


Obesity, Self-Complexity, And Compartmentalization: On The Implications Of Obesity For Self-Concept Organization, Bruce E. Blaine, C. E. Johnson Dec 2005

Obesity, Self-Complexity, And Compartmentalization: On The Implications Of Obesity For Self-Concept Organization, Bruce E. Blaine, C. E. Johnson

Statistics Faculty/Staff Publications

The relationship between obesity and structural aspects of the self-concept was examined in adult women. Participants were 119 adult women [age range: 18-73, M=26.9; body mass index (BMI) range: 16.2-54.7, M=27.3] who completed measures of self-esteem, self-complexity, and the spontaneous self-concept. BMI was associated with less complex and more compartmentalized self-knowledge and more frequent mention of weight-stereotypic traits as self-descriptive. The findings are discussed in the context of research on obesity- related stigma.


Five Years At The Magazine, Frank A. Farris Dec 2005

Five Years At The Magazine, Frank A. Farris

Mathematics and Computer Science

What do the editors of MAA journals do? What is so different about editing expository mathematics? After my five years as editor of Mathematics Magazine, I have strong opinions about these matters. The goal of most mathematics journals is to print the very latest results from the forefront of research. The goal of Mathematics Magazine is to remind us all why we loved mathematics in the first place, with stimulating articles and notes accessible to advanced undergraduates.


A Digital Pixel Sensor Array With Programmable Dynamic Range, A. Kitchen, A. Bermak, Abdesselam Bouzerdoum Dec 2005

A Digital Pixel Sensor Array With Programmable Dynamic Range, A. Kitchen, A. Bermak, Abdesselam Bouzerdoum

Faculty of Informatics - Papers (Archive)

This paper presents a digital pixel sensor (DPS) array employing a time domain analogue-to-digital conversion (ADC) technique featuring adaptive dynamic range and programmable pixel response. The digital pixel comprises a photodiode, a voltage comparator, and an 8-bit static memory. The conversion characteristics of the ADC are determined by an array-based digital control circuit, which linearizes the pixel response, and sets the conversion range. The ADC response is adapted to different lighting conditions by setting a single clock frequency. Dynamic range compression was also experimentally demonstrated. This clearly shows the potential of the proposed technique in overcoming the limited dynamic range …


Some New Results Of Regular Hadamard Matrices And Sbibd Ii, Tianbing Xia, M. Xia, Jennifer Seberry Dec 2005

Some New Results Of Regular Hadamard Matrices And Sbibd Ii, Tianbing Xia, M. Xia, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

In this paper we prove that there exist 4—{k2; 1/2k(k—1); k(k—2)} SDS, regular Hadamard matrices of order 4k2, and SBIBD(4k2, 2k2 + k, k2 + k) for k = 47, 71, 151, 167, 199, 263, 359, 439, 599, 631, 727, 919, 5q1, 5q2N, 7q3, where ql, q2 and q3 are prime power such that ql ≡ 1(mod 4), q2 ≡ 5(mod 8) and q3 ≡ 3(mod 8), N = 2a3bt2, a, b = 0 or 1, t ≠ 0 is an arbitrary integer. We find new SBIBD(4k2, 2k2 + k, k2 + k) for 43 values of k less than …


Culture As Concept And Influence In Environmental Research And Management, Lesley M. Head, D. Trigger, J. Mulcock Dec 2005

Culture As Concept And Influence In Environmental Research And Management, Lesley M. Head, D. Trigger, J. Mulcock

Faculty of Science - Papers (Archive)

Given that human activities have been implicated in the vast majority of contemporary environmental problems, it might be expected that research effort into those activities and the attitudes from which they stem would be both strongly supported by funding agencies, and of central interest to environmental scientists and land managers. In this paper we focus on an undervalued area of environmental humanities research—cultural analysis of the beliefs, practices and often unarticulated assumptions which underlie human–environmental relations. In discussing how cultural processes are central to environmental attitudes and behaviours, and how qualitative research methods can be used to understand them in …


Scaling Byzantine Fault-Tolerant Replication To Wide Area Networks, Yair Amir, Claudiu Danilov, Danny Dolev, Jonathan Kirsch, John Lane, Josh Olsen, David Zage Dec 2005

Scaling Byzantine Fault-Tolerant Replication To Wide Area Networks, Yair Amir, Claudiu Danilov, Danny Dolev, Jonathan Kirsch, John Lane, Josh Olsen, David Zage

Department of Computer Science Technical Reports

No abstract provided.