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Articles 10801 - 10830 of 11785

Full-Text Articles in Physical Sciences and Mathematics

26Al-Containing Acidic And Basic Sodium Aluminum Phosphate Preparation And Use In Studies Of Oral Aluminum Bioavailability From Foods Utilizing 26Al As An Aluminum Tracer, Robert A. Yokel, Aaron A. Urbas, Robert A. Lodder, John P. Selegue, Rebecca L. Florence Apr 2005

26Al-Containing Acidic And Basic Sodium Aluminum Phosphate Preparation And Use In Studies Of Oral Aluminum Bioavailability From Foods Utilizing 26Al As An Aluminum Tracer, Robert A. Yokel, Aaron A. Urbas, Robert A. Lodder, John P. Selegue, Rebecca L. Florence

Pharmaceutical Sciences Faculty Publications

We synthesized 26Al-containing acidic and basic (alkaline) sodium aluminum phosphates (SALPs) which are FDA-approved leavening and emulsifying agents, respectively, and used them to determine the oral bioavailability of aluminum incorporated in selected foods. We selected applicable methods from published syntheses (patents) and scaled them down (∼3000- and 850-fold) to prepare ∼300–400 mg of each SALP. The 26Al was incorporated at the beginning of the syntheses to maximize 26Al and 27Al equilibration and incorporate the 26Al in the naturally-occurring Al-containing chemical species of the products. Near infrared spectroscopy (NIR) and X-ray powder diffraction (XRD) were used …


A Mathematical Model For Treatment-Resistant Mutations Of Hiv, Helen Moore, Weiqing Gu Apr 2005

A Mathematical Model For Treatment-Resistant Mutations Of Hiv, Helen Moore, Weiqing Gu

All HMC Faculty Publications and Research

In this paper, we propose and analyze a mathematical model, in the form of a system of ordinary differential equations, governing mutated strains of human immunodeficiency virus (HIV) and their interactions with the immune system and treatments. Our model incorporates two types of resistant mutations: strains that are not responsive to protease inhibitors, and strains that are not responsive to reverse transcriptase inhibitors. It also includes strains that do not have either of these two types of resistance (wild-type virus) and strains that have both types. We perform our analysis by changing the system of ordinary differential equations (ODEs) to …


The Importance Of Experimental Design In Proteomic Mass Spectrometry Experiments: Some Cautionary Tales, Jeffrey S. Morris, Jianhua Hu, Kevin R. Coombes, Keith A. Baggerly Mar 2005

The Importance Of Experimental Design In Proteomic Mass Spectrometry Experiments: Some Cautionary Tales, Jeffrey S. Morris, Jianhua Hu, Kevin R. Coombes, Keith A. Baggerly

Jeffrey S. Morris

Proteomic expression patterns derived from mass spectrometry have been put forward as potential biomarkers for the early diagnosis of cancer and other diseases. This approach has generated much excitement and has led to a large number of new experiments and vast amounts of new data. The data, derived at great expense, can have very little value if careful attention is not paid to the experimental design and analysis. Using examples from surfaceenhanced laser desorption/ionisation time-of-flight (SELDI-TOF) and matrix-assisted laser desorption–ionisation/time-of-flight (MALDI-TOF) experiments, we describe several experimental design issues that can corrupt a dataset. Fortunately, the problems we identify can be …


Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources Quarterly Progress Report 1/1/05 – 3/31/05, Phillip W. Patton, Mark Rudin Mar 2005

Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources Quarterly Progress Report 1/1/05 – 3/31/05, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The research consortium comprised of representatives from several universities and national laboratories has successfully generated internal and external dose conversion coefficients for twenty radionuclides produced in spallation neutron sources. In addition, the group has identified twenty radionuclide that are missing electron capture files and eighteen additional radionuclides missing substantial physical data. The goal for the current year is to develop a methodology that will allow for producing the dose coefficients for these radionuclides with missing data. Methods to obtain these data are being investigated.


Acute Toxicity Testing Without Animals: More Scientific And Less Of A Gamble, Gillian R. Langley Mar 2005

Acute Toxicity Testing Without Animals: More Scientific And Less Of A Gamble, Gillian R. Langley

Application of Alternative Methods Collection

In this report, we argue specifically that acute toxicity data should not be sought from animal tests. The underlying principle of such tests on rats and mice is that the results can be effectively extrapolated to humans. In fact, after nearly 80 years of use of these tests, the predictivity of rodent data for human acute toxic effects has been disputed but never proven.


Serum Proteomics Profiling: A Young Technology Begins To Mature, Kevin R. Coombes, Jeffrey S. Morris, Jianhua Hu, Sarah R. Edmondson, Keith A. Baggerly Mar 2005

Serum Proteomics Profiling: A Young Technology Begins To Mature, Kevin R. Coombes, Jeffrey S. Morris, Jianhua Hu, Sarah R. Edmondson, Keith A. Baggerly

Jeffrey S. Morris

No abstract provided.


Against 'Individual Risk': A Sympathetic Critique Of Risk Assessment, Matthew D. Adler Mar 2005

Against 'Individual Risk': A Sympathetic Critique Of Risk Assessment, Matthew D. Adler

All Faculty Scholarship

"Individual risk" currently plays a major role in risk assessment and in the regulatory practices of the health and safety agencies that employ risk assessment, such as EPA, FDA, OSHA, NRC, CPSC, and others. Risk assessors use the term "population risk" to mean the number of deaths caused by some hazard. By contrast, "individual risk" is the incremental probability of death that the hazard imposes on some particular person. Regulatory decision procedures keyed to individual risk are widespread. This is true both for the regulation of toxic chemicals (the heartland of risk assessment), and for other health hazards, such as …


An Analysis Of Biometric Technology As An Enabler To Information Assurance, Darren A. Deschaine Mar 2005

An Analysis Of Biometric Technology As An Enabler To Information Assurance, Darren A. Deschaine

Theses and Dissertations

The use of and dependence on, Information technology (IT) has grown tremendously in the last two decades. Still, some believe the United States is only in the infancy of this growth. This explosive growth has opened the door to capabilities that were only dreamed of in the past. As easy as it is to see how advantageous this technology is, it also is clear that with its advantages come distinct responsibilities and new problems that must be addressed. For instance, the minute one begins using information processing systems, the world of information assurance (IA) becomes far more complex. As a …


What Communities Should Do Pre-Event To Support Public Health Post-Event Assessments, Surveillance And Monitoring, Thomas Lyons Carr Iii Feb 2005

What Communities Should Do Pre-Event To Support Public Health Post-Event Assessments, Surveillance And Monitoring, Thomas Lyons Carr Iii

Thomas Lyons (Thom) Carr III Appl.Sc., CEM

[Abstract written March 2008, TLC] Under worst-case planning assumptions used by some major metropolitan areas, a Neighbor-to-Neighbor self-help program model is the primary link between citizens and the professional response personnel of the responsible government agencies.

In the Neighbor-to-Neighbor self-help program model or a Community Emergency Management Plan (CEMP) calls on the citizens in neighborhoods to identify and establish cluster emergency preparedness committees, Cluster Emergency Coordination Centers (CECC) and Community Emergency Response Teams (CERT). Missing from these plans or what is not articulated is how constant Public Health Post-Event Surveillance, Monitoring and Assessments will be done. Given the worst-case planning …


Signal In Noise: Evaluating Reported Reproducibility Of Serum Proteomic Tests For Ovarian Cancer, Keith A. Baggerly, Jeffrey S. Morris, Sarah R. Edmonson, Kevin R. Coombes Feb 2005

Signal In Noise: Evaluating Reported Reproducibility Of Serum Proteomic Tests For Ovarian Cancer, Keith A. Baggerly, Jeffrey S. Morris, Sarah R. Edmonson, Kevin R. Coombes

Jeffrey S. Morris

Proteomic profi ling of serum initially appeared to be dramatically effective for diagnosis of early-stage ovarian cancer, but these results have proven diffi cult to reproduce. A recent publication reported good classifi cation in one dataset using results from training on a much earlier dataset, but the authors have since reported that they did not perform the analysis as described. We examined the reproducibility of the proteomic patterns across datasets in more detail. Our analysis reveals that the pattern that enabled successful classifi cation is biologically implausible and that the method, properly applied, does not classify the data accurately. We …


Reliability, Effect Size, And Responsiveness Of Health Status Measures In The Design Of Randomized And Cluster-Randomized Trials, Paula Diehr Feb 2005

Reliability, Effect Size, And Responsiveness Of Health Status Measures In The Design Of Randomized And Cluster-Randomized Trials, Paula Diehr

Paula Diehr

BACKGROUND: New health status survey instruments are often described by their psychometric (measurement) properties, such as Validity, Reliability, Effect Size, and Responsiveness. For cluster-randomized trials, another important statistic is the Intraclass Correlation (ICC) for the instrument within clusters. Studies using better instruments can be performed with smaller sample sizes, but better instruments may be more expensive in terms of dollars, opportunity cost, or poorer data quality due to the response burden of longer instruments. METHODS: We defined the psychometric statistics in terms of a mathematical model, and examined the power of a two-sample test as a function of the test-retest …


Insights Into Latent Class Analysis, Margaret S. Pepe, Holly Janes Jan 2005

Insights Into Latent Class Analysis, Margaret S. Pepe, Holly Janes

UW Biostatistics Working Paper Series

Latent class analysis is a popular statistical technique for estimating disease prevalence and test sensitivity and specificity. It is used when a gold standard assessment of disease is not available but results of multiple imperfect tests are. We derive analytic expressions for the parameter estimates in terms of the raw data, under the conditional independence assumption. These expressions indicate explicitly how observed two- and three-way associations between test results are used to infer disease prevalence and test operating characteristics. Although reasonable if the conditional independence model holds, the estimators have no basis when it fails. We therefore caution against using …


Standardizing Markers To Evaluate And Compare Their Performances, Margaret S. Pepe, Gary M. Longton Jan 2005

Standardizing Markers To Evaluate And Compare Their Performances, Margaret S. Pepe, Gary M. Longton

UW Biostatistics Working Paper Series

Introduction: Markers that purport to distinguish subjects with a condition from those without a condition must be evaluated rigorously for their classification accuracy. A single approach to statistically evaluating and comparing markers is not yet established.

Methods: We suggest a standardization that uses the marker distribution in unaffected subjects as a reference. For an affected subject with marker value Y, the standardized placement value is the proportion of unaffected subjects with marker values that exceed Y.

Results: We apply the standardization to two illustrative datasets. In patients with pancreatic cancer placement values calculated for the CA 19-9 marker are smaller …


Combining Predictors For Classification Using The Area Under The Roc Curve, Margaret S. Pepe, Tianxi Cai, Zheng Zhang, Gary M. Longton Jan 2005

Combining Predictors For Classification Using The Area Under The Roc Curve, Margaret S. Pepe, Tianxi Cai, Zheng Zhang, Gary M. Longton

UW Biostatistics Working Paper Series

No single biomarker for cancer is considered adequately sensitive and specific for cancer screening. It is expected that the results of multiple markers will need to be combined in order to yield adequately accurate classification. Typically the objective function that is optimized for combining markers is the likelihood function. In this paper we consider an alternative objective function -- the area under the empirical receiver operating characteristic curve (AUC). We note that it yields consistent estimates of parameters in a generalized linear model for the risk score but does not require specifying the link function. Like logistic regression it yields …


"Rassling The Hog": The Influence Of Correlated Item Error On Internal Consistency, Classical Reliability, And Congeneric Reliability, Joseph F. Lucke Jan 2005

"Rassling The Hog": The Influence Of Correlated Item Error On Internal Consistency, Classical Reliability, And Congeneric Reliability, Joseph F. Lucke

Joseph Lucke

The properties of internal consistency ($\alpha$), classical reliability ($\rho$), and congeneric reliability ($\omega$) for a composite test with correlated item error were analytically investigated. Possible sources of correlated item error are contextual effects, item bundles, and item models that ignore additional attributes or higher-order attributes. The relation between reliability and internal consistency is determined by the deviance from true-score equivalence. Reliability (classical or congeneric) is internal consistency plus the relative deviance from true-score equivalence. The influence of correlated item error on $\alpha$, $\rho$, and $\omega$ is conveyed strictly through the total item error covariance. As the total item error covariance …


Convergence Analysis Of Mcmc Method In The Study Of Genetic Linkage With Missing Data, Diana Fisher Jan 2005

Convergence Analysis Of Mcmc Method In The Study Of Genetic Linkage With Missing Data, Diana Fisher

Theses, Dissertations and Capstones

Computational infeasibility of exact methods for solving genetic linkage analysis problems has led to the development of a new collection of stochastic methods, all of which require the use of Markov chains. The purpose of this work is to investigate the complexities of missing data in pedigree analysis using the Monte Carlo Markov Chain (MCMC) method as compared to the exact results. Also, we attempt to determine an association between missing data in a familial pedigree and the convergence to stationarity of a descent graph Markov chain implemented in the stochastic method for parametric linkage analysis.

In particular, we will …


Santa Clara Magazine, Volume 47 Number 3, Winter 2005, Santa Clara University Jan 2005

Santa Clara Magazine, Volume 47 Number 3, Winter 2005, Santa Clara University

Santa Clara Magazine

8 - AFTER AMERICA by Deepa Arora. Thomas J. Reese, S.J., the former editor of the Jesuit weekly magazine, America, is spending a sabbatical year at SCU. He sat down for an exclusive interview with SCM to reflect on what he has witnessed, what inspires him, and the future of the Church.

16 - A HALF-CENTURY OF ART AND HISTORY AT SCU by Victoria Hendel De La O. "Through its exhibitions and collections, the museum allows students and faculty to expand the walls of the classroom," says Rebecca M. Schapp, director of the de Saisset Museum, which is celebrating its …


Measuring Shared Information And Coordinated Activity In Neuronal Networks, K L. Klinkner, C R. Shalizi, Marcelo Camperi Jan 2005

Measuring Shared Information And Coordinated Activity In Neuronal Networks, K L. Klinkner, C R. Shalizi, Marcelo Camperi

Physics and Astronomy

Most nervous systems encode information about stimuli in the respond- ing activity of large neuronal networks. This activity often manifests itself as dynamically coordinated sequences of action potentials. Since multiple electrode recordings are now a standard tool in neuroscience research, it is important to have a measure of such network-wide behav- ioral coordination and information sharing, applicable to multiple neural spike train data. We propose a new statistic, informational coherence , which measures how much better one unit can be predicted by knowing the dynamical state of another. We argue informational coherence is a measure of association and shared information …


Punishment And Rehabilitation Views Of Social Work Majors And Non-Social Work Students: An Exploratory Study, Eric G. Lambert, Sudershan Pasupuleti, Reva I. Allen Jan 2005

Punishment And Rehabilitation Views Of Social Work Majors And Non-Social Work Students: An Exploratory Study, Eric G. Lambert, Sudershan Pasupuleti, Reva I. Allen

Journal of the South Carolina Academy of Science

No abstract provided.


The Journal Of Undergraduate Research: Volume 03 Jan 2005

The Journal Of Undergraduate Research: Volume 03

The Journal of Undergraduate Research

This is the complete issue of the South Dakota State University Journal of Undergraduate Research, Volume 3.


Population And Sustainability, Geoffrey Mcnicoll Jan 2005

Population And Sustainability, Geoffrey Mcnicoll

Poverty, Gender, and Youth

Sustainability refers to the preservation of human-valued natural capital—the resources that provide environmental services—at a level sufficient to assure the well-being of future generations. This Population Council working paper assess the effects on the total and per capita availability of those services. The degradation of environmental services—exemplified by the overuse of aquifers or (at a global level) of the atmospheric carbon sink—is a significant threat to sustainable development, one that is often exacerbated by population growth. The critical management issue in such cases is the design of effective governing institutions to restrain service demand and safeguard supply. Uncertainties arising from …


Chemical And Biochemical Modification Of Surfaces For Control Of Wettability, Adsorption, And Drug Delivery, Susan C. D'Andrea Jan 2005

Chemical And Biochemical Modification Of Surfaces For Control Of Wettability, Adsorption, And Drug Delivery, Susan C. D'Andrea

Seton Hall University Dissertations and Theses (ETDs)

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2005- 2008 Unlv Mcnair Journal, Valerie Avery, Shana Bachus, Karmen K. Boehlke, Andrea Flores, Alden Kelly, Erick Lopez, Carol Preussler, Heather Shay, Ava Bookatz, Shaun Elsasser, Veronica Hicks, Shaida A. Jetha, Anthony Quinn, Thurithabhani Seneviratne, Teddy Boado Sim Jr., Liza Ward, Amris Henry-Rodgers, Jacquelynn Kaaa-Logan, Jason Orozco, Juan C. Plata, Bonnie Bartlett, Kathleen Bell, Vacheral M. Carter, Nydia Diaz, Kimberly Hackstock, Julio A. Luna, Charles Mao, Sandra Ramos, Precious Rideout, Benjamin Lee Watrous, Chet R. Whitley Jan 2005

2005- 2008 Unlv Mcnair Journal, Valerie Avery, Shana Bachus, Karmen K. Boehlke, Andrea Flores, Alden Kelly, Erick Lopez, Carol Preussler, Heather Shay, Ava Bookatz, Shaun Elsasser, Veronica Hicks, Shaida A. Jetha, Anthony Quinn, Thurithabhani Seneviratne, Teddy Boado Sim Jr., Liza Ward, Amris Henry-Rodgers, Jacquelynn Kaaa-Logan, Jason Orozco, Juan C. Plata, Bonnie Bartlett, Kathleen Bell, Vacheral M. Carter, Nydia Diaz, Kimberly Hackstock, Julio A. Luna, Charles Mao, Sandra Ramos, Precious Rideout, Benjamin Lee Watrous, Chet R. Whitley

McNair Journal

Journal articles based on research conducted by undergraduate students in the McNair Scholars Program

Table of Contents

Biography of Dr. Ronald E. McNair

Statements:

Dr. Neal J. Smatresk, UNLV President

Dr. Juanita P. Fain, Vice President of Student Affairs

Dr. William W. Sullivan, Associate Vice President for Retention and Outreach

Mr. Keith Rogers, Deputy Executive Director of the Center for Academic Enrichment and Outreach

McNair Scholars Institute Staff


Development Of Dose Coefficients For Radionuclides Produced In Spallation Targets, Phillip W. Patton, Mark Rudin Jan 2005

Development Of Dose Coefficients For Radionuclides Produced In Spallation Targets, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

Dose coefficients permit simple determination of radiation dose associated with various exposure scenarios, and ultimately permit radiation safety personnel to assess the health risks to workers in a nuclear facility. Specifically, radiation safety personnel use dose coefficients to determine the radiation dose incurred to a tissue or organ system from a given exposure. These parameters are often expressed in terms of Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs).

The research consortium comprised of representatives from several universities and national laboratories has successfully generated internal and external dose conversion coefficients for twenty radionuclides produced in spallation neutron sources. …


Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach Jan 2005

Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach

Bioelectrics Publications

A combined MD simulator and time dependent Laplace solver are used to analyze the electrically driven phosphatidylserine externalization process in cells. Time dependent details of nanopore formation at cell membranes in response to a high-intensity (100kV∕cm), ultrashort (10ns) electric pulse are also probed. Our results show that nanosized pores could typically be formed within about 5ns. These predictions are in very good agreement with recent experimental data. It is also demonstrated that defect formation and PS externalization in membranes should begin on the anode side. Finally, the simulations confirm that PS externalization is a nanopore facilitated event, rather than the …


Design And Cloning Of A Hammerhead Ribozyme Targeted Tohiv-1p7fmrna, Katherine L. Anderson, William H. Jackson Jan 2005

Design And Cloning Of A Hammerhead Ribozyme Targeted Tohiv-1p7fmrna, Katherine L. Anderson, William H. Jackson

Journal of the South Carolina Academy of Science

No abstract provided.


Eye Pathologies Found In Several Decapod Crustaceans, Andrea M. Maniscalco Jan 2005

Eye Pathologies Found In Several Decapod Crustaceans, Andrea M. Maniscalco

Dissertations, Theses, and Masters Projects

No abstract provided.


Symptoms Of Gastro-Oesophageal Reflux Disease And The Severity Of Obstructive Sleep Apnoea Syndrome Are Not Related In Sleep Disorders Center Patients, H.-N. Kim, R. D. Vorona, M. P. Winn, M. Doviak, D. A. Johnson, J. Catesby Ware Jan 2005

Symptoms Of Gastro-Oesophageal Reflux Disease And The Severity Of Obstructive Sleep Apnoea Syndrome Are Not Related In Sleep Disorders Center Patients, H.-N. Kim, R. D. Vorona, M. P. Winn, M. Doviak, D. A. Johnson, J. Catesby Ware

Mathematics & Statistics Faculty Publications

Background: Studies suggest obstructive sleep apnea syndrome (OSAS) frequently manifests in patients with gastroesophageal reflux disease (GERD) and that there may be a causal relationship.

Aim: To determine the relationship between OSAS and symptoms of GERD.

Methods: Consecutive patients referred to the Sleep Disorders Center (SDC) 18 years and older with polysomnographically defined OSAS were evaluated prospectively for GERD using a validated symptoms questionnaire. The GERD and OSAS relationship was assessed by 1) determining frequency of GERD in patients with and without OSAS; 2) ascertaining the relationship between OSAS severity categories and presence of GERD; 3) examining GERD score in …


A Comparison Of Esomeprazole And Lansoprazole For Control Of Intragastric Ph In Patients With Symptoms Of Gastro-Oesophageal Reflux Disease, D. A. Johnson, T. Stacy, M. Ryan, T. Wootton, J. Willia, K. Hornbuckle, W. Brooks, M. Doviak Jan 2005

A Comparison Of Esomeprazole And Lansoprazole For Control Of Intragastric Ph In Patients With Symptoms Of Gastro-Oesophageal Reflux Disease, D. A. Johnson, T. Stacy, M. Ryan, T. Wootton, J. Willia, K. Hornbuckle, W. Brooks, M. Doviak

Mathematics & Statistics Faculty Publications

Background: Intragastric acid suppression is the most direct measure of the pharmacodynamic efficacy of proton pump inhibitors, which are the most effective drugs for acid-related diseases.

Aim: To compare the effectiveness of once and twice daily dosing of lansoprazole and esomeprazole in controlling intragastric acidity ( target gastric pH > 4.0) over a 24-hour period.

Methods: In an open-label, two-way crossover study, 45 Helicobacter pylori-negative patients with gastro-oesophageal reflux disease were randomized to receive one of two regimens: 30 mg lansoprazole or esomeprazole 40 mg once daily. Intragastric pH was assessed by 24-hour pH monitoring on day 5 of each regimen. …


The $\Alpha$ And The $\Omega$ Of Congeneric Test Theory: An Extension Of Reliability And Internal Consistency To Heterogeneous Tests, Joseph F. Lucke Dec 2004

The $\Alpha$ And The $\Omega$ Of Congeneric Test Theory: An Extension Of Reliability And Internal Consistency To Heterogeneous Tests, Joseph F. Lucke

Joseph Lucke

Psychometric theory focuses primarily on tests that are homogeneous, that measure only one attribute of a psychosocial entity. However, the complexity of psychosocial behavior often requires tests that are heterogeneous, that measure more than one attribute. In this presentation, reliability and internal consistency are extended to heterogeneous tests under the rubric of congeneric test theory. The extensions show that reliability and internal consistency have very similar properties. Reliability and internal consistency are shown to be unique up to a linear transformation. Whereas internal consistency is a lower bound to reliability in the homogeneous case, it is a strict lower bound …