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2015

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Articles 11581 - 11610 of 11621

Full-Text Articles in Physical Sciences and Mathematics

Nitrates In Karst Systems: Comparing Impacted Systems To A Relatively Unimpacted System, Julie C. Angel, Eric Wade Peterson Dec 2014

Nitrates In Karst Systems: Comparing Impacted Systems To A Relatively Unimpacted System, Julie C. Angel, Eric Wade Peterson

Eric Wade Peterson

Karst aquifers are highly susceptible to contamination because of the connection with surface water. Nitrate contamination is common; with most karst aquifers exhibiting some degree of impact. This work assesses the potential impacts of anthropogenic activities on the Horn Hollow Valley (HHV) in Carter County Kentucky. HHV is a karst aquifer system that appears to be minimally impacted by nitrate and chloride contamination. Sampling of the HHV area was conducted from June 2005 to November 2006. Nitrate as nitrogen (NO3-N) concentrations were between 0.13 to 1.54 mg/L; chloride concentrations ranged from 1.43 to 66.3 mg/L. Impact from anthropogenic sources are …


Introducing Virtual Water Accounting To The Great Lakes, Stanley Mubako Dec 2014

Introducing Virtual Water Accounting To The Great Lakes, Stanley Mubako

Stanley Mubako

No abstract provided.


An Assessment Of South China Tiger Reintroduction Potential In Hupingshan And Houhe National Nature Reserves, China, Yiyuan Qin, Philip J. Nyhus, Courtney L. Larson, Charles J.W. Carroll, Jeff Muntifering, Thomas D. Dahmer, Lu Jun, Ronald L. Tilson Dec 2014

An Assessment Of South China Tiger Reintroduction Potential In Hupingshan And Houhe National Nature Reserves, China, Yiyuan Qin, Philip J. Nyhus, Courtney L. Larson, Charles J.W. Carroll, Jeff Muntifering, Thomas D. Dahmer, Lu Jun, Ronald L. Tilson

Philip J. Nyhus

Human-caused biodiversity loss is a global problem, large carnivores are particularly threatened, and the tiger (Panthera tigris) is among the world’s most endangered large carnivores. The South China tiger (Panthera tigris amoyensis) is the most critically endangered tiger subspecies and is considered functionally extinct in the wild. The government of China has expressed its intent to reintroduce a small population of South China tigers into a portion of their historic range as part of a larger goal to recover wild tiger populations in China. This would be the world’s first major tiger reintroduction program. A free-ranging population of 15–20 tigers …


Integrated Survival Analysis Using An Event Time Approach In A Bayesian Framework, Daniel Walsh, Victoria Dreitz, Dennis Heisey Dec 2014

Integrated Survival Analysis Using An Event Time Approach In A Bayesian Framework, Daniel Walsh, Victoria Dreitz, Dennis Heisey

Victoria Dreitz

No abstract provided.


Case Studies In Evaluating Time Series Prediction Models Using The Relative Mean Absolute Error, Nicholas G. Reich, Justin Lessler, Krzysztof Sakrejda, Stephen A. Lauer, Sopon Iamsirithaworn, Derek A T Cummings Dec 2014

Case Studies In Evaluating Time Series Prediction Models Using The Relative Mean Absolute Error, Nicholas G. Reich, Justin Lessler, Krzysztof Sakrejda, Stephen A. Lauer, Sopon Iamsirithaworn, Derek A T Cummings

Nicholas G Reich

Statistical prediction models inform decision-making processes in many real-world settings. Prior to using predictions in practice, one must rigorously test and validate candidate models to ensure that the proposed predictions have sufficient accuracy to be used in practice. In this paper, we present a framework for evaluating time series predictions that emphasizes computational simplicity and an intuitive interpretation using the relative mean absolute error metric. For a single time series, this metric enables comparisons of candidate model predictions against naive reference models, a method that can provide useful and standardized performance benchmarks. Additionally, in applications with multiple time series, this …


The Spatial Distribution Of Electric Field Intensity When The Motion Of Electric Charge In Absolute Space, Vildyan Yanbikov Dec 2014

The Spatial Distribution Of Electric Field Intensity When The Motion Of Electric Charge In Absolute Space, Vildyan Yanbikov

Vildyan Yanbikov

When driving an electric or gravitational charge in absolute space. Field created by these particles will have a different distribution in space. In comparison with by a stationary charge. When the charge motion of the deformation field.


Studying The Effects Of Non Oil Exports On Targeted Economic Growth In Iranian 5th Development Plan: A Computable General Equilibrium Approach, Rasoul Bakhsi Dastjerdi Dr., Reza Moosavi Mohseni Dr., Somayye Jafari Dec 2014

Studying The Effects Of Non Oil Exports On Targeted Economic Growth In Iranian 5th Development Plan: A Computable General Equilibrium Approach, Rasoul Bakhsi Dastjerdi Dr., Reza Moosavi Mohseni Dr., Somayye Jafari

Reza Moosavi Mohseni

we investigate the effects of non oil export on Iran’s economic growth using a computable general equilibrium (CGE) and study which tradable sectors has a larger share in reaching to targeted growth rate 8% in 5th socio economic development plan. We calibrate the model by GAMS (with emphasis on foreign trade sector). Numerical solution to the model is based on Iran’s social accounting matrix (SAM). Results show that 2.03% of targeted economic growth rate is achieved by encouraging a 6% growth in export. It also be mentioned that industry and mine sector in Iran, has more influence on growth than …


Copula Modelling Of Dependence In Multivariate Time Series, Michael S. Smith Dec 2014

Copula Modelling Of Dependence In Multivariate Time Series, Michael S. Smith

Michael Stanley Smith

Almost all existing nonlinear multivariate time series models remain linear, conditional on a point in time or latent regime. Here, an alternative is proposed, where nonlinear serial and cross-sectional dependence is captured by a copula model. The copula defines a multivariate time series on the unit cube. A drawable vine copula is employed, along with a factorization which allows the marginal and transitional densities of the time series to be expressed analytically. The factorization also provides for simple conditions under which the series is stationary and/or Markov, as well as being parsimonious. A parallel algorithm for computing the likelihood is …


Legal Issues: Security And Privacy With Mobile Devices, Brian Leonard, Maurice Dawson Dec 2014

Legal Issues: Security And Privacy With Mobile Devices, Brian Leonard, Maurice Dawson

Maurice Dawson

Privacy and security are two items being woven into the fabric of American law concerning mobile devices. This chapter will review and analyze the associated laws and policies that are currently in place or have been proposed to ensure proper execution of security measures for mobile and other devices while still protecting individual privacy. This chapter will address the fact that as the American society significantly uses mobile devices, it is imperative to understand the legal actions surrounding these technologies to include their associated uses. This chapter will also address the fact that with 9/11 in the not so distant …


Use Of Geographical Information Systems To Identify Counties In Georgia With High Risk For Childhood Lead Poisoning, R. Christopher Rustin, Christy Kuriatnyk, Byron Lobsinger, Simone Charles Dec 2014

Use Of Geographical Information Systems To Identify Counties In Georgia With High Risk For Childhood Lead Poisoning, R. Christopher Rustin, Christy Kuriatnyk, Byron Lobsinger, Simone Charles

R. Christopher Rustin

Background: For children in Georgia, lead poisoning is a substantial public health problem. Primary risk factors include low socioeconomic status and poor-quality housing built prior to 1978. The Environmental Health Team of the Georgia Department of Public Health (DPH) utilized geographical information system (GIS) technology and census housing data to identify counties in which children have high risk for lead poisoning. The purpose of this research was to update and refine previous maps developed with older technology and on a different geographic scale so that targeted public health interventions can be developed.

Methods: Data related to stratified and …


Riemann Hypothesis Disproved Using Infinity, Elements, Solution Operator Defined To Solve Riemann But Not Have Solutions 1/2 And Other Solutions With Real Solutions Not 1/2, James T. Struck Dec 2014

Riemann Hypothesis Disproved Using Infinity, Elements, Solution Operator Defined To Solve Riemann But Not Have Solutions 1/2 And Other Solutions With Real Solutions Not 1/2, James T. Struck

James T Struck

Riemann Hypothesis Disproved Using Infinity, Elements, solution operator defined to solve Riemann but not have solutions 1/2 and other Solutions with Real Solutions Not 1/2 The Riemann hypothesis is that all [[Triviality (mathematics)|nontrivial]] zeros of the analytical continuation of the [[Riemann zeta function]] have a real part of 1/2. A proof or disproof of this would have far-reaching implications in [[number theory]], especially for the distribution of [[prime number]]s. This was [[Hilbert's problems|Hilbert's eighth problem]], and is still considered an important open problem a century later. One of James T. Struck's Disproofs of the Riemann Hypothesis is that zeros can …


Zespół Energii Odnawialnej I Zrównoważonego Rozwoju (Eozr), Wojciech M. Budzianowski Dec 2014

Zespół Energii Odnawialnej I Zrównoważonego Rozwoju (Eozr), Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Adaptive Pair-Matching In Randomized Trials With Unbiased And Efficient Effect Estimation, Laura Balzer, M Petersen, M Van Der Laan, The Search Consortium Dec 2014

Adaptive Pair-Matching In Randomized Trials With Unbiased And Efficient Effect Estimation, Laura Balzer, M Petersen, M Van Der Laan, The Search Consortium

Laura B. Balzer

In randomized trials, pair-matching is an intuitive design strategy to protect study validity and to potentially
increase study power. In a common design, candidate units are identified, and their baseline characteristics used
to create the best n∕2 matched pairs.Within the resulting pairs, the intervention is randomized, and the outcomes
measured at the end of follow-up.We consider this design to be adaptive, because the construction of thematched
pairs depends on the baseline covariates of all candidate units. As a consequence, the observed data cannot be
considered as n∕2 independent, identically distributed pairs of units, as common practice assumes. Instead, the
observed …


Experimental Check On The Validity Of The Special Theory Of Relativity, Vildyan Yanbikov Dec 2014

Experimental Check On The Validity Of The Special Theory Of Relativity, Vildyan Yanbikov

Vildyan Yanbikov

Calculation of quantitative characteristics of rotating interferometer Michelson-Morley experiment. The objective of the experiment. Confirmation alternate the Lorentz contraction of the interferometer arms as it rotates. Experimental check on the validity of the special theory of relativity.


Creating Computer Availability Maps, Scott Bacon Dec 2014

Creating Computer Availability Maps, Scott Bacon

Scott Bacon

During the fall semester of 2012, the Kimbel Library and Bryan Information Commons conducted a LibQUAL+ survey to gauge how patron needs were being met. Many survey respondents commented that there were not enough computers for use in the library buildings. This issue was remedied by the addition of over 70 percent more computer workstations in the new commons building, a move that was well received by patrons. However, these desktops still filled up quickly, especially during midterms and finals, so the library decided to create a dynamic system to show patrons which computers were available for use at any …


Simulating Univariate And Multivariate Nonnormal Distributions Through The Method Of Percentiles, Jennifer Koran, Todd C. Headrick, Tzu Chun Kuo Dec 2014

Simulating Univariate And Multivariate Nonnormal Distributions Through The Method Of Percentiles, Jennifer Koran, Todd C. Headrick, Tzu Chun Kuo

Todd Christopher Headrick

This article derives a standard normal-based power method polynomial transformation for Monte Carlo simulation studies, approximating distributions, and fitting distributions to data based on the method of percentiles. The proposed method is used primarily when (1) conventional (or L) moment-based estimators such as skew (or L-skew) and kurtosis (or L -kurtosis) are unknown or (2) data are unavailable but percentiles are known (e.g., standardized test score reports). The proposed transformation also has the advantage that solutions to polynomial coefficients are available in simple closed form and thus obviates numerical equation solving. A procedure is also described for simulating power method …


Spin-Exchange Optical Pumping At High Xenon Densities And Laser Fluxes: Principles And Practice, Boyd M. Goodson, Nicholas Whiting, Hayley Newton, Jason G. Skinner, Kaili Ranta, Panayiotis Nikolaou, Michael J. Barlow, Eduard Y. Chekmenev Dec 2014

Spin-Exchange Optical Pumping At High Xenon Densities And Laser Fluxes: Principles And Practice, Boyd M. Goodson, Nicholas Whiting, Hayley Newton, Jason G. Skinner, Kaili Ranta, Panayiotis Nikolaou, Michael J. Barlow, Eduard Y. Chekmenev

Nicholas Whiting

Once limited to the realm of fundamental physics experiments, hyperpolarized (HP) noble gases have been exploited for a wide range of applications across NMR and MRI. In most cases, hyperpolarized noble gases are prepared by spin-exchange optical pumping (SEOP)...


Hyperpolarization Methods For Mrs, Boyd M. Goodson, Nicholas Whiting, Aaron M. Coffey, Panayiotis Nikolaou, Fan Shi, Brogan M. Gust, Maxwell E. Gemeinhardt, Roman Shchepin, Jason G. Skinner, Jonathan R. Birchall, Michael J. Barlow, Eduard Y. Chekmenev Dec 2014

Hyperpolarization Methods For Mrs, Boyd M. Goodson, Nicholas Whiting, Aaron M. Coffey, Panayiotis Nikolaou, Fan Shi, Brogan M. Gust, Maxwell E. Gemeinhardt, Roman Shchepin, Jason G. Skinner, Jonathan R. Birchall, Michael J. Barlow, Eduard Y. Chekmenev

Nicholas Whiting

This article covers the fundamental principles and practice of NMR hyperpolarization techniques, which are proving useful for in vivo magnetic resonance spectroscopy (MRS) studies of metabolism in animal models, and clinical trials with hyper-enhanced sensitivity. Fundamentally, hyperpolarization methods enhance nuclear spin polarization by orders-of-magnitude, resulting in concomitant improvement in NMR detection sensitivity. The hyperpolarization methods described here – dynamic nuclear polarization (DNP), para-hydrogen induced polarization (PHIP), signal amplification by reversible exchange (SABRE), and spin-exchange optical pumping (SEOP) – are capable of achieving nuclear spin polarization approaching the theoretical maximum of unity on nuclear spin sites of molecular or atomic agents …


The Winograd Schema Challenge And Reasoning About Correlation, Dan Bailey, Amelia Harrison, Yuliya Lierler, Vladimir Lifschitz, Julian Michael Dec 2014

The Winograd Schema Challenge And Reasoning About Correlation, Dan Bailey, Amelia Harrison, Yuliya Lierler, Vladimir Lifschitz, Julian Michael

Yuliya Lierler

The Winograd Schema Challenge is an alternative to the Turing Test that may provide a more meaningful measure of machine intelligence. It poses a set of coreference resolution problems that cannot be solved without human-like reasoning. In this paper, we take the view that the solution to such problems lies in establishing discourse coherence. Specifically, we examine two types of rhetorical relations that can be used to establish discourse coherence: positive and negative correlation. We introduce a framework for reasoning about correlation between sentences, and show how this framework can be used to justify solutions to some Winograd Schema problems.


Constraint Answer Set Programming Versus Satisfiability Modulo Theories Or Constraints Versus Theories, Yuliya Lierler, Benjamin Susman Dec 2014

Constraint Answer Set Programming Versus Satisfiability Modulo Theories Or Constraints Versus Theories, Yuliya Lierler, Benjamin Susman

Yuliya Lierler

Constraint answer set programming is a promising research direction that integrates answer set programming with constraint processing. This research direction often informally relates itself to the field of Satisfiability Modulo Theory. Yet the exact formal link is obscured as the terminology and concepts used in these two research fields differ. The goal of this paper to make the link between these two fields precise.


Alumni Newsletter Summer 2015 Mathematics & Computer Science University Of Missouri St. Louis Letter From The Chair, Jenny Shrensker Dec 2014

Alumni Newsletter Summer 2015 Mathematics & Computer Science University Of Missouri St. Louis Letter From The Chair, Jenny Shrensker

Jenny Shrensker

No abstract provided.


Exploring Student Difficulties With Observation Location, Jamie Bryant, Rita Dawod, Susan M. Fischer, Mary Bridget Kustusch Dec 2014

Exploring Student Difficulties With Observation Location, Jamie Bryant, Rita Dawod, Susan M. Fischer, Mary Bridget Kustusch

Mary Bridget Kustusch

Throughout introductory physics, students create and interpret free body diagrams in which multiple
forces act on an object, typically at a single location (the object’s center of mass). The situation increases in
difficulty when multiple objects are involved, and further when electric and magnetic fields are present. In
the latter, sources of the fields are often identified as a set of electric charges or current-carrying wires, and
students are asked to determine the electric or magnetic field at a separate location defined as the observation
location. Previous research suggests students do not always appropriately account for how a measurement or …


Optimal Full Matching For Survival Outcomes: A Method That Merits More Widespread Use, Peter Austin, Elizabeth Stuart Dec 2014

Optimal Full Matching For Survival Outcomes: A Method That Merits More Widespread Use, Peter Austin, Elizabeth Stuart

Peter Austin

Matching on the propensity score is a commonly used analytic method for estimating the effects of treatments on outcomes. Commonly used propensity score matching methods include nearest neighbor matching and nearest neighbor caliper matching. Rosenbaum (1991) proposed an optimal full matching approach, in which matched strata are formed consisting of either one treated subject and at least one control subject or one control subject and at least one treated subject. Full matching has been used rarely in the applied literature. Furthermore, its performance for use with survival outcomes has not been rigorously evaluated. We propose a method to use full …


Rock Strength Along A Fluvial Transect Of The Colorado Plateau - Quantifying A Fundamental Control On Geomorphology, Natalie Bursztyn, Joel Pederson Dec 2014

Rock Strength Along A Fluvial Transect Of The Colorado Plateau - Quantifying A Fundamental Control On Geomorphology, Natalie Bursztyn, Joel Pederson

Natalie Bursztyn

Bedrock strength is a key parameter that influences slope stability, landscape erosion, and fluvial incision. Yet, it is often ignored or indirectly constrained in studies of landscape evolution, as with the K erodibility parameter in stream-power models. Empirical datasets of rock strength suited to address geomorphic questions are rare, in part because of the difficulty in measuring those rocks at Earth's surface that are heterolithic, weak, or poorly exposed. Here we present a large dataset of measured bedrock strength organized by rock units exposed along the length of the trunk Green–Colorado River through the iconic Colorado Plateau of the western …


Stereocontrolled 1,2-Cis Glycosylation As The Driving Force Of Progress In Synthetic Carbohydrate Chemistry, Swati S. Nigudkar, Alexei V. Demchenko Dec 2014

Stereocontrolled 1,2-Cis Glycosylation As The Driving Force Of Progress In Synthetic Carbohydrate Chemistry, Swati S. Nigudkar, Alexei V. Demchenko

Alexei Demchenko

Recent developments in stereoselective 1,2-cis glycosylation that have emerged during the past decade are surveyed herein. For detailed coverage of the previous achievements in the field the reader is referred to our earlier reviews: A. V. Demchenko, Curr. Org. Chem., 2003, 7, 35–79 and Synlett, 2003, 1225–1240.


On X-Ray Pulsations In Beta Cephei-Type Variables., L. M. Oskinova, H. Todt, D. P. Huenemoerder, S. Hubrig, Richard Ignace, W.-R. Hamann, L. Balona Dec 2014

On X-Ray Pulsations In Beta Cephei-Type Variables., L. M. Oskinova, H. Todt, D. P. Huenemoerder, S. Hubrig, Richard Ignace, W.-R. Hamann, L. Balona

Richard Ignace

Beta Cephei-type variables are early B-type stars that are characterized by oscillations observable in their optical light curves. At least one Beta Cep-variable also shows periodic variability in X-rays. Here we study the X-ray light curves in a sample of beta Cep-variables to investigate how common X-ray pulsations are for this type of stars. We searched the Chandra and XMM-Newton X-ray archives and selected stars that were observed by these telescopes for at least three optical pulsational periods. We retrieved and analyzed the X-ray data for kappa Sco, beta Cru, and alpha Vir. The X-ray light curves of these objects …


Permaculture Design And Practice, Lisa Depiano Dec 2014

Permaculture Design And Practice, Lisa Depiano

Lisa DePiano

The spring class for a 2 part Permaculture Design Certificate (PDC)


The Shielding Of Gravity On Earth, Vildyan Yanbikov Dec 2014

The Shielding Of Gravity On Earth, Vildyan Yanbikov

Vildyan Yanbikov

The shielding of gravity on Earth


On The Intrinsic Value Of Genetic Integrity, Attila Tanyi Dec 2014

On The Intrinsic Value Of Genetic Integrity, Attila Tanyi

Attila Tanyi

In their article “Is There a Prima Facie Duty to Preserve Genetic Integrity in Conservation Biology?” Yasha Rower and Emma Harris argue that there is no underived prima facie obligation to preserve genetic integrity. In particular, it is argued that there is no such obligation because genetic integrity has no intrinsic value. In this commentary I raise doubts about this part of the authors’ argument. I argue that (1) there might well be at least prima facie value in genetic integrity, (2) that the Moorean isolation test the authors use might not work in their favour, and (3) that connecting …


Quantile Rank Maps: A New Tool For Understanding Individual Brain Development, Huaihou Chen, Clare Kelly, F. Xavier Castellanos, Ye He, Xi-Nian Zuo, Philip T. Reiss Dec 2014

Quantile Rank Maps: A New Tool For Understanding Individual Brain Development, Huaihou Chen, Clare Kelly, F. Xavier Castellanos, Ye He, Xi-Nian Zuo, Philip T. Reiss

Philip T. Reiss

We propose a novel method for neurodevelopmental brain mapping that displays how an individual’s values for a quantity of interest compare with age-specific norms. By estimating smoothly age-varying distributions at a set of brain regions of interest, we derive age-dependent region-wise quantile ranks for a given individual, which can be presented in the form of a brain map. Such quantile rank maps could potentially be used for clinical screening. Bootstrap-based confidence intervals are proposed for the quantile rank estimates. We also propose a recalibrated Kolmogorov-Smirnov test for detecting group differences in the age-varying distribution. This test is shown to be …