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Full-Text Articles in Physical Sciences and Mathematics

Twinning Strains In Synfolding Calcite, Proterozoic Sinian System, China, John P. Craddock, Junlai Liu, Yuanyuan Zheng Apr 2018

Twinning Strains In Synfolding Calcite, Proterozoic Sinian System, China, John P. Craddock, Junlai Liu, Yuanyuan Zheng

Faculty Publications

Synfolding calcite was precipitated between layers of Neoproterozoic sandy dolomite and striated parallel to the fold axis of an open anticline with a shallow plunge during folding. The fold had limb dips of 45° and plunged 20° to the south. The synfolding calcite had sub-horizontal grooves that trended parallel to the fold. Limb-hinge-limb calcite samples (3 samples; n = 100 grains) preserved a layer-parallel shortening strain that trended at an acute (45°) angle to the trend of the fold axis and fold lineations. Extension axes were vertical and there was no strain overprint (low NEVs). Shortening strain magnitudes were −2.9% …


Comparison Of Ecosystem Processes In A Woodland And Prairie Pond With Different Hydroperiods, Daniel J. Hornbach, Mark C. Hove, Mira W. Ensley-Field, Matthew R. Glasenapp, Ian A. Goodbar, J. Douglas Harman, Benjamin D. Huber, Emily A. Kangas, Kira X. Liu, Molly Stark-Ragsdale, Long K. Tran Dec 2017

Comparison Of Ecosystem Processes In A Woodland And Prairie Pond With Different Hydroperiods, Daniel J. Hornbach, Mark C. Hove, Mira W. Ensley-Field, Matthew R. Glasenapp, Ian A. Goodbar, J. Douglas Harman, Benjamin D. Huber, Emily A. Kangas, Kira X. Liu, Molly Stark-Ragsdale, Long K. Tran

Faculty Publications

Shallow lakes and ponds constitute a significant number of water bodies worldwide. Many are heterotrophic, indicating that they are likely net contributors to global carbon cycling. Climate change is likely to have important impacts on these waterbodies. In this study, we examined two small Minnesota ponds; a permanent woodland pond and a temporary prairie pond. The woodland pond had lower levels of phosphorus and phytoplankton than the prairie pond. Using the open water oxygen method, we found the prairie pond typically had a higher level of gross primary production (GPP) and respiration (R) than the woodland pond, although the differences …


A Colorimetric Competitive Displacement Assay For The Evaluation Of Catalytic Peptides, Anneliese Gest, Erika M. Aguiluz, Malik T. Mays, Xinyu Liu, Eliza K. Neidhart, Leah S. Witus Nov 2017

A Colorimetric Competitive Displacement Assay For The Evaluation Of Catalytic Peptides, Anneliese Gest, Erika M. Aguiluz, Malik T. Mays, Xinyu Liu, Eliza K. Neidhart, Leah S. Witus

Faculty Publications

No abstract provided.


Teaching Stats For Data Science, Daniel Kaplan Nov 2017

Teaching Stats For Data Science, Daniel Kaplan

Faculty Publications

“Data science” is a useful catchword for methods and concepts original to the field of statistics, but typically being applied to large, multivariate, observational records. Such datasets call for techniques not often part of an introduction to statistics: modeling, consideration of covariates, sophisticated visualization, and causal reasoning. This article re-imagines introductory statistics as an introduction to data science and proposes a sequence of 10 blocks that together compose a suitable course for extracting information from contemporary data. Recent extensions to the mosaic packages for R together with tools from the “tidyverse” provide a concise and readable notation for wrangling, visualization, …


Methods For Real-Time Prediction Of The Mode Of Travel Using Smartphone-Based Gps And Accelerometer Data, Bryan D. Martin, Vittorio Addona, Julian Wolfson, Gediminas Adomavicius, Yingling Fan Sep 2017

Methods For Real-Time Prediction Of The Mode Of Travel Using Smartphone-Based Gps And Accelerometer Data, Bryan D. Martin, Vittorio Addona, Julian Wolfson, Gediminas Adomavicius, Yingling Fan

Faculty Publications

We propose and compare combinations of several methods for classifying transportation activity data from smartphone GPS and accelerometer sensors. We have two main objectives. First, we aim to classify our data as accurately as possible. Second, we aim to reduce the dimensionality of the data as much as possible in order to reduce the computational burden of the classification. We combine dimension reduction and classification algorithms and compare them with a metric that balances accuracy and dimensionality. In doing so, we develop a classification algorithm that accurately classifies five different modes of transportation (i.e., walking, biking, car, bus and rail) …


Digital Hegemonies: The Localness Of Search Engine Results, Andrea Ballatore, Mark Graham, Shilad Sen May 2017

Digital Hegemonies: The Localness Of Search Engine Results, Andrea Ballatore, Mark Graham, Shilad Sen

Faculty Publications

Every day, billions of Internet users rely on search engines to find information about places to make decisions about tourism, shopping, and countless other economic activities. In an opaque process, search engines assemble digital content produced in a variety of locations around the world and make it available to large cohorts of consumers. Although these representations of place are increasingly important and consequential, little is known about their characteristics and possible biases. Analyzing a corpus of Google search results generated for 188 capital cities, this article investigates the geographic dimension of search results, focusing on searches such as “Lagos” and …


Using Survival Analysis To Identify Risk Factors For Treatment Interruption Among New And Retreatment Tuberculosis Patients In Kenya, Enos O. Masini, Omar Mansour, Clare E. Speer, Vittorio Addona, Christy L. Hanson, Joseph K. Sitienei, Hillary K. Kipruto, Martin Muhingo Githiomi, Brenda Nyambura Mungai Oct 2016

Using Survival Analysis To Identify Risk Factors For Treatment Interruption Among New And Retreatment Tuberculosis Patients In Kenya, Enos O. Masini, Omar Mansour, Clare E. Speer, Vittorio Addona, Christy L. Hanson, Joseph K. Sitienei, Hillary K. Kipruto, Martin Muhingo Githiomi, Brenda Nyambura Mungai

Faculty Publications

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Despite high tuberculosis (TB) treatment success rate, treatment adherence is one of the major obstacles to tuberculosis control in Kenya. Our objective was to identify patient-related factors that were associated with time to TB treatment interruption and the geographic distribution of the risk of treatment interruption by county. Data of new and retreatment patients registered in TIBU, a Kenyan national case-based electronic data recording system, between 2013 and 2014 was obtained. Kaplan-Meier curves and log rank tests were used to assess the adherence patterns. Mixed-effects Cox proportional hazards modeling was used for multivariate analysis. Records from 90,170 patients were …


Gender Representation On Journal Editorial Boards In The Mathematical Sciences, Chad M. Topaz, Shilad Sen Aug 2016

Gender Representation On Journal Editorial Boards In The Mathematical Sciences, Chad M. Topaz, Shilad Sen

Faculty Publications

No abstract provided.


Ecosystem Structure And Function In Two Branches Of An Eastern Minnesota, Usa, Trout Stream, Daniel J. Hornbach, Mark Hove, Maya Agata, Ellen Albright, Emily Cavazos, Clara Friedman, Katja Jay, Emily Johnson, Kari Johnson, Anna Staudenmaier Jul 2016

Ecosystem Structure And Function In Two Branches Of An Eastern Minnesota, Usa, Trout Stream, Daniel J. Hornbach, Mark Hove, Maya Agata, Ellen Albright, Emily Cavazos, Clara Friedman, Katja Jay, Emily Johnson, Kari Johnson, Anna Staudenmaier

Faculty Publications

No abstract provided.


Biological Aggregation Driven By Social And Environmental Factors: A Nonlocal Model And It Degenerate Cahn-Hilliard Approximation, Andrew J. Bernoff, Chad Topaz May 2016

Biological Aggregation Driven By Social And Environmental Factors: A Nonlocal Model And It Degenerate Cahn-Hilliard Approximation, Andrew J. Bernoff, Chad Topaz

Faculty Publications

No abstract provided.


Topological Data Analysis Of Biological Aggregation Models, Chad M. Topaz, Lori B. Ziegelmeir, Tom Halverson May 2015

Topological Data Analysis Of Biological Aggregation Models, Chad M. Topaz, Lori B. Ziegelmeir, Tom Halverson

Faculty Publications

No abstract provided.


Flipped Calculus: A Study Of Student Performance And Perceptions, Lori B. Ziegelmeir, Chad M. Topaz Jan 2015

Flipped Calculus: A Study Of Student Performance And Perceptions, Lori B. Ziegelmeir, Chad M. Topaz

Faculty Publications

No abstract provided.