PubMed | Urbana University, Covenant College and University of Illinois at Urbana - Champaign
Type: | Journal: Journal of visualized experiments : JoVE | Year: 2015
Cancer cells respond to matrix mechanical stiffness in a complex manner using a coordinated, hierarchical mechano-chemical system composed of adhesion receptors and associated signal transduction membrane proteins, the cytoskeletal architecture, and molecular motors. Mechanosensitivity of different cancer cells in vitro are investigated primarily with immortalized cell lines or murine derived primary cells, not with primary human cancer cells. Hence, little is known about the mechanosensitivity of primary human colon cancer cells in vitro. Here, an optimized protocol is developed that describes the isolation of primary human colon cells from healthy and cancerous surgical human tissue samples. Isolated colon cells are then successfully cultured on soft (2 kPa stiffness) and stiff (10 kPa stiffness) polyacrylamide hydrogels and rigid polystyrene (~3.6 GPa stiffness) substrates functionalized by an extracellular matrix (fibronectin in this case). Fluorescent microbeads are embedded in soft gels near the cell culture surface, and traction assay is performed to assess cellular contractile stresses using free open access software. In addition, immunofluorescence microscopy on different stiffness substrates provides useful information about primary cell morphology, cytoskeleton organization and vinculin containing focal adhesions as a function of substrate rigidity.
Lagor F.D.,University of Maryland University College |
Davis A.,Covenant College |
Ide K.,University of Maryland University College |
Paley D.A.,University of Maryland University College
Proceedings of the American Control Conference | Year: 2016
This paper considers the closed-loop navigation of a hypothetical ocean-sampling vehicle in the presence of an idealized ocean-eddy pair. This problem embodies many of the challenges of spatiotemporal ocean sampling using minimally actuated Lagrangian sensors. We extend our existing guidance strategy known as the Boundary-Touring Algorithm (BTA) to steer a self-propelled vehicle to a unique streamline in a two-vortex flow. The Gaussian Mixture Kalman Filter (GMKF) provides non-Gaussian state estimation of the vortex parameters based on linear observations of Lagrangian sensor position. Taken together, BTA and GMKF constitute a novel guidance framework for adaptive, Lagrangian data assimilation. Results from numerical experiments are presented for a drifting vehicle, a controlled vehicle that has knowledge of the flow field, and a controlled vehicle that navigates based on its own flow field estimate using the BTA/GMKF framework. © 2016 American Automatic Control Council (AACC).
Janzen D.E.,St. Catherine University of Saint Paul |
Vanderveer D.G.,Clemson University |
Mehne L.F.,Covenant College |
Grant G.J.,University of Tennessee at Chattanooga
Inorganica Chimica Acta | Year: 2010
We wish to report the synthesis of the Ru(II) crown thioether complex, (1,4,7,10,13-pentathiacyclopentadecane)chlororuthenium(II) hexafluorophosphate, [Ru(aneS5)Cl](PF6), and a study of its properties utilizing single crystal X-ray diffraction, electronic spectroscopy, NMR spectroscopy, density functional theory calculations and cyclic voltammetry. The crystal structure shows a single aneS5 macrocycle and a chloro ligand coordinated in a distorted octahedral fashion around the ruthenium(II) center. A significant shortening (0.15 ) of the trans Ru-S bond length occurs in this complex compared to the related PPh3 complex (2.4458(10) to 2.283(1) ) due to the differences in the trans influence of the two ligands. 13C NMR spectroscopy demonstrates that the structure of [Ru(aneS5)Cl]+ is retained in solution. As expected for a Ru(II) complex, the electronic absorption spectrum shows two d-d transitions at 402 and 331 nm. These are red-shifted compared to hexakis(thioether)ruthenium(II) complexes and consistent with the weaker ligand field effect of the chloro ligand. The electrochemical behavior of the complex in acetonitrile shows a single one-electron reversible oxidation-reduction at +0.722 V versus Fc/Fc+ which is assigned as the Ru(II)/Ru(III) couple. DFT calculations for [Ru(aneS5)Cl]+ show a HOMO with orbital contributions from a t2g type orbital of the Ru ion, a π component from a p orbital of the axial S atom of aneS5, and a p orbital of the chloro ligand while the LUMO consists of orbital contributions of dx2-y2 orbital of the Ru center and p orbitals of the four equatorial S donors. © 2010 Elsevier B.V. All rights reserved.
Hunt J.M.,Covenant College |
McGregor J.D.,Clemson University
Software Engineering Education Conference, Proceedings | Year: 2010
Component Based Software Engineering (CBSE) is a technique for designing and assembling systems from existing parts that has important implications for a number of software engineering practices. The basic principles of CBSE, including modularity, substitutability, and composition are important throughout the SE curriculum. The ability to build a component and have confidence that it will function predictably in different environments requires a variety of skills. In this paper we present hands-on projects that use the recently released SEI PSK tool suite to implement exercises in several courses across the computing curriculum, including courses in: software engineering, computational theory, operating systems, programming languages, and verification and validation. © 2010 IEEE.
Olufemi A.J.,Covenant College |
Olaleke O.,Covenant College |
Augusta A.,Covenant College |
Maxwell O.,Covenant College |
Fred I.,Covenant College
Journal of Engineering and Applied Sciences | Year: 2016
This study was based on a conceptual approach to examine how inventory control influences performance of manufacturing firms. The study began with an introduction which was followed by the research objectives and questions. The statement of the research problem was discussed as well as the significance of the study. A study was dedicated to the conceptual and theoretical framework which was followed by a conceptual analysis and discussion based on review from literature. The study concluded with findings from literature and implications for further research. © Medwell Journals, 2016.
Zuidema D.R.,Covenant College |
Williams S.L.,Covenant College |
Wert K.J.,Covenant College |
Bosma K.J.,Covenant College |
And 2 more authors.
Synthetic Communications | Year: 2011
Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol. © Taylor & Francis Group, LLC.
Grant G.J.,University of Tennessee at Chattanooga |
Talbott N.N.,University of Tennessee at Chattanooga |
Bajic M.,University of Tennessee at Chattanooga |
Mehne L.F.,Covenant College |
And 2 more authors.
Polyhedron | Year: 2012
We wish to report the synthesis, crystal structures, spectroscopic and electrochemical properties of several new Pt(II) heteroleptic complexes containing the thiacrown, 9S3 (1,4,7-trithiacyclononane) with a series of substituted phenanthroline ligands and related diimine systems. These five ligands are 5,6-dimethyl-1,10-phenanthroline(5,6-Me 2-phen), 4,7-dimethyl-1,10-phenanthroline(4,7-Me 2-phen), 4,7-diphenyl-1,10- phenanthroline(4,7-Ph 2-phen), 2,2′-bipyrimidine(bpm), and pyrazino[2,3-f]quinoxaline or 1,4,5,8-tetraazaphenanthrene(tap). All complexes have the general formula [Pt(9S3)(N 2)](PF 6) 2 (N 2 = diimine ligand) and form similar structures in which the Pt(II) center is surrounded by a cis arrangement of the two N donors from the diimine chelate and two sulfur atoms from the 9S3 ligand. The third 9S3 sulfur in each structure forms a longer interaction with the platinum resulting in an elongated square pyramidal structure, and this distance is sensitive to the identity of the diimine ligand. In addition, we report the synthesis, structural, electrochemical, and spectroscopic properties of related Pd(II) 9S3 complex with tap. The 195Pt NMR chemical shifts for the six Pt(II) complexes show a value near -3290 ppm, consistent with a cis-PtS 2N 2 coordination sphere although more electron-withdrawing ligands such as tap show resonances shifted by almost 100 ppm downfield. The physicochemical properties of the complexes generally follow the electron-donating or withdrawing properties of the phenanthroline substituents. © 2011 Elsevier Ltd. All rights reserved.
Zuidema D.R.,Covenant College |
Herndon L.B.,Covenant College
Journal of Chemical Education | Year: 2016
Deborah Blum's New York Times bestselling nonfiction book The Poisoner's Handbook was used as supplementary reading in our first-term General/Organic/Biochemistry course. This course serves as both the first course for our Allied Health chemistry sequence and a core science course. Our goal was that, through reading this book, students would learn more about the origin of forensic chemistry in the historical context of the Jazz Age and the toxins that were often involved in poisonings near the beginning of the 20th century. Outcomes and student feedback to this initiative are discussed. © 2015 The American Chemical Society and Division of Chemical Education, Inc.
Zuidema D.R.,Covenant College |
Eames K.J.,Covenant College
Journal of Chemical Education | Year: 2014
Student performance in a high school dual-enrollment chemistry course was compared with student performance in the corresponding traditional college course. The two courses were taught by the same instructor and evaluated using the same American Chemical Society (ACS) standardized examination. Interestingly, the high school dual-enrollment students have outperformed the traditional college students on the college-level exam in each of the years that the dual-enrollment program has been in existence. Dual-enrolled students also consistently did better on the ACS college-level exam than they did on the ACS high school exam. (Figure Presented). © 2014 American Chemical Society and Division of Chemical Education, Inc.
Ngai J.H.,Yale University |
Schwendemann T.C.,Yale University |
Walker A.E.,Yale University |
Walker A.E.,Covenant College |
And 5 more authors.
Advanced Materials | Year: 2010
An annealing technique to achieve single-unit-cell steps and predominant A-site termination was reported. The experiment involves tuning the vapor pressure of La using a LaAlO 3 (LAO) cover substrate in close proximity to the La 0.18 Sr 0.82Al 0.59Ta 0.41O 3 (LSAT) surface during high-temperature annealing. The alumina crucible was then inserted into a tube furnace and annealed using conditions noted in the text. The internal thermocouple of the furnace was used to obtain temperature measurements. Postannealing atomic force microscopy (AFM) imaging shows single-unit-cell steps on the surface, while reflection high-energy electron diffraction (RHEED) and ion scattering spectroscopy (ISS) indicate the presence of a highly ordered surface that is predominantly A-site (SrO) terminated. The results confirm that La near the LSAT surface helps suppress the formation of SrO.