Time filter

Source Type

Danville, KY, United States

Centre College is a private liberal arts college located in Danville, Kentucky, a community of approximately 16,000 in Boyle County, about 35 miles south of Lexington, Kentucky. Centre is an undergraduate four-year institution with an enrollment of approximately 1,375 students. Centre was founded by Presbyterian leaders, with whom it maintains a loose affiliation, and officially chartered by the Kentucky General Assembly in 1819. The College is a member of the Associated Colleges of the South. Wikipedia.

Koffler B.H.,University of Kentucky | Sears J.J.,Centre College at Danville
American Journal of Ophthalmology | Year: 2013

Purpose: To compare the safety and efficacy of orthokeratology as a nonsurgical treatment for myopia in children with alternate methods, such as soft contact lenses, rigid gas permeable lenses, and spectacles, throughout multiple studies. Design: Perspective with literature review. Methods: Analysis of recent studies to determine the safety and effectiveness of orthokeratology versus soft contact lenses, rigid gas permeable lenses, and spectacles in children. Results: In all of the studies reviewed, the use of orthokeratology lenses proved to reduce myopia, to improve visual acuity, and, with the exception of the SMART study, to reduce the rate of axial elongation. Orthokeratology has been shown to be as effective as other methods in treating myopia and to be more effective at treating axial elongation. There were no major adverse events in any of the studies comparing orthokeratology with other methods of myopia treatment. Conclusions: Studies show that the use of orthokeratology is a safe and efficacious nonsurgical treatment for myopia and that it is capable of slowing axial elongation, making it an effective myopic treatment for children. © 2013 BY ELSEVIER INC. ALL RIGHTS RESERVED. Source

Nydam M.L.,Centre College at Danville | De Tomaso A.W.,University of California at Santa Barbara
BMC Evolutionary Biology | Year: 2012

Abstract. Background: Allorecognition, the ability of an organism to distinguish self from non-self, occurs throughout the entire tree of life. Despite the prevalence and importance of allorecognition systems, the genetic basis of allorecognition has rarely been characterized outside the well-known MHC (Major Histocompatibility Complex) in vertebrates and SI (Self-Incompatibility) in plants. Where loci have been identified, their evolutionary history is an open question. We have previously identified the genes involved in self/non-self recognition in the colonial ascidian Botryllus schlosseri, and we can now begin to investigate their evolution. In B. schlosseri, colonies sharing 1 or more alleles of a gene called FuHC (Fusion Histocompatibility) will fuse. Protein products of a locus called fester, located ∼300 kb from FuHC, have been shown to play multiple roles in the histocompatibility reaction, as activating and/or inhibitory receptors. We test whether the proteins encoded by this locus are evolving neutrally or are experiencing balancing, directional, or purifying selection. Results: Nearly all of the variation in the fester locus resides within populations. The 13 housekeeping genes (12 nuclear genes and mitochondrial cytochrome oxidase I) have substantially more structure among populations within groups and among groups than fester. All polymorphism statistics (Tajima's D, Fu and Li's D* and F*) are significantly negative for the East Coast A-type alleles, and Fu and Li's F* statistic is significantly negative for the West Coast A-type alleles. These results are likely due to selection rather than demography, given that 10 of the housekeeping loci have no populations with significant values for any of the polymorphism statistics. The majority of codons in the fester proteins have ω values < 1, but 15-27 codons have > 95% posterior probability of ω values > 1. Conclusion: Fester proteins are evolving non-neutrally. The polymorphism statistics are consistent with either purifying selection or directional selection. The ω statistics show that the majority of the protein is experiencing purifying selection (ω < 1), but that 15-27 codons are undergoing either balancing or directional selection: ω > 1 is compatible with either scenario. The distribution of variation within and among populations points towards balancing selection and away from directional selection. While these data do not provide unambiguous support for a specific type of selection, they contribute to our evolutionary understanding of a critical biological process by determining the forces that affect loci involved in allorecognition. © 2012 Nydam and De Tomaso; licensee BioMed Central Ltd. Source

Montgomery Jr. H.E.,Centre College at Danville | Sen K.D.,University of Hyderabad
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2012

Benchmark numerical results on the ground and excited state eigenvalues and the ground state static and dynamic dipole polarizabilities are reported for a hydrogen atom confined at the center of a spherical box with penetrable walls. The dynamic polarizabilities are negative except when the frequency of incident radiation is below the 1s-2p transition frequency or in the frequencies immediately below a 1s-np transition. © 2012 Published by Elsevier B.V. Source

Montgomery Jr. H.E.,Centre College at Danville | Pupyshev V.I.,Moscow State University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2013

Energies for the first four singlet and triplet S states of a helium atom confined at the center of an impenetrable sphere are reported. All calculations used explicitly correlated Hylleraas basis sets. The first triplet state is shown to lie below the first excited singlet state only when the confinement radius is greater than 0.988a0. A simple configuration interaction calculation was performed in parallel with Hylleraas calculation. The one-electron atomic orbitals of the configuration treatment provide insight into the physical concepts behind the numerical results of the Hylleraas treatment. This was particularly helpful in understanding the level crossing and avoided crossings observed with changing confinement radius. © 2013 Elsevier B.V. All rights reserved. Source

Montgomery Jr. H.E.,Centre College at Danville | Pupyshev V.I.,Moscow State University
European Physical Journal H | Year: 2013

The response of molecular systems to external fields was one of the first areas studied after development of the new quantum mechanics. Early work by Kirkwood and Buckingham developed polarisability lower bounds that are still used today. This work uses an inequality proposed by Linderberg to develop a treatment of polarisability lower bounds that unifies the work of Kirkwood and Buckingham with Hylleraas' variational perturbation theory. In particular, the prehistory of the works of Kirkwood and Buckingham is described. Numerical examples are presented to demonstrate the convergence of approximate wavefunctions in the confined atom problem. The applicability of dimensional scaling and its utility in the analysis of confined systems are also discussed. © EDP Sciences, Springer-Verlag 2013. Source

Discover hidden collaborations