163 research outputs found
Armascirus gimplei Smiley 1992
No full text<i>Armascirus gimplei</i> Smiley, 1992 <p>(Figs. 11–13)</p> <p> <i>Armascirus gimplei</i> Smiley, 1992: 139, fig. 70A, B; Kalúz 2009: 37.</p> <p> <b>Diagnosis.</b> <i>Armascirus gimplei</i> most closely resembles <i>A. ozarkensis</i> and <i>A. cerris</i> in that it has a small hysterosomal (median) shield that is not complemented with dorsal setae and has lateral platelets. It can be differentiated from <i>A. cerris</i> because it has 6 setae after coxae II (not including coxal, genital and anal setae) instead of 7. It can be differentiated from <i>A. ozarkensis</i> based on the lateral platelets, which are conspicuous and as long as the median shield in <i>A. ozarkensis</i> and inconspicuous and only as long as or slightly longer than <i>c</i> <i>2</i> in <i>A. gimplei.</i></p> <p> <b>Remarks.</b> After examining both the holotype and the newly collected specimen, differences between the original description and the specimens were found. Smiley (1992) states that the lateral hysterosomal platelets of <i>A. gimplei</i> are small and that <i>c2</i> is located on the platelets. In reality the platelets are small and inconspicuous, but occur on the integument between <i>d1</i> and <i>c2</i> much as they do in other <i>Armascirus</i>. The structures previously reported as the lateral platelets are the same tiny platelets that occur at the base of all dorsal setae that are situated in the integument away from larger plates and shields.</p> <p>The integument around the setae laterad of coxae III appears to be more sclerotized than the surrounding cuticle. This area does not bear the reticulated pattern of the coxal or dorsal plates. The structure is not visible in the holotype so we were unable to determine if it is present across the species or an anomaly of the specimen examined.</p> <p>In addition, differences between the new specimen and the published leg setal formulae were found as follows: tibiae I with 2 asl, 1 mst, 4 sts; tibiae III with 1 bsl, 5 sts. Unfortunately the holotype is in a poor condition that does not allow these leg segments to be viewed, and therefore these differences cannot be corroborated with the type. Subcapitulum (Fig. 11 a), palp (Fig. 11 b), chelicera (Fig. 11 c), The idiosoma (12a, b) and legs (Fig. 13 a–d) have been illustrated based on the Ozark specimen to aid in identification.</p> <p> <b>Material examined</b> (2 individuals on slides). Female holotype, ex. <i>Tillandsia</i> sp., Mexico, Vera Cruz. 6 April 1966, coll. J. T. Watt. ● 1 female (APGD 10-0730-005), ex. mixed cedar and deciduous litter, USA, Arkansas, Newton Co., Buffalo National River, Steel Creek (36° 01.924 N, 093° 20.040 W), 30 July 2010, by M. J. Skvarla.</p>Published as part of <i>Skvarla, Michael J. & Dowling, Ashley P. G., 2012, Some new armascirine cunaxids (Acari: Prostigmata: Cunaxidae) from the Eastern United States, pp. 1-34 in Zootaxa 3194</i> on pages 16-17, DOI: 10.11646/zootaxa.3194.1.1, <a href="http://zenodo.org/record/201630">http://zenodo.org/record/201630</a>
Error estimates for the bifurcation function for semilinear elliptic boundary value problems
No full textA semilinear elliptic boundary value problem of the form Lu+gx,u,l=0 and a corresponding discrete problem based on the finite element method are considered. The method of alternative problems is used to reduce the boundary value problem to an equivalent finite-dimensional problem Bc,l=0 . The bifurcation function Bc,l is a vector field on Rd for fixed l . The solutions of the reduced problem are in a one-to-one correspondence with the solutions of the boundary value problem. The method of alternative problems is also applied to reduce the discrete problem to an equivalent lower-dimensional problem. An approximate bifurcation function Bhc,l for the lower-dimensional problem is also defined as a vector field on Rd , whose zeros are in a one-to-one correspondence with the solutions of the discrete problem. Estimates of the differences Bc,l-Bh c,l,Bc c,l-B hcc,l , and Ec,l-E hc,l are derived. Here, Ec,l (resp. Ehc,l ) denotes the value of energy functional associated with the boundary value problem (resp. the discrete problem). Morse decompositions are computed for some classical examples, and their bifurcation diagrams are presented. Results from numerical experiments on the orders of convergence for the difference Bc,l-Bh c,l are presented.</p
A survey of the use of cellular automata and cellular automata-like models for simulating a population of biological cells
No full textThe purpose of this thesis is to survey a few of the cellular automata and cellular automata-like models which have been used in mathematical biology applications in recent years. Some of the benefits of using such models will be discussed. Also some issues pertaining to the analysis of such models will be addressed.</p
Global bifurcation of a sinusoidally forced Duffing's equation
No full textIn this Dissertation we study the sinusoidally forced Duffing equation. We show that the Duffing equation with zero Dirichlet boundary conditions has exactly one, two or three solutions depending on the amplitude of the forcing;We also study the nonlinear reaction-diffusion equation for long time behavior using dynamical systems approach. The steady states of the reaction-diffusion equation is governed by the Duffing equation. We prove the existence of a global attractor to which all solutions approach.</p
Celebrating Dr. Lowery's 85th Birthday Disc 2.
No full textThis video features a tribute to celebrate Joseph E. Lowery's 85th birthday in which the birthday celebration is featured and interspersed with video excerpts from moments in Lowery's life. Speakers at the birthday celebration include Woodie White, Johnny Ford, Maxine Waters, Miriam Poe, Ruby Shinhoster, Rita Samuels, Tavis Smiley, the Lowery daughters, and Martin Luther King, III. The video includes remarks by Lowery toward the end of the video. There are musical performances in the video from saxophonist Angela Christie, rapper Fonzworth Bentley, and musician Antonio Allen.The Atlanta University Center Robert W. Woodruff Library acknowledges the generous support of the Joseph & Evelyn Lowery Institute for Justice and Human Rights, the Joseph Echols Lowery Irrevocable Trust, and other donors in supporting the processing and digitization of Morehouse College's Joseph Echols and Evelyn Gibson Lowery Collection
An algorithm for finding all solutions of a nonlinear system
No full textAbstractLet f:X→Rk be a Lipschitz continuous function on a compact subset X⊂Rd. Subdivision algorithms are described that can be used to find all solutions of the equation f(x)=0 that lie in X. Convergence is shown and numerical examples are presented. Modifications of the basic algorithm which speed convergence are given for the case of nondegenerate zeros of a vector field
Existernce, Uniqueness, and Galerkin Approximations for Semilinear Periodically Forcedwave Equations at Resonance
No full textExpansionist Abstraction
No full textThe subject of this thesis is a position in the philosophy of mathematics - defended by Bob Hale and Crispin Wright - known variously as neo-Fregeanism, neo-Logicism or abstractionism, and which claims that knowledge of mathematical objects can be based on principles - known as abstraction principles - which are in important respects like definitions of mathematical language.
In the thesis, I make a distinction between two ways in which the abstraction programme might be carried out. These are the standardly defended static view, according to which abstraction principles can used to discover previously unrecognised objects lying within some fixed domain of quantification. The second is an expansionist view, according to which abstraction principles allow one to introduce new quantificational vocabulary, and thus expand ones domain of quantification to one which contains referents of mathematical terms.
There are then two main aims. The first is to examine the static position, so as to identify the components of that view which make it committed to a standard domain, and to argue against the view. My main argument against the view concerns what has become known as the bad company problem. I argue that there is an epistemological component to the bad company problem which can not be avoided by the static abstractionist.
The second aim of the thesis is to argue for and defend the expansionist view. In particular, I will claim that the expansionist view avoids the bad company problem, and that the expansionist view allows for an abstractionist foundation for set theory - an aim which (or so I will argue) has so far eluded the static view
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