Arthur J. Yates (1882-1961) and His Collection of Lepidoptera

The fine collection of Michigan Lepidoptera assembled by the late Arthur J. Yates has recently been donated by his wife, Mrs. Ethel K. Yates, to the Entomology Museum of Michigan State University

Chebyshev polynomials are not always optimal

The problem is that of finding among all polynomials of degree at most n and normalized to be 1 at c the one with minimal uniform norm on Epsilon. Here, Epsilon is a given ellipse with both foci on the real axis and c is a given real point not contained in Epsilon. Problems of this type arise in certain iterative matrix computations and, in this context, it is generally believed and widely referenced that suitably normalized Chebyshev polynomials are optimal for such constrained approximation problems. It is shown that this is not true in general. Moreover, sufficient conditions are derived which guarantee that Chebyshev polynomials are optimal. Some numerical examples are also presented

New Bernstein type inequalities for polynomials on ellipses

New and sharp estimates are derived for the growth in the complex plane of polynomials known to have a curved majorant on a given ellipse. These so-called Bernstein type inequalities are closely connected with certain constrained Chebyshev approximation problems on ellipses. Also presented are some new results for approximation problems of this type

Optimal Chebyshev polynomials on ellipses in the complex plane

The design of iterative schemes for sparse matrix computations often leads to constrained polynomial approximation problems on sets in the complex plane. For the case of ellipses, we introduce a new class of complex polynomials which are in general very good approximations to the best polynomials and even optimal in most cases

On the constrained Chebyshev approximation problem on ellipses

Constrained Chebyshev approximation problems of the type with minimum (p is an element of Pi(sub n):p(c)=1) and maximum (z is an element of E) with /p(z)/ are considered. Here Pi(sub n) denotes the set of all complex polynomials of degree at most n, E is any ellipse in the complex plane, and c is an element of C/E. Such approximation problems arise in the context of optimizing semi-iterative methods for the solution of large, sparse systems of linear equations Ax=b with complex non-Hermitian coefficient matrices A. The problem of obtaining optimal polynomial preconditioners for conjugate gradient type methods for Ax=b also leads to problems of this type. A new family of polynomials -- q(sub n)(z;c), n is an element of N, and c is an element of C/E -- are introduced as the polynomials which are optimal for a modified version of the Chebyshev approximation problem with Pi(sub n) replaced by a certain subfamily. Some simple properties of q(sub n) are also listed. A necessary and sufficient condition for q(sub n) to be the extremal polynomial for the approximation problem is then derived. Finally, it is shown that q(sub n) is indeed optimal for the problem for all fixed n whenever the distance between c and E is sufficiently large. Results of some numerical tests are presented

Insects Taken at Japanese Beetle Traps Baited with Anethole-Eugenol in Southern Michigan in 1968

A survey of the populations of Jap.anese beetles, Popillia japonica Newman, is made each year in southern Michigan to determine the abundance and distribution of this pest insect. Since little information is available about the insects that are attracted by Japanese beetle attractants in Michigan or anywhere in the United States, a study was made of the insects captured in Japanese beetle traps

A Taxonomic and Ecological Study of the Asilidae of Michigan

Seventy-two species of Asilidae have been recorded from Michigan. An additional seven which may occur are included. Keys to subfamilies, genera and species are given. Two subfamilies and twenty-five genera are represented. A discussion of specific identification, habitat, and distribution is given where possible. The Laphria canis complex, index complex, and aeatus complex are discussed. One new species, Laphria calvescenta is described. Laphria disparella has been raised from synonymy. Machimus virginicus was removed from Asilus sensu-latu and placed in the genus Machimus

The Influence of Design Updates on Users: the Case of Snapchat

Today’s smartphone apps are regularly updated and enhanced through software updates. The case at hand is the popular social multimedia messaging app Snapchat that released a design overhaul in February 2018. While the update neither changed any features nor caused any relevant bugs or crashes, it led to an uproar of Snapchat’s users and significantly decreased its app store ratings and consequently revenue. As a result, Snap Inc., the company behind Snapchat, was forced to reverse design changes to appease their users. The initial adverse effects of the update were surprising; however, after using difference-in-difference tests in combination with sentiment analysis, our results indicate that design updates can be perceived negatively by users. We contribute to IS literature by evaluating the effect of design changes and the role of perceived ease of use in the post-adoption stage