Minimal Obstructions for Partial Representations of Interval Graphs

Interval graphs are intersection graphs of closed intervals. A generalization of recognition called partial representation extension was introduced recently. The input gives an interval graph with a partial representation specifying some pre-drawn intervals. We ask whether the remaining intervals can be added to create an extending representation. Two linear-time algorithms are known for solving this problem. In this paper, we characterize the minimal obstructions which make partial representations non-extendible. This generalizes Lekkerkerker and Boland's characterization of the minimal forbidden induced subgraphs of interval graphs. Each minimal obstruction consists of a forbidden induced subgraph together with at most four pre-drawn intervals. A Helly-type result follows: A partial representation is extendible if and only if every quadruple of pre-drawn intervals is extendible by itself. Our characterization leads to a linear-time certifying algorithm for partial representation extension

Subclasses of Normal Helly Circular-Arc Graphs

A Helly circular-arc model M = (C,A) is a circle C together with a Helly family \A of arcs of C. If no arc is contained in any other, then M is a proper Helly circular-arc model, if every arc has the same length, then M is a unit Helly circular-arc model, and if there are no two arcs covering the circle, then M is a normal Helly circular-arc model. A Helly (resp. proper Helly, unit Helly, normal Helly) circular-arc graph is the intersection graph of the arcs of a Helly (resp. proper Helly, unit Helly, normal Helly) circular-arc model. In this article we study these subclasses of Helly circular-arc graphs. We show natural generalizations of several properties of (proper) interval graphs that hold for some of these Helly circular-arc subclasses. Next, we describe characterizations for the subclasses of Helly circular-arc graphs, including forbidden induced subgraphs characterizations. These characterizations lead to efficient algorithms for recognizing graphs within these classes. Finally, we show how do these classes of graphs relate with straight and round digraphs.Comment: 39 pages, 13 figures. A previous version of the paper (entitled Proper Helly Circular-Arc Graphs) appeared at WG'0

Discovery and Annotation of Two Phages that Infect Microbacterium foliorum: Tedro and Bajuniper

We isolated and purified Tedro and BAjuniper which infect the host Microbacterium foliorium. Tedro is a lytic, cluster EF phage isolated from soil collected in Hawarden, Iowa. Its genome is 56,197 bp long, circularly permuted, and includes 83 protein-coding genes and no tRNA genes. We are examining two of Tedro’s genes, genes 56 and 57, both of which are predicted to encode a DnaE-like DNA polymerase III (alpha) in more detail. Tedro_57 is twice as large as Tedro_56 so we are using additional bioinformatic tools to understand these genes. BAjuniper was isolated from soil collected in a garden in Orange City, Iowa. Its genome is 41,985 bp long. It was assigned to cluster EB. BAjuniper’s genome includes one tRNA gene and we will finalize BAjuniper’s annotation shortly

Charlotte Skrien Interview, ca. 1978

Charlotte Skrien was 87 years old and lived in Morris. Her grandparents came to the United States from Norway. In this interview, Charlotte relates some stories about her grandparents\u27 and mother\u27s trip from Norway to the United States. She also discusses childhood deaths and diseases, as well as medical care during that time. She talks about her son, who played football with the University of Minnesota Gophers.https://digitalcommons.morris.umn.edu/kmrs/1099/thumbnail.jp

Teacher Selection: A Venture for Excellence

This project explores current literature to define the characteristics of excellent teachers and examines whether the Ventures for Excellence teacher selection criteria identify these characteristics. It also includes an assessment of the successfulness of Owatonna Public Schools\u27 teacher selection process using Ventures for Excellence. The project concludes with recommendations to improve the Owatonna Public Schools\u27 teacher selection process. This author is the Director of Human Resources for the Owatonna Public Schools, and intends to use the information gathered in this project to enhance the district\u27s teacher selection process. This author believes that an assessment of the selection process will validate the need to continue using Ventures for Excellence in the selection of excellent teachers

Object - Oriented design using java

Bostonxiv, 340 p, Fig, 24 cm

Object -oriented design using Java

Bostonxiv, 340 p.: Illus.; 24 cm

Java programming : a comprehensive introduction

xxxiv, 1148 p. ; 24 cm