Cusps of lattices in rank 1 Lie groups over local fields

Let G be the group of rational points of a semisimple algebraic group of rank 1 over a nonarchimedean local field. We improve upon Lubotzky's analysis of graphs of groups describing the action of lattices in G on its Bruhat-Tits tree assuming a condition on unipotents in G. The condition holds for all but a few types of rank 1 groups. A fairly straightforward simplification of Lubotzky's definition of a cusp of a lattice is the key step to our results. We take the opportunity to reprove Lubotzky's part in the analysis from this foundation.Comment: to appear in Geometriae Dedicat

Incidents in the Life of a Slave Girl, Education and Abolition

Some thirty years before Harriet Ann Jacobs opened the Jacobs Free School in Alexandria, Virginia in January 1864, one of her first students was her fifty-threeyear-old uncle, Fred. The seventeen-year-old Harriet appreciated her uncle\u27s most earnest desire to learn to read and promised to teach him.1 As slaves, both teacher and student risked the punishment of thirtynine lashes on [the] bare back as well as imprisonment for violating North Carolina\u27s anti-literacy laws targeting African Americans.2 Nevertheless they agreed to meet three times a week in a quiet nook where she instructed him in secret.3 While the primary goal for him was to read the Bible, this moment in Jacobs\u27 slave narrative Incidents in the Life of a Slave Girl revealed her early commitment to African American literacy and education as well as her rejection of the laws of American slavery. In that moment, the vocations of education and abolition took root for Harriet Jacobs

Spring Season Survey of the Urban Blowflies (Diptera: Calliphoridae) of Chicago, Illinois

During May 1980, 1165 blowflies of 12 species were trapped on chemically enhanced rat carrion baits in a dense urban setting in Chicago. In descending order, Cynomyopsis cadaverina, Lucilia sericata, and Phormia regina were the most abundant species recovered (92% of total). These results are contrasted with other nearby blowfly surveys

Set mapping reflection

In this note we will discuss a new reflection principle which follows from the Proper Forcing Axiom. The immediate purpose will be to prove that the bounded form of the Proper Forcing Axiom implies both that 2^omega = omega_2 and that L(P(omega_1)) satisfies the Axiom of Choice. It will also be demonstrated that this reflection principle implies that combinatorial principle Square(kappa) fails for all regular kappa > omega_1.Comment: 11 page

Scales for co-compact embeddings of virtually free groups

Let $\Gamma$ be a group which is virtually free of rank at least 2 and let $\mathcal{F}_{td}(\Gamma)$ be the family of totally disconnected, locally compact groups containing $\Gamma$ as a co-compact lattice. We prove that the values of the scale function with respect to groups in $\mathcal{F}_{td}(\Gamma)$ evaluated on the subset $\Gamma$ have only finitely many prime divisors. This can be thought of as a uniform property of the family $\mathcal{F}_{td}(\Gamma)$.Comment: 12 pages; key words: uniform lattice, virtually free group, totally disconnected group, scale function (Error in references corrected in version 2

Measurement in marketing

We distinguish three senses of the concept of measurement (measurement as the selection of observable indicators of theoretical concepts, measurement as the collection of data from respondents, and measurement as the formulation of measurement models linking observable indicators to latent factors representing the theoretical concepts), and we review important issues related to measurement in each of these senses. With regard to measurement in the first sense, we distinguish the steps of construct definition and item generation, and we review scale development efforts reported in three major marketing journals since 2000 to illustrate these steps and derive practical guidelines. With regard to measurement in the second sense, we look at the survey process from the respondent's perspective and discuss the goals that may guide participants' behavior during a survey, the cognitive resources that respondents devote to answering survey questions, and the problems that may occur at the various steps of the survey process. Finally, with regard to measurement in the third sense, we cover both reflective and formative measurement models, and we explain how researchers can assess the quality of measurement in both types of measurement models and how they can ascertain the comparability of measurements across different populations of respondents or conditions of measurement. We also provide a detailed empirical example of measurement analysis for reflective measurement models