The possible values of critical points between strongly congruence-proper varieties of algebras

We denote by Conc(A) the semilattice of all finitely generated congruences of an (universal) algebra A, and we define Conc(V) as the class of all isomorphic copies of all Conc(A), for A in V, for any variety V of algebras. Let V and W be locally finite varieties of algebras such that for each finite algebra A in V there are, up to isomorphism, only finitely many B in W such that A and B have isomorphic congruence lattices, and every such B is finite. If Conc(V) is not contained in Conc(W), then there exists a semilattice of cardinality aleph 2 in Conc(V)-Conc(W). Our result extends to quasivarieties of first-order structures, with finitely many relation symbols, and relative congruence lattices. In particular, if W is a finitely generated variety of algebras, then this occurs in case W omits the tame congruence theory types 1 and 5; which, in turn, occurs in case W satisfies a nontrivial congruence identity. The bound aleph 2 is sharp

LCS Tool : A Computational Platform for Lagrangian Coherent Structures

We give an algorithmic introduction to Lagrangian coherent structures (LCSs) using a newly developed computational engine, LCS Tool. LCSs are most repelling, attracting and shearing material lines that form the centerpieces of observed tracer patterns in two-dimensional unsteady dynamical systems. LCS Tool implements the latest geodesic theory of LCSs for two-dimensional flows, uncovering key transport barriers in unsteady flow velocity data as explicit solutions of differential equations. After a review of the underlying theory, we explain the steps and numerical methods used by LCS Tool, and illustrate its capabilities on three unsteady fluid flow examples

Martinez Guzman v. Second Judicial Dist. Court, 136 Nev. Adv. Op. 12 (Mar. 26, 2020)

The Court clarified the ambiguity of the meaning “territorial jurisdiction,” a term of art found in NRS 172.105. The Court held that NRS 172.105 incorporates Nevada’s venue statutes and grants a grand jury the authority to “inquire into a [criminal] offense so long as the district court that empaneled the grand jury may appropriately adjudicate the defendant’s guilt for that particular offense.

A History of Nonviolence: Insecurity and the Normative Power of the Imagined in Costa Rica

Crime, violence, and insecurity are among the most important social topics in contemporary Costa Rica. These three issues play a central role in the media, politics, and everyday life, and the impression has emerged that security has changed for the worse and that society is now threatened permanently. However, crime statistics do not support this perception. The paper thus asks why violence and crime generate such huge fear in society. The thesis is that the Costa Rican national identity—with Costa Rica constructed as a nonviolent nation— impedes a realistic discussion about the phenomena and their causes, and simultaneously provides a platform for sensationalism and the social construction of fear.Costa Rica, violence, crime, national identity, public discourse

A Free Energy Model of Boron Carbide

The assessed phase diagram of the boron-carbon system contains a single non-stoichiometric boron-carbide phase of rhombohedral symmetry with a broad, thermodynamically improbable, low temperature composition range. We combine first principles total energy calculations with phenomenological thermodynamic modeling to propose a revised low temperature phase diagram that contains two boron-carbide phases of differing symmetries and compositions. One structure has composition B4C and consists of B11C icosahedra and C-B-C chains, with the placement of carbon on the icosahedron breaking rhombohedral symmetry. This phase is destabilized above 600K by the configurational entropy of alternate carbon substitutions. The other structure, of ideal composition B13C2, has a broad composition range at high temperature, with rhombohedral symmetry throughout, as observed experimentally.Comment: 15 pages, 3 figures, submitted to J. Stat. Phys. August 9th, 201

Computer Assisted Instruction & the ACTFL Proficiency Guidelines

The current study presents the results of one mixed-method analysis of theimplementation of communicative online activities into beginning Spanishclasses, their effects on class performance, and evaluation of the studentgeneratedwork from the online module. Results show that althoughstatistically there may be some doubt as to the effectiveness of an additionof a WebCT/Blackboard ® component into a beginning Spanish program,the environment did provide opportunities for students to demonstratelanguage proficiency. It is the analysis of student writing samplesgathered from the hybrid course, using a rubric based on the ACTFLWriting Proficiency Guidelines, that adds depth and breadth to the study.The article also addresses common issues that arise in traditionalanalyses of technology implementations, and suggests ways that theACTFL Writing Proficiency Guidelines can be useful in the evaluation ofstudent work in qualitative research

Defining Coherent Vortices Objectively from the Vorticity

Rotationally coherent Lagrangian vortices are formed by tubes of deforming fluid elements that complete equal bulk material rotation relative to the mean rotation of the deforming fluid volume. We show that initial positions of such tubes coincide with tubular level surfaces of the Lagrangian-Averaged Vorticity Deviation (LAVD), the trajectory integral of the normed difference of the vorticity from its spatial mean. LAVD-based vortices are objective, i.e., remain unchanged under time-dependent rotations and translations of the coordinate frame. In the limit of vanishing Rossby numbers in geostrophic flows, cyclonic LAVD vortex centers are precisely the observed attractors for light particles. A similar result holds for heavy particles in anticyclonic LAVD vortices. We also establish a relationship between rotationally coherent Lagrangian vortices and their instantaneous Eulerian counterparts. The latter are formed by tubular surfaces of equal material rotation rate, objectively measured by the Instantaneous Vorticity Deviation (IVD). We illustrate the use of the LAVD and the IVD to detect rotationally coherent Lagrangian and Eulerian vortices objectively in several two- and three-dimensional flows