First Record of \u3ci\u3eHarpalus Ochropus\u3c/i\u3e Kirby (Coleoptera: Carabidae) From Minnesota and the Conterminous United States

(excerpt) The epigeal ground beetle Harpalus ochropus Kirby (Coleoptera: Carabidae) has been reported from Alaska and across Canada from British Columbia into Quebec (Bousquet and Larochelle 1993). It is local and rarely collected. Gandhi et al. (2005) surveyed for carabids extensively for several years along the Gunflint Trail and adjacent Boundary Waters Canoe Area in northeastern Minnesota

Concentration fluctuations of large Stokes number particles in a one-dimensional random velocity field

We analyze the behavior of an ensemble of inertial particles in a one-dimensional smooth Gaussian velocity field, in the limit of large inertia, but considering a finite correlation time for the random field. We derive in this limit a perturbative scheme for the calculation of the concentration correlation and of the particle relative velocity distribution, providing analytical expressions for the concentration fluctuation amplitude, its correlation length, and the modification in the particle pair relative velocity variance. The amplitude of the concentration fluctuations is characterized by slow decay at large inertia and a much larger correlation length than that of the random field. The fluctuation structure in velocity space is very different from predictions from short-time correlated random velocity fields, with only few particle pairs crossing at sufficiently small relative velocity to produce correlations. Concentration fluctuations are associated with depletion of the relative velocity variance of colliding particles.Comment: 8 pages, 1 figure, revtex

Chaotic diffusion of particles with finite mass in oscillating convection flows

Deterministic diffusion in temporally oscillating convection is studied for particles with finite mass. The particles are assumed to obey a simple dissipative dynamical system and the particle diffusion is induced by the strange attractor. The diffusion constants are numerically calculated for convection models with free and rigid boundary conditions.Comment: 5 figure

Hydrodynamic limit of the zero range process on a randomly oriented graph

We prove the hydrodynamic limit of a totally asymmetric zero range process on a torus with two lanes and randomly oriented edges. The asymmetry implies that the model is non-reversible. The random orientation of the edges is constructed in a bistochastic fashion which keeps the usual product distribution stationary for the quenched zero range model. It is also arranged to have no overall drift along the Z direction, which suggests diffusive scaling despite the asymmetry present in the dynamics. Indeed, using the relative entropy method, we prove the quenched hydrodynamic limit to be the heat equation with a diffusion coefficient depending on ergodic properties of the orientation of the edges. The zero range process on this graph turns out to be non-gradient. Our main novelty is the introduction of a local equilibrium measure which decomposes the vertices of the graph into components of constant density. A clever choice of these components eliminates the non-gradient problems that normally arise during the hydrodynamic limit procedure.Comment: 30 pages, 2 figure

African Poetry Libraries-A Global Collaboration

In 2014, the African Poetry Book Fund (APBF) and the University of Nebraska (UNL)literary magazine-thePrairie Schooner established African Poetry Libraries in five countries; Ghana, Kenya,Uganda, Gambia and Botswana. The purpose of these libraries wasto support the creativity of aspiring and establishedpoets in their local communities. The University of Nebraska Libraries was asked toserve as consultants on the initiative by working with local volunteers to set up thelibraries and provideongoing assistance and advice to the new libraries during thefirst three years of their inception. The goal of the librariesis to support thelocal community of poets through access to contemporary poetry, and to serve as a resource for poets interested in publication in Africa and around the world.The collections comprise of solicited donations from US and UK publishers and each library receives 300-400 books annually for the first three years, after which the libraries become completely self-directed and self-sufficient. This chapter will describe the highlights of this innovative initiative, and the development of the partnership between theAPBF and the University of Nebraska Libraries that has shaped a global connection between: literary arts organizations and publishers in the US and UK, African libraries, writer’s co-ops, cultural centers, and poets

Continuum description of finite-size particles advected by external flows. The effect of collisions

The equation of the density field of an assembly of macroscopic particles advected by a hydrodynamic flow is derived from the microscopic description of the system. This equation allows to recognize the role and the relative importance of the different microscopic processes implicit in the model: the driving of the external flow, the inertia of the particles, and the collisions among them. The validity of the density description is confirmed by comparisons of numerical studies of the continuum equation with Direct Simulation Monte Carlo (DSMC) simulations of hard disks advected by a chaotic flow. We show that the collisions have two competing roles: a dispersing-like effect and a clustering effect (even for elastic collisions). An unexpected feature is also observed in the system: the presence of collisions can reverse the effect of inertia, so that grains with lower inertia are more clusterized.Comment: Final (strongly modified) version accepted in PRE; 6 pages, 3 figure

Sand stirred by chaotic advection

We study the spatial structure of a granular material, N particles subject to inelastic mutual collisions, when it is stirred by a bidimensional smooth chaotic flow. A simple dynamical model is introduced where four different time scales are explicitly considered: i) the Stokes time, accounting for the inertia of the particles, ii) the mean collision time among the grains, iii) the typical time scale of the flow, and iv) the inverse of the Lyapunov exponent of the chaotic flow, which gives a typical time for the separation of two initially close parcels of fluid. Depending on the relative values of these different times a complex scenario appears for the long-time steady spatial distribution of particles, where clusters of particles may or not appear.Comment: 4 pages, 3 figure

Characterization of the Functional Roles of Six2 During Kidney and Stomach Development

A better understanding of the cellular and molecular mechanisms controlling different aspects of normal and pathological organogenesis is central to human health. To this end, the characterization of the functional roles of genes involved in mammalian organogenesis by using gain- and loss-of-function approaches in animal models is a powerful experimental approach. As described in this thesis, I identify the homeobox gene Six2 as an important gene regulating different aspects of kidney and pyloric sphincter formation. The generated Six2-null mouse strain exhibits major phenotypic alterations in the development of these two structures. Homeobox-containing genes have been shown to play key roles in a variety of developmental processes in multicellular organisms. The previously identified Six/so family of homeobox transcription factors in vertebrates includes six members (Six1-Six6). Six2 was found to be expressed in many tissues during murine development including the developing eyes, kidneys, stomach, branchial arches, limb buds, otic and olfactory epithelia, somites, hindbrain, Rathke’s pouch, and genital eminence. The development of many of these organs relies on mesenchymal-epithelial interactions. Mammalian kidney organogenesis is a classical model of branching morphogenesis and reciprocal inductive interactions responsible for mesenchyme-to-epithelia transition. During kidney development, the metanephric mesenchyme responds to inductive signals emanating from the ureteric bud to generate the epithelia of the nephron, the functional excretory unit of the kidney. The metanephric mesenchyme is a multipotent renal progenitor cell population that is continuously replenished during nephron formation. The detailed analysis of the Six2-null kidney described in Chapter 2 allowed us to identify Six2 as a key factor responsible for the maintenance of this undifferentiated mesenchymal population. Furthermore, in Chapter 3 I described an important genetic interaction between Six2 and Wnt9b, a member of the Wnt family of si