566 research outputs found

    Elevation of \u3ci\u3eCicindela nigrior\u3c/i\u3e to Species Rank

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    Cicindela nigrior Schaupp (1884) has a complex taxonomic history as a subspecies, variety, and aberration of the morphologically plastic tiger beetle C . scutellaris. Schaupp gave the varietal name nigrior to what he apparently thought was a melanistic form of Cicindela scutellaris unicolor Dejean. Leng (1902) listed both nigrior and unicolor as varieties of scutellaris Say. However, Horn (1905) llsted nigrior and unicolor as aberrations of obscura Say (=scutellaris). Later he listed nigrior as a variety of scutellaris unicolor (Horn 1916). The Leng catalog (1920) shows both nigrior and unicolor as subspecies of scutellaris, while Vaurie (1950) and Boyd et al. (1982) placed nigrior as a synonym of unicolor. In this paper we raise the name nigrior” to species level and present morphological, behavioral, and ecological data to Justify species status

    Elevation of Cicindela nigrior to species rank

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    Cicindela nigrior Schaupp (1884) has a complex taxonomic history as a subspecies, variety, and aberration of the morphologically plastic tiger beetle C. scutellaris. Schaupp gave the varietal name nigrior to what he apparently thought was a melanistic form of Cicindela scutellaris unicolor Dejean. Leng (1902) listed both nigrior and unicolor as varieties of scutellaris Say. However, Horn (1905) llsted nigrior and unicolor as aberrations of obscura Say (=scutellaris). Later he listed nigrior as a variety of scutellaris unicolor (Horn 1916). The Leng catalog (1920) shows both nigrior and unicolor as subspecies of scutellaris, while Vaurie (1950) and Boyd et al. (1982) placed nigrior as a synonym of unicolor. In this paper we raise the name "nigrior” to species level and present morphological, behavioral, and ecological data to Justify species status

    Observation of Magnetic Supercooling of the Transition to the Vortex State

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    We demonstrate that the transition from the high-field state to the vortex state in a nanomagnetic disk shows the magnetic equivalent of supercooling. This is evidence that this magnetic transition can be described in terms of a modified Landau first-order phase transition. To accomplish this we have measured the bulk magnetization of single magnetic disks using nanomechanical torsional resonator torque magnetometry. This allows observation of single vortex creation events without averaging over an array of disks or over multiple runs.Comment: 11 pages preprint, 4 figures, accepted to New Journal of Physic

    UGA’s Green Infrastructure Plan: Student Envisioned Plans to Improve Ecosystem Services on Campus

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    Proceedings of the 2011 Georgia Water Resources Conference, April 11, 12, and 13, 2011, Athens, Georgia.Graduate students from the “Nature and Sustainability” studio course at UGA’s College of Environment and Design created Green Infrastructure Plans for UGA’s Campus. Objectives of this service learning project included gathering inventory information, analyzing existing conditions, garnering stakeholder input and crafting plans at two scales. Students individually prepared campus wide plans, and then created site plans for a specific area. These proposed interventions were based on creating or enhancing a network of linkages and hubs (corridors and patches), otherwise known as Green Infrastructure, which supports ecosystem services such as water and nutrient cycling. Unfortunately, legacy land use and substantial impermeable area on campus hinders ecosystem function. In order to reverse these trends to approach a more sustainable trajectory, students sought to preserve, enhance and/or restore critical ecosystem services. This planning process may inform future planning efforts undertaken by the Office of University Architects to improve the green infrastructure of campus and further sustainability goals.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources FacultyThis book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-307) or the other conference sponsors

    Phase transitions and configuration space topology

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    Equilibrium phase transitions may be defined as nonanalytic points of thermodynamic functions, e.g., of the canonical free energy. Given a certain physical system, it is of interest to understand which properties of the system account for the presence of a phase transition, and an understanding of these properties may lead to a deeper understanding of the physical phenomenon. One possible approach of this issue, reviewed and discussed in the present paper, is the study of topology changes in configuration space which, remarkably, are found to be related to equilibrium phase transitions in classical statistical mechanical systems. For the study of configuration space topology, one considers the subsets M_v, consisting of all points from configuration space with a potential energy per particle equal to or less than a given v. For finite systems, topology changes of M_v are intimately related to nonanalytic points of the microcanonical entropy (which, as a surprise to many, do exist). In the thermodynamic limit, a more complex relation between nonanalytic points of thermodynamic functions (i.e., phase transitions) and topology changes is observed. For some class of short-range systems, a topology change of the M_v at v=v_t was proved to be necessary for a phase transition to take place at a potential energy v_t. In contrast, phase transitions in systems with long-range interactions or in systems with non-confining potentials need not be accompanied by such a topology change. Instead, for such systems the nonanalytic point in a thermodynamic function is found to have some maximization procedure at its origin. These results may foster insight into the mechanisms which lead to the occurrence of a phase transition, and thus may help to explore the origin of this physical phenomenon.Comment: 22 pages, 6 figure

    Harmonics generation in electron-ion collisions in a short laser pulse

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    Anomalously high generation efficiency of coherent higher field-harmonics in collisions between {\em oppositely charged particles} in the field of femtosecond lasers is predicted. This is based on rigorous numerical solutions of a quantum kinetic equation for dense laser plasmas which overcomes limitations of previous investigations.Comment: 4 pages, 4 eps-figures include

    Enhanced inverse bremsstrahlung heating rates in a strong laser field

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    Test particle studies of electron scattering on ions, in an oscillatory electromagnetic field have shown that standard theoretical assumptions of small angle collisions and phase independent orbits are incorrect for electron trajectories with drift velocities smaller than quiver velocity amplitude. This leads to significant enhancement of the electron energy gain and the inverse bremsstrahlung heating rate in strong laser fields. Nonlinear processes such as Coulomb focusing and correlated collisions of electrons being brought back to the same ion by the oscillatory field are responsible for large angle, head-on scattering processes. The statistical importance of these trajectories has been examined for mono-energetic beam-like, Maxwellian and highly anisotropic electron distribution functions. A new scaling of the inverse bremsstrahlung heating rate with drift velocity and laser intensity is discussed.Comment: 12 pages, 12 figure

    Beidseitige Informationsasymmetrien in der Arzt-Patient-Beziehung: Implikationen fĂĽr die GKV

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    Die vorliegende Arbeit analysiert die Interdependenzen und Informationsstrukturen im Gesundheitswesen. Hauptansatzpunkt ist die beidseitig asymmetrische Information zwischen Arzt und Patient. Der Patient kann i. d. R. weder die Wirkung der Leistungen des Arztes genau einordnen, noch besitzt der Arzt genauere Informationen über das behandlungsbegleitende Verhalten des Patienten. Die Interdependenzen zwischen diesen Handlungen bestimmen das resultierende Gleichgewicht. Die Einführung einer Selbstbeteiligung für den Patienten führt zu einer verbesserten Compliance, das Niveau der medizinischen Leistung hängt von den Interdependenzen ab. Die Implikationen, die sich aus dem Modell ergeben, lassen auf ein Kommunikationsdefizit zwischen Arzt und Patient schließen. Eine Stärkung der Compliance ist zum einen durch verbesserte Information des Arztes, zum anderen durch finanzielle Anreize, insbesondere durch die Einführung einer Selbstbeteiligung, möglich. Die Krankenkassen als ergänzender Sachwalter der Patienten können in der Arzt-Patient-Beziehung vor allem Aufgaben wie Vertragsabschlüsse übernehmen, benötigen dazu jedoch mehr Gestaltungsfreiheit
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