11,914 research outputs found

    Use of Radiographs for Movement Analysis of the Corn Wireworm, Melanotus communis (Coleoptera: Elateridae)

    Get PDF
    A laboratory technique is described in which "soft” radiographs are used to study wireworm, Melanotus communis Gyllenhal, movement patterns within a soil matrix. Advantages of this technique as compared with destructive sampling are discussed and examples of several possible applications are give

    The Zero Point of Extinction Toward Baade's Window

    Get PDF
    We measure the zero point of the Stanek (1996) extinction map by comparing the observed (V-K) colors of 206 K giant stars with their intrinsic (V-K)_0 colors as derived from their H\beta indices. We find that the zero point of the Stanek map should be changed by \Delta A_V = -0.10 +/- 0.06 mag, obtaining as a bonus a three-fold reduction of the previous statistical error. The most direct way to test for systematic errors in this determination would be to conduct a parallel measurement based on the (V-K) colors of RR Lyraes (type ab).Comment: 10 pages, 1 figur

    Health and internal migration

    Get PDF

    Measuring transverse velocities in gravitationally lensed extragalactic systems using an annual parallax effect

    Full text link
    A parallax method to determine transverse velocity in a gravitationally lensed system is described. Using the annual motion of the Earth around the Sun allows us to probe the local structure of the magnification map that, under certain assumptions, can be used to infer the effective transverse velocity. The method is applied to OGLE data for QSO2237+0305 and the velocity value is estimated to be about (15 +/- 10) km/s if attributed to the lensing galaxy or about (420 +/- 300) km/s if attributed to the quasar. We find this estimate unreasonably small and conclude that we have not measured a parallax effect. We give a short list of properties that a system should possess to allow a successful implementation of this method.Comment: v2: journal reference update

    Eight state supersymmetric UU model of strongly correlated fermions

    Get PDF
    An integrable eight state supersymmtric UU model is proposed, which is a fermion model with correlated single-particle and pair hoppings as well as uncorrelated triple-particle hopping. It has an gl(31)gl(3|1) supersymmetry and contains one symmetry-preserving free parameter. The model is solved and the Bethe ansatz equations are obtained.Comment: Some cosmetic changes; to appear in Phys. Rev.

    Focusing a fountain of neutral cesium atoms with an electrostatic lens triplet

    Full text link
    An electrostatic lens with three focusing elements in an alternating-gradient configuration is used to focus a fountain of cesium atoms in their ground (strong-field-seeking) state. The lens electrodes are shaped to produce only sextupole plus dipole equipotentials which avoids adding the unnecessary nonlinear forces present in cylindrical lenses. Defocusing between lenses is greatly reduced by having all of the main electric fields point in the same direction and be of nearly equal magnitude. The addition of the third lens gave us better control of the focusing strength in the two transverse planes and allowed focusing of the beam to half the image size in both planes. The beam envelope was calculated for lens voltages selected to produced specific focusing properties. The calculations, starting from first principles, were compared with measured beam sizes and found to be in good agreement. Application to fountain experiments, atomic clocks, and focusing polar molecules in strong-field-seeking states is discussed.Comment: 8 pages 10 figure

    The long delayed solution of the Bukhvostov Lipatov model

    Get PDF
    In this paper I complete the solution of the Bukhvostov Lipatov model by computing the physical excitations and their factorized S matrix. I also explain the paradoxes which led in recent years to the suspicion that the model may not be integrable.Comment: 9 page

    A Season Long Investigation of Social Emotional Learning Associated with High School Basketball Participation

    Get PDF
    This qualitative, longitudinal investigation had three purposes: (1) to investigate social emotional learning (SEL) outcomes athletes reported from participating in high school basketball; (2) to identify critical incidents that occurred over the course of a season that were associated with SEL outcomes; and, (3) to explore the processes identified as leading to the athletes’ SEL outcomes. High school varsity basketball players (four males, five females) were interviewed five times over the course of their season. Content analysis revealed that major categories of SEL outcomes identified included: psychological dispositions (e.g., accountability, discipline); psychological skills (e.g., emotional regulation, time management); and interpersonal competencies (e.g., communication, friendship). Student-athletes reported several critical incidences (competitive outcomes, shifting team responsibilities, team conflict, and emotional regulation events) and these were directly related to SEL outcomes. Student-athletes reported learning SEL outcomes from both the totality of their sport experience and from specific critical incidents such as winning and losing big games or handling team conflict. Results are discussed in light of the social emotional learning literature in education and Larson and Brown’s propositions regarding how youth learn via extracurricular activity participation

    Small world effects in evolution

    Get PDF
    For asexual organisms point mutations correspond to local displacements in the genotypic space, while other genotypic rearrangements represent long-range jumps. We investigate the spreading properties of an initially homogeneous population in a flat fitness landscape, and the equilibrium properties on a smooth fitness landscape. We show that a small-world effect is present: even a small fraction of quenched long-range jumps makes the results indistinguishable from those obtained by assuming all mutations equiprobable. Moreover, we find that the equilibrium distribution is a Boltzmann one, in which the fitness plays the role of an energy, and mutations that of a temperature.Comment: 13 pages and 5 figures. New revised versio
    corecore