5,070 research outputs found

    Civil protective orders effective in stopping or reducing partner violence: challenges remain in rural areas with access and enforcement

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    Civil protective orders are a low cost, effective solution in either stopping or significantly reducing partner violence for women. While all women benefit from civil protective orders, this brief finds there are greater obstacles to enforcement in rural places, which result in less benefit for rural than urban women. The authors suggest that policies and services should be tailored to address community-specific barriers and differences such as hours of access, time it takes to obtain or serve an order, and access to information about the process

    Spectral scaling and quantum critical behaviour in the pseudogap Anderson model

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    The pseudogap Anderson impurity model provides a classic example of an essentially local quantum phase transition. Here we study its single-particle dynamics in the vicinity of the symmetric quantum critical point (QCP) separating generalized Fermi liquid and local moment phases, via the local moment approach. Both phases are shown to be characterized by a low-energy scale that vanishes at the QCP; and the universal scaling spectra, on all energy scales, are obtained analytically. The spectrum precisely at the QCP is also obtained; its form showing clearly the non-Fermi liquid, interacting nature of the fixed point.Comment: 7 pages, 2 figure

    Single-particle dynamics of the Anderson model: a local moment approach

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    A non-perturbative local moment approach to single-particle dynamics of the general asymmetric Anderson impurity model is developed. The approach encompasses all energy scales and interaction strengths. It captures thereby strong coupling Kondo behaviour, including the resultant universal scaling behaviour of the single-particle spectrum; as well as the mixed valent and essentially perturbative empty orbital regimes. The underlying approach is physically transparent and innately simple, and as such is capable of practical extension to lattice-based models within the framework of dynamical mean-field theory.Comment: 26 pages, 9 figure

    Ecological Effects of Fear: How Spatiotemporal Heterogeneity in Predation Risk Influences Mule Deer Access to Forage in a Sky‐Island System

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    Forage availability and predation risk interact to affect habitat use of ungulates across many biomes. Within sky‐island habitats of the Mojave Desert, increased availability of diverse forage and cover may provide ungulates with unique opportunities to extend nutrient uptake and/or to mitigate predation risk. We addressed whether habitat use and foraging patterns of female mule deer (Odocoileus hemionus) responded to normalized difference vegetation index (NDVI), NDVI rate of change (green‐up), or the occurrence of cougars (Puma concolor). Female mule deer used available green‐up primarily in spring, although growing vegetation was available during other seasons. Mule deer and cougar shared similar habitat all year, and our models indicated cougars had a consistent, negative effect on mule deer access to growing vegetation, particularly in summer when cougar occurrence became concentrated at higher elevations. A seemingly late parturition date coincided with diminishing NDVI during the lactation period. Sky‐island populations, rarely studied, provide the opportunity to determine how mule deer respond to growing foliage along steep elevation and vegetation gradients when trapped with their predators and seasonally limited by aridity. Our findings indicate that fear of predation may restrict access to the forage resources found in sky islands

    Local quantum phase transition in the pseudogap Anderson model: scales, scaling and quantum critical dynamics

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    The pseudogap Anderson impurity model provides a paradigm for understanding local quantum phase transitions, in this case between generalised fermi liquid and degenerate local moment phases. Here we develop a non-perturbative local moment approach to the generic asymmetric model, encompassing all energy scales and interaction strengths and leading thereby to a rich description of the problem. We investigate in particular underlying phase boundaries, the critical behaviour of relevant low-energy scales, and single-particle dynamics embodied in the local spectrum. Particular attention is given to the resultant universal scaling behaviour of dynamics close to the transition in both the GFL and LM phases, the scale-free physics characteristic of the quantum critical point itself, and the relation between the two.Comment: 39 pages, 19 figure

    Finite temperature dynamics of the Anderson model

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    The recently introduced local moment approach (LMA) is extended to encompass single-particle dynamics and transport properties of the Anderson impurity model at finite-temperature, T. While applicable to arbitrary interaction strengths, primary emphasis is given to the strongly correlated Kondo regime (characterized by the T=0 Kondo scale ωK\omega_{\rm K}). In particular the resultant universal scaling behaviour of the single-particle spectrum D(\omega; T) \equiv F(\frac{\w}{\omega_{\rm K}}; \frac{T}{\omega_{\rm K}}) within the LMA is obtained in closed form; leading to an analytical description of the thermal destruction of the Kondo resonance on all energy scales. Transport properties follow directly from a knowledge of D(ω;T)D(\omega; T). The T/ωKT / \omega_{\rm K}-dependence of the resulting resistivity ρ(T)\rho(T), which is found to agree rather well with numerical renormalization group calculations, is shown to be asymptotically exact at high temperatures; to concur well with the Hamann approximation for the s-d model down to T/ωK1T/\omega_{\rm K} \sim 1, and to cross over smoothly to the Fermi liquid form ρ(T)ρ(0)(T/ωK)2\rho (T) - \rho (0) \propto -(T/\omega_{\rm K})^2 in the low-temperature limit. The underlying approach, while naturally approximate, is moreover applicable to a broad range of quantum impurity and related models

    A longitudinal study of the development of expressive timing

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    Tempo arches have often been reported in polished music performances, but their development during the learning of a new piece has not been studied. We examined the development of expressive timing at three levels of musical structure (piece, section, phrase) as an experienced concert soloist (the second author) prepared the Prelude from J. S. Bach’s Suite No. 6 for solo cello for public performance. We used mixed effect models to assess the development of expressive timing and the effects of the performance cues (PCs) that the cellist used as mental landmarks to guide her performance. Tempo arches appeared early in practice at all three levels of musical structure and changed over time in complex ways, first becoming more pronounced and more asymmetrical and then shrinking somewhat in later performances. Arches were also more pronounced in phrases that contained PCs, suggesting that PCs reminded the cellist where to “breathe” between phrases. The early development of tempo arches suggests that they were an automatic product of basic cognitive or motor processes. The complex trajectory of their later development appeared to be the result, at least in part, of a deliberate communicative strategy intended to draw listeners’ attention to some musical boundaries more than others

    Principles of Discrete Time Mechanics: II. Classical field Theory

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    We apply the principles discussed in an earlier paper to the construction of discrete time field theories. We derive the discrete time field equations of motion and Noether's theorem and apply them to the Schrodinger equation to illustrate the methodology. Stationary solutions to the discrete time Schrodinger wave equation are found to be identical to standard energy eigenvalue solutions except for a fundamental limit on the energy. Then we apply the formalism to the free neutral Klein Gordon system, deriving the equations of motion and conserved quantities such as the linear momentum and angular momentum. We show that there is an upper bound on the magnitude of linear momentum for physical particle-like solutions. We extend the formalism to the charged scalar field coupled to Maxwell's electrodynamics in a gauge invariant way. We apply the formalism to include the Maxwell and Dirac fields, setting the scene for second quantisation of discrete time mechanics and discrete time Quantum Electrodynamics.Comment: 23 pages, LateX, To be published in J.Phys.A: Math.Gen: contact email address: [email protected]

    Penerapan Model Pengajaran Langsung dengan Assessment Project Work sebagai Upaya Peningkatan Motivasi dan Hasil Belajar Menggambar Kelas XI SMKN 3 Sendawar Kutai Barat

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    This research aims to find the improvement of the students\u27 motivation, study result and learning activities in the drawing materials of door frame, door, and wood window after the students are given the direct leaming model by using Project Work Assessment to improve students\u27 drawing motivation and study result at eleventh grade of SMK Negeri 3 Sendawar Kutai Barat. The research in this thesis uses classroom action research by using descriptive quantitative analysis in two cycles. There are 12 students of eleventh grade become the subject of the research. The instruments used to collect the data are questionnaire for students\u27 learning motivation, project assessment, and observation sheet for students\u27 activities. The results of the research are: (1) the students\u27 learning motivation is 75% in the first cycle and it becomes 91.67% in the second cycle; (2) the students; learning result in their spiritual attitude is in a good category. It is 53.33% in the first cycle and it becomes 83.33% in the second cycle. the students\u27 social aspect is in good category. It is 66.67% in the first cycle and it becomes 91.67% in the second cycle. The classical achievement in the skill aspect is 66.67% in the first cycle and it becomes 91.67% in the second cycle; (3) The improvement of the students\u27 leaming activities is in the category of the most dominant. The students do the drawing assignment for 87.50% in the first cycle and it becomes 97.92% in the second cycles. The minimal activity which is conducted by the students is asking the questions to the teacher. It is 20.83% in the first cycle and it becomes 37.50% in the second cycle. Keywords: Building Construction Drawing, Motivation, Activities, Study Result

    A Local Moment Approach to magnetic impurities in gapless Fermi systems

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    A local moment approach is developed for the single-particle excitations of a symmetric Anderson impurity model (AIM), with a soft-gap hybridization vanishing at the Fermi level with a power law r > 0. Local moments are introduced explicitly from the outset, and a two-self-energy description is employed in which the single-particle excitations are coupled dynamically to low-energy transverse spin fluctuations. The resultant theory is applicable on all energy scales, and captures both the spin-fluctuation regime of strong coupling (large-U), as well as the weak coupling regime. While the primary emphasis is on single particle dynamics, the quantum phase transition between strong coupling (SC) and (LM) phases can also be addressed directly; for the spin-fluctuation regime in particular a number of asymptotically exact results are thereby obtained. Results for both single-particle spectra and SC/LM phase boundaries are found to agree well with recent numerical renormalization group (NRG) studies. A number of further testable predictions are made; in particular, for r < 1/2, spectra characteristic of the SC state are predicted to exhibit an r-dependent universal scaling form as the SC/LM phase boundary is approached and the Kondo scale vanishes. Results for the `normal' r = 0 AIM are moreover recovered smoothly from the limit r -> 0, where the resultant description of single-particle dynamics includes recovery of Doniach-Sunjic tails in the Kondo resonance, as well as characteristic low-energy Fermi liquid behaviour.Comment: 52 pages, 19 figures, submitted to Journal of Physics: Condensed Matte
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