535 research outputs found

    Understory influence on leafroller pupunations in Hawke's bay organic apple orchard

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    Leafrollers (Tortricidae) were collected from apple foliage and understorey vegetation in six commercial organic apple orchards in Hawke’s Bay over one season. Assessments were made of plant species present in the understorey at the time of collection. All leafroller larvae were reared to adults on artificial diet to identify leafroller species and parasitoids. Nearly half (47%) of all leafrollers collected in these orchards were located in the understorey, highlighting the importance of understorey and its management for the control of leafroller. Dock, clover and dandeliontype plants contributed 25% to the overall understorey, yet hosted 75% of the leafrollers collected from the understorey. Dolichogenidea sp. was the most abundant parasitoid (79%) attacking leafrollers found amongst the apple foliage, whereas Glyptapanteles demeter was dominant in the understorey (61%). Generally the number of leafrollers in an orchard was proportional to the abundance of broadleaf weeds and inversely proportional to parasitis

    Nearby early-type galaxies with ionized gas. The UV emission from GALEX observations

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    We present GALEX far-ultraviolet (FUV, λeff\lambda_{eff}=1538 \AA) and near-ultraviolet (NUV, λeff\lambda_{eff}=2316 \AA) surface photometry of 40 early-type galaxies (ETGs) selected from a wider sample of 65 nearby ETGs showing emission lines in their optical spectra. We derive FUV and NUV surface brightness profiles, (FUV-NUV) colour profiles and D25_{25} integrated magnitudes. We extend the photometric study to the optical {\it r} band from SDSS imaging for 14 of these ETGs. In general, the (FUV-NUV) radial colour profiles become redder with galactocentric distance in both rejuvenated (4\leq 4 Gyr) and old ETGs. Colour profiles of NGC 1533, NGC 2962, NGC 2974, NGC 3489, and IC 5063 show rings and/or arm-like structures, bluer than the body of the galaxy, suggesting the presence of recent star formation. Although seven of our ETGs show shell systems in their optical image, only NGC 7135 displays shells in the UV bands. We characterize the UV and optical surface brightness profiles, along the major axis, using a Sersic law. The Sersic law exponent, nn, varies from 1 to 16 in the UV bands. S0 galaxies tend to have lower values of nn (5\leq5). The Sersic law exponent n=4n=4 seems to be a watershed: ETGs with n>4n>4 tend to have [α\alpha/Fe] greater than 0.15, implying a short star-formation time scale. We find a significant correlation between the FUV-NUV colour and central velocity dispersions σ\sigma, with the UV colours getting bluer at larger σ\sigma. This trend is likely driven by a combined effect of `downsizing' and of the mass-metallicity relation.Comment: Accepted for publication in MNRAS, 33 pages, 7 figure

    Analytical results for coupled map lattices with long-range interactions

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    We obtain exact analytical results for lattices of maps with couplings that decay with distance as rαr^{-\alpha}. We analyze the effect of the coupling range on the system dynamics through the Lyapunov spectrum. For lattices whose elements are piecewise linear maps, we get an algebraic expression for the Lyapunov spectrum. When the local dynamics is given by a nonlinear map, the Lyapunov spectrum for a completely synchronized state is analytically obtained. The critical lines characterizing the synchronization transition are determined from the expression for the largest transversal Lyapunov exponent. In particular, it is shown that in the thermodynamical limit, such transition is only possible for sufficiently long-range interactions, namely, for αalphac<d\alpha\le alpha_c<d, where dd is the lattice dimension.Comment: 4 pages, 2 figures, corrections included. Phys. Rev. E 68, 045202(R) (2003); correction in pres

    Processing of ultrafine-size particulate metal matrix composites by advanced shear technology

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    Copyright @ 2009 ASM International. This paper was published in Metallurgical & Materials Transactions A 40A(3) and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.Lack of efficient mixing technology to achieve a uniform distribution of fine-size reinforcement within the matrix and the high cost of producing components have hindered the widespread adaptation of particulate metal matrix composites (PMMCs) for engineering applications. A new rheo-processing method, the melt-conditioning high-pressure die-cast (MC-HPDC) process, has been developed for manufacturing near-net-shape components of high integrity. The MC-HPDC process adapts the well-established high shear dispersive mixing action of a twin-screw mechanism to the task of overcoming the cohesive force of the agglomerates under a high shear rate and high intensity of turbulence. This is followed by direct shaping of the slurry into near-net-shape components using an existing cold-chamber die-casting process. The results indicate that the MC-HPDC samples have a uniform distribution of ultrafine-sized SiC particles throughout the entire sample in the as-cast condition. Compared to those produced by conventional high-pressure die casting (HPDC), MC-HPDC samples have a much improved tensile strength and ductility.EP-SR

    Politieke kennis en effecten van nieuws

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    Welk nieuws doet ertoe en hoeveel nieuws doet ertoe, en in welke mate hangt dit af van de politieke kennis van de ontvanger? Dit artikel beschrijft een longitudinale studie naar de verkiezingsstrijd voor het Nederlandse parlement in 2006

    Structural, electronic, and magneto-optical properties of YVO3_3

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    Optical and magneto-optical properties of YVO3_3 single crystal were studied in FIR, visible, and UV regions. Two structural phase transitions at 75 K and 200 K were observed and established to be of the first and second order, respectively. The lattice has an orthorhombic PbnmPbnm symmetry both above 200 K as well as below 75 K, and is found to be dimerized monoclinic Pb11Pb11 in between. We identify YVO3_3 as a Mott-Hubbard insulator with the optical gap of 1.6 eV. The electronic excitations in the visible spectrum are determined by three dd-bands at 1.8, 2.4, and 3.3 eV, followed by the charge-transfer transitions at about 4 eV. The observed structure is in good agreement with LSDA+UU band structure calculations. By using ligand field considerations, we assigned these bands to the transitions to the 4A2g^4A_{2g}, 2Eg+2T1g^2E_{g} + ^2T_{1g}, and 2T2g^2T_{2g} states. The strong temperature dependence of these bands is in agreement with the formation of orbital order. Despite the small net magnetic moment of 0.01 μB\mu_B per vanadium, the Kerr effect of the order of 0.010.01^\circ was observed for all three dd-bands in the magnetically ordered phase TNeˊel<116KT_{\text{N\'eel}}<116 K. A surprisingly strong enhancement of the Kerr effect was found below 75 K, reaching a maximum of 0.10.1^\circ. The effect is ascribed to the non-vanishing net orbital magnetic moment.Comment: Submitted to Phys. Rev.

    Interrogating trans and sexual identities through the conceptual lens of translocational positionality

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    This article explores the confluence of trans identity and sexuality drawing on the concept of translocational positionality. In this discussion, a broad spectrum of gendered positionalities incorporates trans identity which, in turn, acknowledges normative male and female identities as well as non-binary ones. It is also recognised, however, that trans identity overlaps with other positionalities (pertaining to sexuality, for example) to shape social location. In seeking to understand subject positions, a translocational lens acknowledges the contextuality and temporality of social categories to offer an analysis which recognises the overlaps and differentials of co-existing positionalities. This approach enables an analysis which explores how macro, or structural, contexts shape agency (at the micro-level) and also how both are mediated by trans people's multiple and shifting positionalities. In this framing, positionality represents a meso layer between structure and agency. Four case studies are presented using data from a qualitative study which explored trans people's experiences of family, intimacy and domestic abuse. We offer an original contribution to the emerging knowledge-base on trans sexuality by presenting data from four case studies. We do so whilst innovatively applying the conceptual lens of translocational positionality to an analysis which considers macro, meso and micro levels of influence

    Water quality study of the Muchea livestock truck wash

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    Across Australia there is a lack of information on the quality of the water discharged from facilities that are used to wash livestock trucks. This water quality scoping study partially fills that information gap and provides a starting point for future planning, design and construction of livestock truck washes. The study was undertaken in 2011–12 at the Western Australian Muchea Livestock Centre, and aimed to gain insights into water quality associated with the truck wash facility at that site. These insights can help to inform the planning for further construction of truck wash facilities throughout the state, and whether disposing wastewater to Water Corporation’s sewerage system could be part of a new facility. We examined water quality at primary points of the wastewater treatment system to understand the impact of each part of the system and determine the most appropriate site for detailed temporal monitoring. This was followed by a two-day sampling program at one point in the treatment system. We concluded that the minimum infrastructure requirements to satisfy Water Corporation’s maximum allowable limits for disposal to the sewerage system include sieve bend screens (Hunter screens), an anaerobic or settling pond, and a holding pond to ensure sufficient safety margins if sewer disposal was ever delayed. We recommend that further consideration is given to estimating the capital and operational costs of a truck wash facility that meets these minimum requirements, compared to a closed system that retains all wastewater on-site, or other systems that recover nutrients from high-value products. We also recommend that a sampling program be conducted across all truck washes in WA to gain insight into possible geographical variations and the wider applicability of this study’s findings

    Self-help groups challenge health care systems in the US and UK

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    Purpose: This research considers how self-help groups (SHGs) and self- help organizations (SHOs) contribute to consumerist trends in two different societies: United States and United Kingdom. How do the health care systems and the voluntary sectors affect the kinds of social changes that SHGs/SHOs make? Methodology/approach: A review of research on the role of SHGs/SHOs in contributing to national health social movements in the UK and US was made. Case studies of the UK and the US compare the characteristics of their health care systems and their voluntary sector. Research reviews of two community level self-help groups in each country describe the kinds of social changes they made. Findings: The research review verified that SHGs/SHOs contribute to national level health social movements for patient consumerism. The case studies showed that community level SHGs/SHOs successfully made the same social changes but on a smaller scale as the national movements, and the health care system affects the kinds of community changes made. Research limitations: A limited number of SHGs/SHOs within only two societies were studied. Additional SHGs/SHOs within a variety of societies need to be studied. Originality/value of chapter Community SHGs/SHOs are often trivialized by social scientists as just inward-oriented support groups, but this chapter shows that local groups contribute to patient consumerism and social changes but in ways that depend on the kind of health care system and societal context
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