4,333 research outputs found

    Root Weevil (Coleoptera: Curculionidae) and Ground Beetle (Coleoptera: Carabidae) Immigration into Strawberry Plots Protected by Fence or Portable Trench Barriers

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    Physical exclusion shows some potential as a novel root weevil control strategy, but barriers to root weevil immigration may also exclude beneficial insects, such as ground beetles. A field study was undertaken in 1997 to assess the impact of two physical barriers—portable plastic trenches and aluminum fences with Teflon tape—on root weevil and ground beetle immigration into plots of strawberry, Fragaria x ananassa (Duchesne). Barypeithes pellucidus (Boheman) and Nemocestes incomptus (Horn), each comprised 43% of the root weevils caught at the site. Most (86%) of the ground beetles caught in control plots were longer than 1 cm, the width of the gap in the portable trench top. Trenches excluded 75 and 63% of B. pellucidus and N. incomptus, respectively, without significantly reducing immigration of large (<1 cm) ground beetles. Fences excluded 65, 84, and 99% of B. pellucidus, N. incomptus, and large ground beetles, respectively. Adding diatomaceous earth to trenches did not increase their efficacy, and fences without Teflon tape excluded ground beetles but not root weevils. The reduction in the population of root weevils and other strawberry pests caused by the use of barriers reduced damage to strawberry plant leaves and increased strawberry plant survival relative to unprotected control plots. Advantages and disadvantages of these physical control tools are discussed with a view to creating superior tools for root weevil exclusion, compatible with an integrated pest management approach. Portable trenches may offer a means of selectively excluding root weevils but not ground beetles

    Moisture tempers impairment of adult Otiorhynchus sulcatus (Coleoptera: Curculionidae) climbing ability by fluoropolymer, talc dust, and lithium grease

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    As part of a project to develop tools for the physical exclusion of flightless root weevils, adult black vine weevils (BVW), Otiorhynchus sulcatus (F.), were placed in open enclosures with smooth walls of glass, plastic or aluminum to test their ability to escape by climbing. Enclosure walls were left untreated or were treated with substances known to reduce insect climbing ability: fluoropolymer, powdered talc and lithium grease. No BVW escapes were observed under dry conditions, but all treatments allowed some escapes under wet conditions, suggesting that moisture helps BVW adults scale treated surfaces. The results help explain the ability of root weevils to overcome physical barriers under field conditions

    Importance of Collection Overhangs on the Efficacy of Exclusion Fences for Managing Cabbage Flies (Diptera: Anthomyiidae)

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    Fine nylon mesh fences (135 cm high) with varying lengths of downward-sloping collection overhangs were evaluated for efficacy in excluding the female cabbage flies Delia radicum (L.) from plots of radish, Raphanus sativus (L.). During three trials conducted in 1994 and 1995, fences without overhangs, fences with 12.5-cm overhangs, or fences with 50-cm overhangs were tested against fences with standard 25-cm overhangs and unfenced control plots. In fenced plots with standard 25-cm overhangs, the mean number of D. radicum females caught on yellow sticky traps placed within plots was 85% less than those caught in corresponding control plots. The mean numbers of D. radicum females caught in fenced enclosures with no overhangs, 12.5-cm overhangs, or 50-cm overhangs, were 61, 67, and 94% less than those caught in corresponding control plots, respectively. The mean proportion of radishes damaged by D. radicum larvae inside enclosures with 25-cm overhangs was 62% less than in corresponding control plots. The mean proportions of radishes damaged inside fences with no overhangs, 12.5-cm overhangs, or 50-cm overhangs were 33, 59, and 81% less than those caught in corresponding control plots, respectively. Results are discussed in terms of defining an appropriate fence design for commercial use

    Pros and Cons of Adjuvant Interferon in the Treatment of Melanoma

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139970/1/onco0451.pd

    Moisture tempers impairment of adult Otiorhynchus sulcatus (Coleoptera: Curculionidae) climbing ability by fluoropolymer, talc dust, and lithium grease

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    As part of a project to develop tools for the physical exclusion of flightless root weevils, adult black vine weevils (BVW), Otiorhynchus sulcatus (F.), were placed in open enclosures with smooth walls of glass, plastic or aluminum to test their ability to escape by climbing. Enclosure walls were left untreated or were treated with substances known to reduce insect climbing ability: fluoropolymer, powdered talc and lithium grease. No BVW escapes were observed under dry conditions, but all treatments allowed some escapes under wet conditions, suggesting that moisture helps BVW adults scale treated surfaces. The results help explain the ability of root weevils to overcome physical barriers under field conditions

    Electronic and structural properties of grain boundaries in electron-irradiated edge-defined film-fed growth silicon

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    Edge-defined film-fed growth (EFG) is an economical method of producing multicrystalline silicon ribbon for solar cells. Such silicon is heavily doped with carbon. After electron irradiation, the dominant defect found in this material is the G centre, which is associated with the CsCi defect. In this paper, the techniques of scanning cathodoluminescence and electron backscattered diffraction pattern analysis are used to correlate the luminescence from the G centre with the grain boundary structure in electron-irradiated EFG silicon. A localised enhancement of G centre luminescence is found near twin boundaries at temperatures above 20K, whereas no such enhancement is found near low angle grain boundaries at temperatures up to 80K or at twin boundaries below 20K. This behaviour may be caused by thermal ionisation of excitons from traps at the twin boundaries, and their subsequent capture at G centres.</p

    Neutrino mass hierarchy and octant determination with atmospheric neutrinos

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    The recent discovery by the Daya-Bay and RENO experiments, that \theta_{13} is nonzero and relatively large, significantly impacts existing experiments and the planning of future facilities. In many scenarios, the nonzero value of \theta_{13} implies that \theta_{23} is likely to be different from \pi/4. Additionally, large detectors will be sensitive to matter effects on the oscillations of atmospheric neutrinos, making it possible to determine the neutrino mass hierarchy and the octant of \theta_{23}. We show that a 50 kT magnetized liquid argon neutrino detector can ascertain the mass hierarchy with a significance larger than 4 sigma with moderate exposure times, and the octant at the level of 2-3 sigma with greater exposure.Comment: 4 pages, 4 figures. Version published in Phys. Rev. Let

    Ocean acidification increases copper toxicity differentially in two key marine invertebrates with distinct acid-base responses.

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    Published onlineJournal ArticleOcean acidification (OA) is expected to indirectly impact biota living in contaminated coastal environments by altering the bioavailability and potentially toxicity of many pH-sensitive metals. Here, we show that OA (pH 7.71; pCO2 1480 μatm) significantly increases the toxicity responses to a global coastal contaminant (copper ~0.1 μM) in two keystone benthic species; mussels (Mytilus edulis) and purple sea urchins (Paracentrotus lividus). Mussels showed an extracellular acidosis in response to OA and copper individually which was enhanced during combined exposure. In contrast, urchins maintained extracellular fluid pH under OA by accumulating bicarbonate but exhibited a slight alkalosis in response to copper either alone or with OA. Importantly, copper-induced damage to DNA and lipids was significantly greater under OA compared to control conditions (pH 8.14; pCO2 470 μatm) for both species. However, this increase in DNA-damage was four times lower in urchins than mussels, suggesting that internal acid-base regulation in urchins may substantially moderate the magnitude of this OA-induced copper toxicity effect. Thus, changes in metal toxicity under OA may not purely be driven by metal speciation in seawater and may be far more diverse than either single-stressor or single-species studies indicate. This has important implications for future environmental management strategies.CL was supported by a Natural Environment Research Council (NERC) UK Fellowship: NE/G014728/1. CL, RE and RW were supported by a UK-OARP NERC consortium grant NE/H017496/1. SN was supported by a Cefas-Exeter funded studentship. Thanks to Jan Shears, Darren Rowe and John Dowdle for their excellent technical support. The determination of total copper in the seawater media was undertaken by Dr. A. Fisher of the Analytical Research Facility, SoGEES, Plymouth University under ISO 9001:2008 certification. The authors would like to thank John Spicer for his insightful comments on the manuscript
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