23 research outputs found

    A comparision of GHG emissions from UK field crop production under selected arable systems with reference to disease control

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    Crop disease not only threatens global food security by reducing crop production at a time of growing demand, but also contributes to greenhouse gas (GHG) emissions by reducing efficiency of N fertiliser use and farm operations and by driving land use change. GHG emissions associated with adoption of reduced tillage, organic and integrated systems of field crop production across the UK and selected regions are compared with emissions from conventional arable farming to assess their potential for climate change mitigation. The reduced tillage system demonstrated a modest (<20%) reduction in emissions in all cases, although in practice it may not be suitable for all soils and it is likely to cause problems with control of diseases spread on crop debris. There were substantial increases in GHG emissions associated with the organic and integrated systems at national level, principally due to soil organic carbon losses from land use change. At a regional level the integrated system shows the potential to deliver significant emission reductions. These results indicate that the conventional crop production system, coupled to reduced tillage cultivation where appropriate, is generally the best for producing high yields to minimise greenhouse gas emissions and contribute to global food security, although there may be scope for use of the integrated system on a regional basis. The control of crop disease will continue to have an essential role in both maintaining productivity and decreasing GHG emissions.Peer reviewe

    Abstracts of presentations on selected topics at the XIVth international plant protection congress (IPPC) July 25-30, 1999

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    A Glycoprotein in Shells of Conspecifics Induces Larval Settlement of the Pacific Oyster Crassostrea gigas

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    Settlement of larvae of Crassostrea gigas on shell chips (SC) prepared from shells of 11 different species of mollusks was investigated. Furthermore, the settlement inducing compound in the shell of C. gigas was extracted and subjected to various treatments to characterize the chemical cue. C. gigas larvae settled on SC of all species tested except on Patinopecten yessoensis and Atrina pinnata. In SC of species that induced C. gigas larvae to settle, settlement was proportionate to the amount of SC supplied to the larvae. When compared to C. gigas SC, all species except Crassostrea nippona showed lower settlement inducing activities, suggesting that the cue may be more abundant or in a more available form to the larvae in shells of conspecific and C. nippona than in other species. The settlement inducing activity of C. gigas SC remained intact after antibiotic treatment. Extraction of C. gigas SC with diethyl ether (Et2O-ex), ethanol (EtOH-ex), and water (Aq-ex) did not induce larval settlement of C. gigas larvae. However, extraction of C. gigas SC with 2N of hydrochloric acid (HCl-ex) induced larval settlement that was at the same level as the SC. The settlement inducing compound in the HCl-ex was stable at 100°C but was destroyed or degraded after pepsin, trypsin, PNGase F and trifluoromethanesulfonic acid treatments. This chemical cue eluted between the molecular mass range of 45 and 150 kDa after gel filtration and revealed a major band at 55 kDa on the SDS-PAGE gel after staining with Stains-all. Thus, a 55 kDa glycoprotein component in the organic matrix of C. gigas shells is hypothesized to be the chemical basis of larval settlement on conspecifics

    Climate Change, Coral Reef Ecosystems, and Management Options for Marine Protected Areas

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    Marine protected areas (MPAs) provide place-based management of marine ecosystems through various degrees and types of protective actions. Habitats such as coral reefs are especially susceptible to degradation resulting from climate change, as evidenced by mass bleaching events over the past two decades. Marine ecosystems are being altered by direct effects of climate change including ocean warming, ocean acidification, rising sea level, changing circulation patterns, increasing severity of storms, and changing freshwater influxes. As impacts of climate change strengthen they may exacerbate effects of existing stressors and require new or modified management approaches; MPA networks are generally accepted as an improvement over individual MPAs to address multiple threats to the marine environment. While MPA networks are considered a potentially effective management approach for conserving marine biodiversity, they should be established in conjunction with other management strategies, such as fisheries regulations and reductions of nutrients and other forms of land-based pollution. Information about interactions between climate change and more “traditional” stressors is limited. MPA managers are faced with high levels of uncertainty about likely outcomes of management actions because climate change impacts have strong interactions with existing stressors, such as land-based sources of pollution, overfishing and destructive fishing practices, invasive species, and diseases. Management options include ameliorating existing stressors, protecting potentially resilient areas, developing networks of MPAs, and integrating climate change into MPA planning, management, and evaluation

    PHOTOSYNTHESIS AND RESPIRATION IN TRIDACNA GIGAS AS A FUNCTION OF IRRADIANCE AND SIZE

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    Volume: 169Start Page: 230End Page: 24

    Preliminary Evaluation of a Multimodal Early Intervention Program for Behaviorally Inhibited Preschoolers

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    OBJECTIVE: Approximately 15–20 percent of young children can be classified as having a behaviorally inhibited (BI) temperament. Stable BI predicts the development of later anxiety disorders (particularly social anxiety), but not all inhibited children develop anxiety. Parenting characterized by inappropriate warmth/sensitivity and/or intrusive control predicts the stability of BI and moderates risk for anxiety among high-BI children. For these reasons, we developed and examined the preliminary efficacy of the Turtle Program: a multi-modal early intervention for inhibited preschool-aged children. METHOD: Forty inhibited children between the ages of 42–60 months and their parent(s) were randomized to either the Turtle Program (n = 18) or a waitlist control condition (WLC; n = 22). Participants randomized to the Turtle Program condition received 8 weeks of concurrent parent and child group treatment. Participants were assessed at baseline and post-treatment with multi-source assessments, including parent and teacher report measures of child anxiety, diagnostic interviews, and observations of parenting behavior. RESULTS: The Turtle Program resulted in significant beneficial effects relative to the WLC condition on maternal-reported anxiety symptoms of medium to large magnitude; large effects on parent-reported BI; medium to large effects on teacher-rated school anxiety symptoms; and medium effects on observed maternal positive affect/sensitivity. CONCLUSIONS: This study provides encouraging preliminary support for the Turtle Program for young behaviorally inhibited children. Importantly, the effects of the Turtle Program generalized to the school setting. Future studies should examine whether this early intervention program improves long-term developmental outcomes for these at-risk children
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