32 research outputs found

    New live screening of plant-nematode interactions in the rhizosphere

    Get PDF
    Abstract Free living nematodes (FLN) are microscopic worms found in all soils. While many FLN species are beneficial to crops, some species cause significant damage by feeding on roots and vectoring viruses. With the planned legislative removal of traditionally used chemical treatments, identification of new ways to manage FLN populations has become a high priority. For this, more powerful screening systems are required to rapidly assess threats to crops and identify treatments efficiently. Here, we have developed new live assays for testing nematode responses to treatment by combining transparent soil microcosms, a new light sheet imaging technique termed Biospeckle Selective Plane Illumination Microscopy (BSPIM) for fast nematode detection, and Confocal Laser Scanning Microscopy for high resolution imaging. We show that BSPIM increased signal to noise ratios by up to 60 fold and allowed the automatic detection of FLN in transparent soil samples of 1.5 mL. Growing plant root systems were rapidly scanned for nematode abundance and activity, and FLN feeding behaviour and responses to chemical compounds observed in soil-like conditions. This approach could be used for direct monitoring of FLN activity either to develop new compounds that target economically damaging herbivorous nematodes or ensuring that beneficial species are not negatively impacted

    Hypofrontality in Schizophrenia. A meta-analysis of functional imaging studies

    Get PDF
    The definitive version is available at www.blackwell-synergy.com '--Copyright Blackwell PublishingObjective: Hypofrontality is not a well-replicated finding in schizophrenia either at rest or under conditions of task activation. Method: Studies comparing whole brain and frontal blood flow/ metabolism in schizophrenic patients and normal controls were pooled.Voxel-based studies were also combined to examine the pattern of prefrontal activation in schizophrenia. Results: Whole brain flow/metabolism was reduced in schizophrenia to only a small extent.Restin g and activation frontal flow/metabolism were both reduced with a medium effect size.Duration of illness significantly moderated resting hypofrontality, but the moderating effects of neuroleptic treatment were consistent with an influence on global flow/metabolism only.Pooling of voxel-based studies did not suggest an abnormal pattern of activation in schizophrenia. Conclusion: Meta-analysis supports resting hypofrontality in schizophrenia.Task-activated hypofrontality is also supported, but there is little from voxel-based studies to suggest that this is associated with an altered pattern of regional functional architecture.Peer reviewe
    corecore