Estimating the effects of Cry1F Bt-maize pollen on non-target Lepidoptera using a mathematical model of exposure

In farmland biodiversity, a potential risk to the larvae of non-target Lepidoptera from genetically modified (GM) Bt-maize expressing insecticidal Cry1 proteins is the ingestion of harmful amounts of pollen deposited on their host plants. A previous mathematical model of exposure quantified this risk for Cry1Ab protein. We extend this model to quantify the risk for sensitive species exposed to pollen containing Cry1F protein from maize event 1507 and to provide recommendations for management to mitigate this risk.A 14-parameter mathematical model integrating small- and large-scale exposure was used to estimate the larval mortality of hypothetical species with a range of sensitivities, and under a range of simulated mitigation measures consisting of non-Bt maize strips of different widths placed around the field edge.The greatest source of variability in estimated mortality was species sensitivity. Before allowance for effects of large-scale exposure, with moderate within-crop host-plant density and with no mitigation, estimated mortality locally was <10% for species of average sensitivity. For the worst-case extreme sensitivity considered, estimated mortality locally was 99·6% with no mitigation, although this estimate was reduced to below 40% with mitigation of 24-m-wide strips of non-Bt maize. For highly sensitive species, a 12-m-wide strip reduced estimated local mortality under 1·5%, when within-crop host-plant density was zero. Allowance for large-scale exposure effects would reduce these estimates of local mortality by a highly variable amount, but typically of the order of 50-fold.Mitigation efficacy depended critically on assumed within-crop host-plant density; if this could be assumed negligible, then the estimated effect of mitigation would reduce local mortality below 1% even for very highly sensitive species.Synthesis and applications. Mitigation measures of risks of Bt-maize to sensitive larvae of non-target lepidopteran species can be effective, but depend on host-plant densities which are in turn affected by weed-management regimes. We discuss the relevance for management of maize events where cry1F is combined (stacked) with a herbicide-tolerance trait. This exemplifies how interactions between biota may occur when different traits are stacked irrespective of interactions between the proteins themselves and highlights the importance of accounting for crop management in the assessment of the ecological impact of GM plants

EFSA GMO Panel guidance on the evaluation of potential adverse effects of GM plants on non-target organisms

In November 2010, the Panel on Genetically Modified Organisms (GMO Panel) of the European Food Safety Authority (EFSA) issued a Scientific Opinion (SO) that delivers guidance on the environmental risk assessment (ERA) of genetically modified (GM) plants. Beside the ERA SO, the EFSA GMO Panel developed a separate SO that provides specific guidance for the evaluation of potential adverse effects of GM plants on non-target organisms (NTOs). This paper describes some elements of the ERA SO and NTO SO pertaining to NTO risk assessment, with a focus on: (1) problem formulation; (2) protection goals and limits of concern; (3) intended and unintended effects; (4) species selection for testing purposes; and (5) stacked transformation events. Some scientific comments from EU Member States and stakeholders received during the development of both documents through public consultations are also presented

Quantitative analysis of disfluency in children with autism spectrum disorder or language impairment

<div><p>Deficits in social communication, particularly pragmatic language, are characteristic of individuals with autism spectrum disorder (ASD). Speech disfluencies may serve pragmatic functions such as cueing speaking problems. Previous studies have found that speakers with ASD differ from typically developing (TD) speakers in the types and patterns of disfluencies they produce, but fail to provide sufficiently detailed characterizations of the methods used to categorize and quantify disfluency, making cross-study comparison difficult. In this study we propose a simple schema for classifying major disfluency types, and use this schema in an exploratory analysis of differences in disfluency rates and patterns among children with ASD compared to TD and language impaired (SLI) groups. 115 children ages 4–8 participated in the study (ASD = 51; SLI = 20; TD = 44), completing a battery of experimental tasks and assessments. Measures of morphological and syntactic complexity, as well as word and disfluency counts, were derived from transcripts of the Autism Diagnostic Observation Schedule (ADOS). High inter-annotator agreement was obtained with the use of the proposed schema. Analyses showed ASD children produced a higher ratio of content to filler disfluencies than TD children. Relative frequencies of repetitions, revisions, and false starts did not differ significantly between groups. TD children also produced more cued disfluencies than ASD children.</p></div

Number of disfluencies by type and group.

<p>Number of disfluencies by type and group.</p

Results for regression on content mazes versus fillers.

<p>Results for regression on content mazes versus fillers.</p

Percent of content mazes which are repetitions (versus revisions).

<p>Percent of content mazes which are repetitions (versus revisions).</p

Percent of mazes which are content mazes (versus fillers).

<p>Percent of mazes which are content mazes (versus fillers).</p

Results for regression on repetitions versus revisions.

<p>Results for regression on repetitions versus revisions.</p

Percent of content mazes which are cued by a filler (versus content mazes which are not cued).

<p>Percent of content mazes which are cued by a filler (versus content mazes which are not cued).</p

Percent of content mazes which are false starts (versus repetitions and revisions).

<p>Percent of content mazes which are false starts (versus repetitions and revisions).</p