Explore the vast range of titles available.

Signal crayfish, as an invasive alien species in Europe, have caused impacts on aquatic communities and losses of native crayfish. Eradication of recently established populations may be possible in small ponds (<2.5 ha) and short lengths of small watercourses using a nonselective biocide. Between 2004 and 2012, a total of 13 sites in the U.K. were assessed for suitability. Six were treated with natural pyrethrum and crayfish were successfully eradicated from three. In Norway, five sites were assessed and two sites were treated with a synthetic pyrethroid, cypermethrin, both successfully. In Sweden, three sites were treated with another synthetic pyrethroid, deltamethrin, all successfully. Defining the likely extent of population was critical in determining the feasibility of treatment, as well as the ability to treat the whole population effectively. Important constraints on projects included site size, habitat complexity, environmental risks, cooperation of landowners and funding availability. Successful projects were manageably small, had good project leadership, had cooperation from stakeholders, had access to resources and were carried out within one to three years. Factors influencing success included treating beyond the likely maximum geographical extent of the population and taking care to dose the treated area thoroughly (open water, plus the banks, margins, inflows and outflows). Recommendations are given on assessing the feasibility of biocide treatments and project-planning. crayfish; alien species; biological invasion; control; biocide; eradication; signal crayfish Pacifastacus leniusculus; natural pyrethrum; synthetic pyrethroid; toxicity

The introduction of non-indigenous crayfish into Europe is causing the loss of indigenous crayfish, due to transmission of crayfish plague and competition. Other factors are reductions of habitat quality and in some areas harvesting. This study deals with issues facing environmental agencies and other resource managers about how manage crayfish; from prevention of further introductions, to eradication where feasible, or control if it is cost-effective, or where it is not, then applying measures to mitigate the effects of invasion by finding or establishing isolated areas for indigenous crayfish, i.e. ark sites. It provides a range of decision-making tools for management. The study includes a literature-based risk assessment for non-indigenous crayfish in Great Britain. It presents the first evidence of the negative impact of signal crayfish Pacifastacus leniusculus on salmonid fish in a headwater stream. The study shows how the technique of biocide treatment against signal crayfish has developed, the outcomes and the lessons learned from the projects and factors that will contribute to other successful eradication treatments in future. Another new potential method for eradication or control is electric shock treatment, which was field-tested in this study. As an aid to assessing the feasibility of eradication or control, a simple cost-model was developed using the potential impact on salmonid fish and a re-stocking cost as a surrogate for environmental impact of crayfish invading a catchment. This was used to compare the costs of eradication or control and showed the benefit of early eradication and the unsustainably high cost of control by trapping. As signal crayfish are already widespread in England and Wales, risk-based selection criteria were developed to help identify potential ark sites for white-clawed crayfish. In addition, a decision-making tool has been prepared to help conservation managers understand the issue and develop conservation action plans at catchment scale.

BackgroundPrior studies of early antibiotic use and growth have shown mixed results, primarily on cross-sectional outcomes. This study examined the effect of oral antibiotics before age 24 months on growth trajectory at age 2–5 years.MethodsWe captured oral antibiotic prescriptions and anthropometrics from electronic health records through PCORnet, for children with ≥1 height and weight at 0–12 months of age, ≥1 at 12–30 months, and ≥2 between 25 and 72 months. Prescriptions were grouped into episodes by time and by antimicrobial spectrum. Longitudinal rate regression was used to assess differences in growth rate from 25 to 72 months of age. Models were adjusted for sex, race/ethnicity, steroid use, diagnosed asthma, complex chronic conditions, and infections.Results430,376 children from 29 health U.S. systems were included, with 58% receiving antibiotics before 24 months. Exposure to any antibiotic was associated with an average 0.7% (95% CI 0.5, 0.9, p < 0.0001) greater rate of weight gain, corresponding to 0.05 kg additional weight. The estimated effect was slightly greater for narrow-spectrum (0.8% [0.6, 1.1]) than broad-spectrum (0.6% [0.3, 0.8], p < 0.0001) drugs. There was a small dose response relationship between the number of antibiotic episodes and weight gain.ConclusionOral antibiotic use prior to 24 months of age was associated with very small changes in average growth rate at ages 2–5 years. The small effect size is unlikely to affect individual prescribing decisions, though it may reflect a biologic effect that can combine with others.

ObjectiveThe benefits of antibiotic treatment during pregnancy are immediate, but there may be long-term risks to the developing child. Prior studies show an association between early life antibiotics and obesity, but few have examined this risk during pregnancy.SubjectsTo evaluate the association of maternal antibiotic exposure during pregnancy on childhood BMI-z at 5 years, we conducted a retrospective cohort analysis. Using electronic health record data from seven health systems in PCORnet, a national distributed clinical research network, we included children with same-day height and weight measures who could be linked to mothers with vital measurements during pregnancy. The primary independent variable was maternal outpatient antibiotic prescriptions during pregnancy (any versus none). We examined dose response (number of antibiotic episodes), spectrum and class of antibiotics, and antibiotic episodes by trimester. The primary outcome was child age- and sex-specific BMI-z at age 5 years.ResultsThe final sample was 53,320 mother–child pairs. During pregnancy, 29.9% of mothers received antibiotics. In adjusted models, maternal outpatient antibiotic prescriptions during pregnancy were not associated with child BMI-z at age 5 years (β = 0.00, 95% CI −0.03, 0.02). When evaluating timing during pregnancy, dose-response, spectrum and class of antibiotics, there were no associations of maternal antibiotics with child BMI-z at age 5 years.ConclusionIn this large observational cohort, provision of antibiotics during pregnancy was not associated with childhood BMI-z at 5 years.

BackgroundPrivacy-protecting analytic approaches without centralized pooling of individual-level data, such as distributed regression, are particularly important for vulnerable populations, such as children, but these methods have not yet been tested in multi-center pediatric studies.MethodsUsing the electronic health data from 34 healthcare institutions in the National Patient-Centered Clinical Research Network (PCORnet), we fit 12 multivariable-adjusted linear regression models to assess the associations of antibiotic use <24 months of age with body mass index z-score at 48 to <72 months of age. We ran these models using pooled individual-level data and conventional multivariable-adjusted regression (reference method), as well as using the more privacy-protecting pooled summary-level intermediate statistics and distributed regression technique. We compared the results from these two methods.ResultsPooled individual-level and distributed linear regression analyses produced virtually identical parameter estimates and standard errors. Across all 12 models, the maximum difference in any of the parameter estimates or standard errors was 4.4833 × 10−10.ConclusionsWe demonstrated empirically the feasibility and validity of distributed linear regression analysis using only summary-level information within a large multi-center study of children. This approach could enable expanded opportunities for multi-center pediatric research, especially when sharing of granular individual-level data is challenging.