299 research outputs found

    Degradation of some illicit compounds in sewage sludge batch tests

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    The batch tests enabled determination of the degradation of the compounds at different temperatures and times, using various sludge types after characterization. Removal rates of cocaine (91.0%), benzoylecgonine (90.6%), heroin (97.9%), morphine (99.7%), 6 monoacetylmorphine (93.3%) and diazepam (99.7%) were measured after 3 hours equilibration; partition coefficients (Kd) for these six substances ranged from 1.2 – 68.1 Kg L-1. The degradation of compounds at 19 ± 0.5o C was relatively greater but it still occurred slowly at 4 ± 0.5o C, at between 5 and 10%. Work encompassed in this study directly measures illicit drug removal rates in laboratory studies for the first time. The application of batch studies in calculating removal rates in sewage works is an improvement over prior studies where assumptions on removal rates at STW were made

    Fate of drugs and their metabolites in the environment

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    The individual use of these pharmacologically active substances which generate great but underappreciated levels of other toxicologically potent and associated bioactive metabolites through purposeful and inadvertent discharge to the environment via excreta and by illegal disposal has become a global issue. This work reviews aspects of drugs occurrence, metabolism, transport routes, stability, analysis and environmental distribution of these emerging contaminants and highlights current developments in investigating and monitoring their fate and potential effects in aquatic environments. Gas chromatography-mass spectrometry (GCMS) and high performance liquid chromatography are the preferred methods for trace drugs analysis in wastewaters as their measurements depend largely on successful application of a fast and reliable method for qualitative and quantitative determination. The application of this method to the actual influents, effluents, sludge and environmental sediments from sewage treatment works (STWs) allows the assessment of drugs content and the extent at which STW helps in the transport of these pollutants (via different media) into the environment. The capability is also outlined for furthering our understanding of fate and behaviour of drugs with particular reference to illicit drugs, abused pharmaceuticals and environmental processes in our quest to understand the overall issues of drugs and make available exposure data for the aquatic realm

    Sensing the Danger Signals: cis-Jasmone Reduces Aphid Performance on Potato and Modulates the Magnitude of Released Volatiles

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    In response to herbivory, plants synthesize and release variable mixtures of herbivore-induced plant volatiles (HIPVs) as indirect defense traits. Such induction of indirect plant defense can also be “switched on” by certain chemicals known as priming agents. Preceding work showed that the plant HIPV cis-jasmone (CJ) induced the emission of aphid defense-related volatiles affecting their behavioral response. However, little is known about the extent to which CJ-induced volatiles impacts aphid performance. In the current study, we conducted growth assays of potato aphids, Macrosiphum euphorbiae, observing their reproduction, development, and survival on CJ-primed potato plants. Adult M. euphoribae produced fewer neonates on CJ-treated plants compared to untreated plants. The weight and survival of M. euphorbiae reproduced neonates were significantly lower on CJ-treated plants. Additionally, there was a significant reduction in mean relative growth rate (MRGR) of M. euphoribae nymphs that fed on CJ-treated plants. Furthermore, the intrinsic rate of population increase (rm) of M. euphoribae was significantly reduced on CJ-treated plants. Volatile analysis showed that CJ treatment significantly increased the emission of differently assigned volatile groups that have functional or biosynthetic characteristics, i.e., alcohols, benzenoids, homoterpenes, ketones, and sesquiterpenes at all sampling periods. Such enhanced volatile emissions were persistent over 7 days, suggesting a long-lasting effect of CJ defense priming. A negative correlation was found between volatile emission and MRGR of M. euphoribae. Principal component analysis (PCA) of data for the volatiles showed that (Z)-3-hexen-1-ol, α-pinene, (E)-ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), cis-jasmone, indole, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT) were the main volatiles contributing to the emitted blends, suggesting possible involvement in the reduced performance of M. euphorbiae. Overall, our findings demonstrate that priming potato with CJ significantly results in elevated emission of known biologically active volatiles, which may negatively impact aphid settling and other performance traits on primed plants

    cis-Jasmone Elicits Aphid-Induced Stress Signalling in Potatoes

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    Elicitation of plant defense signaling that results in altered emission of volatile organic compounds (VOCs) offers opportunities for protecting plants against arthropod pests. In this study, we treated potato, Solanum tuberosum L., with the plant defense elicitor cis-jasmone (CJ), which induces the emission of defense VOCs and thus affects the behavior of herbivores. Using chemical analysis, electrophysiological and behavioral assays with the potato-feeding aphid Macrosiphum euphorbiae, we showed that CJ treatment substantially increased the emission of defense VOCs from potatoes compared to no treatment. Coupled GC-electroantennogram (GC-EAG) recordings from the antennae of M. euphorbiae showed robust responses to 14 compounds present in induced VOCs, suggesting their behavioral role in potato/aphid interactions. Plants treated with CJ and then challenged with M. euphorbiae were most repellent to alate M. euphorbiae. Principal component analysis (PCA) of VOC collections suggested that (E)-2-hexenal, (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), (E)-β-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate (MeSA), CJ, and methyl benzoate (MeBA) were the main VOCs contributing to aphid behavioral responses, and that production of TMTT, (E)-β-farnesene, CJ, and DMNT correlated most strongly with aphid repellency. Our findings confirm that CJ can enhance potato defense against aphids by inducing production of VOCs involved in aphid-induced signalling

    Progression criteria in trials with an internal pilot : an audit of publicly funded randomised controlled trials

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    Background With millions of pounds spent annually on medical research in the UK, it is important that studies are spending funds wisely. Internal pilots offer the chance to stop a trial early if it becomes apparent that the study will not be able to recruit enough patients to show whether an intervention is clinically effective. This study aims to assess the use of internal pilots in individually randomised controlled trials funded by the Health Technology Assessment (HTA) programme and to summarise the progression criteria chosen in these trials. Methods Studies were identified from reports of the HTA committees’ funding decisions from 2012 to 2016. In total, 242 trials were identified of which 134 were eligible to be included in the audit. Protocols for the eligible studies were located on the NIHR Journals website, and if protocols were not available online then study managers were contacted to provide information. Results Over two-thirds (72.4%) of studies said in their protocol that they would include an internal pilot phase for their study and 37.8% of studies without an internal pilot had done an external pilot study to assess the feasibility of the full study. A typical study with an internal pilot has a target sample size of 510 over 24 months and aims to recruit one-fifth of their total target sample size within the first one-third of their recruitment time. There has been an increase in studies adopting a three-tiered structure for their progression rules in recent years, with 61.5% (16/26) of studies using the system in 2016 compared to just 11.8% (2/17) in 2015. There was also a rise in the number of studies giving a target recruitment rate in their progression criteria: 42.3% (11/26) in 2016 compared to 35.3% (6/17) in 2015. Conclusions Progression criteria for an internal pilot are usually well specified but targets vary widely. For the actual criteria, red/amber/green systems have increased in popularity in recent years. Trials should justify the targets they have set, especially where targets are low

    Identification and application of bacterial volatiles to attract a generalist aphid parasitoid: from laboratory to greenhouse assays

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    BACKGROUND Recent studies have shown that microorganisms emit volatile compounds that affect insect behaviour. However, it remains largely unclear whether microbes can be exploited as a source of attractants to improve biological control of insect pests. In this study, we used a combination of coupled gas chromatography‐electroantennography (GC–EAG) and Y‐tube olfactometer bioassays to identify attractive compounds in the volatile extracts of three bacterial strains that are associated with the habitat of the generalist aphid parasitoid Aphidius colemani, and to create mixtures of synthetic compounds to find attractive blends for A. colemani. Subsequently, the most attractive blend was evaluated in two‐choice cage experiments under greenhouse conditions. RESULTS GC–EAG analysis revealed 20 compounds that were linked to behaviourally attractive bacterial strains. A mixture of two EAG‐active compounds, styrene and benzaldehyde applied at a respective dose of 1 μg and 10 ng, was more attractive than the single compounds or the culture medium of the bacteria in Y‐tube olfactometer bioassays. Application of this synthetic mixture under greenhouse conditions resulted in significant attraction of the parasitoids, and outperformed application of the bacterial culture medium. CONCLUSION Compounds isolated from bacterial blends were capable of attracting parasitoids both in laboratory and greenhouse assays, indicating that microbial cultures are an effective source of insect attractants. This opens new opportunities to attract and retain natural enemies of pest species and to enhance biological pest control

    A randomised controlled trial and cost-effectiveness evaluation of "booster" interventions to sustain increases in physical activity in middle-aged adults in deprived urban neighbourhoods

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    Background: Systematic reviews have identified a range of brief interventions which increase physical activity in previously sedentary people. There is an absence of evidence about whether follow up beyond three months can maintain long term physical activity. This study assesses whether it is worth providing motivational interviews, three months after giving initial advice, to those who have become more active. Methods/Design: Study candidates (n = 1500) will initially be given an interactive DVD and receive two telephone follow ups at monthly intervals checking on receipt and use of the DVD. Only those that have increased their physical activity after three months (n = 600) will be randomised into the study. These participants will receive either a "mini booster" (n = 200), "full booster" (n = 200) or no booster (n = 200). The "mini booster" consists of two telephone calls one month apart to discuss physical activity and maintenance strategies. The "full booster" consists of a face-to-face meeting with the facilitator at the same intervals. The purpose of these booster sessions is to help the individual maintain their increase in physical activity. Differences in physical activity, quality of life and costs associated with the booster interventions, will be measured three and nine months from randomisation. The research will be conducted in 20 of the most deprived neighbourhoods in Sheffield, which have large, ethnically diverse populations, high levels of economic deprivation, low levels of physical activity, poorer health and shorter life expectancy. Participants will be recruited through general practices and community groups, as well as by postal invitation, to ensure the participation of minority ethnic groups and those with lower levels of literacy. Sheffield City Council and Primary Care Trust fund a range of facilities and activities to promote physical activity and variations in access to these between neighbourhoods will make it possible to examine whether the effectiveness of the intervention is modified by access to community facilities. A one-year integrated feasibility study will confirm that recruitment targets are achievable based on a 10% sample.Discussion: The choice of study population, study interventions, brief intervention preceding the study, and outcome measure are discussed

    Novel pheromone-mediated reproductive behaviour in the stag beetle, Lucanus cervus

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    This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: The datasets generated during and/or analysed during the current study are available via the corresponding authors on reasonable request.The iconic European stag beetle (Lucanus cervus) (Coleoptera: Lucanidae) is one of the largest terrestrial beetles in Europe. Due to decreasing population numbers, thought to be a consequence of habitat loss, this beetle has become a near-threatened species across much of Europe, and a reliable monitoring system is required to measure its future population trends. As part of a programme aimed at conserving UK populations, we have investigated the chemical ecology of the beetle, with a view to developing an efficient semiochemical-based monitoring system. Such a scheme will be beneficial not only in the UK but across the European range of the species, where the beetle is of conservation concern. Here, we report on a surprising discovery of a male-produced pheromone, which provokes initial sexual receptivity in females, and which has not been previously identified in the animal kingdom. Furthermore, we assign sex pheromone function to a previously described female-specific compound.Biotechnology and Biological Sciences Research Council (BBSRC)People’s Trust for Endangered SpeciesBritish Ecological Societ
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