1,500 research outputs found
The Relationship between Substance Abuse and Suicide among Adolescents
Suicide, prominent in adolescents, presents a major public health problem. This study examined the relationship between substance abuse and suicide among adolescents after adjusting for socio-demographic, interpersonal violence, and mental health variables. Data were drawn from the Youth Risk Behavior Survey. Suicidal measures included ideation, plan, attempts, and severe attempts. Substance abuse, depression, purging, and forced sex were the major predictors. Our findings may be of value to educators, providers, and policymakers in helping to target teens contemplating suicide. To curb incidence of suicidal thoughts and behavior among teens, routine screenings for substance abuse in schools is recommended
The success of the horse-chestnut leaf-miner, Cameraria ohridella, in the UK revealed with hypothesis-led citizen science
Citizen science is an increasingly popular way of undertaking research and simultaneously engaging people with science. However, most emphasis of citizen science in environmental science is on long-term monitoring. Here, we demonstrate the opportunities provided by short-term hypothesis-led citizen science. In 2010, we ran the ‘Conker Tree Science’ project, in which over 3500 people in Great Britain provided data at a national scale of an insect (horse-chestnut leaf-mining moth, Cameraria ohridella) undergoing rapid range-expansion. We addressed two hypotheses, and found that (1) the levels of damage caused to leaves of the horse-chestnut tree, Aesculus hippocastanum, and (2) the level of attack by parasitoids of C. ohridella larvae were both greatest where C. ohridella had been present the longest. Specifically there was a rapid rise in leaf damage during the first three years that C. ohridella was present and only a slight rise thereafter, while estimated rates of parasitism (an index of true rates of parasitism) increased from 1.6 to 5.9% when the time C. ohridella had been present in a location increased from 3 to 6 years. We suggest that this increase is due to recruitment of native generalist parasitoids, rather than the adaptation or host-tracking of more specialized parasitoids, as appears to have occurred elsewhere in Europe. Most data collected by participants were accurate, but the counts of parasitoids from participants showed lower concordance with the counts from experts. We statistically modeled this bias and propagated this through our analyses. Bias-corrected estimates of parasitism were lower than those from the raw data, but the trends were similar in magnitude and significance. With appropriate checks for data quality, and statistically correcting for biases where necessary, hypothesis-led citizen science is a potentially powerful tool for carrying out scientific research across large spatial scales while simultaneously engaging many people with science
A dearth of data: fitting parasitoids into ecological networks
Studying parasitoids can provide insights into global diversity estimates, climate change impacts, and agroecosystem service provision. However, this potential remains largely untapped due to a lack of data on how parasitoids interact with other organisms. Ecological networks are a useful tool for studying and exploiting the impacts of parasitoids, but their construction is hindered by the magnitude of undescribed parasitoid species, a sparse knowledge of host ranges, and an under-representation of parasitoids within DNA-barcode databases (we estimate <5% have a barcode). Here, we advocate the use of DNA metabarcoding to construct the host-parasitoid component of multilayer networks. While the incorporation of parasitoids into network-based analyses has far ranging applications, we focus on its potential for assessing ecosystem service provision within agroecosystems
Swash on steep and gently-sloping beaches
In the last twenty years, the importance of sediment transport in the swash zone has been established. The disproportionately high sediment transport rates in this region make its inclusion in general nearshore models vital. As part of this U.K. Natural Environmental Research Council project (grant number: NERlA/S/1999/00144), high frequency (8 Hz) measurements were made of the water depth and vertical variations in suspended sediment concentration and water velocity, using state-of-the-art instrumentation. Further measurements included nearshore and offshore wave conditions, tidal elevations, wave run-up limits, groundwater variations, sediment grain size distributions, beach slopes and changes in morphology at time-scales from minutes to weeks. Fieldwork was carried out on a gently-sloping (tan p - 0.03; d50 ~ 0.27 mm) and steep beach (tan p - 0.09; d50 ~ 0.55 mm). Both experience similar wave climates which allows a direct comparison between hydrodynamics and sediment transport in the swash zone.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Human factors in the design of medical devices – approaches to meeting international standards in the European Union and USA
This paper focuses on the challenges of meeting agency requirements as it pertains to the application of human factors in the medical device development (MDD) process. Individual case studies of the design
and development process for 18 medical device manufacturers located in the US and EU were analysed and compared using a multiple case study design. The results indicate that there are four main challenges
in implementing international standards. These include a lack of direct access to users for the purposes of device development; a lack of understanding by users with regards to the impact of their feedback on the development process; contract formalities limiting user exchanges; and the attitude of clinical users
directly impacting on the device developer's invitation to participate in the development processes. The barriers presented in this research have the potential to be resolved but only with greater commitment by both medical device users and developers
The future of product design utilising printed electronics
This paper addresses the teaching of emerging technologies to design students, using ‘printed electronics’ as an example as it recently became viable to mass manufacture and is ready for use in designs. Printed electronics is introduced as a disruptive technology, and approaches employed in knowledge transfer to industrial/product designers is reviewed. An overview of the technology is provided; the printing processes; material properties; a comparison with conventional electronics; and product examples are identified. Two case studies illustrate approaches for knowledge transfer to student designers. The assessment criteria and design outcomes from the case study projects are reviewed and future/new approaches proposed. The paper concludes that there is a need to develop a thorough knowledge transfer strategy for printed electronics to designers, informed by case studies and extending beyond simply showing examples of existing technology. This is necessary for future proofing both in technological advances and designing for the future
Comparing the Structure and Robustness of Passifloraceae - Floral Visitor and True Pollinator Networks in a Lowland Atlantic Forest
We investigated the plant-pollinator interactions of Passifloraceae occurring in fragments of lowland semi-deciduous Atlantic forest. We described floral biology, pollination syndromes and the pollinators of Passiflora alata, Passiflora kermesina, Passiflora suberosa, Passiflora malacophylla and Mitostemma glaziovii. We examined the robustness of the interaction networks to species loss, a plausible scenario resulting from forest fragmentation. The effects of pollination syndrome (flower size) on network robustness was also examined. Passiflora alata, P. malacophylla and P. suberosa were pollinated by bees of different corporal sizes. P. kermesina and M. glaziovii presented the highest diversity of visitors and were pollinated mainly by hummingbirds and butterflies, respectively. Through the analysis of the networks we differentiate the structures of the flower-visitor network with the ‘true’ plant-pollinator network. The robustness of the flower-visitor network to animal loss was generally high, but it declined when only true pollinators were included in the network. The sequential loss of plants from the flower-visitor network resulted in low robustness: the loss of key plants could have significant cascading effects on the animals feeding on them within the forest fragment. Future studies should consider the interactions between all flowering plants and animals in this habitat in order to guide conservation and management plans for these forest fragments
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