303 research outputs found

    Do plant species influence soil CO2 and N2O fluxes in a diverse tropical forest?

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    To test whether plant species influence greenhouse gas production in diverse ecosystems, we measured wet season soil CO2 and N2O fluxes close to ~300 large (>35 cm in diameter at breast height (DBH)) trees of 15 species at three clay-rich forest sites in central Amazonia. We found that soil CO2 fluxes were 38% higher near large trees than at control sites >10 m away from any tree (P < 0.0001). After adjusting for large tree presence, a multiple linear regression of soil temperature, bulk density, and liana DBH explained 19% of remaining CO2 flux variability. Soil N2O fluxes adjacent to Caryocar villosum, Lecythis lurida, Schefflera morototoni, and Manilkara huberi were 84%-196% greater than Erisma uncinatum and Vochysia maxima, both Vochysiaceae. Tree species identity was the most important explanatory factor for N2O fluxes, accounting for more than twice the N2O flux variability as all other factors combined. Two observations suggest a mechanism for this finding: (1) sugar addition increased N2O fluxes near C. villosum twice as much (P < 0.05) as near Vochysiaceae and (2) species mean N2O fluxes were strongly negatively correlated with tree growth rate (P = 0.002). These observations imply that through enhanced belowground carbon allocation liana and tree species can stimulate soil CO2 and N2O fluxes (by enhancing denitrification when carbon limits microbial metabolism). Alternatively, low N2O fluxes potentially result from strong competition of tree species with microbes for nutrients. Species-specific patterns in CO2 and N2O fluxes demonstrate that plant species can influence soil biogeochemical processes in a diverse tropical forest

    Alternatives for Scheduling Departures for Efficient Surface Metering in ATD-2: Exploration in a Human-in-the-Loop Simulation

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    Human-in-the-Loop (HITL) simulation was conducted to explore the impacts of various surface metering goals on operations and Ramp Controllers at Charlotte Douglas International Airport (CLT). Three conditions were compared: Baseline, with no surface metering, instructions to meet advisory times at the gate only, and instructions to meet advisory times at the gate as well as the times at the scheduled taxiway spot, where aircraft are delivered to Air Traffic Control (ATC). Results showed increased compliance for taxiway spot times when compliance was first met for gate advisories. Instructing Ramp Controllers to meet advisory times at the gate improves spot time compliance and therefore surface scheduling predictability at CLT. Results also demonstrated there was increased compliance overall with gate and spot times in the second condition. This was likely due to higher Ramp Controller workload in the third condition

    The Microbiology of Permeable Pavements

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    SUMMARY Pervious pavement systems (meaning permeable pavements within this context and used interchangeably) are known to retain and degrade hydrocarbons within the structure of the pavement. The key to this decontamination has been shown to be the naturally occurring microbial communities living on the pavement building materials. Research by Formpave and Coventry University has shown that once oil is trapped on a suitable strongly oil-retaining geotextile membrane layer, the oil rapidly becomes a food source for the microbial communities. Oil is metabolised by aerobic bacteria and fungi that convert the oil into sugars such as glucose for growth and reproduction. Over time, a network of microbial growth spreads over the surface of Inbitex forming a biofilm, further improving the filtration and purification properties of the system. The presence of a large food source growing on the oil attracts larger predatory organisms such as protozoa and metazoa to the biofilm. These organisms play an important role in maintaining the free-draining characteristics of the geotextile and also the vigorous growth of the oil degrading organisms. An understanding of the processes underpinning the environmental benefits of permeable pavements is essential in order to optimise the operation of the system

    Marine wild-capture fisheries after nuclear war

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    Unidad de excelencia María de Maeztu CEX2019-000940-MIdentificadors digitals: Digital object identifier for the 'European Research Council' (http://dx.doi.org/10.13039/501100000781) Digital object identifier for 'Horizon 2020' (http://dx.doi.org/10.13039/501100007601) - BIGSEA projectNuclear war, beyond its devastating direct impacts, is expected to cause global climatic perturbations through injections of soot into the upper atmosphere. Reduced temperature and sunlight could drive unprecedented reductions in agricultural production, endangering global food security. However, the effects of nuclear war on marine wild-capture fisheries, which significantly contribute to the global animal protein and micronutrient supply, remain unexplored. We simulate the climatic effects of six war scenarios on fish biomass and catch globally, using a state-of-the-art Earth system model and global process-based fisheries model. We also simulate how either rapidly increased fish demand (driven by food shortages) or decreased ability to fish (due to infrastructure disruptions), would affect global catches, and test the benefits of strong prewar fisheries management. We find a decade-long negative climatic impact that intensifies with soot emissions, with global biomass and catch falling by up to 18 ± 3% and 29 ± 7% after a US-Russia war under business-as-usual fishing-similar in magnitude to the end-of-century declines under unmitigated global warming. When war occurs in an overfished state, increasing demand increases short-term (1 to 2 y) catch by at most ∼30% followed by precipitous declines of up to ∼70%, thus offsetting only a minor fraction of agricultural losses. However, effective prewar management that rebuilds fish biomass could ensure a short-term catch buffer large enough to replace ∼43 ± 35% of today's global animal protein production. This buffering function in the event of a global food emergency adds to the many previously known economic and ecological benefits of effective and precautionary fisheries management

    Marine wild-capture fisheries after nuclear war

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    Nuclear war, beyond its devastating direct impacts, is expected to cause global climatic perturbations through injections of soot into the upper atmosphere. Reduced temperature and sunlight could drive unprecedented reductions in agricultural production, endangering global food security. However, the effects of nuclear war on marine wild-capture fisheries, which significantly contribute to the global animal protein and micronutrient supply, remain unexplored. We simulate the climatic effects of six war scenarios on fish biomass and catch globally, using a state-of-the-art Earth system model and global process-based fisheries model. We also simulate how either rapidly increased fish demand (driven by food shortages) or decreased ability to fish (due to infrastructure disruptions), would affect global catches, and test the benefits of strong prewar fisheries management. We find a decade-long negative climatic impact that intensifies with soot emissions, with global biomass and catch falling by up to 18 ± 3% and 29 ± 7% after a US–Russia war under business-as-usual fishing—similar in magnitude to the end-of-century declines under unmitigated global warming. When war occurs in an overfished state, increasing demand increases short-term (1 to 2 y) catch by at most ∼30% followed by precipitous declines of up to ∼70%, thus offsetting only a minor fraction of agricultural losses. However, effective prewar management that rebuilds fish biomass could ensure a short-term catch buffer large enough to replace ∼43 ± 35% of today’s global animal protein production. This buffering function in the event of a global food emergency adds to the many previously known economic and ecological benefits of effective and precautionary fisheries management

    The addition of a goal-based motivational interview to standardised treatment as usual to reduce dropouts in a service for patients with personality disorder: a feasibility study

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    <p>Abstract</p> <p>Background</p> <p>Rates of non-completion of treatments for personality disorder are high and there are indications that those who do not complete treatment have worse outcomes than those who do. Improving both cost-efficiency and client welfare require attention to engaging people with personality disorder in treatment. A motivational interview, based on the Personal Concerns Inventory, may have the ability to enhance engagement and retention in therapy. Here, we report the protocol for a feasibility study for a randomised controlled trial (RCT).</p> <p>Methods</p> <p>All referrals accepted to the psychological service of Nottinghamshire Healthcare NHS Trust's outpatient service for people with personality disorder are eligible for inclusion. Consenting participants are randomised to receive the Personal Concerns Inventory interview plus treatment as usual or treatment as usual only. We aim to recruit 100 participants over 11/2 years. A randomised controlled trial will be considered feasible if <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> the recruitment rate to the project is 54% of all referrals (95% CI 54-64), <abbrgrp><abbr bid="B2">2</abbr></abbrgrp> 80% of clients find the intervention acceptable in terms of its practicability and usefulness (95% CI 80-91), and <abbrgrp><abbr bid="B3">3</abbr></abbrgrp> 80% of therapists report finding the intervention helpful (95% CI 80-100). In a full-scale randomised controlled trial, the primary outcome measure will be completion of treatment i.e., entry into and completion of ≥ 75% of sessions offered. Therefore, information will be collected on recruitment rates, attendance at therapy sessions, and completion of treatment. The feasibility of examining the processes of engagement will be tested by assessing the value, coherence, and attainability of goals pre-treatment, and engagement in treatment. The costs associated with the intervention will be calculated, and the feasibility of calculating the cost-benefits of the intervention will be tested. The views of clients and therapists on the intervention, collected using semi-structured interviews, will be analysed using thematic analysis.</p> <p>Discussion</p> <p>The Personal Concerns Interview as a preparation for treatment of people with personality has the potential to maximise treatment uptake, reduce unfilled places in treatment programmes, and prevent group treatments faltering through non-attendance. Most importantly, it has the potential to improve patient outcomes, helping them to function better and reduce hospitalisation.</p> <p>Trial Registration</p> <p>ClinicalTrials.Gov.UK Identifier - NCT01132976</p
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