391 research outputs found

    Baseline performance and emissions data for a single-cylinder, direct-injected diesel engine

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    Comprehensive fuel consumption, mean effective cylinder pressure, and emission test results for a supercharged, single-cylinder, direct-injected, four-stroke-cycle, diesel test engine are documented. Inlet air-to-exhaust pressure ratios were varied from 1.25 to 3.35 in order to establish the potential effects of turbocharging techniques on engine performance. Inlet air temperatures and pressures were adjusted from 34 to 107 C and from 193 to 414 kPa to determine the effects on engine performance and emissions. Engine output ranged from 300 to 2100 kPa (brake mean effective pressure) in the speed range of 1000 to 3000 rpm. Gaseous and particulate emission rates were measured. Real-time values of engine friction and pumping loop losses were measured independently and compared with motored engine values

    Communications Biophysics

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    Contains reports on six research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-02

    Studies of thermionic materials for space power applications informal monthly report, oct. 1 - oct. 31, 1963

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    Thermionic space power material - isostatic pressing, vapor deposited tungsten, high temperature properties, cesium thermionic cell life testing, and irradiation studie

    Enhancing the experience of carers in the chemotherapy outpatient setting: an exploratory randomised controlled trial to test impact, acceptability and feasibility of a complex intervention co-designed by carers and staff

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    PurposeSupporting someone through chemotherapy can be emotionally and physically demanding. However, research has yet to establish the type of support carers require or the best way to provide this. This study tested the feasibility and acceptability of a complex intervention for carers that was co-designed by staff and carers of patients starting chemotherapy.MethodsForty-seven carers were recruited, randomised between the intervention (n?=?24) and control (n?=?23) groups. A questionnaire was completed pre- and post-intervention measuring knowledge of chemotherapy and its side effects, experience of care, satisfaction with outpatient services, coping and emotional wellbeing. The intervention process was evaluated by carers and healthcare professionals (HCPs) in focus groups.ResultsRecruitment to the study was unproblematic and attrition from it was low, suggesting the intervention and study processes were acceptable to patients and carers. Carers in receipt of the ‘Take Care’ intervention reported statistically significantly better understanding of symptoms and side effects and their information needs being more frequently met than carers in the control. Confidence in coping improved between baseline and follow-up for the intervention group and declined for the control although differences were insufficient to achieve statistical significance. There was no significant difference between the two groups’ emotional wellbeing. HCP and carer focus groups confirmed the feasibility and acceptability of the intervention.ConclusionsThe ‘Take Care’ intervention proved acceptable to carers and HCPs and demonstrates considerable promise and utility in practice. Study findings support the conduct of a fully powered RCT to determine the intervention’s effectiveness and cost-effectiveness

    Importance Of Recruitment To Accurately Predict The Impacts Of Human-Caused Mortality On Wolf Populations

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    Reliable analyses can help wildlife managers make good decisions, which are particularly critical for controversial decisions such as wolf (Canis lupus) harvest. Creel and Rotella (2010) recently predicted substantial population declines in Montana wolf populations due to harvest, in contrast to predictions made by Montana Fish, Wildlife and Parks (MFWP). Here we replicate their analyses considering only those years in which field monitoring was consistent, and we consider the effect of annual variation in recruitment on wolf population growth. We also use model selection to evaluate models of recruitment and human-caused mortality rates in wolf populations in the Northern Rocky Mountains. Using data from 27 area-years of intensive wolf monitoring, we show that variation in both recruitment and human-caused mortality affect annual wolf population growth rates and that human-caused mortality rates have increased with the sizes of wolf populations. We also show that either recruitment rates have decreased with population sizes or that the ability of current field resources to document recruitment rates has recently become less successful as the number of wolves in the region has increased. Predictions of wolf population growth in Montana from our top models are consistent with field observations and estimates previously made by MFWP. Familiarity with limitations of raw data helps generate more reliable inferences and conclusions in analyses of publicly-available datasets. Additionally, development of efficient monitoring methods for wolves is a pressing need, so that analyses such as ours will be possible in future years when fewer resources will be available for monitoring

    Hippocampal long-term potentiation is disrupted during expression and extinction but is restored after reinstatement of morphine place preference

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    Learned associations between environmental cues and morphine use play an important role in the maintenance and/or relapse of opioid addiction. Although previous studies suggest that context-dependent morphine treatment alters glutamatergic transmission and synaptic plasticity in the hippocampus, their role in morphine conditioned place preference (CPP) and reinstatement remains unknown. We investigated changes in synaptic plasticity and NMDAR expression in the hippocampus after the expression, extinction, and reinstatement of morphine CPP. Here we report that morphine CPP is associated with increased basal synaptic transmission, impaired hippocampal long-term potentiation (LTP), and increased synaptic expression of the NR1 and NR2b NMDAR subunits. Changes in synaptic plasticity, synaptic NR1 and NR2b expression, and morphine CPP were absent when morphine was not paired with a specific context. Furthermore, hippocampal LTP was impaired and synaptic NR2b expression was increased after extinction of morphine CPP, indicating that these alterations in plasticity may be involved in the mechanisms underlying the learning of drug–environment associations. After extinction of morphine CPP, a priming dose of morphine was sufficient to reinstate morphine CPP and was associated with LTP that was indistinguishable from saline control groups. In contrast, morphine CPP extinguished mice that received a saline priming dose did not show CPP and had disrupted hippocampal LTP. Finally, we found that reinstatement of morphine CPP was prevented by the selective blockade of the NR2b subunit in the hippocampus. Together, these data suggest that alterations in synaptic plasticity and glutamatergic transmission play an important role in the reinstatement of morphine CPP

    Spatiotemporal Control of Opioid Signaling and Behavior

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    SummaryOptogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here, we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically sensitive, mu-opioid-like receptor, which we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels and internalizes with kinetics similar to that of the mu-opioid receptor. To assess in vivo utility, we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways
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