6,697 research outputs found
Noradrenergic induction of odor-specific neural habituation and olfactory memories
For many mammals, individual recognition of conspecifics relies on olfactory cues. Certain individual recognition memories are thought to be stored when conspecific odor cues coincide with surges of noradrenaline (NA) triggered by intensely arousing social events. Such familiar stimuli elicit reduced behavioral responses, a change likely related to NA-dependent plasticity in the olfactory bulb (OB). In addition to its role in these ethological memories, NA signaling in the OB appears to be relevant for the discrimination of more arbitrary odorants as well. Nonetheless, no NA-gated mechanism of long-term plasticity in the OB has ever been directly observed in vivo. Here, we report that NA release from locus ceruleus (LC), when coupled to odor presentation, acts locally in the main OB to cause a specific long-lasting suppression of responses to paired odors. These effects were observed for both food odors and urine, an important social recognition cue. Moreover, in subsequent behavioral tests, mice exhibited habituation to paired urine stimuli, suggesting that this LC-mediated olfactory neural plasticity, induced under anesthesia, can store an individual recognition memory that is observable after recovery
The Naas Motorway Bypass - A Cost Benefit Analysis. Quarterly Economic Commentary Special Article, January 1984
The paper examines the Naas Motorway Bypass which cost £16m at 1983
prices. Twelve thousand vehicles a day using the bypass save over 10 minutes
between 8 am and 8 pm and 6 minutes at other times. Five thousand vehicles a
day using the present route through Naas also benefit by saving 4 minutes due
to reduced congestion in the town. In addition to time savings, the bypass
reduces accidents and fuel costs. Ninety-one per cent of the benefits accrue in
time savings. The internal rate of return on the project is estimated at 20.51
per cent, assuming 2 per cent annual traffic and income growth. The
sensitivity tests of the results show that even with zero growth in incomes and
traffic for twenty years, a high proportion of leisure time savings with zero
value and no increase in the value of fuel savings the project would have an
internal rate of return which meets the test discount rate used by the
Department of Finance.
The environmental aspects of the bypass are positive in terms of noise and
smoke and lead pollution reduction. The impact on farm severence and
natural amenities on the motorway route has been mitigated by several design
features of the bypass
Knowledge and behavioural interventions to reduce human health risk from private groundwater systems: A global review and pooled analysis based on development status
Groundwater contamination constitutes a significant health risk for private well users residing in rural areas. As the responsibility to safeguard rural private domestic groundwater typically rests with non-expert homeowners, interventions promoting risk mitigation and awareness represent the most viable means of preventing supply contamination. However, no global review or pooled analyses of these interventions has been undertaken to date. The current study sought to identify and quantify the performance of private well interventions from 1990 to 2018 via a global systematised review and pooled analysis. The PICO (Population-Intervention-Comparison-Outcome) approach was employed for literature identification. Relevant studies were statistically analysed across two quantitative outcome (performance) types, namely knowledge and behaviour, controlling for intervention characteristics and country development status. Mean behavioural and knowledge attainment across interventions was 53% and 48%, respectively, with interventions in economically developed regions exhibiting higher behavioural outcomes (56% vs. 45%) than those in developing regions. Geographically, interventions were located in southern or southeast Asia (n = 23), North America (n = 15), Central America (n = 1) and Africa (n = 1), with none identified in Australia/Oceania, Europe, or South America. Behavioural outcomes were significantly associated with presence of educational/research coordinator (p = 0.023), with these interventions attaining higher levels of efficacy (+74%) than those implemented by other coordinator types. Findings indicate that instructor-led, practical interventions allied with both large- and local-scale awareness-raising campaigns represent an optimum approach for future private well risk interventions. Subsequent adoption of such interventions may lead to increased levels of private well maintenance and provide a point of reference for myriad water and health communication contexts
Publication guidelines for quality improvement in health care: evolution of the SQUIRE project
In 2005, draft guidelines were published for reporting studies of quality improvement interventions as the initial step in a consensus process for development of a more definitive version. This article contains the full revised version of the guidelines, which the authors refer to as SQUIRE (Standards for QUality Improvement Reporting Excellence). This paper also describes the consensus process, which included informal feedback from authors, editors and peer reviewers who used the guidelines; formal written commentaries; input from a group of publication guideline developers; ongoing review of the literature on the epistemology of improvement and methods for evaluating complex social programmes; a two-day meeting of stakeholders for critical discussion and debate of the guidelines’ content and wording; and commentary on sequential versions of the guidelines from an expert consultant group. Finally, the authors consider the major differences between SQUIRE and the initial draft guidelines; limitations of and unresolved questions about SQUIRE; ancillary supporting documents and alternative versions that are under development; and plans for dissemination, testing and further development of SQUIRE
Movements Around Transit Tunnels in Mixed Ground
This paper describes the ground movements measured at a Test Section during construction of twin rapid transit tunnels in Cambridge, Massachusetts. The Test Section was located in an area of rock, soft ground and mixed face tunneling, with the alignment of the twin tunnels approximately 100 feet below ground surface. Overburden soils consist primarily of a very dense, saturated glacial till containing cobbles and boulders, with a weakly metamorphosed, fractured shale bedrock below. Instrumentation at the Test Section was installed in three cross-sections: one with the tunnel headings entirely in rock, a second with the tunnel headings in soft ground, and a third in a mixed face area. The field measurements are analyzed to show the effects of ground losses at the tunnel headings vs. distance away from headings, the effects of single vs. twin tunnel construction, and the effects of mixed face vs. rock and soft ground tunneling on ground movements
Recommended from our members
An injectable bone marrow-like scaffold enhances T cell immunity after hematopoietic stem cell transplantation.
Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for multiple disorders, but deficiency and dysregulation of T cells limit its utility. Here we report a biomaterial-based scaffold that mimics features of T cell lymphopoiesis in the bone marrow. The bone marrow cryogel (BMC) releases bone morphogenetic protein-2 to recruit stromal cells and presents the Notch ligand Delta-like ligand-4 to facilitate T cell lineage specification of mouse and human hematopoietic progenitor cells. BMCs subcutaneously injected in mice at the time of HSCT enhanced T cell progenitor seeding of the thymus, T cell neogenesis and diversification of the T cell receptor repertoire. Peripheral T cell reconstitution increased ~6-fold in mouse HSCT and ~2-fold in human xenogeneic HSCT. Furthermore, BMCs promoted donor CD4+ regulatory T cell generation and improved survival after allogeneic HSCT. In comparison to adoptive transfer of T cell progenitors, BMCs increased donor chimerism, T cell generation and antigen-specific T cell responses to vaccination. BMCs may provide an off-the-shelf approach for enhancing T cell regeneration and mitigating graft-versus-host disease in HSCT
How well do we forecast the aurora?
Michaela K Mooney and co-authors evaluate a space weather forecast model in the same way that weather forecasts are assessed, work that won the 2019 Rishbeth Prize for best poster
Distinction between the Poole-Frenkel and tunneling models of electric field-stimulated carrier emission from deep levels in semiconductors
The enhancement of the emission rate of charge carriers from deep-level defects in electric field is routinely used to determine the charge state of the defects. However, only a limited number of defects can be satisfactorily described by the Poole-Frenkel theory. An electric field dependence different from that expected from the Poole-Frenkel theory has been repeatedly reported in the literature, and no unambiguous identification of the charge state of the defect could be made. In this article, the electric field dependencies of emission of carriers from DX centers in AlxGa1-xAs:Te, Cu pairs in silicon, and Ge:Hg have been studied applying static and terahertz electric fields, and analyzed by using the models of Poole-Frenkel and phonon assisted tunneling. It is shown that phonon assisted tunneling and Poole-Frenkel emission are two competitive mechanisms of enhancement of emission of carriers, and their relative contribution is determined by the charge state of the defect and by the electric-field strength. At high-electric field strengths carrier emission is dominated by tunneling independently of the charge state of the impurity. For neutral impurities, where Poole-Frenkel lowering of the emission barrier does not occur, the phonon assisted tunneling model describes well the experimental data also in the low-field region. For charged impurities the transition from phonon assisted tunneling at high fields to Poole-Frenkel effect at low fields can be traced back. It is suggested that the Poole-Frenkel and tunneling models can be distinguished by plotting logarithm of the emission rate against the square root or against the square of the electric field, respectively. This analysis enables one to unambiguously determine the charge state of a deep-level defect
- …