146,593 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dawn R. Bazely, John Reynolds, Sue and another Field researcher stand together at Camp Finney
No full textDawn R. Bazely, John Reynolds, Sue and another Field researcher stand together at Camp Finney,Wapusk National Park in front of many gas drums. Just beyond the gas drums a water body and large expanses of grassland can be see
Steve Hanson, Peter Dueck, and Dawn Bazely
No full textSteve Hanson, Peter Dueck, and Dawn Bazely at the the Wapusk National Park posing together during their field research projec
Dawn Anderson, Colleagues\u27 College 2018
No full textDawn Anderson, professor of kinesiology, shares how she stays up to day with research in her field
South-north asymmetry of field-aligned currents in the magnetotail observed by Cluster
No full textWe statistically investigated features of the field-aligned current (FAC) distribution in plasma sheet boundary layers between 17 and 19 RE in the magnetotail using the curlometer technique to calculate the current from four-point magnetic field measurements taken in 2001. The results show that the FAC distribution in the plasma sheet boundary layers in the magnetotail has dusk-dawn asymmetry, earthward-tailward (polarity) asymmetry, and north-south asymmetry. The occurrence and polarities of FACs in the Northern Hemisphere are different from those in the Southern Hemisphere. The average density and the standard deviation of the FACs that are most likely to be connected to the Earth are 4.90 nA m−2 and 2.55 nA m−2 in the Northern Hemisphere and 4.21 nA m−2 and 1.80 nA m−2 in the Southern Hemisphere, respectively. For investigating the mechanism of the north-south asymmetry, we mapped the FACs along the field line into the polar region. The footprints of the FACs also show a difference between the Southern and Northern hemispheres (as a function of mapped latitude). These characteristics suggest a north-south asymmetry of the FACs in the magnetosphere. Further investigation is needed to identify the causes of this asymmetry, although the configuration of the magnetosphere, the polar cap boundary, the conductivity in the ionosphere, or the various solar wind-magnetosphere interaction processes all may be contributors. That the FAC densities are different between the hemispheres suggests that an important source of these currents must be a voltage generator
Evaluating the long term impacts of transport policy: the case of passenger rail privatisation in Great Britain
No full textBritain’s national rail system was ‘privatised’ as a result of the 1993 Railways Act, with most of the organisational and ownership changes implemented by 1997. This thesis examines the long term impacts of the privatisation initiative on the passenger rail service. A key issue when examining long term changes is that of the counterfactual – what would have happened if the changes had not occurred? A simple econometric model of the demand for passenger rail services was developed and used in conjunction with extrapolative methods for key variables such as fares, train kms and GDP to determine demand-side counterfactuals. Extrapolative methods were also used to determine counterfactual infrastructure and train operation costs. Although since privatisation rail demand has grown strongly, the analysis indicates that transitional disruptions suppressed demand by around 4% over a prolonged period (1994/95 to 2005/6), whilst the Hatfield accident reduced demand by about 5%, albeit over a short period (2000/1 to 2005/6). A welfare analysis indicates that although consumers gained as a result of privatisation, for most years this has been offset by increases in costs. An exception is provided by the two years immediately before the Hatfield accident. Overall the loss in welfare since the reforms were introduced far exceeds the net receipts from the sale of rail businesses. It is found that although the reforms have had advantages in terms of lower fares and better service levels than otherwise would have been the case, this has been offset by adverse transitional effects and high costs, which in turn may be linked with higher transaction costs
Rotational modulation and local time dependence of Saturn's infrared H3+ auroral intensity
No full textPlanetary auroral emissions reveal the configuration of magnetospheric field-aligned current systems. In this study, Cassini Visual and Infrared Mapping Spectrometer (VIMS) observations of Saturn's pre-equinox infrared H3+ aurorae were analysed to show (a) rotational modulation of the auroral intensity in both hemispheres and (b) a significant local time dependence of the emitted intensity. The emission intensity is modulated by the ‘planetary period’ rotation of auroral current systems in each hemisphere. The northern auroral intensity also displays a lesser anti-phase dependence on the southern rotating current system, indicating that part of the southern current system closes in the northern hemisphere. The southern hemisphere aurorae were most intense in the post-dawn sector, in agreement with some past measurements of auroral field-aligned currents, UV aurora and SKR emitted power. A corresponding investigation of the northern hemisphere auroral intensity reveals a broader dawn-noon enhancement, possibly due to the interaction of the southern rotating current system with that of the north. The auroral intensity was reduced around dusk and post-midnight in both hemispheres. These observations can be explained by the interaction of a rotating field-aligned current system in each hemisphere with one fixed in local time, which is related to the solar wind interaction with magnetospheric field lines
Sequencing data: A genomic network to monitor Earth
No full textWe propose that a network of genomic observatories should be established to take the planet's 'biological pulse'. We invite participants to assist in the shaping of this network (see genomicobservatories.org).
DNA sequences are becoming core components of Earth-monitoring systems, and data output is soaring from genomics and other observing technologies. But sequence data alone are of limited value without the context of time and location.
Genomic observatories would integrate genomic information with environmental, socio-ecological and other biological data. Sequencing model ecosystems would accelerate ecological understanding.
Despite reduced sequencing costs, genomic studies are still expensive to analyse and interpret, and the expense of field collection of DNA samples remains incompressible. Genomic observatories would consolidate these efforts.
These observatories must be supported by field stations, marine labs, museums, standards organizations, research networks and sequencing centres. They should be established at existing scientifically important sites
Dawn singing in Brown Creeper (Certhia americana)
No full textThe dawn chorus of birds is an impressive display in which many individuals of a variety of species sing concurrently before sunrise. Brown Creeper (Certhia americana) is a small passerine bird that has not been well studied and is thought not to sing during the dawn chorus. Here, we used automated recordings to analyze Brown Creeper singing during the 2015–2017 breeding seasons from April through August in order to identify patterns in the timing and quantity of singing. We found that Brown Creepers did sing before sunrise, most often between April and early June and then more sporadically through mid July. We did not find any seasonal changes in song rates before sunrise, but we did find non-linear seasonal trends in both the timing and total duration of dawn singing bouts. Dawn choruses began earlier and lasted longer from April through mid June after which they began later and became shorter. Our results highlight the benefit of using automated recording techniques to study natural history of difficult to study species and add to our understanding of Brown Creeper natural history
Best Practices for Field Days: Modified Delphi used for Observation Tool Development
No full textThis archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.A team of 40 people from across the country were invited to the Best Practices for Field Days
(BPFD) Delphi panel to develop an effective observation instrument for determining the quality
of field day components that represent best practices. Thirty nine people accepted the
invitation and 27 people participated.Heimlich, Joe; Carlson, Stephan; Tanner, Dawn; Storksdieck, Martin. (2009). Best Practices for Field Days: Modified Delphi used for Observation Tool Development. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/172452
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