1,966 research outputs found
Transition to Turbulence in Shear above the Tropopause
2000 FLORIDA AVE NW, WASHINGTON, USA, DC,
2000
GeoCLEF 2006: the CLEF 2006 Ccross-language geographic information retrieval track overview
After being a pilot track in 2005, GeoCLEF advanced to be a regular track within CLEF 2006. The
purpose of GeoCLEF is to test and evaluate cross-language geographic information retrieval (GIR): retrieval for
topics with a geographic specification. For GeoCLEF 2006, twenty-five search topics were defined by the
organizing groups for searching English, German, Portuguese and Spanish document collections. Topics were
translated into English, German, Portuguese, Spanish and Japanese. Several topics in 2006 were significantly
more geographically challenging than in 2005. Seventeen groups submitted 149 runs (up from eleven groups and
117 runs in GeoCLEF 2005). The groups used a variety of approaches, including geographic bounding boxes,
named entity extraction and external knowledge bases (geographic thesauri and ontologies and gazetteers)
Anatomy of Cirrus Clouds: Results from the Emerald Airborne Campaigns
2000 FLORIDA AVE NW, WASHINGTON, USA, DC,
2000
Observations and modelling of microphysical variability, aggregation and sedimentation in tropical anvil cirrus outflow regions
Aircraft measurements of the microphysics of a tropical convective anvil (at
temperatures ~−60 °C) forming above the Hector storm, over the
Tiwi Islands, Northern Australia, have been conducted with a view to
determining ice crystal aggregation efficiencies from in situ measurements.
The observed microphysics have been compared to an explicit bin-microphysical
model of the anvil region, which includes crystal growth by vapour diffusion
and aggregation and the process of differential sedimentation.
It has been found in flights made using straight and level runs perpendicular
to the storm that the number of ice crystals initially decreased with
distance from the storm as aggregation took place resulting in larger
crystals, followed by their loss from the cloud layer due to sedimentation.
The net result was that the mass (i.e. Ice Water Content) in the anvil
Ci cloud decreased, but also that the average particle size (weighted by
number) remained relatively constant along the length of the anvil outflow.
Comparisons with the explicit microphysics model showed that the changes in
the shapes of the ice crystal spectra as a function of distance from the
storm could be explained by the model if the aggregation efficiency was set
to values of Eagg~0.5 and higher. This result is supported by
recent literature on aggregation efficiencies for complex ice particles and
suggests that either the mechanism of particle interlocking is important to
the aggregation process, or that other effects are occuring, such as
enhancement of ice-aggregation by high electric fields that arise as a
consequence of charge separation within the storm.
It is noteworthy that this value of the ice crystal aggregation efficiency is
much larger than values used in cloud resolving models at these temperatures,
which typically use E~0.0016. These results are important to
understanding how cold clouds evolve in time and for the treatment of the
evolution of tropical Ci in numerical models
Grouping practices in the primary school: what influences change?
During the 1990s, there was considerable emphasis on promoting particular kinds of pupil grouping as a means of raising educational standards. This survey of 2000 primary schools explored the extent to which schools had changed their grouping practices in responses to this, the nature of the changes made and the reasons for those changes. Forty eight percent of responding schools reported that they had made no change. Twenty two percent reported changes because of the literacy hour, 2% because of the numeracy hour, 7% because of a combination of these and 21% for other reasons. Important influences on decisions about the types of grouping adopted were related to pupil learning and differentiation, teaching, the implementation of the national literacy strategy, practical issues and school self-evaluation
Baryon polarization in low-energy unpolarized meson-baryon scattering
We compute the polarization of the final-state baryon, in its rest frame, in
low-energy meson--baryon scattering with unpolarized initial state, in
Unitarized BChPT. Free parameters are determined by fitting total and
differential cross-section data (and spin-asymmetry or polarization data if
available) for , and scattering. We also compare our
results with those of leading-order BChPT
Species-specific functional morphology of four US atlantic coast dune grasses: Biogeographic implications for dune shape and coastal protection
Coastal dunes arise from feedbacks between vegetation and sediment supply. Species-specific differences in plant functional morphology affect sand capture and dune shape. In this study, we build on research showing a relationship between dune grass species and dune geomorphology on the US central Atlantic Coast. This study seeks to determine the ways in which four co-occurring dune grass species (Ammophila breviligulata, Panicum amarum, Spartina patens, Uniola paniculata) differ in their functional morphology and sand accretion. We surveyed the biogeography, functional morphology, and associated change in sand elevation of the four dune grass species along a 320-kilometer distance across the Outer Banks. We found that A. breviligulata had dense and clumped shoots, which correlated with the greatest sand accretion. Coupled with fast lateral spread, it tends to build tall and wide foredunes. Uniola paniculata had fewer but taller shoots and was associated with ~ 42% lower sand accretion. Coupled with slow lateral spread, it tends to build steeper and narrower dunes. Panicum amarum had similar shoot densities and associated sand accretion to U. paniculata despite its shorter shoots, suggesting that shoot density is more important than morphology. Finally, we hypothesize, given the distributions of the grass species, that foredunes may be taller and wider and have better coastal protection properties in the north where A. breviligulata is dominant. If under a warming climate A. breviligulata experiences a range shift to the north, as appears to be occurring with U. paniculata, changes in grass dominance and foredune morphology could make for more vulnerable coastlines
The role of advance directives in end-of-life decisions in Austria: survey of intensive care physicians
<p>Abstract</p> <p>Background</p> <p>Currently, intensive care medicine strives to define a generally accepted way of dealing with end-of-life decisions, therapy limitation and therapy discontinuation.</p> <p>In 2006 a new advance directive legislation was enacted in Austria. Patients may now document their personal views regarding extension of treatment. The aim of this survey was to explore Austrian intensive care physicians' experiences with and their acceptance of the new advance directive legislation two years after enactment (2008).</p> <p>Methods</p> <p>Under the aegis of the OEGARI (Austrian Society of Anaesthesiology, Resuscitation and Intensive Care) an anonymised questionnaire was sent to the medical directors of all intensive care units in Austria. The questions focused on the physicians' experiences regarding advance directives and their level of knowledge about the underlying legislation.</p> <p>Results</p> <p>There were 241 questionnaires sent and 139 were turned, which was a response rate of 58%. About one third of the responders reported having had no experience with advance directives and only 9 directors of intensive care units had dealt with more than 10 advance directives in the previous two years. Life-supporting measures, resuscitation, and mechanical ventilation were the predominantly refused therapies, wishes were mainly expressed concerning pain therapy.</p> <p>Conclusion</p> <p>A response rate of almost 60% proves the great interest of intensive care professionals in making patient-oriented end-of-life decisions. However, as long as patients do not make use of their right of co-determination, the enactment of the new law can be considered only a first important step forward.</p
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