10,045 research outputs found
Investigating the source of Planck-detected AME: high resolution observations at 15 GHz
The Planck 28.5 GHz maps were searched for potential Anomalous Microwave
Emission (AME) regions on the scale of or smaller, and several
new regions of interest were selected. Ancillary data at both lower and higher
frequencies were used to construct spectral energy distributions (SEDs), which
seem to confirm an excess consistent with spinning dust models. Here we present
higher resolution observations of two of these new regions with the Arcminute
Microkelvin Imager Small Array (AMI SA) between 14 and 18 GHz to test for the
presence of a compact (10 arcmin or smaller) component. For
AME-G107.1+5.2, dominated by the {\sc Hii} region S140, we find evidence for
the characteristic rising spectrum associated with the either the spinning dust
mechanism for AME or an ultra/hyper-compact \textsc{Hii} region across the AMI
frequency band, however for AME-G173.6+2.8 we find no evidence for AME on
scales of arcmin.Comment: 13 pages, 8 figures, 4 tables. Submitted to Advances in Astronomy AME
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Tree of Life Synagogue Shooting in Pittsburgh: Preparedness, Prehospital Care, and Lessons Learned
On Saturday, October 27, 2018, a man with anti-Semitic motivations entered Tree of Life synagogue in the Squirrel Hill section of Pittsburgh, Pennsylvania; he had an AR-15 semi-automatic rifle and three handguns, opening fire upon worshippers. Eventually 11 civilians died at the scene and eight people sustained non-fatal injuries, including five police officers. Each person injured but alive at the scene received care at one of three local level-one trauma centers. The injured had wounds often seen in war-settings, with the signature of high velocity weaponry. We describe the scene response, specific elements of our hospital plans, the overall out-of-hospital preparedness in Pittsburgh, and the lessons learned
Assessing the influence of the rhizosphere on soil hydraulic properties using X-ray Computed Tomography and numerical modelling
Understanding the dynamics of water distribution in soil is crucial for enhancing our knowledge of managing soil and water resources. The application of X-ray Computed Tomography (CT) to the plant and soil sciences is now well established. However, few studies have utilised the technique for visualising water in soil pore spaces. Here we utilise this method to visualise the water in soil in situ and in three-dimensions at successive reductive matric potentials in bulk and rhizosphere soil. The measurements are combined with numerical modelling to determine the unsaturated hydraulic conductivity, providing a complete picture of the hydraulic properties of the soil. The technique was performed on soil cores that were sampled adjacent to established roots (rhizosphere soil) and from soil that had not been influenced by roots (bulk soil). A water release curve was obtained for the different soil types using measurements of their pore geometries derived from CT imaging and verified using conventional methods e.g. pressure plates. The water, soil and air phases from the images were segmented and quantified using image analysis. The water release characteristics obtained for the contrasting soils showed clear differences in hydraulic properties between rhizosphere and bulk soil, especially in clay soil. The data suggests that soils influenced by roots (rhizosphere soil) are less porous due to increased aggregation when compared to bulk soil. The information and insights obtained on the hydraulic properties of rhizosphere and bulk soil will enhance our understanding of rhizosphere biophysics and improve current water uptake models
Simulation of phosphorus implantation into silicon with a single-parameter electronic stopping power model
We simulate dopant profiles for phosphorus implantation into silicon using a
new model for electronic stopping power. In this model, the electronic stopping
power is factorized into a globally averaged effective charge Z1*, and a local
charge density dependent electronic stopping power for a proton. There is only
a single adjustable parameter in the model, namely the one electron radius rs0
which controls Z1*. By fine tuning this parameter, we obtain excellent
agreement between simulated dopant profiles and the SIMS data over a wide range
of energies for the channeling case. Our work provides a further example of
implant species, in addition to boron and arsenic, to verify the validity of
the electronic stopping power model and to illustrate its generality for
studies of physical processes involving electronic stopping.Comment: 11 pages, 7 figures. See http://bifrost.lanl.gov/~reed
Weathering the storm: developments in the acoustic sensing of wind and rain
An Acoustic Rain Gauge (ARG) analyses the underwater sound levels across a wide frequency range, classifies the observed spectrum according to likely source and then determines the local wind speed or rain rate as appropriate. Thispaper covers a trial on the Scotian Shelf off Canada, comparing the geophysical information derived from the acoustic signals with those obtained from other sources
Three-dimensional imaging of the extracellular matrix and cell interactions in the developing prenatal mouse cornea
As the outer lens in the eye, the cornea needs to be strong and transparent. These properties are governed by the arrangement of the constituent collagen fibrils, but the mechanisms of how this develops in mammals is unknown. Using novel 3-dimensional scanning and conventional transmission electron microscopy, we investigated the developing mouse cornea, focusing on the invading cells, the extracellular matrix and the collagen types deposited at different stages. Unlike the well-studied chick, the mouse cornea had no acellular primary stroma. Collagen fibrils initially deposited at E13 from the presumptive corneal stromal cells, become organised into fibril bundles orthogonally arranged between cells. Extensive cell projections branched to adjacent stromal cells and interacted with the basal lamina and collagen fibrils. Types I, II and V collagen were expressed from E12 posterior to the surface ectoderm, and became widespread from E14. Type IX collagen localised to the corneal epithelium at E14. Type VII collagen, the main constituent of anchoring filaments, was localised posterior to the basal lamina. We conclude that the cells that develop the mouse cornea do not require a primary stroma for cell migration. The cells have an elaborate communication system which we hypothesise helps cells to align collagen fibrils
Identification of a primary stroma and novel endothelial cell projections in the developing human cornea
Purpose: To investigate the initial events in the development of the human cornea, focusing on cell migration, and extracellular matrix synthesis and organization. To determine whether elastic fibers are present in the extracellular matrix during early human corneal development. Methods: Human corneas were collected from week 7 to week 17 of development. An elastic fiber-enhancing stain, tannic acid–uranyl acetate, was applied to all tissue. Three-dimensional serial block-face scanning electron microscopy combined with conventional transmission electron microscopy was used to analyze the corneal stroma. Results: An acellular collagenous primary stroma with an orthogonal arrangement of fibrils was identified in the central cornea from week 7 of corneal development. At week 7.5, mesenchymal cells migrated toward the central cornea and associated with the acellular collagenous matrix. Novel cell extensions from the endothelium were identified. Elastic fibers were found concentrated in the posterior peripheral corneal stroma from week 12 of corneal development. Conclusions: This study provides novel evidence of an acellular primary stroma in the early development of the embryonic human cornea. Cell extensions exist as part of a communication system and are hypothesized to assist in the migration of the mesenchymal cells and the development of the mature cornea. Elastic fibers identified in early corneal development may play an important role in establishing corneal shape
Employable knowledge: benchmarking education about standardization in the UK
For academics and students in the United Kingdom the main source of standards is via British Standards Institution (BSI). The research demonstrates that British, European and International Standards play a key role in many areas of education. In some disciplines their inclusion in the course is mandatory, e.g. in building construction and performing risk assessments of equipment. Where not a requirement, other courses successfully encourage students to understand and apply specific standards and principles from them, to their design and project work, in topic areas such as quality management and user-computer interface design. Assessment practice is a key part of learning and academics have indicated how this fitted into the learning activity, e.g. by expecting students to develop an understanding of standards and reference them in all assessed work.
Likewise, students taking part in the survey also suggest that they were actively engaged with one or more standards and that their understanding was measured through an assessed activity. However, students also emphasised the importance of additional support, e.g. introduction to standards in the workplace or as part of work placements, by library staff as an information resource, and by presentations from BSI experts.
Employers have also indicated the importance of students’ knowledge, understanding and appreciation of relevant standards in the right context, emphasising their desire for standards to be included more widely in the curriculum.
The draft recommendations from this study were subject to International review and comment, the results from this review served to strengthen the recommendations of this work.
This research was commissioned by British Standards Institution (BSI).
This research was produced in association with the Department for Business, Innovation and Skills as part of its ongoing programme of support for standardization.
Grateful thanks are due to all those who filled in the questionnaire or who attended the workshops
Discovery of 28 pulsars using new techniques for sorting pulsar candidates
Modern pulsar surveys produce many millions of candidate pulsars, far more
than can be individually inspected. Traditional methods for filtering these
candidates, based upon the signal-to-noise ratio of the detection, cannot
easily distinguish between interference signals and pulsars. We have developed
a new method of scoring candidates using a series of heuristics which test for
pulsar-like properties of the signal. This significantly increases the
sensitivity to weak pulsars and pulsars with periods close to interference
signals. By applying this and other techniques for ranking candidates from a
previous processing of the Parkes Multi-beam Pulsar Survey, 28 previously
unknown pulsars have been discovered. These include an eccentric binary system
and a young pulsar which is spatially coincident with a known supernova
remnant.Comment: To be published in Monthly Notices of the Royal Astronomical Society.
11 pages, 9 figure
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