202 research outputs found
Imaging the Gamma-Ray Sky with SPI aboard INTEGRAL
The spectrometer SPI on INTEGRAL allows for the first time simultaneous
imaging of diffuse and point-like emission in the hard X-ray and soft gamma-ray
regime. To fully exploit the capabilities of the instrument, we implemented the
MREM image deconvolution algorithm, initially developed for COMPTEL data
analysis, to SPI data analysis. We present the performances of the algorithm by
means of simulations and apply it to data accumulated during the first 2
mission years of INTEGRAL. Skymaps are presented for the 1809 keV gamma-ray
line, attributed to the radioactive decay of 26Al, and for continuum energy
bands, covering the range 20 keV - 3 MeV. The 1809 keV map indicates that
emission is clearly detected by SPI from the inner Galactic radian and from the
Cygnus region. The continuum maps reveal the transition between a point-source
dominated hard X-ray sky to a diffuse emission dominated soft gamma-ray sky.
From the skymaps, we extract a Galactic ridge emission spectrum that matches
well SPI results obtained by model fitting. By comparing our spectrum with the
cumulative flux measured by IBIS from point sources, we find indications for
the existence of an unresolved or diffuse emission component above ~100 keV.Comment: 12 pages, 7 figure
An improved ontological representation of dendritic cells as a paradigm for all cell types
The Cell Ontology (CL) is designed to provide a standardized representation of cell types for data annotation. Currently, the CL employs multiple is_a relations, defining cell types in terms of histological, functional, and lineage properties, and the majority of definitions are written with sufficient generality to hold across multiple species. This approach limits the CLâs utility for cross-species data integration. To address this problem, we developed a method for the ontological representation of cells and applied this method to develop a dendritic cell ontology (DC-CL). DC-CL subtypes are delineated on the basis of surface protein expression, systematically including both species-general and species-specific types and optimizing DC-CL for the analysis of flow cytometry data. This approach brings benefits in the form of increased accuracy, support for reasoning, and interoperability with other ontology resources.
104. Barry Smith, âToward a Realistic Science of Environmentsâ, Ecological Psychology, 2009, 21 (2), April-June, 121-130.
Abstract: The perceptual psychologist J. J. Gibson embraces a radically externalistic view of mind and action. We have, for Gibson, not a Cartesian mind or soul, with its interior theater of contents and the consequent problem of explaining how this mind or soul and its psychological environment can succeed in grasping physical objects external to itself. Rather, we have a perceiving, acting organism, whose perceptions and actions are always already tuned to the parts and moments, the things and surfaces, of its external environment. We describe how on this basis Gibson sought to develop a realist science of environments which will be âconsistent with physics, mechanics, optics, acoustics, and chemistryâ
On Type Ia Supernovae From The Collisions of Two White Dwarfs
We explore collisions between two white dwarfs as a pathway for making Type
Ia Supernovae (SNIa). White dwarf number densities in globular clusters allow
10-100 redshift <1 collisions per year, and observations by (Chomiuk et al.
2008) of globular clusters in the nearby S0 galaxy NGC 7457 have detected what
is likely to be a SNIa remnant. We carry out simulations of the collision
between two 0.6 solar mass white dwarfs at various impact parameters and mass
resolutions. For impact parameters less than half the radius of the white
dwarf, we find such collisions produce approximately 0.4 solar masses of Ni56,
making such events potential candidates for underluminous SNIa or a new class
of transients between Novae and SNIa.Comment: 4 pages, 4 figures, 1 tabl
Spatial Distribution of Nucleosynthesis Products in Cassiopeia A: Comparison Between Observations and 3D Explosion Models
We examine observed heavy element abundances in the Cassiopeia A supernova
remnant as a constraint on the nature of the Cas A supernova. We compare bulk
abundances from 1D and 3D explosion models and spatial distribution of elements
in 3D models with those derived from X-ray observations. We also examine the
cospatial production of 26Al with other species. We find that the most reliable
indicator of the presence of 26Al in unmixed ejecta is a very low S/Si ratio
(~0.05). Production of N in O/S/Si-rich regions is also indicative. The
biologically important element P is produced at its highest abundance in the
same regions. Proxies should be detectable in supernova ejecta with high
spatial resolution multiwavelength observations.Comment: To appear in the Conference Proceedings for the "10th Symposium on
Nuclei in the Cosmos (NIC X)", July 27 - August 1 2008, Mackinack Island,
Michigan, US
VO: Vaccine Ontology
Vaccine research, as well as the development, testing, clinical trials, and commercial uses of vaccines involve complex processes with various biological data that include gene and protein expression, analysis of molecular and cellular interactions, study of tissue and whole body responses, and extensive epidemiological modeling. Although many data resources are available to meet different aspects of vaccine needs, it remains a challenge how we are to standardize vaccine annotation, integrate data about varied vaccine types and resources, and support advanced vaccine data analysis and inference. To address these problems, the community-based Vaccine Ontology (VO, "http://www.violinet.org/vaccineontology":http://www.violinet.org/vaccineontology) has been developed through collaboration with vaccine researchers and many national and international centers and programs, including the National Center for Biomedical Ontology (NCBO), the Infectious Disease Ontology (IDO) Initiative, and the Ontology for Biomedical Investigations (OBI). VO utilizes the Basic Formal Ontology (BFO) as the top ontology and the Relation Ontology (RO) for definition of term relationships. VO is represented in the Web Ontology Language (OWL) and edited using the Protégé-OWL. Currently VO contains more than 2000 terms and relationships. VO emphasizes on classification of vaccines and vaccine components, vaccine quality and phenotypes, and host immune response to vaccines. These reflect different aspects of vaccine composition and biology and can thus be used to model individual vaccines. More than 200 licensed vaccines and many vaccine candidates in research or clinical trials have been modeled in VO. VO is being used for vaccine literature mining through collaboration with the National Center for Integrative Biomedical Informatics (NCIBI). Multiple VO applications will be presented.

An improved ontological representation of dendritic cells as a paradigm for all cell types
<p>Abstract</p> <p>Background</p> <p>Recent increases in the volume and diversity of life science data and information and an increasing emphasis on data sharing and interoperability have resulted in the creation of a large number of biological ontologies, including the Cell Ontology (CL), designed to provide a standardized representation of cell types for data annotation. Ontologies have been shown to have significant benefits for computational analyses of large data sets and for automated reasoning applications, leading to organized attempts to improve the structure and formal rigor of ontologies to better support computation. Currently, the CL employs multiple <it>is_a </it>relations, defining cell types in terms of histological, functional, and lineage properties, and the majority of definitions are written with sufficient generality to hold across multiple species. This approach limits the CL's utility for computation and for cross-species data integration.</p> <p>Results</p> <p>To enhance the CL's utility for computational analyses, we developed a method for the ontological representation of cells and applied this method to develop a dendritic cell ontology (DC-CL). DC-CL subtypes are delineated on the basis of surface protein expression, systematically including both species-general and species-specific types and optimizing DC-CL for the analysis of flow cytometry data. We avoid multiple uses of <it>is_a </it>by linking DC-CL terms to terms in other ontologies via additional, formally defined relations such as <it>has_function</it>.</p> <p>Conclusion</p> <p>This approach brings benefits in the form of increased accuracy, support for reasoning, and interoperability with other ontology resources. Accordingly, we propose our method as a general strategy for the ontological representation of cells. DC-CL is available from <url>http://www.obofoundry.org</url>.</p
Simulating the Common Envelope Phase of a Red Giant Using SPH and Uniform Grid Codes
We use three-dimensional hydrodynamical simulations to study the rapid infall
phase of the common envelope interaction of a red giant branch star of mass
equal to 0.88 \msun and a companion star of mass ranging from 0.9 down to 0.1
\msun. We first compare the results obtained using two different numerical
techniques with different resolutions, and find overall very good agreement. We
then compare the outcomes of those simulations with observed systems thought to
have gone through a common envelope. The simulations fail to reproduce those
systems in the sense that most of the envelope of the donor remains bound at
the end of the simulations and the final orbital separations between the
donor's remnant and the companion, ranging from 26.8 down to 5.9 \rsun, are
larger than the ones observed. We suggest that this discrepancy vouches for
recombination playing an essential role in the ejection of the envelope and/or
significant shrinkage of the orbit happening in the subsequent phase.Comment: 45 pages, 19 figures, accepted to Ap
The Gallery 2010
This is a digital copy of the print book produced by the Gallery 2010 team. Contents: p. 1 Life Around Westby, p. 9 Graphic Design, p. 19 Illustration, p. 27 Jewelry, p. 37 Painting, p. 45 Photography, p. 57 Printmaking, p. 67 Three-Dimensional, p. 77 Rowan Gallery Openings.
A Compact Disc (CD) included with the print book is not included here.
Files for individual sections may be viewed on the detailed metadata page by clicking on the book title.https://rdw.rowan.edu/the_gallery/1006/thumbnail.jp
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