19,402 research outputs found
The segregation of starless and protostellar clumps in the Hi-GAL l=224deg region
Stars form in dense, dusty structures, which are embedded in larger clumps of
molecular clouds often showing a clear filamentary structure on large scales (>
1pc). One of the best-studied regions in the Hi-GAL survey can be observed
toward the l=224deg field. Here, a filamentary region has been studied and it
has been found that protostellar clumps are mostly located along the main
filament, whereas starless clumps are detected off this filament and are
instead found on secondary, less prominent filaments. We want to investigate
this segregation effect and how it may affect the clumps properties. We mapped
the 12CO(1-0) line and its main three isotopologues toward the two most
prominent filaments observed toward the l=224deg field using the Mopra radio
telescope, in order to set observational constraints on the dynamics of these
structures and the associated starless and protostellar clumps. Compared to the
starless clumps, the protostellar clumps are more luminous, more turbulent and
lie in regions where the filamentary ambient gas shows larger linewidths. We
see evidence of gas flowing along the main filament, but we do not find any
signs of accretion flow from the filament onto the Hi-GAL clumps. We analyze
the radial column density profile of the filaments and their gravitational
stability. The more massive and highly fragmented main filament appears to be
thermally supercritical and gravitationally bound, assuming that all of the
non-thermal motion is contributing thermal-like support, suggesting a later
stage of evolution compared to the secondary filament. The status and
evolutionary phase of the Hi-GAL clumps would then appear to correlate with
that of the host filament.Comment: Accepted for publication on "Astronomy and Astrophysics
Assessment of potential ICT-related collaboration and innovation capacity in east Africa
Due to a significant investment in digital infrastructure and a pro-innovation policy and regulatory framework, the Innovation Ecosystems in Nairobi, Dar es Salaam and Kampala have considerably expanded over the last five years, incorporating new national and international Innovation Stakeholders. This is important in the context of realising the objectives of National Development Plans, and addressing high levels of youth and graduate unemployment. This paper presents a sub-set of results from a comprehensive baseline analysis of Innovation Ecosystems in these cities with a focus on assessing the current level of ICT-related Collaboration, Innovation Absorption capacity and challenges to be addressed. In order to benefit from these developments, it is recommended that the public sector take a leadership role in establishing necessary mechanisms that will stimulate multi-stakeholder collaboration amongst existing Innovation Actors to foster a sustainable Collaborative Open Innovation and Entrepreneurial culture
Surface parameters of stannic oxide in powder, ceramic, and gel form by nitrogen adsorption techniques Interim report
Surface parameters of stannic oxide in powder, ceramic, and gel form by nitrogen adsorption techniques - analysis of adsorption isotherm
Categories of insight and their correlates: An exploration of relationships among classic-type insight problems, rebus puzzles, remote associates and esoteric analogies.
A central question in creativity concerns how insightful ideas emerge. Anecdotal examples of insightful scientific and technical discoveries include Goodyear's discovery of the vulcanization of rubber, and Mendeleev's realization that there may be gaps as he tried to arrange the elements into the Periodic Table. Although most people would regard these discoveries as insightful, cognitive psychologists have had difficulty in agreeing on whether such ideas resulted from insights or from conventional problem solving processes. One area of wide agreement among psychologists is that insight involves a process of restructuring. If this view is correct, then understanding insight and its role in problem solving will depend on a better understanding of restructuring and the characteristics that describe it.
This article proposes and tests a preliminary classification of insight problems based on several restructuring characteristics: the need to redefine spatial assumptions, the need to change defined forms, the degree of misdirection involved, the difficulty in visualizing a possible solution, the number of restructuring sequences in the problem, and the requirement for figure-ground type reversals. A second purpose of the study was to compare performance on classic spatial insight problems with two types of verbal tests that may be related to insight, the Remote Associates Test (RAT), and rebus puzzles. In doing so, we report on the results of a survey of 172 business students at the University of Waikato in New Zealand who completed classic-type insight, RAT and rebus problems
Mopra CO Observations of the Bubble HII Region RCW120
We use the Mopra radio telescope to test for expansion of the molecular gas
associated with the bubble HII region RCW120. A ring, or bubble, morphology is
common for Galactic HII regions, but the three-dimensional geometry of such
objects is still unclear. Detected near- and far-side expansion of the
associated molecular material would be consistent with a three-dimensional
spherical object. We map the transitions of CO,
CO, CO, and CO, and detect emission from all
isotopologues. We do not detect the masing lines of
CHOH at 108.8939 GHz. The strongest CO emission is from the
photodissociation region (PDR), and there is a deficit of emission toward the
bubble interior. We find no evidence for expansion of the molecular material
associated with RCW120 and therefore can make no claims about its geometry. The
lack of detected expansion is roughly in agreement with models for the
time-evolution of an HII region like RCW120, and is consistent with an
expansion speed of . Single-position CO spectra show
signatures of expansion, which underscores the importance of mapped spectra for
such work. Dust temperature enhancements outside the PDR of RCW120 coincide
with a deficit of emission in CO, confirming that these temperature
enhancements are due to holes in the RCW120 PDR. H emission shows that
RCW120 is leaking of the ionizing photons into the interstellar
medium (ISM) through PDR holes at the locations of the temperature
enhancements. H-alpha emission also shows a diffuse "halo" from leaked photons
not associated with discrete holes in the PDR. Overall of all
ionizing photons are leaking into the nearby ISM.Comment: 35 pages, 14 figures. Accepted to Ap
SLoMo: automated site localization of modifications from ETD/ECD mass spectra
Recently, software has become available to automate localization of phosphorylation sites from CID data and to assign associated confidence scores. We present an algorithm, SLoMo (Site Localization of Modifications), which extends this capability to ETD/ECD mass spectra. Furthermore, SLoMo caters for both high and low resolution data and allows for site-localization of any UniMod post-translational modification. SLoMo accepts input data from a variety of formats (e.g., Sequest, OMSSA). We validate SLoMo with high and low resolution ETD, ECD, and CID data
NLC-2 graph recognition and isomorphism
NLC-width is a variant of clique-width with many application in graph
algorithmic. This paper is devoted to graphs of NLC-width two. After giving new
structural properties of the class, we propose a -time algorithm,
improving Johansson's algorithm \cite{Johansson00}. Moreover, our alogrithm is
simple to understand. The above properties and algorithm allow us to propose a
robust -time isomorphism algorithm for NLC-2 graphs. As far as we
know, it is the first polynomial-time algorithm.Comment: soumis \`{a} WG 2007; 12
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