2,728 research outputs found
Module identification in bipartite and directed networks
Modularity is one of the most prominent properties of real-world complex
networks. Here, we address the issue of module identification in two important
classes of networks: bipartite networks and directed unipartite networks. Nodes
in bipartite networks are divided into two non-overlapping sets, and the links
must have one end node from each set. Directed unipartite networks only have
one type of nodes, but links have an origin and an end. We show that directed
unipartite networks can be conviniently represented as bipartite networks for
module identification purposes. We report a novel approach especially suited
for module detection in bipartite networks, and define a set of random networks
that enable us to validate the new approach
Vascular smooth muscle cell apoptosis in aneurysmal, occlusive, and normal human aortas
AbstractPurpose: Apoptosis is a physiologic mechanism of cell death that regulates mass and architecture in many tissues. Apoptosis has been described as a feature in human vascular atherosclerosis and large vessel structural integrity. We examined the extent of vascular smooth muscle cell (VSMC) apoptosis in aneurysmal, occlusive, and normal human aortic tissue. Methods: Tissue samples of aneurysmal, occlusive, and normal human infrarenal aorta were evaluated. DNA fragmentation detection methods, immunohistochemistry, and DNA electrophoresis determined VSMC density, VSMC apoptosis, and apoptosis markers. Apoptotic cells and VSMC nuclei were counted with the use of computer-generated image analysis. Aortic subtypes were compared statistically by analysis of variance. Results: Seventeen aneurysmal, ten occlusive, and five normal human aortas were evaluated. By α1-actin immunostaining, VSMC density was least in aneurysmal aortas (271.8 ± 13.5 cells/high-power field [HPF]) compared with occlusive aorta (278.2 ± 39.4 cells/HPF) and normal aortas (291.0 ± 25.4 cells/HPF; P = not significant). Presence of apoptotic VSMCs was demonstrated by terminal deoxynucleotidyl transferase fragment end labeling and propidium iodide nuclear staining. VSMC apoptosis was greatest within aneurysmal aortas with 11.7 ± 1.5 cells/HPF compared with occlusive aortas with 3.3 ± 0.8 cells/HPF (P <.05) and normal aortas with 3.75 ± 4.6 cells/HPF (P <.05). Significant differences in apoptosis markers, p53 or bcl-2, could not be demonstrated by immunohistochemistry or DNA electrophoresis in aortic subtypes. Conclusion: Apoptosis of VSMCs is increased and VSMC density is decreased within the medial layer of aneurysmal aortic tissue. Structural degeneration of aortic tissue at the cellular level contributes to aneurysmal formation. (J Vasc Surg 2000;31:567-576.
New Solutions to the Firing Squad Synchronization Problems for Neural and Hyperdag P Systems
We propose two uniform solutions to an open question: the Firing Squad
Synchronization Problem (FSSP), for hyperdag and symmetric neural P systems,
with anonymous cells. Our solutions take e_c+5 and 6e_c+7 steps, respectively,
where e_c is the eccentricity of the commander cell of the dag or digraph
underlying these P systems. The first and fast solution is based on a novel
proposal, which dynamically extends P systems with mobile channels. The second
solution is substantially longer, but is solely based on classical rules and
static channels. In contrast to the previous solutions, which work for
tree-based P systems, our solutions synchronize to any subset of the underlying
digraph; and do not require membrane polarizations or conditional rules, but
require states, as typically used in hyperdag and neural P systems
Moving beyond âtheâ business case:How to make corporate sustainability work
One of the most investigated research topics in the corporate sustainability literature is âtheâ business case. Long lionized for linking the profit motive to corporate environmental initiatives, the business case for sustainability is now vehemently criticized. These critics generally argue for a return to the state and stronger regulatory frameworks. Others counter that because the private sector's capabilities are uniquely suited to realizing effective sustainability innovations and outcomes, we must not abandon but further develop our business case understanding. In this view, firms' voluntary efforts are key for innovative solutions to sustainability problems. This article overviews and unites these seemingly disparate positions. We move the field forward by placing in context criticisms and also opportunities for more meaningful positive impacts from corporate sustainability. Specifically, we argue that an effective business case orientation requires shifting to a broader âall stakeholders winâ approach. This entails impact orientation, collaborative approaches, and economic restraint
Wide-field dynamic astronomy in the near-infrared with Palomar Gattini-IR and DREAMS
There have been a dramatic increase in the number of optical and radio transient surveys due to astronomical transients such as gravitational waves and gamma ray bursts, however, there have been a limited number of wide-field infrared surveys due to narrow field-of-view and high cost of infrared cameras, we present two new wide-field near-infrared fully automated surveyors; Palomar Gattini-IR and the Dynamic REd All-sky Monitoring Survey (DREAMS). Palomar Gattini-IR, a 25 square degree J-band imager that begun science operations at Palomar Observatory, USA in October 2018; we report on survey strategy as well as telescope and observatory operations and will also providing initial science results. DREAMS is a 3.75 square degree wide-field imager that is planned for Siding Spring Observatory, Australia; we report on the current optical and mechanical design and plans to achieve on-sky results in 2020. DREAMS is on-track to be one of the first astronomical telescopes to use an Indium Galium Arsenide (InGaAs) detector and we report initial on-sky testing results for the selected detector package. DREAMS is also well placed to take advantage and provide near-infrared follow-up of the LSST
Structural properties of discs and bulges of early-type galaxies
We have used the EFAR sample of galaxies to study the light distributions of
early-type galaxies. We decompose the 2D light distribution of the galaxies in
a flattened spheroidal component with a Sersic radial light profile and an
inclined disc component with an exponential light profile. We show that the
brightest, bulge dominated elliptical galaxies have a fairly broad distribution
in the Sersic profile shape parameter n_B, with a median of about 3.7 and a
sigma of ~0.9. Other galaxies have smaller n_B values, meaning that spheroids
are in general less concentrated than the n_B=4 de Vaucouleurs-law profile.
The results of our light decompositions are robust, even though without
kinematic information we cannot prove that the spheroids and discs are really
pressure- and rotation-supported stellar systems. If we assume that the
detected spheroids and discs are indeed separate components, we can draw the
following conclusions: 1) the spheroid and disc scale sizes are correlated; 2)
bulge-to-total luminosity ratios, bulge effective radii, and bulge n_B values
are all positively correlated; 3) the bivariate space density distribution of
elliptical galaxies in the (luminosity, scale size)-plane is well described by
a Schechter luminosity function in and a log-normal scale-size distribution at
a given luminosity; 4) at the brightest luminosities, the scale size
distribution of elliptical galaxies is similar to those of bright spiral
galaxies; at fainter luminosities the elliptical scale size distribution peaks
at distinctly smaller sizes than the spiral galaxy distribution; and 5) bulge
components of early-type galaxies are typically a factor 1.5 to 2.5 smaller
than the disks of spiral galaxies, while disc components of early-type galaxies
are typically twice as large as the discs of spiral galaxies. [abridged]Comment: 16 pages, 18 figures. Accepted for publication in the MNRA
Corporate social responsibility disclosures in international construction business: trends and prospects
There is increasing sophistication in corporate social responsibility (CSR) disclosures by international construction companies (ICCs). Nevertheless, a systematic analysis of the trends and prospects is yet to appear. This study fills that knowledge gap by providing an understanding of the idiosyncrasies of CSR disclosure and by offering suggestions for future reporting exercises. By examining the top fifty ICCsâ CSR/sustainability reports using content analysis, it found that the more negative impacts a company may have, the more remedial strategies it will disclose in a CSR report. ICCs from economically more developed countries maintain a high level of CSR disclosure, while their counterparts from developing countries have caught up in this CSR cause. As a way to improve the consistency and integrity of disclosed information, ICCs are increasingly adopting CSR reporting guidance frameworks and using third-party assurances. CSR disclosures present a high degree of uniformity while they also show nuanced and intriguing diversity. This research helps understand comprehensively the trends of CSR disclosure in international construction. It will help ICCs extrapolate their future CSR reporting exercises.postprin
Formation and evolution of S0 galaxies: a SAURON case study of NGC7332
We present SAURON integral-field observations of the S0 galaxy NGC7332.
Existing broad-band ground-based and HST photometry reveals a double disk
structure and a boxy bulge interpreted as a bar viewed close to edge-on. The
SAURON two-dimensional stellar kinematic maps confirm the existence of the bar
and inner disk but also uncover the presence of a cold counter-rotating stellar
component within the central 250 pc. The Hbeta and [OIII] emission line maps
show that the ionised gas has a complex morphology and kinematics, including
both a component counter-rotating with respect to the stars and a fainter
co-rotating one. Analysis of the absorption line-strength maps show that
NGC7332 is young everywhere. The presence of a large-scale bar can explain most
of those properties, but the fact that we see a significant amount of unsettled
gas, together with a few peculiar features in the maps, suggest that NGC7332 is
still evolving. Interactions as well as bar-driven processes must thus have
played an important role in the formation and evolution of NGC7332, and
presumably of S0 galaxies in general.Comment: 12 pages, 12 figures, accepted for publication in MNRA
New Cancer Immunotherapy Agents in Development: a report from an associated program of the 31
This report is a summary of \u27New Cancer Immunotherapy Agents in Development\u27 program, which took place in association with the 31st Annual Meeting of the Society for Immunotherapy of Cancer (SITC), on November 9, 2016 in National Harbor, Maryland. Presenters gave brief overviews of emerging clinical and pre-clinical immune-based agents and combinations, before participating in an extended panel discussion with multidisciplinary leaders, including members of the FDA, leading academic institutions and industrial drug developers, to consider topics relevant to the future of cancer immunotherapy
GNOSIS: The first instrument to use fiber bragg gratings for OH suppression
The near-infrared is an important part of the spectrum in astronomy, especially in cosmology because the light from objects in the early universe is redshifted to these wavelengths. However, deep near-infrared observations are extremely difficult to makeThe GNOSIS team acknowledges funding by ARC LIEF
grant LE100100164. C.Q.T. gratefully acknowledges support by the National
Science Foundation Graduate Research Fellowship under grant
No. DGE-1035963
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