10,850 research outputs found
Photometric properties and luminosity function of nearby massive early-type galaxies
We perform photometric analyses for a bright early-type galaxy (ETG) sample
with 2949 galaxies ( mag) in the redshift range of 0.05 to
0.15, drawn from the SDSS DR7 with morphological classification from Galaxy Zoo
1. We measure the Petrosian and isophotal magnitudes, as well as the
corresponding half-light radius for each galaxy. We find that for brightest
galaxies ( mag), our Petrosian magnitudes, and isophotal
magnitudes to 25 and 1\% of the sky brightness are on
average 0.16 mag, 0.20 mag, and 0.26 mag brighter than the SDSS Petrosian
values, respectively. In the first case the underestimations are caused by
overestimations in the sky background by the SDSS PHOTO algorithm, while the
latter two are also due to deeper photometry. Similarly, the typical half-light
radii () measured by the SDSS algorithm are smaller than our
measurements. As a result, the bright-end of the -band luminosity function
is found to decline more slowly than previous works. Our measured luminosity
densities at the bright end are more than one order of magnitude higher than
those of Blanton et al. (2003), and the stellar mass densities at and are a few tenths
and a factor of few higher than those of Bernardi et al. (2010). These results
may significantly alleviate the tension in the assembly of massive galaxies
between observations and predictions of the hierarchical structure formation
model.Comment: 43 pages, 14 figures, version accepted for publication in the
Astrophysical Journa
End-to-End User Participation in Information Systems Development: A Case Study Based on a Control Perspective
Despite its well recognized importance, user participation in information systems development (ISD) is often limited, passive, symbolic, or marginal in practice. Users are thought to be in a weak position to influence the process and outcome of ISD. As an exploratory case study, this research reports on a refreshing user participation experience to examine what kinds of user behavior can exert strong control over ISD and how. In developing a core business system for a large commercial bank, a group of business experts collocated with the developers as part of the development team. Results show that strong control by users was achieved through their end-toend participation, which was instrumental for ISD success in terms of high quality and smooth rollout. In particular, users’ influence was strengthened over time through their participation by doing in completing some of the key tasks usually done by the IS staff. This research contributes toward a new theory on user participation from a control perspective
Positive surface charge of GluN1 N-terminus mediates the direct interaction with EphB2 and NMDAR mobility.
Localization of the N-methyl-D-aspartate type glutamate receptor (NMDAR) to dendritic spines is essential for excitatory synaptic transmission and plasticity. Rather than remaining trapped at synaptic sites, NMDA receptors undergo constant cycling into and out of the postsynaptic density. Receptor movement is constrained by protein-protein interactions with both the intracellular and extracellular domains of the NMDAR. The role of extracellular interactions on the mobility of the NMDAR is poorly understood. Here we demonstrate that the positive surface charge of the hinge region of the N-terminal domain in the GluN1 subunit of the NMDAR is required to maintain NMDARs at dendritic spine synapses and mediates the direct extracellular interaction with a negatively charged phospho-tyrosine on the receptor tyrosine kinase EphB2. Loss of the EphB-NMDAR interaction by either mutating GluN1 or knocking down endogenous EphB2 increases NMDAR mobility. These findings begin to define a mechanism for extracellular interactions mediated by charged domains
Observer-based fault-tolerant control for a class of networked control systems with transfer delays
Abstract not availableZehui Mao, Bin Jiang, Peng Sh
Evaluation of ecological migrants’ adaptation to their new living area in Three-River Headwater wetlands, China
AbstractEcological migration is an important policy for sustainable ecosystem management, which usually relocates a large number of residents from their traditional living regions with high ecological sensitivity to other areas with low ecological sensitivity as part of the government's initiative to restore and recover seriously degraded ecosystems. Evaluation of ecological migrants’ adaptation to their new living area is essential for assessing the success of migration and directing the design and implementation of measures to improve the effectiveness of migration. In this research, the adaptation of ecological migrants to their new living area was investigated and analyzed in Three-River Headwater region, a typical and significant migration area in China. The questionnaire survey method was applied. Three many issues related to migrants’ adaptation were discussed, namely the determination of suitable migration population size, the choice of follow-up industry and the integration issue in ecological migration. The result indicated that the majority of migrants could adapt to their new living places and could live with a better life standard. In spite of this, the unsuitability for new work was the major problem for the ecological migration with 72% people unable for their new work
A novel adenoviral vector carrying an all-in-one Tet-On system with an autoregulatory loop for tight, inducible transgene expression
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