441 research outputs found
z ~ 4 Hα Emitters in the Great Observatories Origins Deep Survey: Tracing the Dominant Mode for Growth of Galaxies
We present evidence for strong Hα emission in galaxies with spectroscopic redshifts in the range of 3.8 10^(11) M_☉) galaxies at z ~ 3. This "strong Hα phase" of star formation plays a dominant role in galaxy growth at z ~ 4, and they are likely progenitors of massive red galaxies at lower redshifts
The Evolution of Density Structure of Starless and Protostellar Cores
We present a near-infrared extinction study of nine dense cores at
evolutionary stages between starless to Class I. Our results show that the
density structure of all but one observed cores can be modeled with a single
power law rho \propto r^p between ~ 0.2R-R of the cores. The starless cores in
our sample show two different types of density structures, one follows p ~ -1.0
and the other follows p ~ -2.5, while the protostellar cores all have p ~ -2.5.
The similarity between the prestellar cores with p ~ -2.5 and protostellar
cores implies that those prestellar cores could be evolving towards the
protostellar stage. The slope of p ~ -2.5 is steeper than that of an singular
isothermal sphere, which may be interpreted with the evolutionary model of
cores with finite mass.Comment: 19 pages, 3 figures, accepted for publication in the Astrophysical
Journa
Outflows and Massive Stars in the protocluster IRAS 05358+3543
We present new near-IR H2, CO J=2-1, and CO J = 3-2 observations to study
outflows in the massive star forming region IRAS 05358+3543. The
Canada-France-Hawaii Telescope H2 images and James Clerk Maxwell Telescope CO
data cubes of the IRAS 05358 region reveal several new outflows, most of which
emerge from the dense cluster of sub-mm cores associated with the Sh 2-233IR NE
cluster to the northeast of IRAS 05358. We used Apache Point Observatory (APO)
JHK spectra to determine line of sight velocities of the outflowing material.
Analysis of archival VLA cm continuum data and previously published VLBI
observations reveal a massive star binary as a probable source of one or two of
the outflows. We have identified probable sources for 6 outflows and candidate
counterflows for 7 out of a total of 11 seen to be originating from the IRAS
05358 clusters. We classify the clumps within Sh 2-233IR NE as an early
protocluster and Sh 2-233IR SW as a young cluster, and conclude that the
outflow energy injection rate approximately matches the turbulent decay rate in
Sh 2-233IR NE.Comment: 15 figures, 42 pages, accepted for publication in the Astrophysical
Journal. Full size figures are included at
http://casa.colorado.edu/~ginsbura/iras05358.htm. Data can be accessed from
figshare: http://figshare.com/articles/IRAS_05358_3543_Data_Cubes/80631
Metrology Camera System of Prime Focus Spectrograph for Subaru Telescope
The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber
spectrograph designed for the prime focus of the 8.2m Subaru telescope. The
metrology camera system of PFS serves as the optical encoder of the COBRA fiber
motors for the configuring of fibers. The 380mm diameter aperture metrology
camera will locate at the Cassegrain focus of Subaru telescope to cover the
whole focal plane with one 50M pixel Canon CMOS sensor. The metrology camera is
designed to provide the fiber position information within 5{\mu}m error over
the 45cm focal plane. The positions of all fibers can be obtained within 1s
after the exposure is finished. This enables the overall fiber configuration to
be less than 2 minutes.Comment: 10 pages, 12 figures, SPIE Astronomical Telescopes and
Instrumentation 201
POINeT: protein interactome with sub-network analysis and hub prioritization
<p>Abstract</p> <p>Background</p> <p>Protein-protein interactions (PPIs) are critical to every aspect of biological processes. Expansion of all PPIs from a set of given queries often results in a complex PPI network lacking spatiotemporal consideration. Moreover, the reliability of available PPI resources, which consist of low- and high-throughput data, for network construction remains a significant challenge. Even though a number of software tools are available to facilitate PPI network analysis, an integrated tool is crucial to alleviate the burden on querying across multiple web servers and software tools.</p> <p>Results</p> <p>We have constructed an integrated web service, POINeT, to simplify the process of PPI searching, analysis, and visualization. POINeT merges PPI and tissue-specific expression data from multiple resources. The tissue-specific PPIs and the numbers of research papers supporting the PPIs can be filtered with user-adjustable threshold values and are dynamically updated in the viewer. The network constructed in POINeT can be readily analyzed with, for example, the built-in centrality calculation module and an integrated network viewer. Nodes in global networks can also be ranked and filtered using various network analysis formulas, i.e., centralities. To prioritize the sub-network, we developed a ranking filtered method (S3) to uncover potential novel mediators in the midbody network. Several examples are provided to illustrate the functionality of POINeT. The network constructed from four schizophrenia risk markers suggests that EXOC4 might be a novel marker for this disease. Finally, a liver-specific PPI network has been filtered with adult and fetal liver expression profiles.</p> <p>Conclusion</p> <p>The functionalities provided by POINeT are highly improved compared to previous version of POINT. POINeT enables the identification and ranking of potential novel genes involved in a sub-network. Combining with tissue-specific gene expression profiles, PPIs specific to selected tissues can be revealed. The straightforward interface of POINeT makes PPI search and analysis just a few clicks away. The modular design permits further functional enhancement without hampering the simplicity. POINeT is available at <url>http://poinet.bioinformatics.tw/</url>.</p
A Cascaded Approach for ultraly High Performance Lesion Detection and False Positive Removal in Liver CT Scans
Liver cancer has high morbidity and mortality rates in the world. Multi-phase
CT is a main medical imaging modality for detecting/identifying and diagnosing
liver tumors. Automatically detecting and classifying liver lesions in CT
images have the potential to improve the clinical workflow. This task remains
challenging due to liver lesions' large variations in size, appearance, image
contrast, and the complexities of tumor types or subtypes. In this work, we
customize a multi-object labeling tool for multi-phase CT images, which is used
to curate a large-scale dataset containing 1,631 patients with four-phase CT
images, multi-organ masks, and multi-lesion (six major types of liver lesions
confirmed by pathology) masks. We develop a two-stage liver lesion detection
pipeline, where the high-sensitivity detecting algorithms in the first stage
discover as many lesion proposals as possible, and the lesion-reclassification
algorithms in the second stage remove as many false alarms as possible. The
multi-sensitivity lesion detection algorithm maximizes the information
utilization of the individual probability maps of segmentation, and the
lesion-shuffle augmentation effectively explores the texture contrast between
lesions and the liver. Independently tested on 331 patient cases, the proposed
model achieves high sensitivity and specificity for malignancy classification
in the multi-phase contrast-enhanced CT (99.2%, 97.1%, diagnosis setting) and
in the noncontrast CT (97.3%, 95.7%, screening setting)
Intelligent Optimization Algorithms: A Stochastic Closed-Loop Supply Chain Network Problem Involving Oligopolistic Competition for Multiproducts and Their Product Flow Routings
Recently, the first oligopolistic competition model of the closed-loop supply chain network
involving uncertain demand and return has been established. This model belongs to the context
of oligopolistic firms that compete noncooperatively in a Cournot-Nash framework. In this paper,
we modify the above model in two different directions. (i) For each returned product from
demand market to firm in the reverse logistics, we calculate the percentage of its optimal product
flows in each individual path connecting the demand market to the firm. This modification
provides the optimal product flow routings for each product in the supply chain and increases the
optimal profit of each firm at the Cournot-Nash equilibrium. (ii) Our model extends the method
of finding the Cournot-Nash equilibrium involving smooth objective functions to problems
involving nondifferentiable objective functions. This modification caters for more real-life
applications as a lot of supply chain problems involve nonsmooth functions. Existence of the
Cournot-Nash equilibrium is established without the assumption of differentiability of the given
functions. Intelligent algorithms, such as the particle swarm optimization algorithm and the
genetic algorithm, are applied to find the Cournot-Nash equilibrium for such nonsmooth
problems. Numerical examples are solved to illustrate the efficiency of these algorithms
Patient-controlled epidural Levobupicvacaine with or without Fentanyl for post-cesarean section pain relief
Purpose. The purpose of this study was to compare the analgesic properties of levobupivacaine with or without fentanyl for patient-controlled epidural analgesia after Cesarean section in a randomized, double-blinded study. Methods. We enrolled American Society of Anesthesiologists class I/II, full-term pregnant women at National Taiwan University Hospital who received patient-controlled epidural analgesia after Cesarean section between 2009 and 2010. Eighty women were randomly assigned into two groups. In group A, the 40 subjects received drug solutions made of 0.6 mg/ml levobupivacaine plus 2 mcg/ml fentanyl, and in group B the 40 subjects received 1 mg/ml levobupivacaine. Maintenance was self-administered boluses and a continuous background infusion. Results. There were no significant differences in the resting and dynamic pain scales and total volume of drug used between the two groups. Patient satisfaction was good in both groups. Conclusion. Our study showed that pure epidural levobupivacaine can provide comparative analgesic properties to the levobupivacaine-fentanyl combination after Cesarean section. Pure levobupivacaine may serve as an alternative pain control regimen to avoid opioid-related adverse events in parturients
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