13,604 research outputs found
Delays in diagnosis and treatment of lung cancer: Lessons from US healthcare settings.
YZ is supported by an Academic Clinical Fellowship in General Practice, awarded by Health Education East of England. GL is supported by a Cancer Research UK Clinician Scientist Fellowship (A18180).This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.canep.2015.08.00
Type Iax Supernovae
Type Iax supernovae (SN Iax), also called SN 2002cx-like supernovae, are the
largest class of peculiar white dwarf (thermonuclear) supernovae, with over
fifty members known. SN Iax have lower ejecta velocity and lower luminosities,
and these parameters span a much wider range, than normal type Ia supernovae
(SN Ia). SN Iax are spectroscopically similar to some SN Ia near maximum light,
but are unique among all supernovae in their late-time spectra, which never
become fully nebular. SN Iax overwhelmingly occur in late-type host galaxies,
implying a relatively young population. The SN Iax 2012Z is the only white
dwarf supernova for which a pre-explosion progenitor system has been detected.
A variety of models have been proposed, but one leading scenario has emerged: a
type Iax supernova may be a pure-deflagration explosion of a carbon-oxygen (or
hybrid carbon-oxygen-neon) white dwarf, triggered by helium accretion to the
Chandrasekhar mass, that does not necessarily fully disrupt the star.Comment: Author version of a chapter in the 'Handbook of Supernovae', edited
by A. Alsabti and P. Murdin, Springer. 31 pages, 6 figure
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Systematic alteration of ATAC-seq for profiling open chromatin in cryopreserved nuclei preparations from livestock tissues.
The use of Assay for Transposase-Accessible Chromatin (ATAC-seq) to profile chromatin accessibility has surged over the past years, but its applicability to tissues has been very limited. With the intent of preserving nuclear architecture during long-term storage, cryopreserved nuclei preparations from chicken lung were used to optimize ATAC-seq. Sequencing data were compared with existing DNase-seq, ChIP-seq, and RNA-seq data to evaluate library quality, ultimately resulting in a modified ATAC-seq method capable of generating high quality chromatin accessibility data from cryopreserved nuclei preparations. Using this method, nucleosome-free regions (NFR) identified in chicken lung overlapped half of DNase-I hypersensitive sites, coincided with active histone modifications, and specifically marked actively expressed genes. Notably, sequencing only the subnucleosomal fraction dramatically improved signal, while separation of subnucleosomal reads post-sequencing did not improve signal or peak calling. The broader applicability of this modified ATAC-seq technique was tested using cryopreserved nuclei preparations from pig tissues, resulting in NFR that were highly consistent among biological replicates. Furthermore, tissue-specific NFR were enriched for binding motifs of transcription factors related to tissue-specific functions, and marked genes functionally enriched for tissue-specific processes. Overall, these results provide insights into the optimization of ATAC-seq and a platform for profiling open chromatin in animal tissues
Reynolds number effect on the wake of two staggered cylinders
Author name used in this publication: Y. Zhou2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Favre- and Reynolds-averaged velocity measurements: Interpreting PIV and LDA measurements in combustion
Previous studies using particle image velocimetry (PIV) and laser Doppler anemometry
(LDA) have raised the question of how these measurements should be compared. This study
reports on the difference between Favre-averaged and Reynolds-averaged velocity statistics
for a turbulent burner using PIV and LDA for unconditional and conditional velocity
measurements. The experimental characterization of flow fields of premixed and stratified
methane/air flames is carried out under globally turbulent lean conditions (global equivalence
ratio at 0.75), over a range of stratifications and swirl numbers. Unconditioned velocity data
was acquired using aluminium oxide to seed the flow field. Conditioned measurements were
performed using vegetable oil aerosol as seed, which burns through the flame front, thus
allowing only the non-reacting flow velocities to be obtained. A critical comparison of
unconditioned velocity profiles measured using both PIV and LDA, including axial, radial,
and tangential components is made against conditioned and reconstructed mean velocities at
different cross-sections of the flame. The comparison reveals how the differences between
the Favre-averaged (unconditioned) and the Reynolds-averaged (conditioned) velocity
measurements in the flame brush region can be accounted for using the mean progress of
reaction, and highlights the limits of the accuracy and agreement between PIV and LDA
measurements.The authors would like to thank the University of Engineering and Technology Peshawar
(Pakistan) and the University of Cambridge for their financial contributions to this workThis is the author accepted manuscript. The advanced access article on the publisher's website can be found at: http://www.sciencedirect.com/science/article/pii/S1540748914002193# © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved
Common carp (Cyprinus carpio L.) alters its feeding niche in response to changing food resources: direct observations in simulated ponds
We used customized fish tanks as model fish ponds to observe grazing, swimming, and conspecific social behavior of common carp (Cyprinus carpio) under variable food-resource conditions to assess alterations in feeding niche. Different food and feeding situations were created by using only pond water or pond water plus pond bottom sediment or pond water plus pond bottom sediment and artificial feeding. All tanks were fertilized twice, prior to stocking and 2 weeks later after starting the experiment to stimulate natural food production. Common carp preferred artificial feed over benthic macroinvertebrates, followed by zooplankton. Common carp did not prefer any group of phytoplankton in any treatment. Common carp was mainly benthic in habitat choice, feeding on benthic macroinvertebrates when only plankton and benthic macroinvertebrates were available in the system. In the absence of benthic macroinvertebrates, their feeding niche shifted from near the bottom of the tanks to the water column where they spent 85% of the total time and fed principally on zooplankton. Common carp readily switched to artificial feed when available, which led to better growth. Common carp preferred to graze individually. Behavioral observations of common carp in tanks yielded new information that assists our understanding of their ecological niche. This knowledge could be potentially used to further the development of common carp aquaculture
Functional MRI of postnatal visual development in normal rat superior colliculi
Theme: Engineering the Future of BiomedicineThis study employed blood oxygenation level-dependent functional MRI (BOLD-fMRI) to evaluate the visual responses in the superior colliculus of the developing rat brain from the time of eyelid opening to adulthood. Upon flash illumination to the contralateral eye, the regional BOLD response underwent a systematic increase in amplitude with age especially after the third postnatal week. However, no significant difference in BOLD signal increase was found between postnatal days 14 and 21. Our results constitute the first fMRI report in demonstrating the critical period of visual functions in the rat brain during maturation. This can be potentially useful in establishing the links between changes in relation to visual sensory development. ©2009 IEEE.published_or_final_versionThe 31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2009), Minneapolis, MN., 3-6 September 2009. In Proceedings of the 31st EMBC, 2009, p. 4436-443
Noninvasive fMRI investigation of interaural level difference processing the rat auditory subcortex
published_or_final_versio
Turbulent wake of an inclined cylinder with water running
Author name used in this publication: Y. Zhou2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Alternative drag coefficient in the wake of an isolated bluff body
Author name used in this publication: Y. Zhou2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
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