Academia Sinica

About: Academia Sinica is a facility organization based out in Taipei, Taiwan. It is known for research contribution in the topics: Population & Galaxy. The organization has 52086 authors who have published 65998 publications receiving 1728114 citations. The organization is also known as: Central Research Academy.

H0LiCOW – I. H0 Lenses in COSMOGRAIL's wellspring: program overview

Abstract: Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark energy, neutrino physics and the spatial curvature of the Universe, as well as discovering new physics. We present H0LiCOW (H-0 Lenses in COSMOGRAIL's Wellspring), a program that aims to measure H-0 with <3.5 per cent uncertainty from five lens systems (B1608+ 656, RXJ1131-1231, HE 0435-1223, WFI2033-4723 and HE 1104-1805). We have been acquiring (1) time delays through COSMOGRAIL and Very Large Array monitoring, (2) high-resolution Hubble Space Telescope imaging for the lens mass modelling, (3) wide-field imaging and spectroscopy to characterize the lens environment and (4) moderate-resolution spectroscopy to obtain the stellar velocity dispersion of the lenses for mass modelling. In cosmological models with one-parameter extension to flat Lambda cold dark matter, we expect to measure H-0 to <3.5 per cent in most models, spatial curvature Omega(k) to 0.004, w to 0.14 and the effective number of neutrino species to 0.2 (1s uncertainties) when combined with current cosmic microwave background (CMB) experiments. These are, respectively, a factor of similar to 15, similar to 2 and similar to 1.5 tighter than CMB alone. Our data set will further enable us to study the stellar initial mass function of the lens galaxies, and the co-evolution of supermassive black holes and their host galaxies. This program will provide a foundation for extracting cosmological distances from the hundreds of time-delay lenses that are expected to be discovered in current and future surveys.

An intensity map of hydrogen 21-cm emission at redshift z ≈ 0.8

Abstract: Observations of 21-cm radio emission by neutral hydrogen at redshifts z approximately 0.5 to approximately 2.5 are expected to provide a sensitive probe of cosmic dark energy. This is particularly true around the onset of acceleration at z approximately 1, where traditional optical cosmology becomes very difficult because of the infrared opacity of the atmosphere. Hitherto, 21-cm emission has been detected only to z = 0.24. More distant galaxies generally are too faint for individual detections but it is possible to measure the aggregate emission from many unresolved galaxies in the 'cosmic web'. Here we report a three-dimensional 21-cm intensity field at z = 0.53 to 1.12. We then co-add neutral-hydrogen (H i) emission from the volumes surrounding about 10,000 galaxies (from the DEEP2 optical galaxy redshift survey). We detect the aggregate 21-cm glow at a significance of approximately 4sigma.

Cancer-associated fibroblasts regulate the plasticity of lung cancer stemness via paracrine signalling.

Abstract: Cancer stem cells (CSCs) are a promising target for treating cancer, yet how CSC plasticity is maintained in vivo is unclear and is difficult to study in vitro. Here we establish a sustainable primary culture of Oct3/4(+)/Nanog(+) lung CSCs fed with CD90(+) cancer-associated fibroblasts (CAFs) to further advance our knowledge of preserving stem cells in the tumour microenvironment. Using transcriptomics we identify the paracrine network by which CAFs enrich CSCs through de-differentiation and reacquisition of stem cell-like properties. Specifically, we find that IGF1R signalling activation in cancer cells in the presence of CAFs expressing IGF-II can induce Nanog expression and promote stemness. Moreover, this paracrine signalling predicts overall and relapse-free survival in stage I non-small cell lung cancer (NSCLC) patients. IGF-II/IGF1R signalling blockade inhibits Nanog expression and attenuates cancer stem cell features. Our data demonstrate that CAFs constitute a supporting niche for cancer stemness, and targeting this paracrine signalling may present a new therapeutic strategy for NSCLC.