721 research outputs found
OCTAD-S: Digital Fast Fourier Transform Spectrometers by FPGA
We have developed a digital fast Fourier transform (FFT) spectrometer made of
an analog-to-digital converter (ADC) and a field-programmable gate array
(FPGA). The base instrument has independent ADC and FPGA modules, which allow
us to implement different spectrometers in a relatively easy manner. Two types
of spectrometers have been instrumented, one with 4.096 GS/s sampling speed and
2048 frequency channels and the other with 2.048 GS/s sampling speed and 32768
frequency channels. The signal processing in these spectrometers has no dead
time and the accumulated spectra are recorded in external media every 8 ms. A
direct sampling spectroscopy up to 8 GHz is achieved by a microwave
track-and-hold circuit, which can reduce the analog receiver in front of the
spectrometer. Highly stable spectroscopy with a wide dynamic range was
demonstrated in a series of laboratory experiments and test observations of
solar radio bursts.Comment: 20 pages, 7 figures, accepted for publication in Earth, Planets and
Spac
Short-chain ubiquitination is associated with the degradation rate of a cell-surface-resident bile salt export pump (BSEP/ABCB11). MOL #49288 2
was enhanced by BSEP mutations, E297G and D482G. Moreover, biotin-labeling studies using MDCK II cells demonstrated that the degradation of cell-surface-resident chimeric protein fusing ubiquitin to BSEP was faster than that of BSEP itself. In conclusion, BSEP/Bsep is modified with two to three ubiquitins, and its ubiquitination is modulated by 4PBA treatment and PFIC2-type mutations. Modulation of short-chain ubiquitination can regulate the change in the degradation rate of cell-surface-resident BSEP by 4PBA treatment and PFIC2-type mutations
Similarities and uniqueness of Ly emitters among star-forming galaxies at z=2.5
We conducted a deep narrow-band imaging survey with the Subaru Prime Focus
Camera on the Subaru Telescope and constructed a sample of Ly emitters
(LAEs) at z=2.53 in the UDS-CANDELS field where a sample of H emitters
(HAEs) at the same redshift is already obtained from our previous narrow-band
observation at NIR. The deep narrow-band and multi broadband data allow us to
find LAEs of stellar masses and star-formation rates (SFRs) down to
M and 0.2 M/yr, respectively. We show
that the LAEs are located along the same mass-SFR sequence traced by normal
star-forming galaxies such as HAEs, but towards a significantly lower mass
regime. Likewise, LAEs seem to share the same mass--size relation with typical
star-forming galaxies, except for the massive LAEs, which tend to show
significantly compact sizes. We identify a vigorous mass growth in the central
part of LAEs: the stellar mass density in the central region of LAEs increases
as their total galaxy mass grows. On the other hand, we see no Ly line
in emission for most of the HAEs. Rather, we find that the Ly feature
is either absent or in absorption (Ly absorbers; LAAs), and its
absorption strength may increase with reddening of the UV continuum slope. We
demonstrate that a deep Ly narrow-band imaging like this study is able
to search for not only LAEs but also LAAs in a certain redshift slice. This
work suggests that LAEs trace normal star-forming galaxies in the low-mass
regime, while they remain as a unique population because the majority of HAEs
are not LAEs.Comment: 20 pages, 18 figures, 3 tables, accepted for publication in MNRA
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