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"Song L"
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A fast radio burst source at a complex magnetized site in a barred galaxy
Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts
1
–
3
. Recent observations of a Galactic FRB
4
–
8
suggest that at least some FRBs originate from magnetars, but the origin of cosmological FRBs is still not settled. Here we report the detection of 1,863 bursts in 82 h over 54 days from the repeating source FRB 20201124A (ref.
9
). These observations show irregular short-time variation of the Faraday rotation measure (RM), which scrutinizes the density-weighted line-of-sight magnetic field strength, of individual bursts during the first 36 days, followed by a constant RM. We detected circular polarization in more than half of the burst sample, including one burst reaching a high fractional circular polarization of 75%. Oscillations in fractional linear and circular polarizations, as well as polarization angle as a function of wavelength, were detected. All of these features provide evidence for a complicated, dynamically evolving, magnetized immediate environment within about an astronomical unit (
au
; Earth–Sun distance) of the source. Our optical observations of its Milky-Way-sized, metal-rich host galaxy
10
–
12
show a barred spiral, with the FRB source residing in a low-stellar-density interarm region at an intermediate galactocentric distance. This environment is inconsistent with a young magnetar engine formed during an extreme explosion of a massive star that resulted in a long gamma-ray burst or superluminous supernova.
Analysis of a set of 1,863 bursts from the repeating source FRB 20201124A provides evidence of a complicated magnetized site within about an astronomical unit from the source in a barred galaxy.
Journal Article
Comparative metabolomics reveals the metabolic variations between two endangered Taxus species (T. fuana and T. yunnanensis) in the Himalayas
Background
Plants of the genus
Taxus
have attracted much attention owing to the natural product taxol, a successful anti-cancer drug.
T. fuana
and
T. yunnanensis
are two endangered
Taxus
species mainly distributed in the Himalayas. In our study, an untargeted metabolomics approach integrated with a targeted UPLC-MS/MS method was applied to examine the metabolic variations between these two
Taxus
species growing in different environments.
Results
The level of taxol in
T. yunnanensis
is much higher than that in
T. fuana
, indicating a higher economic value of
T. yunnanensis
for taxol production. A series of specific metabolites, including precursors, intermediates, competitors of taxol, were identified. All the identified intermediates are predominantly accumulated in
T. yunnanensis
than
T. fuana
, giving a reasonable explanation for the higher accumulation of taxol in
T. yunnanensis
. Taxusin and its analogues are highly accumulated in
T. fuana
, which may consume limited intermediates and block the metabolic flow towards taxol. The contents of total flavonoids and a majority of tested individual flavonoids are significantly accumulated in
T. fuana
than
T. yunnanensis
, indicating a stronger environmental adaptiveness of
T. fuana
.
Conclusions
Systemic metabolic profiling may provide valuable information for the comprehensive industrial utilization of the germplasm resources of these two endangered
Taxus
species growing in different environments.
Journal Article
Disney Princess storybook collection
A collection of 19 stories featuring princesses from Disney films.
BOOK
Maternal immune activation leads to selective functional deficits in offspring parvalbumin interneurons
Abnormalities in prefrontal gamma aminobutyric acid (GABA)ergic transmission, particularly in fast-spiking interneurons that express parvalbumin (PV), are hypothesized to contribute to the pathophysiology of multiple psychiatric disorders, including schizophrenia, bipolar disorder, anxiety disorders and depression. While primarily histological abnormalities have been observed in patients and in animal models of psychiatric disease, evidence for abnormalities in functional neurotransmission at the level of specific interneuron populations has been lacking in animal models and is difficult to establish in human patients. Using an animal model of a psychiatric disease risk factor, prenatal maternal immune activation (MIA), we found reduced functional GABAergic transmission in the medial prefrontal cortex (mPFC) of adult MIA offspring. Decreased transmission was selective for interneurons expressing PV, resulted from a decrease in release probability and was not observed in calretinin-expressing neurons. This deficit in PV function in MIA offspring was associated with increased anxiety-like behavior and impairments in attentional set shifting, but did not affect working memory. Furthermore, cell-type specific optogenetic inhibition of mPFC PV interneurons was sufficient to impair attentional set shifting and enhance anxiety levels. Finally, we found that
in vivo
mPFC gamma oscillations, which are supported by PV interneuron function, were linearly correlated with the degree of anxiety displayed in adult mice, and that this correlation was disrupted in MIA offspring. These results demonstrate a selective functional vulnerability of PV interneurons to MIA, leading to affective and cognitive symptoms that have high relevance for schizophrenia and other psychiatric disorders.
Journal Article
Evidence of Minijet Emission in a Large Emission Zone from a Magnetically Dominated Gamma-Ray Burst Jet
The second brightest gamma-ray burst (GRB) in history, GRB 230307A, provides an ideal laboratory to study the mechanism of GRB prompt emission thanks to its extraordinarily high photon statistics and its single-episode activity. Here we demonstrate that the rapidly variable components of its prompt emission compose an overall broad single pulse-like profile. Although these individual rapid components are aligned in time across all energy bands, this overall profile conspires to show a well-defined energy-dependent behavior that is typically seen in single GRB pulses. Such a feature demonstrates that the prompt emission of this burst is from many individual emitting units that are casually linked in a emission site at a large distance from the central engine. Such a scenario is in natural consistency with the internal-collision-induced magnetic reconnection and turbulence framework, which invokes many minijets due to local magnetic reconnection that constantly appear and disappear in a global magnetically dominated jet.
Journal Article
The patterns of rehabilitation service use and personal recovery among persons with psychiatric disability
IntroductionRehabilitation services are supposed to facilitate recovery. However, there is no concrete evidence in Taiwan.ObjectivesThis study examined the patterns of rehabilitation service use and the association between the pattern of use and personal recovery.MethodsThirty-two community psychiatric rehabilitation centers in Taiwan agreed to participate in this study. A sample of 592 participants filled out the questionnaires. Eight kinds of rehabilitation services were included: Independent living and self-care training, interpersonal and social skills training, daily life arrangement and community life rehabilitation, physical activities, symptom management training, occupational therapy, sheltered workshops, and vocational training. Recovery was measured by the Stage of Recovery Scale. Cluster analysis was utilized to classify service use patterns among the participants. ANOVA was used to examine the association between the pattern of use and recovery.ResultsThe results revealed five patterns of use: (1) Overall middle level with emphasis on work, (2) independent living plus occupational rehabilitation, (3) independent living plus vocational rehabilitation, (4) overall low-level of use, and (5) overall high-level of use. The differences among the five groups of participants in each kind of rehabilitation service were significant (Eta2=19.2%). The recovery status of overall high users was significantly better than middle-level and low users. The recovery status of low-level users was significantly worse than the other four groups.ConclusionsThe findings imply that greater rehabilitation service use is conducive to recovery. Comprehensive use of various types of service or the combination of independent living and other types seem to facilitate recovery.Disclosure of InterestNone Declared
Journal Article
A Detailed View of Low-frequency Quasi-periodic Oscillation in the Broadband 0.2–200 keV with Insight-HXMT and NICER
We report the X-ray timing results of the black hole candidate MAXI J1820+070 during its 2018 outburst using the Hard X-ray Modulation Telescope (Insight-HXMT) and Neutron Star Interior Composition Explorer Mission (NICER) observations. Low-frequency quasi-periodic oscillations (LFQPOs) are detected in the low/hard state and the hard intermediate state, which lasted for ∼90 days. Thanks to the large effective area of Insight-HXMT at high energies and NICER at low energies, we are able to present the energy dependence of the LFQPO characteristics and phase lags from 0.2 to 200 keV, which has never been explored by previous missions. We find that the centroid frequency of the LFQPOs does not change significantly with energy, while the full width at half maximum and fractional rms show a complex evolution with energy. The LFQPO phase lags at high energies and low energies show consistent energy-dependence relations taking the ∼2 keV as reference. Our results suggest that the LFQPOs from high energy come from the LT precession of the relativistic jet, while the low-energy radiation is mainly from the perpendicular innermost regions of the accretion disk.
Journal Article
Fan-beamed X-Ray Emission from 1 to above 130 keV from the Ultraluminous X-Ray Pulsar RX J0209.6-7427 in the Small Magellanic Cloud
We present detailed timing and spectral analyses of the transient X-ray pulsar RX J0209.6−7427 in the Small Magellanic Cloud during its 2019 giant outburst. With a better known distance than most galactic X-ray pulsars, its peak luminosity is determined to be (1.11 ± 0.06) × 1039 erg s−1; it is thus a bona fide pulsating ultraluminous X-ray source (PULX). Owing to the broad energy band of Insight-HXMT, its pulsed X-ray emission was detected from 1 keV up to the 130–180 keV band, which is the highest energy emission detected from any PULXs outside the Milky Way. This allows us to conclude that its main pulsed X-ray emission is from the fan beam of the accretion column, and its luminosity is thus intrinsic. We also estimate its magnetic field of (4.8–8.6) × 1012 or (1.7–2.2) × 1013 G, from its spin evolution or transition in the accretion column structure during the outburst; we suggest that the two values of the magnetic field strength correspond to the dipole and multipole magnetic fields of the neutron star, similar to the recent discovery in the Galactic PULX Swift J0243.6+6124. Therefore, the nature of the neutron star and its ULX emission can be understood within the current theoretical frame of accreting neutron stars. This may have implications for understanding the nature of those farther away extragalactic PULXs.
Journal Article