76 research outputs found
The ISM scaling relations using inner HI and an application of estimating dust mass
We select a disk-like galaxy sample with observations of the ,
and dust from Herschel Reference Survey (HRS), and derive inner HI masses
within the optical radius. We find that the inner gas-to-dust ratio is almost
independent of gas-phase metallicity, and confirm that the inner gas mass
(+) shows tighter relationship with dust mass and monochromatic 500
luminosity than the integral gas mass. It supports that dust is more
closely associated with co-spatial cold gas than the overall cold gas. Based on
the newly calibrated relationship between inner gas mass and dust mass, we
predict dust masses for disk-dominated galaxies from the xCOLD GASS sample. The
predicted dust masses show scaling relations consistent with fiducial ones in
the literature, supporting their robustness. Additionally, we find that at a
given dust mass and star formation rate (SFR), the galactic WISE W3
luminosities show significant dependence on the [NII] luminosity and the
stellar mass surface density. Such dependence highlights the caveat of using
the W3 luminosity as integral SFR indicator, and is consistent with findings of
studies which target star-forming regions in more nearby galaxies and
accurately derive dust masses based on mapping-mode spectroscopy.Comment: 21 pages, 8 figures, 3 tables. Accepted for Publication in Ap
Real higher-order Weyl photonic crystal
Higher-order Weyl semimetals are a family of recently predicted topological
phases simultaneously showcasing unconventional properties derived from Weyl
points, such as chiral anomaly, and multidimensional topological phenomena
originating from higher-order topology. The higher-order Weyl semimetal phases,
with their higher-order topology arising from quantized dipole or quadrupole
bulk polarizations, have been demonstrated in phononics and circuits. Here, we
experimentally discover a class of higher-order Weyl semimetal phase in a
three-dimensional photonic crystal (PhC), exhibiting the concurrence of the
surface and hinge Fermi arcs from the nonzero Chern number and the nontrivial
generalized real Chern number, respectively, coined a real higher-order Weyl
PhC. Notably, the projected two-dimensional subsystem with kz = 0 is a real
Chern insulator, belonging to the Stiefel-Whitney class with real Bloch
wavefunctions, which is distinguished fundamentally from the Chern class with
complex Bloch wavefunctions. Our work offers an ideal photonic platform for
exploring potential applications and material properties associated with the
higher-order Weyl points and the Stiefel-Whitney class of topological phases
Strong [O III] {\lambda}5007 Compact Galaxies Identified from SDSS DR16 and Their Scaling Relations
Green pea galaxies are a special class of star-forming compact galaxies with
strong [O III]{\lambda}5007 and considered as analogs of high-redshift
Ly{\alpha}-emitting galaxies and potential sources for cosmic reionization. In
this paper, we identify 76 strong [O III]{\lambda}5007 compact galaxies at z <
0.35 from DR1613 of the Sloan Digital Sky Survey. These galaxies present
relatively low stellar mass, high star formation rate, and low metallicity.
Both star-forming main sequence relation (SFMS) and mass-metallicity relation
(MZR) are investigated and compared with green pea and blueberry galaxies
collected from literature. It is found that our strong [O III] {\lambda}5007
compact galaxies share common properties with those compact galaxies with
extreme star formation and show distinct scaling relations in respect to those
of normal star-forming galaxies at the same redshift. The slope of SFMS is
higher, indicates that strong [O III]{\lambda}5007 compact galaxies might grow
faster in stellar mass. The lower MZR implies that they may be less chemically
evolved and hence on the early stage of star formation. A further environmental
investigation confirms that they inhabit relatively low-density regions. Future
largescale spectroscopic surveys will provide more details on their physical
origin and evolution.Comment: 12 pages, 8 figures, 1 table. Published in A
Application of Oligosaccharides to Induce Innate Immunity in Plants
Plants have innate immune systems and protective mechanisms to resist the attack of pathogenic microorganisms. Unlike mammals, they lack mobile defensive cells and therefore rely on autonomous cell events for protection. These cells have a wide range of recognition capabilities for detecting pathogens, thus filling the gap of the adaptive immune system. These protective mechanisms will remain inactive or latent until they are activated after exposure to inducers or application of stimuli. Only after they are affected by pathogens or the same elicitors do they begin to show an active state. The role of oligosaccharides in plant immunity is gradually attracting widespread attention. Therefore, this paper summarizes the functions of oligosaccharides related to plant immunity and provides examples of induced defense events. The recognition of sugar molecules as signal molecules in plants has also been proposed. In this review, we focus on the development andapplication of oligosaccharides in plant immunity and their potential value in agricultural field
What you don't know... can't hurt you? A natural field experiment on relative performance feedback in higher education
This paper studies the effect of providing feedback to college students on their position in the grade distribution by using a natural field experiment. This information was updated every six months during a three-year period. We find that greater grades transparency decreases educational performance, as measured by the number of examinations passed and grade point average (GPA). However, self-reported satisfaction, as measured by surveys conducted after feedback is provided but before students take their examinations, increases. We provide a theoretical framework to understand these results, focusing on the role of prior beliefs and using out-of-trial surveys to test the model. In the absence of treatment, a majority of students underestimate their position in the grade distribution, suggesting that the updated information is “good news” for many students. Moreover, the negative effect on performance is driven by those students who underestimate their position in the absence of feedback. Students who overestimate initially their position, if anything, respond positively. The performance effects are short lived—by the time students graduate, they have similar accumulated GPA and graduation rates
Data Release of the AST3-2 Automatic Survey from Dome A, Antarctica
AST3-2 is the second of the three Antarctic Survey Telescopes, aimed at
wide-field time-domain optical astronomy. It is located at Dome A, Antarctica,
which is by many measures the best optical astronomy site on the Earth's
surface. Here we present the data from the AST3-2 automatic survey in 2016 and
the photometry results. The median 5 limiting magnitude in -band is
17.8 mag and the light curve precision is 4 mmag for bright stars. The data
release includes photometry for over 7~million stars, from which over 3,500
variable stars were detected, with 70 of them newly discovered. We classify
these new variables into different types by combining their light curve
features with stellar properties from surveys such as StarHorse.Comment: 16 pages, 20 figures, accepted for publication in MNRA
Genome-wide identification of resistance genes and response mechanism analysis of key gene knockout strain to catechol in Saccharomyces cerevisiae
Engineering Saccharomyces cerevisiae for biodegradation and transformation of industrial toxic substances such as catechol (CA) has received widespread attention, but the low tolerance of S. cerevisiae to CA has limited its development. The exploration and modification of genes or pathways related to CA tolerance in S. cerevisiae is an effective way to further improve the utilization efficiency of CA. This study identified 36 genes associated with CA tolerance in S. cerevisiae through genome-wide identification and bioinformatics analysis and the ERG6 knockout strain (ERG6Δ) is the most sensitive to CA. Based on the omics analysis of ERG6Δ under CA stress, it was found that ERG6 knockout affects pathways such as intrinsic component of membrane and pentose phosphate pathway. In addition, the study revealed that 29 genes related to the cell wall-membrane system were up-regulated by more than twice, NADPH and NADP+ were increased by 2.48 and 4.41 times respectively, and spermidine and spermine were increased by 2.85 and 2.14 times, respectively, in ERG6Δ. Overall, the response of cell wall-membrane system, the accumulation of spermidine and NADPH, as well as the increased levels of metabolites in pentose phosphate pathway are important findings in improving the CA resistance. This study provides a theoretical basis for improving the tolerance of strains to CA and reducing the damage caused by CA to the ecological environment and human health
Exoplanets in the Antarctic Sky I. The first data release of AST3-II (CHESPA) and new found variables within the southern CVZ of TESS
Located at Dome A, the highest point of the Antarctic plateau, the Chinese Kunlun station is considered to be one of the best ground-based photometric sites because of its extremely cold, dry, and stable atmosphere. A target can be monitored from there for over 40 days without diurnal interruption during a polar winter. This makes Kunlun station a perfect site to search for short-period transiting exoplanets. Since 2008, an observatory has existed at Kunlun station, and three telescopes are working there. Using these telescopes, the AST3 project has been carried out over the last 6 yr with a search for transiting exoplanets as one of its key programs (CHESPA). In the austral winters of 2016 and 2017, a set of target fields in the southern continuous viewing zone (CVZ) of TESS were monitored by the AST3-II telescope. In this paper, we introduce the CHESPA and present the first data release containing photometry of 26,578 bright stars (m(i) <= 15). The best photometric precision at the optimum magnitude for the survey is around 2 mmag. To demonstrate the data quality, we also present a catalog of 221 variables with a brightness variation greater than 5 mmag from the 2016 data. Among these variables, 179 are newly identified periodic variables not listed in the AAVSO database (https://www.aavso.org/), and 67 are listed in the Candidate Target List. These variables will require careful attention to avoid false-positive signals when searching for transiting exoplanets. Dozens of new transiting exoplanet candidates will be released in a subsequent paper
- …