604 research outputs found
Bagging Affecting Sugar and Anthocyanin Metabolism in the Ripening Period of Grape Berries
Grapevine is one of the most important fruit-bearing plants worldwide, for which bagging treatments can effectively improve fruit quality. However, the low-light conditions caused by bagging can delay grape berry maturation. Here, we analyzed glucose, fructose, and anthocyanin contents and the expression of sugar and anthocyanin-metabolism pathway genes in the grape berries of two cultivars, ‘Shenhua’ and ‘Shenfeng’, under different bagging treatments. Color development was incomplete in bagged grape berries and their soluble sugar contents were lower than those detected in un-bagged fruits. However, fruit color and SSC could be rapidly restored to normal levels after removing bags. Light affects the accumulation of sugar in grape berries, especially near the maturation period, as well as the contents and compositions of anthocyanins in the skin of grape berries. Although light helps in the accumulation of anthocyanins, significant differences were detected in anthocyanin composition between the two grapevine varieties. In addition, the expressions of myofibroblastic regulatory genes in the anthocyanin pathway were affected by light, and the light-responsive elements elongated hypocotyl 5 and constitutive photomorphogenic 1 acted synergistically to control grape berry coloration. Overall, these results provide a theoretical basis for the maturation mechanism in grape berries
(R)-7-Bromo-2,3,4,4a-tetrahydro-1H-xanthen-1-one
The title compound, C13H11BrO2, contains a tricyclic ring system with one chiral center which exhibits an R configuration. The crystal structure is devoid of any classical hydrogen bonding
(R)-2-(2-Methoxyphenyl)-2,5-dihydrothiophene-3-carbaldehyde
In the title compound, C12H12O2S, the asymmetric unit contains two independent molecules. The chiral C atoms of both molecules were established to be in the R configuration. In both molecules, the 2,5-dihydrothiophene rings adopt S-envelope conformations wherein the S atoms are displaced by 0.315 (5) and −0.249 (5) Å from the mean planes of the remaining ring atoms. In the crystal, the molecules are linked by weak C—H⋯O interactions
Bis(5-phenyl-1H-1,2,4-triazol-3-yl) disulfide dihydrate
A crystallographic twofold axis passing through the centre of the disulfide linkage in the title compound, C16H12N6S2·2H2O, results in one-half of the molecule and one uncoordinated water molecule described in the asymmetric unit. In the molecule, the mean planes of the benzene and triazole rings are close to being coplanar and are separated by a dihedral angle of 2.08 (15)°. The triazole rings are twisted by a dihedral angle of 37.67 (6)° from the disulfide linkage. The crystal packing is stabilized by intermolecular N—H⋯O and O—H⋯N hydrogen bonds with the water molecules, forming a three-dimensional supramolecular network
1RXS J232953.9+062814: a New SU UMa Dwarf Nova below the Period Minimum
1RXS J232953.9+062814 was identified as a cataclysmic variable by Wei et al.
(1999). Four low-resolution spectra of 1RXS J232953.9+062814 were obtained by
using the 2.16-m telescope of the National Astronomical Observatories, in which
two of them were at outburst, and the other two were at quiescence. The system
is about 16.8 B and 16.5 V at quiescence, and 12.6 B and 12.6 V at outburst.
The quiescent spectra were dominated by double-peaked Balmer emissions, which
indicates a hydrogen-rich system with a high-inclination accretion disc. MgH
and TiO absorption bands appeared in the quiescent spectrum imply a companion
with a spectral type of early M dwarf. If we take it as a M0 dwarf, the system
is located at a distance of 350 pc with a proper motion velocity 150 km
s. The superhump period of 0.046311 days (Uemura et al. 2001) was
confirmed by our V photometry. The short period and the hydrogen-rich nature
reveal that this system is another SU Ursae Majoris-type dwarf nova below the
period minimum after V485 Centauri. 1RXS J232953.9+062814 is one of the most
important systems for studying the evolutionary scenario of cataclysmic
variables since it is much brighter than V485 Cen.Comment: 4 pages, 2 figures, accepted by Chin. J. Astron. Astrophy
Object Tracking with Adaptive Multicue Incremental Visual Tracker
Generally, subspace learning based methods such as the Incremental Visual Tracker (IVT) have been shown to be quite effective for visual tracking problem. However, it may fail to follow the target when it undergoes drastic pose or illumination changes. In this work, we present a novel tracker to enhance the IVT algorithm by employing a multicue based adaptive appearance model. First, we carry out the integration of cues both in feature space and in geometric space. Second, the integration directly depends on the dynamically-changing reliabilities of visual cues. These two aspects of our method allow the tracker to easily adapt itself to the changes in the context and accordingly improve the tracking accuracy by resolving the ambiguities. Experimental results demonstrate that subspace-based tracking is strongly improved by exploiting the multiple cues through the proposed algorithm
ACHIKO-M Database for high myopia analysis and its evaluation
Myopia is the leading public health concern with high prevalence in developed countries. In this paper, we present the ACHIKO-M fundus image database with both myopic and emmetropic cases for high myopia study. The database contains 705 myopic subjects and 151 normal subjects with both left eye and right eye images for each subject. In addition, various clinical data is also available, allowing correlation study of different risk factors. We evaluated two state-of-the-art automated myopia detection algorithms on this database to show how it can be used. Both methods achieve more than 90% accuracy for myopia diagnosis. We will also discuss how ACHIKO-M can be a good database for both scientific and clinical research of myopia
Applying hybrid clustering in pulsar candidate sifting with multi-modality for FAST survey
Pulsar search is always the basis of pulsar navigation, gravitational wave
detection and other research topics. Currently, the volume of pulsar candidates
collected by Five-hundred-meter Aperture Spherical radio Telescope (FAST) shows
an explosive growth rate that has brought challenges for its pulsar candidate
filtering System. Particularly, the multi-view heterogeneous data and class
imbalance between true pulsars and non-pulsar candidates have negative effects
on traditional single-modal supervised classification methods. In this study, a
multi-modal and semi-supervised learning based pulsar candidate sifting
algorithm is presented, which adopts a hybrid ensemble clustering scheme of
density-based and partition-based methods combined with a feature-level fusion
strategy for input data and a data partition strategy for parallelization.
Experiments on both HTRU (The High Time Resolution Universe Survey) 2 and FAST
actual observation data demonstrate that the proposed algorithm could
excellently identify the pulsars: On HTRU2, the precision and recall rates of
its parallel mode reach 0.981 and 0.988. On FAST data, those of its parallel
mode reach 0.891 and 0.961, meanwhile, the running time also significantly
decrease with the increment of parallel nodes within limits. So, we can get the
conclusion that our algorithm could be a feasible idea for large scale pulsar
candidate sifting of FAST drift scan observation
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