21 research outputs found
The Mini-batch Stochastic Conjugate Algorithms with the unbiasedness and Minimized Variance Reduction
We firstly propose the new stochastic gradient estimate of unbiasedness and
minimized variance in this paper. Secondly, we propose the two algorithms:
Algorithml and Algorithm2 which apply the new stochastic gradient estimate to
modern stochastic conjugate gradient algorithms SCGA 7and CGVR 8. Then we prove
that the proposed algorithms can obtain linearconvergence rate under
assumptions of strong convexity and smoothness. Finally, numerical experiments
show that the new stochastic gradient estimatecan reduce variance of stochastic
gradient effectively. And our algorithms compared SCGA and CGVR can convergent
faster in numerical experimentson ridge regression model.Comment: 17 pages, 3 figure
Study of Three Rotating Radio Transients with FAST
Rotating radio transients (RRATs) are peculiar astronomical objects whose
emission mechanism remains under investigation. In this paper, we present
observations of three RRATs, J1538+2345, J1854+0306 and J1913+1330, observed
with the Five-hundred-meter Aperture Spherical radio Telescope (FAST).
Specifically, we analyze the mean pulse profiles and temporal flux density
evolutions of the RRATs. Owing to the high sensitivity of FAST, the derived
burst rates of the three RRATs are higher than those in previous reports. RRAT
J1854+0306 exhibited a time-dynamic mean pulse profile, whereas RRAT J1913+1330
showed distinct radiation and nulling segments on its pulse intensity trains.
The mean pulse profile variation with frequency is also studied for RRAT
J1538+2345 and RRAT J1913+1330, and the profiles at different frequencies could
be well fitted with a cone-core model and a conal-beam model, respectively.Comment: Sci. China-Phys. Mech. Astron. 62, 959503 (2019
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
The Complete Genome of a New Betabaculovirus from Clostera anastomosis.
Clostera anastomosis (Lepidoptera: Notodontidae) is a defoliating forest insect pest. Clostera anastomosis granulovirus-B (ClasGV-B) belonging to the genus Betabaculovirus of family Baculoviridae has been used for biological control of the pest. Here we reported the full genome sequence of ClasGV-B and compared it to other previously sequenced baculoviruses. The circular double-stranded DNA genome is 107,439 bp in length, with a G+C content of 37.8% and contains 123 open reading frames (ORFs) representing 93% of the genome. ClasGV-B contains 37 baculovirus core genes, 25 lepidopteran baculovirus specific genes, 19 betabaculovirus specific genes, 39 other genes with homologues to baculoviruses and 3 ORFs unique to ClasGV-B. Hrs appear to be absent from the ClasGV-B genome, however, two non-hr repeats were found. Phylogenetic tree based on 37 core genes from 73 baculovirus genomes placed ClasGV-B in the clade b of betabaculoviruses and was most closely related to Erinnyis ello GV (ErelGV). The gene arrangement of ClasGV-B also shared the strongest collinearity with ErelGV but differed from Clostera anachoreta GV (ClanGV), Clostera anastomosis GV-A (ClasGV-A, previously also called CaLGV) and Epinotia aporema GV (EpapGV) with a 20 kb inversion. ClasGV-B genome contains three copies of polyhedron envelope protein gene (pep) and phylogenetic tree divides the PEPs of betabaculoviruses into three major clades: PEP-1, PEP-2 and PEP/P10. ClasGV-B also contains three homologues of P10 which all harbor an N-terminal coiled-coil domain and a C-terminal basic sequence. ClasGV-B encodes three fibroblast growth factor (FGF) homologues which are conserved in all sequenced betabaculoviruses. Phylogenetic analysis placed these three FGFs into different groups and suggested that the FGFs were evolved at the early stage of the betabaculovirus expansion. ClasGV-B is different from previously reported ClasGV-A and ClanGV isolated from Notodontidae in sequence and gene arrangement, indicating the virus is a new notodontid betabaculovirus
Phylogenetic tree based on concatenation of 37 conserved core proteins from 73 baculovirus genomes.
<p>Phylogenetic analysis was performed using the Maximum Likelihood method and bootstrap analysis for 1000 replicates was performed. Only bootstrap values over 50% were shown. The bar lengths are proportional to the distances of the baculoviruses.</p
Circular map of ClasGV-B genome.
<p>ORFs and transcription direction are indicated as arrows. Core genes were indicated by red arrows, genes shared by all lepidopteran baculoviruses were indicated by blue arrows, betabaculovirus-specific genes were indicated by green arrows, genes with homologues to other baculoviruses were indicated by grey arrows, unique genes were indicated by open arrows and non-<i>hrs</i> were indicated by pink squares. The highly collinearly conserved region found in alpha- and betabaculoviruses was shown. Genome position was shown by a 20 kb scale in the inner circle.</p
ClasGV-B genes grouped according to function.
<p>*Core genes are shown in bold and lepidopteran baculovirus specific genes are underlined.</p><p>ClasGV-B genes grouped according to function.</p