22 research outputs found
Monotone Cubic B-Splines
We present a method for fitting monotone curves using cubic B-splines with a
monotonicity constraint on the coefficients. We explore different ways of
enforcing this constraint and analyze their theoretical and empirical
properties. We propose two algorithms for solving the spline fitting problem:
one that uses standard optimization techniques and one that trains a
Multi-Layer Perceptrons (MLP) generator to approximate the solutions under
various settings and perturbations. The generator approach can speed up the
fitting process when we need to solve the problem repeatedly, such as when
constructing confidence bands using bootstrap. We evaluate our method against
several existing methods, some of which do not use the monotonicity constraint,
on some monotone curves with varying noise levels. We demonstrate that our
method outperforms the other methods, especially in high-noise scenarios. We
also apply our method to analyze the polarization-hole phenomenon during star
formation in astrophysics. The source code is accessible at
\texttt{\url{https://github.com/szcf-weiya/MonotoneSplines.jl}}
The Decrease of Specific Angular Momentum and the Hot Toroid Formation: The Massive Clump G10.6-0.4
This is the first paper of our series of high resolution (1") studies of the
massive star forming region G10.6--0.4. We present the emission line
observations of the hot core type tracers (OCS, OCS, SO) with
0.5 resolution. By comparing the results to the high--resolution
NH absorption line observation, we confirm for the first time the
rotationally flattened hot toroid in the central 0.1 pc region, which has a
rotational axis perpendicular to its geometrical major axis.
In addition, we present the observations of NH, CS, and
CHCN with 1 resolution, and follow the dynamics of the molecular
accretion flow from the 0.3 pc radius to the inner 0.03 pc radius. With
reference to the rotational axis of the hot toroid, we measure the rotational
velocity from the molecular emission in the region. The results are consistent
with an envelope with a rapid decrease of the specific angular momentum from
the outer to the inner region. These new results improve the current
understanding of the molecular accretion flow in an ultracompact (UC)
H\textsc{ii} region created by the embedded O-type cluster.Comment: 26 pages, 5 figures, Accepted by Ap
Effects of Methyl Jasmonate on Fruit Coloration and Quality Improvement in Pears (<i>Pyrus bretschneideri</i>)
Red-skinned pears with a bright red color and abundant health benefits are favored by consumers. However, fruit coloration and inner quality are usually affected by adverse factors, which lead to a decline in fruit quality and commerciality. Methyl jasmonate (MeJA) has been reported to be involved in many plant processes, including anthocyanin accumulation, while the value of MeJA application for fruit coloration and quality improvement in red-skinned pears is still largely unclear. The application of 0, 0.5, 1.0, or 2.0 mM MeJA at different fruit development stages significantly promoted red coloration in ‘Danxiahong’ pears. Moreover, MeJA treatment increased the fruit soluble solids, improved the total sugar content, decreased the fruit acid content, and significantly increased the total sugar/total acid ratio. However, no significant effect was observed on the fruit’s shape or longitudinal or transverse diameters. RT-qPCR analysis indicated that the expression of anthocyanin biosynthetic regulatory and structural genes, including PbrMYB10, PbrbHLH3, PbrWD40, PbrPAL, PbrCHI, PbrDFR, and other genes, was induced by MeJA treatments. Overall, our findings demonstrate that the application of MeJA plays a significant role in promoting anthocyanin accumulation in pear peels, leading to enhanced fruit coloration. Furthermore, MeJA treatment also positively impacts the improvement of the inner fruit quality. These results not only provide valuable insights into the mechanism of MeJA-mediated coloration but also contribute to a better understanding of the overall role of MeJA in pear fruit development and quality enhancement
Oxidation Behavior and Mechanism of Al4SiC4 in MgO-C-Al4SiC4 System
Al4SiC4 powder with high purity was synthesized using the powder mixture of aluminum (Al), silicon (Si), and carbon (C) at 1800 °C in argon. Their oxidation behavior and mechanism in a MgO-C-Al4SiC4 system was investigated at 1400–1600 °C. XRD, SEM, and energy dispersive spectrometry (EDS) were adopted to analyze the microstructure and phase evolution. The results showed that the composition of oxidation products was closely related to the atom diffusion velocity and the compound oxide layer was generated on Al4SiC4 surface. In addition, the effect of different CO partial pressure on the oxidation of Al4SiC4 crystals was also studied by thermodynamic calculation. This work proves the great potential of Al4SiC4 in improving the MgO-C materials
Transcriptome Analysis Reveals Roles of Sucrose in Anthocyanin Accumulation in ‘Kuerle Xiangli’ (<i>Pyrus sinkiangensis</i> Yü)
Pear (Pyrus L.) is one of the most important temperate fruit crops worldwide, with considerable economic value and significant health benefits. Red-skinned pears have an attractive appearance and relatively high anthocyanin accumulation, and are especially favored by customers. Abnormal weather conditions usually reduce the coloration of red pears. The application of exogenous sucrose obviously promotes anthocyanins accumulation in ‘Kuerle Xiangli’ (Pyrus sinkiangensis Yü); however, the underlying molecular mechanism of sucrose-mediated fruit coloration remains largely unknown. In this study, comprehensive transcriptome analysis was performed to identify the essential regulators and pathways associated with anthocyanin accumulation. The differentially expressed genes enriched in Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes items were analyzed. The transcript levels of some anthocyanin biosynthetic regulatory genes and structural genes were significantly induced by sucrose treatment. Sucrose application also stimulated the expression of some sugar transporter genes. Further RT-qPCR analysis confirmed the induction of anthocyanin biosynthetic genes. Taken together, the results revealed that sucrose promotes pear coloration most likely by regulating sugar metabolism and anthocyanin biosynthesis, and this study provides a comprehensive understanding of the complex molecular mechanisms underlying the coloration of red-skinned pear
The genetic locus underlying red foliage and fruit skin traits is mapped to the same location in the two pear bud mutants ‘Red Zaosu’ and ‘Max Red Bartlett’
Abstract Background Red-skinned pears are attractive to consumers because of their aesthetic appeal and the antioxidant-associated health benefits provided by the anthocyanins in their red skin. In China, the ‘Red Zaosu’ (RZS) red bud mutation of the Zaosu (ZS) pear has been used as a parent in Asian pear breeding to generate new cultivars with crispy red fruit and red tender shoots resembling those of the ‘Max Red Bartlett’ (MRB) pears. Results In this study, a segregation ratio of 1:1 was observed between plants with red or green shoots in four families with RZS as the only red shoot gene donor parent, suggesting that the red shoot trait of RZS is associated with a dominant gene. Three markers, In1400–1, In1579–1 and In1579–3, were chosen from 22 pairs of indel primers targeting regions in the vicinity of the previously identified red fruit skin locus of MRB and were able to effectively distinguish the eight red shoot plants from the eight green shoot plants. Linkage analysis indicated that the genetic distance between the two marker loci (In1579–1 and In1579–3) and the red shoot locus of RZS were both 1.4 cM, while the genetic distance between the In1400–1 marker and the red shoot locus was 2.1 cM. The physical position of the red locus in RZS should be in the 368.6 kb candidate interval at the bottom of LG4. Conclusions The genetic locus responsible for the red tender shoots of RZS was located in the same interval of the red fruit skin gene of MRB, meaning that the bud mutation loci of RZS and MRB may be the same or adjacent to each other, and the red shoot trait and the red fruit skin trait in RZS may be controlled by the same, or a closely linked locus. As a result, breeders could use red shoots as a morphological marker to select for the red-skinned hybrids from RZS families
Additional file 2: Figure S1. of Identification of candidate genes involved in the sugar metabolism and accumulation during pear fruit post-harvest ripening of ‘Red Clapp’s Favorite’ (Pyrus communis L.) by transcriptome analysis
The pathway of starch and sucrose metabolism. Note: PCP008001 and PCP030959 were involved in the process of 3.2.1.26 (Marked in red); PCP011895 was involved in the process of 3.1.1.11 (Marked in blue); PCP006674 was involved in the process of 2.4.1.15 and 3.1.3.12 (Marked in blue); a novel gene 004807 was involved in the process of 2.7.7.27 (Marked in green). (JPEG 396Â kb
Additional file 1: Table S1. of Identification of candidate genes involved in the sugar metabolism and accumulation during pear fruit post-harvest ripening of ‘Red Clapp’s Favorite’ (Pyrus communis L.) by transcriptome analysis
KEGG annotation details of unigenes (for qPCR). (DOCX 12Â kb
Chromosome level high-density integrated genetic maps improve the Pyrus bretschneideri ‘DangshanSuli’ v1.0 genome
Abstract Background Chromosomal level reference genomes provide a crucial foundation for genomics research such as genome-wide association studies (GWAS) and whole genome selection. The chromosomal-level sequences of both the European (Pyrus communis) and Chinese (P. bretschneideri) pear genomes have not been published in public databases so far. Results To anchor the scaffolds of P. bretschneideri ‘DangshanSuli’ (DS) v1.0 genome into pseudo-chromosomes, two genetic maps (MH and YM maps) were constructed using half sibling populations of Chinese pear crosses, ‘Mantianhong’ (MTH) × ‘Hongxiangsu’ (HXS) and ‘Yuluxiang’ (YLX) × MTH, from 345 and 162 seedlings, respectively, which were prepared for SNP discovery using genotyping-by-sequencing (GBS) technology. The MH and YM maps, each with 17 linkage groups (LGs), were constructed from 2606 and 2489 SNP markers and spanned 1847 and 1668 cM, respectively, with average marker intervals of 0.7. The two maps were further merged with a previously published genetic map (BD) based on the cross ‘Bayuehong’ (BYH) × ‘Dangshansuli’ (DS) to build a new integrated MH-YM-BD map. By using 7757 markers located on the integrated MH-YM-BD map, 898 scaffolds (400.57 Mb) of the DS v1.0 assembly were successfully anchored into 17 pseudo-chromosomes, accounting for 78.8% of the assembled genome size. About 88.31% of them (793 scaffolds) were directionally anchored with two or more markers on the pseudo-chromosomes. Furthermore, the errors in each pseudo-chromosome (especially 1, 5, 7 and 11) were manually corrected and pseudo-chromosomes 1, 5 and 7 were extended by adding 19, 12 and 14 scaffolds respectively in the newly constructed DS v1.1 genome. Synteny analyses revealed that the DS v1.1 genome had high collinearity with the apple genome, and the homologous fragments between pseudo-chromosomes were similar to those found in previous studies. Moreover, the red-skin trait of Asian pear was mapped to an identical locus as identified previously. Conclusions The accuracy of DS v1.1 genome was improved by using larger mapping populations and merged genetic map. With more than 400 MB anchored to 17 pseudo-chromosomes, the new DS v1.1 genome provides a critical tool that is essential for studies of pear genetics, genomics and molecular breeding
Legislative Documents
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