2,128 research outputs found

    Soliton collisions in Bose-Einstein condensates with current-dependent interactions

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    We study general collisions between chiral solitons in Bose-Einstein condensates subject to combined attractive and current-dependent interatomic interactions. A simple analysis based on the linear superposition of the solitons allows us to determine the relevant time and space scales of the dynamics, which is illustrated by extensive numerical simulations. By varying the differential amplitude, the relative phase, the average velocity, and the relative velocity of the solitons, we characterize the different dynamical regimes that give rise to oscillatory and interference phenomena. Apart from the known inelastic character of the collisions, we show that the chiral dynamics involves an amplitude reduction with respect to the case of regular solitons. To compare with feasible ultracold gas experiments, the influence of harmonic confinement is analyzed in both the emergence and the interaction of chiral solitons.Comment: 15 pages, 12 figure

    Optimal optical Ferris wheel solitons in a nonlocal Rydberg medium

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    We propose a scheme for the creation of stable optical Ferris wheel(OFW) solitons in a nonlocal Rydberg electromagnetically induced transparency(EIT) medium. Depending on a careful optimization to both the atomic density and the one-photon detuning, we obtain an appropriate nonlocal potential provided by the strong interatomic interaction in Rydberg states which can perfectly compensate for the diffraction of the probe OFW field. Numerical results show that the fidelity keeps larger than 0.96 while the propagation distance has exceeded 160 diffraction lengths. Higher-order OFW solitons with arbitrary winding numbers are also discussed. Our study provides a straightforward route to generate spatial optical solitons in the nonlocal response region of cold Rydberg gases.Comment: Optics Letters in pres

    p38Ī± MAPK regulates proliferation and differentiation of osteoclast progenitors and bone remodeling in an aging-dependent manner.

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    Bone mass is determined by the balance between bone formation, carried out by mesenchymal stem cell-derived osteoblasts, and bone resorption, carried out by monocyte-derived osteoclasts. Here we investigated the potential roles of p38 MAPKs, which are activated by growth factors and cytokines including RANKL and BMPs, in osteoclastogenesis and bone resorption by ablating p38Ī± MAPK in LysM+monocytes. p38Ī± deficiency promoted monocyte proliferation but regulated monocyte osteoclastic differentiation in a cell-density dependent manner, with proliferating p38Ī±-/- cultures showing increased differentiation. While young mutant mice showed minor increase in bone mass, 6-month-old mutant mice developed osteoporosis, associated with an increase in osteoclastogenesis and bone resorption and an increase in the pool of monocytes. Moreover, monocyte-specific p38Ī± ablation resulted in a decrease in bone formation and the number of bone marrow mesenchymal stem/stromal cells, likely due to decreased expression of PDGF-AA and BMP2. The expression of PDGF-AA and BMP2 was positively regulated by the p38 MAPK-Creb axis in osteoclasts, with the promoters of PDGF-AA and BMP2 having Creb binding sites. These findings uncovered the molecular mechanisms by which p38Ī± MAPK regulates osteoclastogenesis and coordinates osteoclastogenesis and osteoblastogenesis

    Metric networks for enhanced perception of non-local semantic information

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    IntroductionMetric learning, as a fundamental research direction in the field of computer vision, has played a crucial role in image matching. Traditional metric learning methods aim at constructing two-branch siamese neural networks to address the challenge of image matching, but they often overlook to cross-source and cross-view scenarios.MethodsIn this article, a multi-branch metric learning model is proposed to address these limitations. The main contributions of this work are as follows: Firstly, we design a multi-branch siamese network model that enhances measurement reliability through information compensation among data points. Secondly, we construct a non-local information perception and fusion model, which accurately distinguishes positive and negative samples by fusing information at different scales. Thirdly, we enhance the model by integrating semantic information and establish an information consistency mapping between multiple branches, thereby improving the robustness in cross-source and cross-view scenarios.ResultsExperimental tests which demonstrate the effectiveness of the proposed method are carried out under various conditions, including homologous, heterogeneous, multi-view, and crossview scenarios. Compared to the state-of-the-art comparison algorithms, our proposed algorithm achieves an improvement of ~1, 2, 1, and 1% in terms of similarity measurement Recall@10, respectively, under these four conditions.DiscussionIn addition, our work provides an idea for improving the crossscene application ability of UAV positioning and navigation algorithm

    Effects of different soil water holding capacities on vegetable residue return and its microbiological mechanism

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    With the gradual expansion of the protected vegetable planting area, dense planting stubbles and increasing labor cost, the treatment of vegetable residues has become an urgent problem to be solved. Soil bacterial community structure plays an important role in vegetable residue return and is susceptible to environmental changes. Therefore, understanding the influences of different soil water holding capacities on plant residue decomposition and soil bacterial communities is important for biodegradation. During the whole incubation period, the weight loss ratio of plant residue with 100% water holding capacity was 69.60 to 75.27%, which was significantly higher than that with 60% water holding capacity in clay and sandy soil, indicating that high water holding capacity promoted the decomposition of plant residue. The degradation of lignin and cellulose was also promoted within 14 days. Furthermore, with the increase in soil water holding capacity, the contents of NH4+ increased to 5.36 and 4.54 times the initial value in the clay and sandy soil, respectively. The increase in napA and nrfA resulted in the conversion of NO3ā€“ into NH4+. The increase in water holding capacity made the bacterial network structure more compact and changed the keystone bacteria. The increase in water holding capacity also increased the relative abundance of Firmicutes at the phylum level and Symbiobacterium, Clostridium at the genus level, which are all involved in lignin and cellulose degradation and might promote their degradation. Overall, these findings provide new insight into the effects of different soil water holding capacities on the degradation of plant residues in situ and the corresponding bacterial mechanisms

    Characteristics of polycyclic aromatic hydrocarbons in PM2.5 emitted from different cooking activities in China

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    Nineteen polycyclic aromatic hydrocarbons (PAHs) in PM2.5 emitted from five different cooking activities were characterized, and their influencing factors were determined. The total quantified particle-bounded PAH concentrations (Sigma PAHs) in the airs from the cooking activities were 4.2-36.5-fold higher than those in corresponding backgrounds. The highest I PAHs pound were seen in cafeteria frying (783 +/- 499 ng/m(3)), followed by meat roasting (420 +/- 191 ng/m(3)), fish roasting (210 +/- 105 ng/m(3)), snack-street boiling (202 +/- 230 ng/m(3)), and cafeteria boiling (150 +/- 65 ng/m(3)). The main influencing factors on the PAH emissions were cooking methods, fat contents in raw materials, and oil consumptions. Four- to six-ringed PAHs had the highest contributions to the Sigma PAHs (avg. 87.5%). Diagnostic ratios of individual PAH were similar between the two charbroiling and other three conventional Chinese cooking methods, respectively, demonstrating the dominance of cooking methods in the PAH emissions. Remarkably high benzo(b)fluoranthene/benzo(k)fluoranthene (BbF/BkF) ratio (8.31) was seen in the snack-street boiling, attributed to the coal combustion as cooking fuel. Both fluoranthene/(fluoranthene + pyrene) [FLT/(FLT + PYR)] and benzo(a)anthracene/(benzo(a)anthracene + chrysene) [BaA/(BaA + CHR)] ratios were higher for the oil-based cooking than those from the water-based ones. In addition, two ratios of indeno(1,2,3-cd)pyrene/(indeno(1,2,3-cd)pyrene + benzo(g,h,i)perylene) [IPY/(IPY + BPE)] and benzo(a)pyrene/(benzo(a)pyrene + benzo(g,h,i)perylene) [BaP/(BaP + BPE)] were higher for two charbroiling than the three conventional Chinese cooking methods. The characterization work in this study is particularly important since cooking is a potential contributor of atmospheric PAHs in urban China. Carcinogenic potencies of PAHs were assessed by comparison with the air quality guideline and health risk estimation. The BaP and BaP equivalent were higher for the oil-based than the water-based cooking activities

    Distribution, characterization, and induction of CD8+ regulatory T cells and IL-17-producing CD8+ T cells in nasopharyngeal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>CD8<sup>+ </sup>effector cells often have an antitumor function in patients with cancer. However, CD8<sup>+</sup>Foxp3<sup>+ </sup>regulatory T cells (Tcregs) and interleukin (IL)-17-producing CD8<sup>+ </sup>T cells (Tc17 cells) also derive from the CD8<sup>+ </sup>T cell lineage. Their role in the antitumor response remains largely unknown. In the present study, we aimed to investigate the distribution, characterization, and generation of CD8<sup>+ </sup>Tcregs and Tc17 cells in NPC patients.</p> <p>Methods</p> <p>Peripheral blood and tumor biopsy tissues from 21 newly diagnosed patients with nasopharyngeal carcinoma (NPC) were collected, along with peripheral blood from 21 healthy donors. The biological characteristics of Tcregs and Tc17 cells from blood and tumor tissues were examined by intracellular staining, tetramer staining and fluorescence-activated cell sorting (FACS) analysis. The suppressive function of Tcregs was investigated using a proliferation assay that involved co-culture of sorted CD8<sup>+</sup>CD25<sup>+ </sup>T cells with naĆÆve CD4<sup>+ </sup>T cells <it>in vitro</it>.</p> <p>Results</p> <p>We observed an increased prevalence of Tcregs and Tc17 cells among tumor-infiltrating lymphocytes (TILs) and different distribution among peripheral blood mononuclear cells (PBMCs) in NPC patients. Cytokine profiles showed that the Tcregs expressed a high level of IL-10 and low level of transforming growth factor Ī², whereas Tc17 cells expressed a high level of tumor necrosis factor Ī±. Interestingly, both subsets expressed a high level of interferon Ī³ in TILs, and the Tcregs suppressed naĆÆve CD4<sup>+ </sup>T cell proliferation by a cell contact-dependent mechanism <it>in vitro</it>. Moreover, we demonstrated the existence of Epstein-Barr virus latent membrane protein (LMP) 1 and LMP2 antigen-specific Tcregs in NPC.</p> <p>Conclusions</p> <p>Our data provide new insights into the composition and function of CD8<sup>+ </sup>T-cell subsets in NPC, which may have an important influence on NPC immunotherapy.</p

    Population genetic structure of the deepā€sea mussel Bathymodiolus platifrons (Bivalvia: Mytilidae) in the Northwest Pacific

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    Ā© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Evolutionary Applications 11 (2018): 1915-1930, doi:10.1111/eva.12696.Studying population genetics of deepā€sea animals helps us understand their history of habitat colonization and population divergence. Here, we report a population genetic study of the deepā€sea mussel Bathymodiolus platifrons (Bivalvia: Mytilidae) widely distributed in chemosynthesisā€based ecosystems in the Northwest Pacific. Three mitochondrial genes (i.e., atp6, cox1, and nad4) and 6,398 genomewide single nucleotide polymorphisms (SNPs) were obtained from 110 individuals from four hydrothermal vents and two methane seeps. When using the three mitochondrial genes, nearly no genetic differentiation was detected for B. platifrons in the Northwest Pacific. Nevertheless, when using SNP datasets, all individuals in the South China Sea (SCS) and three individuals in Sagami Bay (SB) together formed one genetic cluster that was distinct from the remaining individuals. Such genetic divergence indicated a genetic barrier to gene flow between the SCS and the open Northwest Pacific, resulting in the coā€occurrence of two cryptic semiā€isolated lineages. When using 125 outlier SNPs identified focusing on individuals in the Okinawa Trough (OT) and SB, a minor genetic subdivision was detected between individuals in the southern OT (Sā€OT) and those in the middle OT (Mā€OT) and SB. This result indicated that, although under the influence of the Kuroshio Current and the North Pacific Intermediate Water, subtle geographic barriers may exist between the Sā€OT and the Mā€OT. Introgression analyses based on these outlier SNPs revealed that Hatoma Knoll in the Sā€OT represents a possible contact zone for individuals in the OTā€SB region. Furthermore, migration dynamic analyses uncovered stronger gene flow from Daiā€yon Yonaguni Knoll in the Sā€OT to the other local populations, compared to the reverse directions. Taken together, the present study offered novel perspectives on the genetic connectivity of B. platifrons mussels, revealing the potential interaction of ocean currents and geographic barriers with adaption and reproductive isolation in shaping their migration patterns and genetic differentiation in the Northwest Pacific.General Research Fund Grant Number: HKBU12302917; Hong Kong Baptist University Grant Number: 15ā€1012ā€P0
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