SummaryChina is the origin and evolutionary centre of Oriental pears. Pyrus betuleafolia is a wild species native to China and distributed in the northern region, and it is widely used as rootstock. Here, we report the de novo assembly of the genome of P. betuleafolia‐Shanxi Duli using an integrated strategy that combines PacBio sequencing, BioNano mapping and chromosome conformation capture (Hi‐C) sequencing. The genome assembly size was 532.7 Mb, with a contig N50 of 1.57 Mb. A total of 59 552 protein‐coding genes and 247.4 Mb of repetitive sequences were annotated for this genome. The expansion genes in P. betuleafolia were significantly enriched in secondary metabolism, which may account for the organism's considerable environmental adaptability. An alignment analysis of orthologous genes showed that fruit size, sugar metabolism and transport, and photosynthetic efficiency were positively selected in Oriental pear during domestication. A total of 573 nucleotide‐binding site (NBS)‐type resistance gene analogues (RGAs) were identified in the P. betuleafolia genome, 150 of which are TIR‐NBS‐LRR (TNL)‐type genes, which represented the greatest number of TNL‐type genes among the published Rosaceae genomes and explained the strong disease resistance of this wild species. The study of flavour metabolism‐related genes showed that the anthocyanidin reductase (ANR) metabolic pathway affected the astringency of pear fruit and that sorbitol transporter (SOT) transmembrane transport may be the main factor affecting the accumulation of soluble organic matter. This high‐quality P. betuleafolia genome provides a valuable resource for the utilization of wild pear in fundamental pear studies and breeding.

An error occurred in Eq. (11) of the paper where the square root should be removed. The correct equation for the ratio of the soliton oscillation frequency to the trap frequency readswhich indeed follows from Eq. (10) with the given definition of the effective mass M s . Neither the further discussion in the paper nor the conclusions are affected or altered by this change. In particular, the numerical data for the frequency ratios, presented in the text below Eq. (11), were evaluated with the correct formula.

Families of dark solitons exist in superfluid Fermi gases. The energy-velocity dispersion and number of depleted particles completely determines the dynamics of dark solitons on a slowly-varying background density. For the unitary Fermi gas we determine these relations from general scaling arguments and conservation of local particle number. We find solitons to oscillate sinusoidally at the trap frequency reduced by a factor of 1/ √ 3. Numerical integration of the time-dependent Bogoliubov-de Gennes equation determines spatial profiles and soliton dispersion relations across the BEC-BCS crossover and proves consistent with the scaling relations at unitarity. PACS numbers: 03.75.Lm,67.85.De,67.85.Lm,03.75.Ss Dark solitons are elementary nonlinear excitations that play a key role in understanding complex dynamics of superfluids [1,2]. Superfluid Fermi gases have only recently become accessible experimentally and their nonlinear wave dynamics are largely unexplored [3,4]. These systems offer the intriguing possibility to tune between the perturbatively accessible regimes of Bose-Einstein condensation (BEC) of preformed pairs and Bardeen-Cooper-Schrieffer (BCS) superfluidity and a strongly correlated regime of unitarity-limited interactions. While the existence and properties of dark solitons in the BEC regime can be inferred from the solutions of Gross-Pitaevskii (GP) mean-field theory and experiments with atomic BECs, it is an outstanding question what happens outside this regime. So far, only numerical solutions for stationary dark solitons within Bogoliubov-de Gennes (BdG) mean-field theory have been available [5].In this work, we report theoretical results supporting the existence and detailing the properties of a family of traveling (grey) solitons that are parameterized by their velocity of propagation v s . We are aware of parallel efforts to understand soliton dynamics in trapped Fermi gases [6] and to determine grey soliton profiles [7]. For the unitary gas, we find a closed analytic form of the energy-velocity dispersion relation that is fully determined from a set of general assumptions: (a) Upon adiabatic change of the environment, the soliton can adjust its dynamical state and consistently conserve locally both energy and particle number. (b) Energy and particle number vanish as v s approaches the speed of sound. (c) The superfluid order parameter has a well defined phase step across the soliton that also vanishes under the conditions of (b).Assumption (a) means that solitons can move adiabatically between regions of different background density without disintegration and radiation. This non-trivial property is known to be true for GP solitons [8]. For the unitary gas the assumptions are supported by the excellent agreement found between the analytic dispersion and our numerical results based on BdG mean-field theory (see Figs. 1b and 2b,d). The meanfield calculations further allow us to obtain spatial soliton profiles and dispersion relations for arbitrary interactions outside the unitarity limit. ...

We investigate a two-component atomic Fermi gas with population imbalance in the presence of Rashba-type spin-orbit coupling (SOC). As a competition between SOC and population imbalance, the finite-temperature phase diagram reveals a large variety of new features, including the expanding of the superfluid state regime and the shrinking of both the phase separation and the normal regimes. For sufficiently strong SOC, the phase separation region disappears, giving way to the superfluid state. We find that the tricritical point moves toward a regime of low temperature, high magnetic field, and high polarization as the SOC increases.

We study soliton collisions and the decay of solitons into sound in superfluid Fermi gases across the Bose-Einstein condensate to Bardeen-Cooper-Schrieffer (BEC-BCS) crossover by performing numerical simulations of the time-dependent Bogoliubov-de Gennes equations. This decay process occurs when the solitons are accelerated to the bulk pair-breaking speed by an external potential. A similar decay process may occur when solitons are accelerated by an inelastic collision with another soliton. We find that soliton collisions become increasingly inelastic as we move from the BEC to the BCS regime, and the excess energy is converted into sound. We interpret this effect as being due to the evolution of Andreev bound states localized within the soliton.

Background Chrysosplenium L. (Saxifragaceae) is a genus of plants widely distributed in Northern Hemisphere and usually found in moist, shaded valleys and mountain slopes. This genus is ideal for studying plant adaptation to low light conditions. Although some progress has been made in the systematics and biogeography of Chrysosplenium, its chloroplast genome evolution remains to be investigated. Results To fill this gap, we sequenced the chloroplast genomes of six Chrysosplenium species and analyzed their genome structure, GC content, and nucleotide diversity. Moreover, we performed a phylogenetic analysis and calculated non-synonymous (Ka) /synonymous (Ks) substitution ratios using the combined protein-coding genes of 29 species within Saxifragales and two additional species as outgroups, as well as a pair-wise estimation for each gene within Chrysosplenium. Compared with the outgroups in Saxifragaceae, the six Chrysosplenium chloroplast genomes had lower GC contents; they also had conserved boundary regions and gene contents, as only the rpl32 gene was lost in four of the Chrysosplenium chloroplast genomes. Phylogenetic analyses suggested that the Chrysosplenium separated to two major clades (the opposite group and the alternate group). The selection pressure estimation (Ka/Ks ratios) of genes in the Chrysosplenium species showed that matK and ycf2 were subjected to positive selection. Conclusion This study provides genetic resources for exploring the phylogeny of Chrysosplenium and sheds light on plant adaptation to low light conditions. The lower average GC content and the lacking gene of rpl32 indicated selective pressure in their unique habitats. Different from results previously reported, our selective pressure estimation suggested that the genes related to photosynthesis (such as ycf2) were under positive selection at sites in the coding region.

A thermochromic material library with a tunable luminescence color-switching window and temperature-responsive window was applied in ultrahigh-level optical data encryption and decryption.

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