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In the prevailing model of galaxy formation and evolution, the process of gas accretion on to central galaxies undergoes a transition from cold-dominated to hot-dominated modes. This shift occurs when the mass of the parent dark matter haloes exceeds a critical threshold known as M shock. Moreover, cold gas usually flows on to central galaxies through filamentary structures, currently referred to as cold streams. However, the evolution of cold streams in haloes with masses around M shock, particularly how they are disrupted, remains unclear. To address this issue, we conduct a set of idealized hydrodynamic simulations. Our simulations show that (1) for a gas metallicity |$Z=0.001{\!-\!}0.1\, \mathrm{Z}_{\odot }$|⁠ , cold stream with an inflow rate |$\sim 3\, {\rm {M}_{\odot }}\, \mathrm{yr}^{-1}$| per each can persist and effectively transport cold and cool gas to the central region (<0.2 virial radius) in haloes with mass |$10^{12}\, {\rm {M}_{\odot }}$|⁠ , but is disrupted at a radius around 0.2 virial radius due to compression heating for haloes with mass |$3 \times 10^{12}\, {\rm {M}_{\odot }}$|⁠. (2) At z ∼ 2, the maximum halo mass that capable of hosting and sustaining cold streams M stream is between 1 × 1012 M⊙ and |$1.5\times 10^{12}\,\rm {{M}_{\odot }}$| for gas metallicity |${\it Z}=0.001\, \mathrm{Z}_{\odot }$|⁠ , while for a higher gas metallicity |${\it Z}=0.1\, \mathrm{Z}_{\odot }$|⁠ , this value increases to |$\sim 1.5\times 10^{12}\,\rm {{M}_{\odot }}$|⁠. (3) The evolution and ultimate fate of cold streams are determined primarily by the rivalry between radiative cooling and compression. Stronger heating due to compression in haloes more massive than M stream can surpass cooling and heat the gas in cold streams to the hot (⁠|$\ge 10^6\,$|  K) phase. [ABSTRACT FROM AUTHOR]

Background and Aims Understanding adaptive genetic variation and whether it can keep pace with predicted future climate change is critical in assessing the genetic vulnerability of species and developing conservation management strategies. The lack of information on adaptive genetic variation in relict species carrying abundant genetic resources hinders the assessment of genetic vulnerability. Using a landscape genomics approach, this study aimed to determine how adaptive genetic variation shapes population divergence and to predict the adaptive potential of Pterocarya macroptera (a vulnerable relict species in China) under future climate scenarios. Methods We applied restriction site-associated DNA sequencing (RAD-seq) to obtain 8244 single-nucleotide polymorphisms (SNPs) from 160 individuals across 28 populations. We examined the pattern of genetic diversity and divergence, and then identified outliers by genetic differentiation (F ST) and genotype–environment association (GEA) methods. We further dissected the effect of geographical/environmental gradients on genetic variation. Finally, we predicted genetic vulnerability and adaptive risk under future climate scenarios. Key Results We identified three genetic lineages within P. macroptera : the Qinling-Daba-Tianmu Mountains (QDT), Western Sichuan (WS) and Northwest Yunnan (NWY) lineages, which showed significant signals of isolation by distance (IBD) and isolation by environment (IBE). IBD and IBE explained 3.7–5.7 and 8.6–12.8 % of the genetic structure, respectively. The identified GEA SNP-related genes were involved in chemical defence and gene regulation and may exhibit higher genetic variation to adapt to the environment. Gradient forest analysis revealed that the genetic variation was mainly shaped by temperature-related variables, indicating its adaptation to local thermal environments. A limited adaptive potential was suggested by the high levels of genetic vulnerability in marginal populations. Conclusions Environmental gradient mainly shaped the population differentiation of P. macroptera. Marginal populations may be at high risk of extinction, and thus proactive management measures, such as assisted gene flow, are required to ensure the survival of these populations. [ABSTRACT FROM AUTHOR]

Purpose: Microbial resources are abundant in fermented grains of the Chinese Fen-flavor Baijiu, which is closely related to the quality of Baijiu. The purpose of this study was to investigate the microbial community structure and function in Daqu and fermented grains. Methods: We systematically compared two technical approaches, amplicon sequencing, and metagenomic sequencing, to analyze the microbial communities during Baijiu fermentation. Result: The results showed that lactic acid bacteria (LAB) and yeasts were the main microorganisms in the fermentation process. Firmicutes (Lactobacillus, Pediococcus, and Weissella) were the dominant bacteria, and Ascomycota (Issatchenkia or Pichia) was the dominant fungus in fermented grains. Moreover, Pichia kudriavzevii, Lichtheimia ramosa, and Companilactobacillus paralimentarius were the dominant species at the initial stage of fermentation by metagenomic sequencing. Latilactobacillus curvatus, Loigolactobacillus coryniformis subsp. coryniformis, and Lentilactobacillus parabuchneri became dominant during the middle stage of fermentation. Lentilactobacillus parabuchneri and Lactobacillus acetotolerans were the dominant species in the final stage of fermentation. Spearman correlation analysis showed that LAB inhibited the growth of yeasts. Conclusion: Combining the two sequencing methods provided valuable insights into the dynamic succession of microorganisms during the fermentation of Baijiu. It had had a particular significance for mining microbial species resources in fermented grains. [ABSTRACT FROM AUTHOR]

Since the Anthropocene, biodiversity loss owing to human activity and climate change has worsened. Quercus gilva is an evergreen oak species native to China, Japan, and South Korea and is threatened by a long history of human impact. The purpose of this study was to (1) reassess the threatened category of Q. gilva based on a detailed survey, and (2) identify the genetic structure and diversity of Q. gilva based on genomic data. First, we conducted a detailed survey of the populations in China. Second, we collated all the literature and information. Finally, genome-wide genetic variation was analyzed based on 65 individuals from 22 populations. We found that Q. gilva has suffered rapid population decline, and at present, most populations are very small. The evolutionary path of Q. gilva was from the southwest to east of China and then to Japan and South Korea. Quercus gilva showed no distinct genetic structure and had a relatively low genetic diversity. Among the 22 populations, most populations in southwestern China, South Korea, and Japan had high genetic diversity. The populations in Jingning (Zhejiang province; ZJN), Wuyuan (Jinaxi province; JWY), and Zherong (Fujian province; FZR) suffered a strong bottleneck. In conclusion, Q. gilva is an endangered species native to East Asia. Because of the very low genetic diversity of Q. gilva and most populations are small, we need to (1) strengthen the protection of this species, (2) conduct conservation actions with in-situ reinforcement populations, and (3) select populations with high genetic diversity as provenances for afforestation efforts. Finally, we suggest that in the future, genetic diversity should be considered as the sixth criterion for IUCN to evaluate the threatened category. [ABSTRACT FROM AUTHOR]

Quercus litseoides, an endangered montane cloud forest species, is endemic to southern China. To understand the genomic features, phylogenetic relationships, and molecular evolution of Q. litseoides, the complete chloroplast (cp) genome was analyzed and compared in Quercus section Cyclobalanopsis. The cp genome of Q. litseoides was 160,782 bp in length, with an overall guanine and cytosine (GC) content of 36.9%. It contained 131 genes, including 86 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. A total of 165 simple sequence repeats (SSRs) and 48 long sequence repeats with A/T bias were identified in the Q. litseoides cp genome, which were mainly distributed in the large single copy region (LSC) and intergenic spacer regions. The Q. litseoides cp genome was similar in size, gene composition, and linearity of the structural region to those of Quercus species. The non-coding regions were more divergent than the coding regions, and the LSC region and small single copy region (SSC) were more divergent than the inverted repeat regions (IRs). Among the 13 divergent regions, 11 were in the LSC region, and only two were in the SSC region. Moreover, the coding sequence (CDS) of the six protein-coding genes (rps12, matK, atpF, rpoC2, rpoC1, and ndhK) were subjected to positive selection pressure when pairwise comparison of 16 species of Quercus section Cyclobalanopsis. A close relationship between Q. litseoides and Quercus edithiae was found in the phylogenetic analysis of cp genomes. Our study provided highly effective molecular markers for subsequent phylogenetic analysis, species identification, and biogeographic analysis of Quercus. [ABSTRACT FROM AUTHOR]

The latitudinal diversity gradient (LDG) is one of the most extensive and important biodiversity patterns on the Earth. Various studies have established that species diversity increases with higher taxa numbers from the polar to the tropics. Studies of multicellular biotas have supported the LDG patterns from land (e.g., plants, animals, forests, wetlands, grasslands, fungi, and so forth) to oceans (e.g., marine organisms from freshwater invertebrates, continental shelve, open ocean, even to the deep sea invertebrates). So far, there are several hypotheses proposed to explore the diversity patterns and mechanisms of LDG, however, there has been no consensus on the underlying causes of LDG over the past few decades. Thus, we reviewed the progress of LDG studies in recent years. Although several explanations for the LDG have been proposed, these hypotheses are only based on species richness, evolution and the ecosystems. In this review, we summarize the effects of evolution and ecology on the LDG patterns to synthesize the formation mechanisms of the general biodiversity distribution patterns. These intertwined factors from ecology and evolution in the LDG are generally due to the wider distribution of tropical areas, which hinders efforts to distinguish their relative contributions. However, the mechanisms of LDG always engaged controversies, especially in such a context that the human activity and climate change has affected the biodiversity. With the development of molecular biology, more genetic/genomic data are available to facilitate the estimation of global biodiversity patterns with regard to climate, latitude, and other factors. Given that human activity and climate change have inevitably impacted on biodiversity loss, biodiversity conservation should focus on the change in LDG pattern. Using large-scale genetic/genomic data to disentangle the diversity mechanisms and patterns of LDG, will provide insights into biodiversity conservation and management measures. Future perspectives of LDG with integrative genetic/genomic, species, evolution, and ecosystem diversity patterns, as well as the mechanisms that apply to biodiversity conservation, are discussed. It is imperative to explore integrated approaches for recognizing the causes of LDG in the context of rapid loss of diversity in a changing world. [ABSTRACT FROM AUTHOR]

Background: The biomechanical and tendon-bone incorporation properties of allograft-augmented hybrid grafts for anterior cruciate ligament (ACL) reconstruction compared with traditional autografts are unknown. Hypothesis: Using an autograft for ACL reconstruction yields better results on biomechanical testing, radiographic analysis, and histological evaluation versus using a hybrid graft. Study Design: Controlled laboratory study. Methods: A total of 66 adult male Sprague Dawley rats underwent unilateral ACL reconstruction with an autograft (AT group; n = 33) or a hybrid graft (HB group; n = 33). The grafts used in both groups were harvested from the peroneus longus tendon and were fixed by suturing to the surrounding periosteum. Samples were harvested for biomechanical testing, micro–computed tomography (CT), and histological evaluation at 4, 8, and 12 weeks postoperatively. Bone tunnels on the femoral and tibial sides were divided into 3 subregions: intra-articular (IA), midtunnel (MT), and extra-articular (EA). A cylinder-like volume of interest in the bone tunnel and a tubular-like volume of interest around the bone tunnel were used to evaluate new bone formation and bone remodeling, respectively, via micro-CT. Results: In the AT group, there were significantly higher failure loads and stiffness at 8 weeks (failure load: 3.04 ± 0.40 vs 2.09 ± 0.54 N, respectively; P =.006) (stiffness: 3.43 ± 0.56 vs 1.75 ± 0.52 N/mm, respectively; P <.001) and 12 weeks (failure load: 9.10 ± 1.13 vs 7.14 ± 0.94 N, respectively; P =.008) (stiffness: 4.45 ± 0.75 vs 3.36 ± 0.29 N/mm, respectively; P =.008) than in the HB group. With regard to new bone formation in the bone tunnel, in the AT group, the bone volume/total volume (BV/TV) was significantly higher than in the HB group on the tibial side at 8 weeks (IA: 22.21 ± 4.98 vs 5.16 ± 3.98, respectively; P <.001) (EA: 19.66 ± 7.19 vs 10.85 ± 2.16, respectively; P =.030) and 12 weeks (IA: 30.50 ± 5.04 vs 17.11 ± 7.31, respectively; P =.010) (MT: 21.15 ± 2.58 vs 15.55 ± 4.48, respectively; P =.041) (EA: 20.75 ± 3.87 vs 10.64 ± 3.94, respectively; P =.003). With regard to bone remodeling around the tunnel, the BV/TV was also significantly higher on the tibial side at 8 weeks (MT: 33.17 ± 8.05 vs 15.21 ± 7.60, respectively; P =.007) (EA: 25.19 ± 6.38 vs 13.94 ± 7.10, respectively; P =.030) and 12 weeks (IA: 69.46 ± 4.45 vs 47.80 ± 6.16, respectively; P <.001) (MT: 33.15 ± 3.88 vs 13.76 ± 4.07, respectively; P <.001) in the AT group than in the HB group. Sharpey-like fibers had formed at 8 weeks in the AT group. A large number of fibroblasts withdrew at 12 weeks. In the AT group, the width of the interface was significantly narrower at 4 weeks (85.86 ± 17.49 vs 182.97 ± 14.35 μm, respectively; P <.001), 8 weeks (58.86 ± 10.99 vs 90.15 ± 11.53 μm, respectively; P =.002), and 12 weeks (42.70 ± 7.96 vs 67.29 ± 6.55 μm, respectively; P =.001) than in the HB group. Conclusion: Using an autograft for ACL reconstruction may result in improved biomechanical properties and tendon-bone incorporation compared with a hybrid graft. Clinical Relevance: Augmenting small autografts with allograft tissue may result in decreased biomechanical performance and worse tendon-bone incorporation, increasing the risk of graft failure. [ABSTRACT FROM AUTHOR]

[CuII(L)2.C12H10N2] with flufenamic acid (HL=C14H10F3NO2) and phenanthroline (C12H10N2O) was synthesized and characterized by C, H and N elemental analysis, single-crystal X-ray diffraction and, IR spectra. The urease inhibitory and antibacterial activities of the complex were tested. The complex showed strong inhibitory activity against jack bean urease with an IC50 value of 0.265 μM. Four bacteria, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and proteusbacillus vulgaris, were used in the antibacterial test. The complex showed strong inhibitory activity against the species with IC50 values of 2.016, 35.037, 10.680, and 3.820 μM. The interactions of the complex with human serum albumin (HSA) were studied through fluorescence spectroscopy. By analyzing the experimental data, we concluded that the fluorescence quenching mechanism of the complex with serum albumin was static quenching. The binding mode of the complex with DNA through UV spectroscopy was electrostatic binding or groove. [ABSTRACT FROM AUTHOR]