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Based on the financing motivation of equity pledges, this study explores whether and how monetary policy adjustment affects the stock pledge behaviour of listed companies. The empirical findings show that monetary policy adjustments significantly affect the stock pledge of listed companies; that is, a tightening monetary policy increases the stock pledge phenomenon of listed companies, and an expansionary monetary policy reduces the stock pledge phenomenon. Heterogeneity analysis revealed that monetary policy had a greater impact on the stock pledges of non-state-owned enterprises, enterprises with weak government–enterprise relationships and enterprises without bank–enterprise relationship. The results of mechanism tests suggested that a quantitative monetary policy only affects the stock pledge behaviour of listed companies through financing costs and that a price-based monetary policy affects the stock pledge behaviour of listed companies through financing costs and financing scale. This article expands the literature on the impact of monetary policies on equity pledges and enriches studies on macroeconomic policies and microfirm behaviour.

Objective To investigate the value of gap balance technique guided by computer-assisted navigation in total knee replacement. Methods A total of 63 patients with primary knee osteoarthritis and underwent total knee replacement from January to June 2018 were recruited in this study. They were randomly divided into experimental group (n=31, gap balance technique guided by computer-assisted navigation) and control group (n=31, osteotomy technique). The tension of medial and lateral ligaments in the flexion and extension space was recorded, and the limb alignment, incision length, operative time, blood loss volume, drainage volume, incidence of postoperative complications, and visual analogue scale (Vas) score and knee society knee score (KSS) in 1, 6 and 12 months after operation were recorded and compared between 2 groups. Results The operative time in experimental group was significantly longer than that in the control group (P < 0.05), but there were no significant differences in incision length, blood loss, drainage volume and incidence of postoperative complications between 2 groups (P>0.05). The limb alignment was better in the experimental group than the control group [(0.63±0.54)° vs (1.98±0.52)°, P < 0.05]. In 1 month after operation, the experimental group achieved significantly better Vas score (3.53±0.51 vs 4.24±0.49, P < 0.05), but similar KSS score (69.3±5.1 vs 67.5±3.7, P>0.05) when compared with the control group. But, in 6 and 12 months after surgery, no statistic differences were seen in the above 2 scores (P>0.05). For the patients from the experimental group, the tension of medial and lateral ligaments in the flexion and extension space ranged from 70 to 95 N, with an average of 84 N. Conclusion Gap balance technique guided by computer-assisted navigation can improve the accuracy of osteotomy in total knee replacement, with postoperative benefits of significantly reducing pain and rapid recovery during the early postoperative period, but having no obvious effect on outcome after 1 year's follow-up.

Objective To evaluate the effect of mechanical stretching in promoting tendon healing and reducing tendon adhesion during the healing of extensor flexor tendon in rats and its effects on the expression of transforming growth factor-β3 (TGF-β3) and cyclic AMP response element-binding protein (CREB). Methods Eighteen male SD rats were randomized into 3 equal groups and subjected to sham operation, flexor tendon injury of the second to fifth digits of the hind limbs without interventions (model group), or flexor tendon injury with daily passive mechanical stretching of the tendon for 1 week after the operation. The tendon was exposed only without injuries in the sham-operated group. At 1, 2, 4, and 8 weeks after the operation, tendon healing of the rats was evaluated by anatomical observation and histological examination, and the expression of TGF-β1, TGF-β3 and CREB in the tendon was detected using real-time fluorescence quantitative PCR and immunohistochemistry. Results Compared with the model group, the rats in mechanical stretching group showed better tendon healing with reduced tendon adhesion, less granular tissue and more regular cell alignment in the tendon (P < 0.05). During tendon healing, the expression of TGF-β3 and CREB mRNAs in the injured tendon were significantly higher at all the time points and the expression of TGF-β1 mRNA at the first week after the operation was significantly lower in mechanical stretching group than in the model group (P < 0.05); TGF-β1 mRNA expression was comparable between the two groups at all the later time points. Immunohistochemical studies showed significantly stronger TGF-β3 and CREB expression in the injured tendons in the mechanical stretching group after the operation, and TGF-β1 expression began to decrease significantly at 1 week after the operation (P < 0.05). Conclusion Mechanical stretching can promote the healing of the flexor tendon and reduce postoperative tendon adhesion in close relation with increased expression of TGF-β3 and CREB and reduced expression of TGF-β1 in the early stage of tendon healing.

Plants and soil bacteria exert a vital function in mediating soil ecosystem multifunctionality (EMF). Nevertheless, plant and soil bacteria interaction during forest secondary succession is poorly understood, and their roles in soil EMF remain largely unexplored. The dynamics of soil physicochemical properties and bacterial diversity was studied in southwest China during forest succession from coniferous to monsoon broadleaf evergreen. Interdomain ecological networks (IDEN) were adopted for investigating plant–bacteria associations. With the purpose of assessing how soil factors, bacterial community and plant diversity influenced soil EMF, the structural equation model (SEM) was used. It was discovered that both soil bacterial diversity and soil EMF gradually increased with the succession. IDEN analysis revealed that plant–bacteria ecological networks differed significantly across successional stages. Keystone plant species richness (KSR) increased with succession, which benefited soil bacteria diversity (path coefficient = 0.802, p < 0.001) while having a direct negative impact on pH (path coefficient = −0.602, p < 0.05) and C:N (path coefficient = −0.759, p < 0.001). Soil pH and C:N ratio declines were observed during forest secondary succession and were found to be inversely related to soil EMF. Furthermore, soil pH was found to be inversely related to bacterial diversity. The SEM analysis explained 88.2% of the variation in soil multifunctionality. The findings suggested that keystone plant species played a key function in regulating the variations of soil bacterial community and EMF (total effect = 0.813). Our study clarified the critical functions of keystone species in driving soil bacterial diversity and multifunctionality during forest succession and provided a new perspective on the relationship between above‐ and below‐ground. [ABSTRACT FROM AUTHOR]

Elastic interface states, which are usually generated at the interface of two connected domains with opposite topological invariant, have been successfully demonstrated in periodic structures. Therefore, the interface states determined by the position of interface between two domain walls in one-dimensional elastic systems are rarely reported, which were mainly restricted by the mirror-symmetric geometry of the unit cell. Jointing interface-dependent interface states were mostly implemented with analogs of quantum valley Hall effects in two-dimensional systems. Herein, we first observe two types of elastic interface states simultaneously occurred in one-dimensional combined metamaterials, where two interface modes separately located at two connected domain walls and they can be actively tuned simply through deforming two components on two sides. Flexible and versatile frequency shift and switch on–off characteristics of combination of two interface modes are demonstrated, which may be employed in the multifunctional elastic wave filters, tunable energy harvesting, and elastography devices. Our primitive cell of the soft metamaterial, which breaks the inversion symmetry along the horizontal direction, may be generalized to realize tunable elastic valley Hall edge states. [ABSTRACT FROM AUTHOR]

Plants live in association with a diversity of soil microorganisms, which are extremely important in affecting plant growth and soil biogeochemical cycling.By adopting plant trait‐based approaches, we explored the linkages between rhizosphere soil microbial activity and plant resource acquisition strategy of above‐ and below‐ground across a range of tree species in a subtropical evergreen mixed forest. The microbial activities were represented by diverse extracellular enzymes relevant to carbon, nitrogen and phosphorus cycling and soil organic carbon (SOC) mineralization.At the species level, leaf and root traits were mainly represented by two leading dimensions, that is, the 'fast‐slow' economics spectrum on which leaf and root traits were well aligned and the orthogonal collaboration gradient in the root.Both extracellular enzymes and SOC mineralization in the rhizosphere varied greatly across plant species. We found that diverse rhizosphere soil microbial activities positively correlated with the classical 'fast‐slow' conservation gradient of plant resource acquisition (especially above‐ground), that is, the rhizosphere soil microbes associated with fast‐growing plant species feature higher metabolism than that of slow‐growing plant species. In comparison, rhizosphere soil microbial activities were independent of the plant collaboration gradient in the root, and it might be an alternative exploitative strategy in foraging soil nutrients for plants.Synthesis. Our study strengthens the multivariate nature of plant resource acquisition in adapting to above‐ and below‐ground stresses. The findings on the linkages between rhizosphere soil microbial activity and plant resource acquisition strategy have the potential to improve our understanding and prediction of plant species turnover impacts on soil biogeochemical cycles. [ABSTRACT FROM AUTHOR]

Environment stress is a major threat to the existence of coral reefs and has generated a lot of interest in the coral research community. Under the environmental stress, corals can experience tissue loss and/or the breakdown of symbiosis between the cnidarian host and its symbiotic algae causing the coral tissue to appear white as the skeleton can be seen by transparency. Image analysis is a common method used to assess tissue response under the environmental stress. However, the traditional approach is limited by the dynamic nature of the coral-algae symbiosis. Here, we observed coral tissue response in the scleractinian coral, Montipora capricornis, using high frequency image analysis throughout the experiment, as opposed to the typical start/end point assessment method. Color analysis reveals that the process can be divided into five stages with two critical stages according to coral tissue morphology and color ratio. We further explore changes to the morphology of individual polyps by means of the Pearson correlation coefficient and recurrence plots, where the quasi-periodic and nonstationary dynamics can be identified. The recurrence quantification analysis also allows the comparison between the different polyps. Our research provides a detailed visual and mathematical analysis of coral tissue response to environmental stress, which potentially shows universal applicability. Moreover, our approach provides a robust quantitative advancement for improving our insight into a suite of biotic responses in the perspective of coral health evaluation and fate prediction. [ABSTRACT FROM AUTHOR]

Autumn phenology plays a key role in regulating the terrestrial carbon and water balance and their feedbacks to the climate. However, the mechanisms underlying autumn phenology are still poorly understood, especially in subtropical forests. In this study, we extracted the autumn photosynthetic transition dates (APTD) in subtropical China over the period 2003–2017 based on a global, fine‐resolution solar‐induced chlorophyll fluorescence (SIF) dataset (GOSIF) using four fitting methods, and then explored the temporal–spatial variations of APTD and its underlying mechanisms using partial correlation analysis and machine learning methods. We further predicted the APTD shifts under future climate warming conditions by applying process‐based and machine learning‐based models. We found that the APTD was significantly delayed, with an average rate of 7.7 days per decade, in subtropical China during 2003–2017. Both partial correlation analysis and machine learning methods revealed that soil moisture was the primary driver responsible for the APTD changes in southern subtropical monsoon evergreen forest (SEF) and middle subtropical evergreen forest (MEF), whereas solar radiation controlled the APTD variations in the northern evergreen‐broadleaf deciduous mixed forest (NMF). Combining the effects of temperature, soil moisture and radiation, we found a significantly delayed trend in APTD during the 2030–2100 period, but the trend amplitude (0.8 days per decade) was much weaker than that over 2003–2017. In addition, we found that machine learning methods outperformed process‐based models in projecting APTD. Our findings generate from different methods highlight that soil moisture is one of the key players in determining autumn photosynthetic phenological processes in subtropical forests. To comprehensively understand autumn phenological processes, in‐situ manipulative experiments are urgently needed to quantify the contributions of different environmental and physiological factors in regulating plants' response to ongoing climate change. [ABSTRACT FROM AUTHOR]

Caryota obtusa of Arecaceae is a fascinating palm tree native to southwestern China, India, Myanmar, Thailand, Laos and Vietnam. It is an economically important and threatened species and appears as a canopy dominant in some karst areas in Yunnan. We aim to clarify the forest structure, species diversity, population status and regeneration dynamics of C. obtusa in the karst forest ecosystem of Yunnan, China. We established 56 vegetation plots dominated by C. obtusa in 10 counties of southern Yunnan. Based on the plot data, we analyzed the community stratification, floristic composition and C. obtusa 's population structure. We used questionnaires to interview local people and recorded the human activity history in C. obtusa -dominated forests. Caryota obtusa palm forests were distributed on limestone mountain slopes and gullies. There were seven forest community types. The stratification of each community included arborous layer, shrub layer and understory. The communities had rich species composition. For all the plots as a whole of each community type, Shannon–Wiener diversity index of either woody or herbaceous species ranged from 2.1 to 3.8. The diameter at breast height (DBH)-class frequency distribution of C. obtusa was a multimodal type. The regeneration was sporadic and dependent on intermediate natural disturbances. In the current population structure, a number of C. obtusa trees with small DBHs consisted mainly of the forest communities with no or a slight degree of human disturbances. Intensive human activities terribly hindered recruitment of C. obtuse , followed by the medium intensity of human activities. [ABSTRACT FROM AUTHOR]

Pinus yunnanensis forest is a unique forest type in southwest China and one of the main forest types in Yunnan Province, which also has great ecological, economic and social significance. Understanding the changes in the stoichiometric characteristics is a key to study the nutrient cycling, limiting factors and stability mechanisms of the forest ecosystem. However, the stoichiometric characteristics, stability of the ecosystem of P. yunnanensis natural forests and whether they are limited by nutrients are still poorly understood. Based on a K-S test, ANOVA analysis and OLS regression analysis, we analyzed the concentrations of leaf C, N and P in 48 woody species of natural P. yunnanensis forests from 122 plots to explore the pattern of leaf C:N:P stoichiometry. Our results showed that the mean values of leaf C, N and P plus C:N, C:P and N:P for the 48 woody species were 451.12, 11.05 and 1.11 mg/g and 45.03, 496.98 and 11.27, respectively. The coefficients of variation of leaf C, N and P plus C:N, C:P and N:P were 5.29%, 36.75%, 51.53%, 29.63%, 43.46% and 41.68%, respectively. The geometric mean values of leaf N, P and N:P were 10.49 and 1.00 mg/g and 10.51, respectively. Leaf C and N, and C and P relationships showed significant negative correlations, but a significant positive correlation was observed between leaf N and P. There were significant differences in leaf N and C:N across functional groups. There were significant differences in leaf C and P between evergreen and deciduous, conifer and broadleaf trees. Significant differences in leaf C:P were only observed between evergreen and deciduous trees, and significant differences in leaf N:P were observed between conifer and broadleaf trees. The relatively low N:P in all sampled trees indicated that N was a limiting factor in the distribution of natural P. yunnanensis forests. However, the higher leaf C:N and C:P ratios indicated that the P. yunnanensis natural forest ecosystem was in a relatively stable state. [ABSTRACT FROM AUTHOR]

Summary: The adoption of diverse resource acquisition strategies is critical for plant growth and species coexistence. Root phosphatase is of particular importance in the acquisition of soil phosphorus (P), yet it is often overlooked in studies of root trait syndromes.Here, we evaluated the role of root phosphatase activity (RPA) within the root economics space and the order‐based variation of RPA, as well as the correlations between RPA and a suite of leaf traits and soil properties over a range of evergreen tree species in a subtropical forest.Root phosphatase activity exhibited a high degree of inter‐specific variation. We found that there were two leading dimensions of the multidimensional root economics space, the root diameter–specific root length axis (collaboration trait gradient) and the root tissue density–root nitrogen concentration axis (classical trait gradient), and RPA aligned with the former. Root phosphatase activity is used as a 'do it yourself' strategy of soil P acquisition, and was found to be inversely correlated with mycorrhizal colonization, which suggests a trade‐off in plant P acquisition strategies. Compared with soil and foliar nutrient status, root traits mattered most for the large inter‐specific changes in RPA. Furthermore, RPA generally decreased from first‐ to third‐order roots.Taken together, such diverse P‐acquisition strategies are conducive to plant coexistence within local forest communities. The use of easily measurable root traits and their tight correlations with RPA could be a feasible and promising approach to estimating species‐specific RPA values, which would be helpful for better understanding plant P acquisition and soil P cycling. See also the Commentary on this article by Yaffar et al., 234: 773–775. [ABSTRACT FROM AUTHOR]