Phylogenetic diversity is a better predictor of wetland community resistance to Alternanthera philoxeroides invasion than species richness.

Highly biodiversity communities have been shown to better resist plant invasions through complementarity effects. Species richness (SR) is a widely used biodiversity metric but lacks explanatory power when there are only a few species. Communities with low SR can have a wide variety of phylogenetic diversities (PD), which might allow for a better prediction of invasibility. We assessed the effect of diversity reduction of a wetland community assemblage typical of the Beijing area on biotic resistance to invasion of the exotic weed Alternanthera philoxeroides and compared the reduction in SR and PD in predicting community invasibility. The eight studied resident species performed similarly when grown alone and when grown in eight-species communities together with the invasive A. philoxeroides. Variation partitioning showed that PD contributed more to variation in both A. philoxeroides traits and community indicators than SR. All A. philoxeroides traits and community indicators, except for evenness index, showed a linear relationship with PD. However, only stem length of A. philoxeroides differed between the one- and two-species treatments, and the diversity index of the communities differed between the one- and two-species treatments and between the one- and four-species treatments. Our results showed that in natural or semi-natural wetlands with relatively low SR, PD may be a better predictor of invasibility than SR. When designing management strategies for mitigating A. philoxeroides invasion, deliberately raising PD is expected to be more efficient than simply increasing species number.

Effects of parental light environment on growth and morphological responses of clonal offspring.

Environments experienced by parent ramets of clonal plants can potentially influence fitness of clonal offspring ramets. Such clonal parental effects may result from heritable epigenetic changes, such as DNA methylation, which can be removed by application of DNA de-methylation agents such as 5-azacytidine. To test whether parental shading effects occur via clonal generation and whether DNA methylation plays a role in such effects, parent plants of the clonal herb Alternanthera philoxeroides were first subjected to two levels of light intensity (high versus low) crossed with two levels of DNA de-methylation (no or with de-methylation by application of 5-azacytidine), and then clonal offspring taken from each of these four types of parent plant were subjected to the same two light levels. Parental shading effects transmitted via clonal generation decreased growth and modified morphology of clonal offspring. Offspring responses were also influenced by DNA methylation level of parent plants. For clonal offspring growing under low light, parental shading effects on growth and morphology were always negative, irrespective of the parental de-methylation treatment. For clonal offspring growing under high light, parental shading effects on offspring growth and morphology were negative when the parents were not treated with 5-azacytidine, but neutral when they were treated with 5-azacytidine. Overall, parental shading effects on clonal offspring performance of A. philoxeroides were found, and DNA methylation is likely to be involved in such effects. However, parental shading effects contributed little to the tolerance of clonal offspring to shading.

Supraclavicular block versus interscalene brachial plexus block for shoulder surgery: A meta-analysis of clinical control trials.

BACKGROUND: The ultrasound-guided interscalene block (ISB) has been considered a standard technique in managing pain after shoulder surgery. However, this method was associated with the incidence of hemi-diaphragmatic paresis. In contrast to ISB, supraclavicular block (SCB) was suggested to provide effective anaesthesia for shoulder surgery with a low rate of side-effects. Thus, we performed a meta-analysis of randomised controlled trials (RCTs) to compare SCB with ISB for evaluating the efficacy and safety. METHOD: The literature was searched from PubMed, Wiley Online Library, EMBASE, and the Cochrane Library by two reviewers up to April 2017. All available RCTs written in English that met the criteria were included. Two authors pulled data from relevant articles and assessed the quality with the Cochrane Handbook. Review Manager 5.3 software was used to analyse the data. RESULTS: Five RCTs and one prospective clinical study met the eligibility criteria and were included in the meta-analysis. We considered that there were no statistically significant differences between supraclavicular and interscalene groups in procedural time (P = 0.81), rescue analgesia (P = 0.53), and dyspnoea (P = 0.6). The incidence of hoarseness and Horner syndrome was statistically lower in the SCB group than in the ISB group (P = 0.0002 and P < 0.00001, respectively). CONCLUSION: The meta-analysis showed that ultrasound-guided SCB could become a feasible alternative technique to the ISB in shoulder surgery.

MicroRNA-100 inhibits bone morphogenetic protein-induced osteoblast differentiation by targeting Smad1.

OBJECTIVE: MicroRNAs (miRNAs) act as key regulators of diverse cellular activities by regulating the expression of protein-coding genes. Osteoblast differentiation, a fundamental step in skeletal development, involves the activation of several signaling pathways, including transforming growth factor ß (TGF-ß), bone morphogenetic protein (BMP), and Wnt signaling pathways. MATERIALS AND METHODS: miRNA expression was measured using TaqManRT-PCR. Western blot was used to detect the protein expression of Smad1. Luciferase reporter assay was used to measure the luciferase activity. RESULTS: In this study, we found that miR-100 was expressed in mesenchymal progenitor cell lines; furthermore, its expression was reduced during osteoblast differentiation. Retroviral overexpression of miR-100 decreased Smad1 protein levels, whereas miR-100 inhibition had the opposite effect, suggesting that miR-100 acts as an endogenous attenuator of Smad1 in osteoblast differentiation. CONCLUSIONS: Together, our data demonstrate that miR-100 acts as an important endogenous negative regulator of BMP-induced osteoblast differentiation.

Effects of clonal fragmentation on intraspecific competition of a stoloniferous floating plant.

Disturbance is common and can fragment clones of plants. Clonal fragmentation may affect the density and growth of ramets so that it could alter intraspecific competition. To test this hypothesis, we grew one (low density), five (medium density) or nine (high density) parent ramets of the floating invasive plant Pistia stratiotes in buckets, and newly produced offspring ramets were either severed (with fragmentation) or remained connected to parent ramets (no fragmentation). Increasing density reduced biomass of the whole clone (i.e. parent ramet plus its offspring ramets), showing intense intraspecific competition. Fragmentation decreased biomass of offspring ramets, but increased biomass of parent ramets and the whole clone, suggesting significant resource translocation from parent to offspring ramets when clones were not fragmented. There was no interaction effect of density x fragmentation on biomass of the whole clone, and fragmentation did not affect competition intensity index. We conclude that clonal fragmentation does not alter intraspecific competition between clones of P. stratiotes, but increases biomass production of the whole clone. Thus, fragmentation may contribute to its interspecific competitive ability and invasiveness, and intentional fragmentation should not be recommended as a measure to stop the rapid growth of this invasive species.