B-Doping-Induced Lattice Expansion of Pd Metallene Nanoribbons for Oxygen Reduction Reaction.

Pd-based metallene is regarded as an efficient catalyst in the field of oxygen reduction reaction (ORR) because of its fantastic physicochemical features. The morphological structure control, lattice strain engineering, and electronic structure modulation of Pd-based metallene are effective tactics to enhance its electrocatalytic performance. In this work, we fabricate atomically thin B-doped Pd metallene nanoribbons (B-Pd MNRs) for efficient alkaline ORR. The atomically thin nanoribbon structure of B-Pd MNRs can expose many surface atoms as catalytically active sites. Moreover, the incorporation of boron effectively induces the lattice expansion and modulates the electronic structure of Pd, which can synergistically weaken the adsorption of intermediate species on B-Pd MNRs. Therefore, the B-Pd MNRs display excellent activity and durability for ORR. This work opens an avenue to the synthesis of atomically thin heteroatom-doped metallene nanoribbons for energy electrocatalytic applications.

Nitrogen-intercalated Pd metallene nanoribbons with optimized electronic structure for oxygen reduction catalysis.

Herein, we propose nitrogen (N)-intercalated Pd metallene nanoribbons (N-Pd MNRs), which exhibit favorable and stable oxygen reduction reaction (ORR) performance in alkaline media. The ultrathin configuration of the N-Pd MNRs exposes more atoms, thus acting as active sites. More importantly, N intercalation triggers electronic interaction between Pd and N to establish Pd-N bonds and induces lattice strain, which optimizes the electronic structure of the metallene nanoribbons, thereby modulating the binding strength between the intermediates and active sites. This work offers new insights into the rational design of N intercalated metallene nanoribbons for efficient ORR catalysis.

Pleomorphic Dematiomelanommayunnanense gen. et sp. nov. (Ascomycota, Melanommataceae) from grassland vegetation in Yunnan, China.

During a survey of microfungi associated with grasslands and related vegetation types from Yunnan Province in China, various ascomycetous and coelomycetous fungi were isolated. This study reports the discovery of four strains of ascomycetous and coelomycetous fungi from dead stalks of Hypericummonogynum L. (Hypericaceae) and Rubusparvifolius L. (Rosaceae) in the Zhaotong region of Yunnan Province, China. The isolates were characterized using multi-locus phylogenetic analyses and were found to represent a new monophyletic lineage in Melanommataceae (Pleosporales, Dothideomycetes). This new clade was named as Dematiomelanommayunnanense gen. et sp. nov. which consists of both sexual and asexual morphs. The sexual morph is characterized by globose to subglobose ascomata with a central ostiole, cylindrical asci with a pedicel and ocular chamber, and muriform, ellipsoidal to fusiform ascospores. The asexual morph has synanamorphs including both brown, muriform macroconidia and hyaline, round to oblong or ellipsoidal microconidia. These findings contribute to the understanding of fungal diversity in grasslands and related vegetation types in Yunnan Province, China.

Trajectories of soil microbial recovery in response to restoration strategies in one of the largest and oldest open-pit phosphate mine in Asia.

Southwestern China has the largest geological phosphorus-rich mountain in the world, which is seriously degraded by mining activities. Understanding the trajectory of soil microbial recovery and identifying the driving factors behind such restoration, as well as conducting corresponding predictive simulations, can be instrumental in facilitating ecological rehabilitation. Here, high-throughput sequencing and machine learning-based approaches were employed to investigate restoration chronosequences under four restoration strategies (spontaneous re-vegetation with or without topsoil; artificial re-vegetation with or without the addition of topsoil) in one of the largest and oldest open-pit phosphate mines worldwide. Although soil phosphorus (P) is extremely high here (max = 68.3 mg/g), some phosphate solubilizing bacteria and mycorrhiza fungi remain as the predominant functional types. Soil stoichiometry ratios (C:P and N:P) closely relate to the bacterial variation, but soil P content contributes less to microbial dynamics. Meanwhile, as restoration age increases, denitrifying bacteria and mycorrhizal fungi significantly increased. Significantly, based on partial least squares path analysis, it was found that the restoration strategy is the primary factor that drives soil bacterial and fungal composition as well as functional types through both direct and indirect effects. These indirect effects arise from factors such as soil thickness, moisture, nutrient stoichiometry, pH, and plant composition. Moreover, its indirect effects constitute the main driving force towards microbial diversity and functional variation. Using a hierarchical Bayesian model, scenario analysis reveals that the recovery trajectories of soil microbes are contingent upon changes in restoration stage and treatment strategy; inappropriate plant allocation may impede the recovery of the soil microbial community. This study is helpful for understanding the dynamics of the restoration process in degraded phosphorus-rich ecosystems, and subsequently selecting more reasonable recovery strategies.

First result from the Jinping Underground Nuclear Astrophysics experiment JUNA: precise measurement of the 92 keV 25Mg(p, γ)26Al resonance.

The 25Mg(p, γ)26Al reaction plays an important role in the study of cosmic 1.809 MeV γ-ray as a signature of ongoing nucleosynthesis in the Galaxy. At astrophysical temperature around 0.1 GK, the 25Mg(p, γ)26Al reaction rates are dominated by the 92 keV resonance capture process. We report a precise measurement of the 92 keV 25Mg(p, γ)26Al resonance in the day-one experiment at Jinping Underground Nuclear Astrophysics experiment (JUNA) facility in the China Jinping Underground Laboratory (CJPL). The resonance strength and ground state feeding factor are determined to be 3.8±0.3 ×10-10 eV and 0.66±0.04, respectively. The results are in agreement with those reported in the previous direct underground measurement within uncertainty, but with significantly reduced uncertainties. Consequently, we recommend new 25Mg(p, γ)26Al reaction rates which are by a factor of 2.4 larger than those adopted in REACLIB database at the temperature around 0.1 GK. The new results indicate higher production rates of 26gAl and the cosmic 1.809 MeV γ-ray. The implication of the new rates for the understanding of other astrophysical situations is also discussed.

Disruption of transcription factor RhMYB123 causes the transformation of stamen to malformed petal in rose (Rosa hybrida).

KEY MESSAGE: We find that the R2R3 MYB transcription factor RhMYB123 has a novel function to regulate stamen-petal organ specification in rose. Rose is one of the ornamental plants with economic importance worldwide. Malformed flower seriously affects the ornamental value and fertility of rose. However, the regulatory mechanism is largely unknown. In this work, we identified a R2R3 MYB transcription factor RhMYB123 from rose, the expression of which significantly decreased from flower differentiation stage to floral organ development stage. Phylogenetic analysis indicated that it belongs to the same subgroup as MYB123 of Arabidopsis and located in nucleus. In addition, RhMYB123 was confirmed to have transcriptional activation function by dual luciferase assay. Silencing RhMYB123 using Virus-Induced Gene Silencing (VIGS) in rose could increase the number of malformed petaloid stamen. Furthermore, we identified 549 differential expressed genes (DEGs) in TRV-RhMYB123 lines compared to TRV controls by RNA-seq of floral buds (flower differentiation stage). Among of those genes, expression of 3 MADS box family genes related to floral organ development reduced in TRV-RhMYB123 lines, including AGAMOUS (RhAG), AGAMOUS LIKE 15 (RhAGL15), and SHATTERPROOF 1 (RhSHP1). Given, previous studies have shown that auxin plays a crucial role in floral meristem initiation and stamen-petal organ specification. We also found 6 DEGs were involved in auxin signal transduction, of which five were reduced expression in TRV-RhMYB123. Taken together, our findings suggested that RhMYB123 may govern the development of malformed petaloid stamen by regulating the expressions of some MADS box family members and auxin signaling pathway elements.

Taxonomy and phylogenetic appraisal of Spegazzinia musae sp. nov. and S. deightonii (Didymosphaeriaceae, Pleosporales) on Musaceae from Thailand.

Tropical plants host a range of fungal niches including endophytes, pathogens, epiphytes and saprobes. A study undertaken to discover the saprobic fungal species associated with Musa sp. (banana) from northern Thailand found two hyphomycetous taxa of Spegazzinia (Didymosphaeriaceae, Pleosporales). These were collected during the dry season and their morpho-molecular taxonomic relationships were investigated. Based on phylogenetic analysis of combined SSU, LSU, ITS and TEF1-α sequence data (77% ML, 0.99 BYPP) and contrasting morphological features to the sister taxon, we introduce Spegazzinia musae as a novel species from a decaying leaf of Musa sp. Details on the taxonomy, ecology and geographical distribution of Spegazzinia species are provided. In addition, we report S. deightonii as a new host record from Musa sp. Our data further validate the taxonomic placement of Spegazzinia in Didymosphaeriaceae.

Root hemiparasitism in Malania oleifera (Olacaceae), a neglected aspect in research of the highly valued tree species.

Malania oleifera (Olacaceae) is a valued tree species, mostly because its seeds have high precious fatty acid content (particularly nervonic acid). However, seedling mortality rates are often high and regeneration of this tree has been problematic, which greatly hinders its utilization at a large scale. Cultivation difficulties of some tree species in the family Olacaceae have been attributed to their root hemiparasitic habit. Prompted by field observations and the taxonomic proximity of M. oleifera to root hemiparasites in Olacaceae, we hypothesized that tuberous structures observed on the roots of M. oleifera are parasitic organs known as haustoria. To test this hypothesis, we collected root samples from M. oleifera plants of various ages and growth conditions, investigated the morphological and anatomical features of tuberous structures and their connections to neighboring roots. Our analyses confirmed that M. oleifera are root hemiparasites. To the best of our knowledge, this is the first empirical report on root hemiparasitism in M. oleifera. Because life strategies of root hemiparasitic plants differ greatly from autotrophic plants, the root hemiparasitic habit needs to be taken into account for successful seedling regeneration of M. oleifera. This study establishes the foundation for investigations into a long-neglected but essential aspect in research of these highly valued tree species.

Current re-vegetation patterns and restoration issues in degraded geological phosphorus-rich mountain areas: A synthetic analysis of Central Yunnan, SW China.

China has the largest area of inland geological phosphorus-rich (GPR) mountains in the world, where vegetation restoration is key to safeguarding the environment. We reviewed the published literature and collected new data in order to analyze re-vegetation patterns and the status of plant communities in central Yunnan. The aim of our analysis was to suggest future improvements to restoration strategies in GPR mountain regions. Our results showed that spontaneous recovery was the most widespread type of restoration. N-fixing species such as Coriaria nepalensis and Alnus nepalensis play a vital role in succession. In the past, monoculture tree plantation was the primary method used in afforestation activities in central Yunnan; in recent years however, several different methods of restoration have been introduced including the use of agroforestry systems. For practical restoration, we found that spontaneous recovery was capable of delivering the best results, but that during its early stages, restoration results were affected by several factors including erosion risk, the origin of propagates and environmental variation. In contrast, methods employing human-made communities performed better in their early stages, but were constrained by higher costs and vulnerability to degradation and erosion. The use of N-fixing species such as A. nepalensis and Acacia mearnsii in plantations were unsuccessful in restoring full ecosystem functions. The success of restoration activities in GPR mountain regions could be improved through the following measures: (1) developing a better understanding of the respective advantages and disadvantages of current natural and human-engineered restoration approaches; (2) elucidating the feedback mechanism between phosphorus-rich soil and species selected for restoration, especially N-fixing species; (3) introducing market incentives aimed at encouraging specific restoration activities such as agroforestry, and improving the industry value chain.

Improving the Mapping of Smith-Waterman Sequence Database Searches onto CUDA-Enabled GPUs.

Sequence alignment lies at heart of the bioinformatics. The Smith-Waterman algorithm is one of the key sequence search algorithms and has gained popularity due to improved implementations and rapidly increasing compute power. Recently, the Smith-Waterman algorithm has been successfully mapped onto the emerging general-purpose graphics processing units (GPUs). In this paper, we focused on how to improve the mapping, especially for short query sequences, by better usage of shared memory. We performed and evaluated the proposed method on two different platforms (Tesla C1060 and Tesla K20) and compared it with two classic methods in CUDASW++. Further, the performance on different numbers of threads and blocks has been analyzed. The results showed that the proposed method significantly improves Smith-Waterman algorithm on CUDA-enabled GPUs in proper allocation of block and thread numbers.

Host shoot clipping depresses the growth of weedy hemiparasitic Pedicularis kansuensis.

Root hemiparasitic plants show optimal growth when attached to a suitable host by abstracting water and nutrients. Despite the fact that damage to host plants in the wild occurs frequently in various forms (e.g. grazing), effects of host damage on growth and physiological performance of root hemiparasites remain unclear. In this study, host shoot clipping was conducted to determine the influence of host damage on photosynthetic and growth performance of a weedy root hemiparasite, Pedicularis kansuensis, and its interaction with a host, Elymus nutans. Photosynthetic capacity, tissue mineral nutrient content and plant biomass of P. kansuensis were significantly improved when attached to a host plant. Host clipping had no effect on quantum efficiency (ΦPSII), but significantly reduced the growth rate and biomass of P. kansuensis. In contrast, clipping significantly improved photosynthetic capacity and accumulation of potassium in E. nutans. No significant decrease in biomass was observed in clipped host plants. By changing nutrient absorption and allocation, clipping affected the interaction between P. kansuensis and its host. Our results showed that host clipping significantly suppressed the growth of weedy P. kansuensis, but did not affect biomass accumulation in E. nutans. We propose that grazing (a dominant way of causing host damage in the field) may have a potential in the control against the weedy hemiparasite.

Nutrient requirements differ in two Pedicularis species in the absence of a host plant: implication for driving forces in the evolution of host preference of root hemiparasitic plants.

BACKGROUND AND AIMS: Facultative root hemiparasitic plants generally have a wide host range, but in most cases show an obvious host preference. The reasons for the marked difference in growth performance of hemiparasites when attached to different hosts are not fully understood. In this study, the hypothesis was tested that hemiparasites showing a preference for different hosts have different nutrient requirements. METHODS: Two facultative root hemiparasitic Pedicularis species (P. rex and P. tricolor) with a different host dependency and preference were used to test their responses to inorganic solutes. The effects of nitrogen, phosphorus and potassium on growth of the hemiparasitic plants not attached to a host were determined, using an orthogonal design in pot cultivation under greenhouse conditions. Variables including biomass, shoot nutrient concentration, root:shoot (R:S) ratios and the number of haustoria were measured. KEY RESULTS: As in autotrophic plants, nutrient deficiency reduced dry weight (DW) and nutrient concentrations in the root hemiparasites. Nitrogen and phosphorus significantly influenced growth of both Pedicularis species, while potassium availability influenced only shoot DW of P. rex. Nitrogen had far more effect on growth of P. rex than on P. tricolor, while phosphorus deficiency caused more marked growth depression in P. tricolor than in P. rex. Pedicularis rex grew faster than P. tricolor in a range of nutrient supplies. Different patterns of biomass allocation between the two Pedicularis species were observed. While P. rex invested more into roots (particularly fine rootlets) than P. tricolor, the number of haustoria produced by P. rex was relatively much lower than that produced by P. tricolor, which had a much smaller root system. CONCLUSIONS: The two Pedicularis species differ in nutrient requirements and biomass allocation. Distinct interspecific traits in growth and nutrient requirements can be driving forces for the differential interactions between hemiparasites and their hosts.

Designing a tailored Web-based educational mammography program.

Breast cancer has become increasingly prevalent in Taiwanese women, especially in younger women. Unfortunately, early breast cancer detection may be hampered by Taiwanese women's beliefs about breast cancer, risk factors, and mammography. The Internet has become a powerful way to disseminate health information, but health education Web sites are frequently neither patient-centered nor theoretically based. We used the Transtheoretical Model as the theoretical basis for the design of a tailored Web-based educational program aimed at correcting Taiwanese women's misconceptions about breast cancer and mammography and increasing their intent to obtain routine mammography. In this article, we describe the Web-based educational intervention and the results of an initial preliminary evaluation study.

Effects of a Web-based course on nursing skills and knowledge learning.

The purpose of the study was to assess the effectiveness of supplementing traditional classroom teaching with Web-based learning design when teaching intramuscular injection nursing skills. Four clusters of nursing students at a junior college in eastern Taiwan were randomly assigned to experimental and control groups. A total of 147 students (80 in the experimental group, 67 in the control group) completed the study. All participants received the same classroom lectures and skill demonstration. The experimental group interacted using a Web-based course and were able to view the content on demand. The students and instructor interacted via a chatroom, the bulletin board, and e-mail. Participants in the experimental group had significantly higher scores on both intramuscular injection knowledge and skill learning. A Web-based design can be an effective supplementing learning tool for teaching nursing knowledge and skills.

Application of bubble separation for quantitative analysis of choline in Dioscorea (yam) tubers.

A modified assay based on the AACC official method 86-45 (AACC, 2000) for the determination of choline in three cereals and three varieties of Dioscorea (yam) tubers was developed. When tested in wheat, rice, and oat flour, choline estimated by the modified method was 34.0-45.3% higher than that of the original AACC method. In a system with higher contents of starch and mucilage, such as Dioscorea (yam) tubers, extra procedures in sample preparation needed to be carried out to separate starch and mucilage. The choline contents of the following Dioscorea (yam) tubers using the original AACC method and the present modified AACC method through coupling an additional bubble separation procedure, respectively, were (mean +/- SD, mg/g solid) Keelung yam (D. pseudojaponicaY.) 0.92 +/- 0.09 and 2.21 +/- 0.12, Yangmingshan yam (D. alata L.) 0.77 +/- 0.09 and 1.78 +/- 0.28, and Ming-Chien yam (D. purpurea) 0.44 +/- 0.09 and 1.35 +/- 0.19. Choline was 231-306% higher than when the original AACC method was used. Dioscorea (yam) tubers were much higher in choline content than they were in cereals. Bubble separation is an appropriate procedure in the practice for the maximum assay of choline in yams. It is accurate, rapid, easy to handle, and especially good for recovering choline from a starch and polysaccharide-protein-containing system.