Soil pH, total phosphorus, climate and distance are the major factors influencing microbial activity at a regional spatial scale

Considering the extensive functional redundancy in microbial communities and great difficulty in elucidating it based on taxonomic structure, studies on the biogeography of soil microbial activity at large spatial scale are as important as microbial community structure. Eighty-four soil samples were collected across a region from south to north China (about 1,000 km) to address the questions if microbial activity displays biogeographic patterns and what are driving forces. These samples represented different soil types, land use and climate. Redundancy analysis and nonmetric multidimensional scaling clearly revealed that soil microbial activities showed distinct differentiation at different sites over a regional spatial scale, which were strongly affected by soil pH, total P, rainfall, temperature, soil type and location. In addition, microbial community structure was greatly influenced by rainfall, location, temperature, soil pH and soil type and was correlated with microbial activity to some extent. Our results suggest that microbial activities display a clear geographic pattern that is greatly altered by geographic distance and reflected by climate, soil pH and total P over large spatial scales. There are common (distance, climate, pH and soil type) but differentiated aspects (TP, SOC and N) in the biogeography of soil microbial community structure and activity

High throughput Single-cell Cultivation on Microfluidic Streak Plates

This paper describes the microfluidic streak plate (MSP), a facile method for high-throughput microbial cell separation and cultivation in nanoliter sessile droplets. The MSP method builds upon the conventional streak plate technique by using microfluidic devices to generate nanoliter droplets that can be streaked manually or robotically onto petri dishes prefilled with carrier oil for cultivation of single cells. In addition, chemical gradients could be encoded in the droplet array for comprehensive dose-response analysis. The MSP method was validated by using single-cell isolation of Escherichia coli and antimicrobial susceptibility testing of Pseudomonas aeruginosa PAO1. The robustness of the MSP work flow was demonstrated by cultivating a soil community that degrades polycyclic aromatic hydrocarbons. Cultivation in droplets enabled detection of the richest species diversity with better coverage of rare species. Moreover, isolation and cultivation of bacterial strains by MSP led to the discovery of several species with high degradation efficiency, including four Mycobacterium isolates and a previously unknown fluoranthene-degrading Blastococcus species

Acreditación de la educación superior en China

La creciente preocupación por la calidad de la educación superior en China surgió como una consecuencia natural de la expansión de la educación superior, que empezó en 1999 y ha continuado hasta la fecha; la tasa bruta de matrícula aumentó considerablemente, desde el 9,8 % en 1998 hasta el 21 % en 2005. El número total de estudiantes matriculados en el sistema de educación superior chino en 2005 superó los 23 millones. La multiplicación por dos de la matrícula a lo largo de los últimos siete años convierte al sistema chino de educación superior en el mayor sistema nacional del mundo.Peer Reviewe

On the Resistance-Harary Index of Graphs Given Cut Edges

Graphs are often used to describe the structure of compounds and drugs. Each vertex in the graph represents the molecule and each edge represents the bond between the atoms. The resistance distance between any two vertices is equal to the resistance between the two points of an electrical network. The Resistance-Harary index is defined as the sum of reciprocals of resistance distances between all pairs of vertices. In this paper, the extremal graphs with maximum Resistance-Harary index are determined in connected graphs with given vertices and cut edges

Interactions between Phosphoric/Tannic Acid and Different Forms of FeOOH

Alpha, beta, gamma, and delta hydroxyl ferric oxides (FeOOH), as the most common rust layers on iron surface, play different roles in iron preservation. Using modern surface analysis technologies such as X-ray diffraction (XRD), infrared spectra (IR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), we studied the interactions between these four types of synthetic FeOOH and phosphoric and tannic acid of different concentrations and proportions. A 3% tannic acid + 10% phosphoric acid + FeOOH was the most suitable formula for rust stabilizer and its reaction products were made up of iron phosphate and chelate of iron and tannin. This research provided technical basis in distinguishing FeOOH and selecting rust layer stabilizer for the preservation of iron, especially iron cultural relics

Chinese Herbal Medicine as an Adjunctive Therapy for Breast Cancer: A Systematic Review and Meta-Analysis

Chinese herbal medicine (CHM) has been widely used as an adjunctive therapy for breast cancer, while its efficacy remains unexplored. The purpose of this study is to evaluate the efficacy of CHM combined with chemotherapy for breast cancer. The study results showed that CHM combined with chemotherapy significantly increased tumor response and KPS as compared to using chemotherapy alone (RR = 1.36; 95% CI = 1.24–1.48; P<0.00001; RR = 1.38; 95% CI = 1.26–1.52; P<0.00001, resp.). Besides, CHM as an adjunctive therapy significantly reduced the nausea and vomiting at toxicity grade of III–IV (RR = 0.37; 95% CI = 0.27–0.52; P<0.00001). Moreover, the combined therapy significantly prevented the decline of WBC in patients under chemotherapy at toxicity grade of III–IV (RR = 0.49; 95% CI = 0.34–0.69; P<0.00001) and prevented the decline of platelet at toxicity grade of III–IV or I–IV (RR = 0.29; 95% CI = 0.12–0.73; P=0.008; RR = 0.77; 95% CI = 0.63–0.94; P=0.009, resp.). This study suggests that CHM combined with chemotherapy in comparison with chemotherapy alone can significantly enhance tumor response, improve KPS, and alleviate toxicity induced by chemotherapy in breast cancer patients. However, a firm conclusion could not be reached due to the lack of high quality trials and large-scale RCTs, so further trials with higher quality and larger scale are needed

Anonymous and Efficient Message Authentication Scheme for Smart Grid

Smart grid has emerged as the next-generation electricity grid with power flow optimization and high power quality. Smart grid technologies have attracted the attention of industry and academia in the last few years. However, the tradeoff between security and efficiency remains a challenge in the practical deployment of the smart grid. Most recently, Li et al. proposed a lightweight message authentication scheme with user anonymity and claimed that their scheme is provably secure. But we found that their scheme fails to achieve mutual authentication and mitigate some typical attacks (e.g., impersonation attack, denial of service attack) in the smart grid environment. To address these drawbacks, we present a new message authentication scheme with reasonable efficiency. Security and performance analysis results show that the proposed scheme can satisfy the security and lightweight requirements of practical implementations and deployments of the smart grid