Bacterial community composition in reclaimed and unreclaimed tailings of Dexing copper mine, China

An investigation was conducted to compare the microbial community structures between contaminated and reclaimed mine tailings of Dexing copper mine, Jiangxi province, China. Sample T1 was obtained from tailings site, where reclamation of phytostabilization has been conducted for 20 years successfully whereas, the other one (sample T4) was obtained from the unreclaimed tailings site. Physico-chemical characteristics, chemical speciation of heavy metals Cu, Cd and Zn were revealed to compare the effects of reclamation. A polymerase chain reaction (PCR)-based cloning approach was employed to investigate the bacterial community composition in these two samples. Results indicate the improved physico-chemical conditions and decreased bioavailability of heavy metals Cd and Zn significantly in the sample collected from reclaimed site compared with the other unreclaimed mine tailings site. Phylogenetic analysis indicated that bacteria in these two samples fell into 12 putative phylogenetic divisions. Sample T1 had 12 phyla were present, and the community was predominated by Planctomycetes (20%), α-proteobacteria (16%), Chloroflexi (12%) and Acidobacteria (10%). On the other hand, sample T4 had only 4 phyla and was predominated by y-proteobacteria (86%). The diversity of microbes in sample T1 significantly increased when compared with sample T4. The structure of microbial community composition in the first sample also was optimized to sustain more phyla associated with a healthier soil after reclamation. From the results, it could be deduced that the inventories of bacterial populations such as Planctomycetes, Chloroflexi, α-proteobacteria, Acidobacteria and Actinobacteria predominated in sample T1, but were essentially absent in sample T4. This may serve as potential bioindicator for the reclamation evaluation of tailings.Keywords: Mine tailings, reclamation, bacterial community composition, bioindicatorsAfrican Journal of Biotechnology Vol. 12(30), pp. 4841-484

Preparation of PVA-GO Composite Hydrogel and Effect of Ionic Coordination on Its Properties

This paper adopts a method combining hybrid self-assembly, cyclic freezing-thawing and annealing treatment to prepare polyvinyl alcohol (PVA) and graphene oxide (GO) composite hydrogel. Then, the PVA-GO composite hydrogels are re-swelled in different ionic solutions (NaCl, MgCl2, CaCl2 and AlCl3) to improve mechanical strength, toughness and wear resistance by the ionic coordination bonds. The microstructure and morphology are characterized by Fourier transforms infrared spectroscopy (FTIR), x-ray diffraction (XRD) and Scanning electron microscopy (SEM), finding that the internal structure is porous three-dimensional network. Mechanical experiments indicate that the composite hydrogel with GO content of 0.05 wt% immersed in MgCl2 solution displays the best mechanical properties overall. Its tensile strength can reach 11.10 MPa and the elastic modulus reaches 1.72 MPa, which is 175% and 85% higher than the pure PVA, respectively. Sliding friction experiments illustrate that the composite hydrogel immersed in AlCl3 solution exhibits the lowest friction coefficient, and the higher the valence state of metal cation is, the better the wear reduction effect is. We expect to enrich the development of PVA-GO hydrogels in tissue engineering through synergy of hydrogen bonds and ionic coordination bonds

A Survey on Label-efficient Deep Image Segmentation: Bridging the Gap between Weak Supervision and Dense Prediction

The rapid development of deep learning has made a great progress in image segmentation, one of the fundamental tasks of computer vision. However, the current segmentation algorithms mostly rely on the availability of pixel-level annotations, which are often expensive, tedious, and laborious. To alleviate this burden, the past years have witnessed an increasing attention in building label-efficient, deep-learning-based image segmentation algorithms. This paper offers a comprehensive review on label-efficient image segmentation methods. To this end, we first develop a taxonomy to organize these methods according to the supervision provided by different types of weak labels (including no supervision, inexact supervision, incomplete supervision and inaccurate supervision) and supplemented by the types of segmentation problems (including semantic segmentation, instance segmentation and panoptic segmentation). Next, we summarize the existing label-efficient image segmentation methods from a unified perspective that discusses an important question: how to bridge the gap between weak supervision and dense prediction -- the current methods are mostly based on heuristic priors, such as cross-pixel similarity, cross-label constraint, cross-view consistency, and cross-image relation. Finally, we share our opinions about the future research directions for label-efficient deep image segmentation.Comment: Accepted to IEEE TPAM

RICD: A rice indica cDNA database resource for rice functional genomics

<p>Abstract</p> <p>Background</p> <p>The <it>Oryza sativa </it>L. <it>indica </it>subspecies is the most widely cultivated rice. During the last few years, we have collected over 20,000 putative full-length cDNAs and over 40,000 ESTs isolated from various cDNA libraries of two <it>indica </it>varieties Guangluai 4 and Minghui 63. A database of the rice <it>indica </it>cDNAs was therefore built to provide a comprehensive web data source for searching and retrieving the <it>indica </it>cDNA clones.</p> <p>Results</p> <p>Rice <it>Indica </it>cDNA Database (RICD) is an online MySQL-PHP driven database with a user-friendly web interface. It allows investigators to query the cDNA clones by keyword, genome position, nucleotide or protein sequence, and putative function. It also provides a series of information, including sequences, protein domain annotations, similarity search results, SNPs and InDels information, and hyperlinks to gene annotation in both The Rice Annotation Project Database (RAP-DB) and The TIGR Rice Genome Annotation Resource, expression atlas in RiceGE and variation report in Gramene of each cDNA.</p> <p>Conclusion</p> <p>The online rice <it>indica </it>cDNA database provides cDNA resource with comprehensive information to researchers for functional analysis of <it>indica </it>subspecies and for comparative genomics. The RICD database is available through our website <url>http://www.ncgr.ac.cn/ricd</url>.</p

A two-step lineage reprogramming strategy to generate functionally competent human hepatocytes from fibroblasts

Terminally differentiated cells can be generated by lineage reprogramming, which is, however, hindered by incomplete conversion with residual initial cell identity and partial functionality. Here, we demonstrate a new reprogramming strategy by mimicking the natural regeneration route, which permits generating expandable hepatic progenitor cells and functionally competent human hepatocytes. Fibroblasts were first induced into human hepatic progenitor-like cells (hHPLCs), which could robustly expand in vitro and efficiently engraft in vivo. Moreover, hHPLCs could be efficiently induced into mature human hepatocytes (hiHeps) in vitro, whose molecular identity highly resembles primary human hepatocytes (PHHs). Most importantly, hiHeps could be generated in large quantity and were functionally competent to replace PHHs for drug-metabolism estimation, toxicity prediction and hepatitis B virus infection modeling. Our results highlight the advantages of the progenitor stage for successful lineage reprogramming. This strategy is promising for generating other mature human cell types by lineage reprogramming.</p

Physiological and transcriptomic responses of Lanzhou Lily (Lilium davidii, var. unicolor) to cold stress.

Low temperature induces changes in plants at physiological and molecular levels, thus affecting growth and development. The Lanzhou lily (Lilium davidii, var. unicolor) is an important medicinal plant with high economic value. However, the molecular mechanisms underlying its photosynthetic and antioxidation responses to low temperature still remain poorly understood. This study subjected the Lanzhou lily to the two temperatures of 20°C (control) and 4°C (low temperature) for 24 h. Physiological parameters related to membrane integrity, photosynthesis, antioxidant system, and differentially expressed genes were investigated. Compared with control, low temperature increased the relative electrical conductivity by 43.2%, while it decreased net photosynthesis rate, ratio of variable to maximal fluorescence, and catalase activity by 47.3%, 10.1%, and 11.1%, respectively. In addition, low temperature significantly increased the content of soluble protein, soluble sugar, and proline, as well as the activity of superoxide dismutase and peroxidase. Comparative transcriptome profiling showed that a total of 238,109 differentially expressed genes were detected. Among these, 3,566 were significantly upregulated while 2,982 were significantly downregulated in response to low temperature. Gene Ontology enrichment analysis indicated that in response to low temperature, the mostly significantly enriched differentially expressed genes were mainly involved in phosphorylation, membrane and protein kinase activity, as well as photosynthesis, light harvesting, light reaction, and alpha,alpha-trehalose-phosphate synthase activity. Kyoto Encyclopedia of Genes and Genomes enrichment analysis also indicated that the most significantly enriched pathways involved ribosome biogenesis in eukaryotes, phenylalanine metabolism, circadian rhythm, porphyrin and chlorophyll metabolism, photosynthesis of antenna proteins, photosynthesis, and carbon fixation in photosynthetic organisms. Moreover, the expression patterns of 10 randomly selected differentially expressed genes confirmed the RNA-Seq results. These results expand the understanding of the physiological and molecular mechanisms underlying the response of the Lanzhou lily to low temperature stress

Adsorption behavior of glucose on pyrite surface investigated by TG, FTIR and XRD analyses

The interaction of glucose with pyrite has been investigated by a series of surface analyses, such as amounts adsorbed, TG, FTIR and XRD measurements. The adsorption experiment reveals that glucose would rapidly adsorb on the pyrite surface within 60 min. However, physical adhesion characterized as multi-molecular layer adsorption may occur based on adsorption isotherm type. All results obtained by TG and FTIR suggest that no adsorption took place after several times of washing. XRD results indicate that crystal structure of pyrite was not obviously destructed after glucose was added. The interplane distances of (111), (400) after interaction between glucose and pyrite were widened, which showed the similar manner with that of before interaction. All these convincing data imply that physical adsorption predominantly governs the interaction of glucose on pyrite

Comparative study of interaction between pyrite and cysteine by thermogravimetric and electrochemical techniques

Adsorption mechanism of l-cysteine on pyrite was investigated by thermogravimetric and electrochemical techniques. TG curves provided the direct evidence for chemisorption of cysteine on pyrite surface. Once cysteine adsorbed to pyrite surface, Ecorr (corrosion potential) sharply lowered whereas Icorr (corrosion current) increased rapidly. Pyrite became more susceptible to be oxidized even at lower potential as cysteine was added. However, the mechanism for pyrite oxidation does not fundamentally change, although cysteine can obviously accelerate oxidation rate of pyrite. These findings have important implications for understanding the mechanism of bacterial adhesion to pyrite and even metal sulfide bioleaching

Tactics for Xinjiang Tourism Industrial Belt Based on Performance Evaluation

In this paper, some tactics are considered in Xinjiang tourism industrial belt based on performance evaluation. First, we applied the Balanced Scorecard (BSC) to establish an evaluation system for Xinjiang tourism development in four dimensions: tourism performance, resource utilization, basic supporting capacity, and market attention. Second, the performance of tourism development in 14 Prefectures was evaluated using the Analytic Hierarchy Process (AHP) in 2018. Third, because the Prefectures were divided into four tourism industrial belts, a discussion was conducted to identify and understand the difference among them and their corresponding influence on regional tourism development using the Theil index and Entropy method. The result shows that (1) In all dimensions, the differences within each industrial belt were greater than those between industrial belts. (2) The tourism industrial belts displayed a differentiation phenomenon, in the dimension of significant difference being distinct for different belts. Finally (3), it is found that the resource utilization of all belts is significantly different

Involvement of Toll-Like Receptor 2 and Pro-Apoptotic Signaling Pathways in Bone Remodeling in Osteomyelitis

Background and Aims: Osteomyelitis is a common manifestation of invasive Staphylococcus aureus infection characterized by bone loss and destruction. We investigated the role of toll-like receptor 2 (TLR2) in bacterial recognition and clearance in response to infection with an osteomyelitis isolate of S. aureus. Methods: Apoptosis was assessed in the osteoblastic cell line MC3T3-E1 by Annexin V-FITC/PI staining and flow cytometry. The expression of TLR2 and apoptosis-related and mitogen-activated protein kinase pathway proteins was assessed by qRT-PCR and western blotting. Alkaline phosphatase (ALP) activity and calcium deposition were assessed by ALP activity assay and Alizarin red staining. Results: S. aureus induced apoptosis, upregulated TLR2 expression, and activated mitogen-activated protein kinase pathways in a time dependent manner. Inhibition of the c-Jun N-terminal kinase (JNK) pathway downregulated TLR2 and suppressed the S. aureus induced activation of pro-apoptotic pathways. Short-hairpin RNA mediated silencing of TLR2 reversed S. aureus induced apoptosis and decrease in ALP activity and calcium deposition, and inhibition of JNK had a similar effect. Conclusion: We showed that osteoblast apoptosis and osteogenic differentiation in response to bacterial invasion are dependent on TLR2 expression and JNK activation, suggesting novel potential therapeutic targets for the treatment of osteomyelitis