Determination of pesticide residues in muscle of Cyprinus carpio from River Ravi

The levels of dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), endosulfan, endosulfan sulfate, carbofuran, and cartap were determined in muscles of Cyprinus Carpio sampled from 10 different sites of River Ravi between Shahdara to Balloki Headworks to assess level of contamination of these pesticides by GC-ECD (gas chromatograph equipped with electron capture detector) method. All fish samples were found contaminated with different concentrations of DDT, DDE, endosulfan, and carbofuran. DDT and DDE concentrations were higher than maximum residue limits (MRL) in food standards, while endosulfan sulfate and cartap were not detected. These findings indicate that pesticide concentrations in fish muscles decreased in the order: DDT > DDE > carbofuran > endosulfan. Furthermore, the sampling sites after Degh fall and beyond Hudiara Nulla Fall river sampling sites were more polluted. It is proposed that constant monitoring programs are needed to assess potential exposure risks.     

Development of odorous gas sampler and investigation of its practicality

The existing gas sampler is deficient in regard to its efficiency, handling and ability. In order to solve these problems, a new gas sampler was developed and its function was investigated. The sampler is a vessel made of aluminium and contains a polyester bag inside the vessel. The vacuum method is employed for taking the gas. The maximum capacity of the gas volume that can be taken is about 15 liters and sampling time can be from 15 sec to 10 min per sample. In addition, many odor surveys were carried out and the practicality of the new sampler was investigated. It was concluded that the new sampler was easy to handle and was more efficient than the existing gas sampler.     

China's Grain for Green Program has reduced soil erosion in the upper reaches of the Yangtze River and the middle reaches of the Yellow River

Severe soil erosion in the upper reaches of the Yangtze River and the middle reaches of the Yellow River is a serious environmental problem in western China. In order to control this soil erosion, the national government implemented the Grain for Green Program (GGP) in Sichuan Province (in the upper reaches of the Yangtze River) and Shaanxi Province (in the middle reaches of the Yellow River) in 1999. To evaluate the effects of the GGP on soil erosion, the present study investigated the relationships between annual precipitation and three parameters, annual runoff, sediment concentration, and sediment discharge, for these rivers. As the area covered by the GGP increased, sediment concentration and sediment discharge both decreased, and the correlation with the GGP area was much stronger than the correlation with annual precipitation. Therefore, China's GGP appears to be controlling soil erosion in the upper reaches of the Yangtze River and the middle reaches of the Yellow River.     

Sulfate reduction in groundwater: characterization and applications for remediation

Sulfate is ubiquitous in groundwater, with both natural and anthropogenic sources. Sulfate reduction reactions play a significant role in mediating redox conditions and biogeochemical processes for subsurface systems. They also serve as the basis for innovative in situ methods for groundwater remediation. An overview of sulfate reduction in subsurface environments is provided, along with a brief discussion of characterization methods and applications for addressing acid mine drainage. We then focus on two innovative, in situ methods for remediating sulfate-contaminated groundwater, the use of zero-valent iron and the addition of electron-donor substrates. The advantages and limitations associated with the methods are discussed, with examples of prior applications.     

Optimum parameters for fault detection and diagnosis system of batch reaction using multiple neural networks

Batch process usually differs from the continuous process because of its time-varying variables and the process parameters. An early detection and isolation of faults in the process will help to reduce the process upsets and keep it safe and reliable. This paper discusses on the application of multi-layer perceptron neural network in detecting various faults in batch chemical reactor based on an esterification process that involves the reaction of ethanol and acetic acid catalyzed by sulfuric acid. A multi-layer feed forward neural network with double hidden layers has been used in the neural network architecture. The detection was based on the different patterns generated between normal and faulty conditions. An optimum network configuration was found when the network produced the minimal error with respect to the training, testing and data validation.     

Strong responsiveness to noise interference in an anuran from the southern temperate forest

Animals adopt different strategies to communicate by means of sound in noisy environments. Some animals increase, while others decrease, their vocal activity in the presence of interference. Anuran amphibians from diverse latitudes exhibit both kinds of responses. Recent studies have shown that males of Batrachyla taeniata and Batrachyla antartandica from the temperate austral forest do not call in response to the presentation of advertisement calls of sympatric congeneric species, but their responsiveness to other kinds of interference has not been tested. To explore the diversity in responsiveness to acoustic intrusion in a single species, we exposed males of B. taeniata to prolonged prerecorded natural abiotic noises of wind, creek, and rain and to a band-pass noise centered at 2,000 Hz, at 67 dB sound pressure level (SPL). The subjects drastically increased their call rate when exposed to all four sounds. Frogs also responded by augmenting their vocal activity to exposures of band-pass noise at increasing intensities (55–79 dB SPL). The increase in vocal activity in response to noise is strong relative to those of other anurans from the temperate forest studied previously under similar exposures. These results reveal a remarkable activation of vocal response to acoustic interference of continuous abiotic noise, which would allow compensating for limitations in the active communication space under background sounds. This strategy contrasts with the decrease in vocal output amid interference from heterospecific signals reported formerly for this frog, a tactic that would restrict energy expenditure to relevant acoustic competition with conspecifics.     

Bacterial community structure of Tricholoma matsutake stipe soil by high-throughput sequencing北大核心CSCD

In order to understand the interaction between microorganisms in soil attached to the stipes of Tricholoma matsutake, we utilized high-throughput sequencing technology using an Illumina HiSeq 2500 System (San Diego, CA, USA) to explore the bacterial community structure in such soils and analyzed the effects of microorganisms on the formation and growth of T. matsutake. A total of 6 730 sequences were obtained from the samples, and these sequences were clustered into 928 operational taxonomic units (OTUs) at a 97% similarity level. In addition, these OTUs were grouped into 22 bacterial phyla (including 62 classes, 90 orders, 162 families, and 275 genera) and 2 archaeal phyla (including 4 classes, 6 orders, 7 families, and 8 genera). Proteobacteria was the dominant phylum present in all the samples, and these bacteria were significantly more abundant in soils attached to stipe of T. matsutake than they were in the control samples. Similarly, Beta-proteobacteria were the dominant class, and bacteria in this class were less abundant than they were in the control samples. Moreover, the genus Burkholderia within the Proteobacteria was more abundant in the control samples than in the T. matsutake soil samples. Generally, Proteobacteria, especially the genus Burkholderia, played an important role in the growth of T. matsutake, whereas other bacteria, such as Unknown-Ellin 60, would probably inhibit the growth of T. matsutake. This study showed that bacteria might be involved in the growth of T. matsutake and the formation of its fruiting bodies, but they had no positive relationship with bacterial abundance, which may provide theoretical guidance for the cultivation of T. matsutake. © 2018 Science Press. All rights reserved.     

Cloning and expression of RING-finger E3 ubiquitin ligase CsSDIR1 gene in tea plant (Camellia sinensis)北大核心CSCD

Protein ubiquitination regulates many aspects of plant development and stress response. The RING-finger type E3 ubiquitin ligase SDIR1 (salt and drought induced ring finger 1) gene plays a key role in plant stress response. In this study, the full-length cDNA and the promoter sequences of CsSDIR1 were isolated from tea plants using the RT-PCR technology, and its bioinformatics characteristics were systematically analyzed. The expression patterns of CsSDIR1 in various tissues and in response to cold, drought, salt, and ABA treatments were also investigated by quantitative real-time RT-PCR (qRT-PCR). The sequence of CsSDIR1 contains a complete open reading frame of 831 bp, coding for a 276-long amino acid protein with a molecular weight of (Mr) 30.085 × 103 and a theoretical isoelectric point of 6.54. CsSDIR1 was predicted to be a hydrophobic protein localized on the intracellular membranes. The analysis of the amino acid sequence characteristics showed that CsSDIR1 contains two putative transmembrane domains at the N-terminus and a C3H2C3 RING-finger domain at the C-terminus; it shares high similarity with other plants' SDIR1, and has the closest relationship to Actinidia sinensis. A cis-acting regulatory elements prediction showed that the CsSDIR1 promoter contains many cis-acting elements, especially drought and salt stress response elements. The qRT-PCR analysis indicated that the CsSDIR1 gene has a high expression level in stems, followed by roots, leaves, and flowers; the expression of the CsSDIR1 gene is up-regulated by ABA, salt, and drought treatments, whereas it is down-regulated in response to cold stress. These results demonstrated that the CsSDIR1 gene might be involved in the plant stress response of tea trees. © 2018 Science Press. All rights reserved.     

Identification of Bacillus methylotrophicus and its application in preventing fly maggot production in the environment北大核心CSCD

This research aimed to screen Bacillus spp. to prevent the production of fly maggot on kitchen wastes from soil in the experimental bases of the South China Agricultural University. A nutrient-rich medium was used to isolate the Bacillus spp. with high temperature treatment. The seventeen Bacillus strains were obtained and assigned to three groups by using Insertion Sequence based PCR (IS-PCR) DNA fingerprinting patterns. The homology of the 16S rDNA gene was 100% between Group I and Bacillus methylotrophicus CBMB 205T, 99.61% between Group II and Bacillus aerophilus 28KT, and 99.87% between Group III and Bacillus cereus ATCC 14579T. The results of kitchen waste tests proved that the representative bacteria of Group I RF2 had the ability to prevent fly maggot production on kitchen wastes. Furthermore, the results of physiological and biochemical tests, carbon utilization tests, and antagonists against plant pathogen tests showed that the bacteria from Group I RF2 had the ability to decompose glucose into pyruvate and then decarboxylate pyruvate to diacetyl under alkaline conditions, convert ammonia to intracellular amino acids or other kinds of nitrogenous compounds, use many kinds of carbon source for self-growth, and be antagonistic against plant pathogenic rice sheath blight disease, banana fusarium wilt, and Fusarium oxysporum. Besides, the bacteria from RF2 could secret organic acids to dissolve insoluble phosphate [Ca3(PO4)2] for its own growth by decreasing the pH. Group I RF2 was a strong plant-promotion bacterium, and had good prospects of application for preventing fly maggot production on kitchen wastes. © 2018 Science Press. All rights reserved.     

Discovery of novel halogenase genes using sequence-driven metagenomics approach北大核心CSCD

It is of great significance to ability to obtain new natural products with diverse activities through the study of soil microorganisms. However, less than 1% of the total soil microorganisms can be cultured under laboratory conditions, thus limiting the discovery of new compounds. Metagenomics, by which the genomic DNA of soil microorganisms can be extracted and expressed in heterologous hosts, provides a new approach for the functional study of soil microorganisms. Natural halides have good bioactivities, including antibacterial and antitumor activities. Halogenases play an important role in biosynthesis, and introducing bioactivities of halogenated compounds. To investigate the potential of halogenated compounds production from soil microorganisms, a soil metagenomic library was screened by PCR for clones harboring reduced flavin adenine dinucleotide (FADH2) - dependent halogenase genes. Sixty-five positive clones were identified from the library, and the amino acid sequences of halogenase genes within the positive clones were analyzed. Phylogenetic analyses revealed that more than 85% of these genes were separated from known halogenases to form new clades in the phylogenetic tree; moreover the soilderived halogenases showed high diversity. By further biosynthetic gene analysis of the positive clones, a new type I polyketide biosynthetic gene sequence was identified, which is probably related to the biosynthesis of the halogenated type I polyketide. In conclusion, novel and diverse halogenase genes were identified on sixty-five metagenomic clones using a sequence-driven metagenomic approach, laying a foundation for the further discovery of novel natural halides biosynthetic gene clusters and halides. © 2018 Science Press. All rights reserved.