RECONSTRUCTION ON THE VOLTAGE OF THE PRE-SLIDING STATE OF THE TRAGICHOUS MOUNTAIN SLOPE LANDSCAPE «AK KAIN»

The method of reconstruction and investigation of the pre-landslide condition of the tragic landslide «Ak-Kain» of the Northern Tien Shan is proposed. A model and a finite element algorithm for studying the stress-strain state (VAT) of soil sediments of an obliquely layered structure are briefly presented. The established zones and places of accumulation of dangerous stress concentrations along the inclined layer that led to the tragedy are shown. The plots show the found other areas of hazardous stress concentrations prone to destruction.

Temporal Variation of Culture Independent Bacterial Diversity Based on Amplicon Sequencing of the North Sikkim Hot Spring Solfataric Soil Sediments

The solfataric soil sediments of the hot springs of Sikkim located at Yume Samdung and Lachen valley were studied for deciphering the uncultured bacterial diversity. The main aim here is to present a comparative study and generate a baseline data on the post-monsoon seasonal variation for the months of October and December, analysed through 16S rRNA V3-V4 amplicon sequencing. At phylum level, in the New Yume Samdung (NYS) hot spring soil sample, in the month of October it was dominated by Proteobacteria (21.03%) followed by Thermi (12.33%) and Bacteroidetes (9.95%) whereas in December it was dominated by Proteobacteria (23.61%) followed by Chloroflexi (19.15%) and Bacteroidetes (16.55%). For Old Yume Samdung (OYS) hot spring soil sample, in the month of October, it was dominated by Proteobacteria (25.22%) followed by Bacteroidetes (11.76%) and Thermi (8.11%) whereas in December it was dominated by Proteobacteria (20.58%) followed by Chloroflexi (18.88%) and Thermi (9.89%). And in the case of Tarum (TAR) hot spring soil sediments, in the month of October, it was dominated by Proteobacteria (27.51%) followed by Bacteroidetes (12.29%) and Actinobacteria (11.1%) whereas in December it was dominated by Proteobacteria (16.76%) followed by Bacteroidetes (16.54%) and Thermi (14.17%). At genus level, in NYS, in October it was dominated by Meiothermus (12.33%) and in December it was Roseiflexus (8.59%). For OYS, it was dominated by Meiothermus (8.11%) in October and by unclassified Chloroflexales (10.94%) in December. And in TAR, it was dominated by unclassified Bacteroidales (10.29%) in October and by Meiothermus (14.12%) in December.

Ion-imprinted resin for use in an automated solid phase extraction system for determining 90Sr in environmental and human samples

In 90Sr analysis, determining its daughter 90Y improves the sensitivity of the radiometric methods. We found that to imprint a cavity made of [Y(6-(4-Vinylphenylcarbamoyl)pyridine-2-carboxylate)3] into a polystyrene skeleton yields a solid phase extraction resin with high selectivity for Y and Ln(III) over transition metals, alkaline, and alkaline-earth cations. We used this resin in an automated chromatography system to extract 90Y from milk, grass, vegetables, soil, sediments, water, human bones, and milk teeth samples. We found that the ion-imprinted resin could be used to separate light Ln(III) using a pH gradient, favoring the targeting of molecules used in nuclear medicine.

Identification and Quantification of Soil Pesticides in Coastal Lakshmipur District of Bangladesh

This study was carried out to determine the presence and quantity of some selected pesticides from soil sediments collected from some ponds and canals located in the Lakshmipur district of Bangladesh. The high performance liquid chromatography (HPLC) technique was used to determine the concentration of pesticide residues. Some soil samples were found to be contaminated with carbamate (carbofuran and carbaryl) and organophosphorus (diazinon) pesticides. The concentration of carbofuran pesticide ranged from 0.303 μg/kg to 1.851 μg/kg. The highest concentration of carbofuran pesticide was found in SSP6 (1.851 μg/kg) and the lowest concentration was found in SSP9 (0.303 μg/kg). Carbaryl pesticide was found to be present in the sediment of only one pond, the concentration being 1.047 μg/kg. Organophosphorus (diazinon) pesticide was found in soil samples and the concentrations ranged from 0.147 μg/kg to 0.759 μg/kg, which were higher than the EEC-recommended limit of 0.1 μg/kg. Asiat. Soc. Bangladesh, Sci. 46(2): 191-200, December 2020

Hercide Atrazine Alters the Microbiota of the Filametous Green Alga Cladophora sp. Cultured from Thailand

The attached green alga Cladophora known to harbor microbiota that play important roles in ecosystem, is one of the most common freshwater filamentous green algae in rivers globally, including those in the northern part of Thailand. These rivers mostly run through agricultural regions where herbicides are heavily used to improve crop quality and quantity. The extensively-used herbicide atrazine persists in soil sediments through transport by surface runoff to rivers. The effect of such herbicide contamination on Cladophora microbiota in Thailand have not been investigated. To acquire this information, 16S rDNA amplicons were used to compare microbiota of Cladophora sp. cultures treated with a spectrum of atrazine concentrations. The results showed that the Cladophora microbiome included at least 106 possible Operational taxonomic units (OTUs) representing twelve bacterial phyla which are Acidobacteria, Actinobacteria, Armatimonadetes, Chloroflexi, Cyanobacteria, Deinococcus-Thermus, Epsilonbacteraeota, Nitrospirae, Patescibacteria, Planctomycetes, Proteobacteria, and WPS-2, representing both core and local algal bacteria. The presence of atrazine was also correlated with changes in richness of bacterial taxa suggesting that these algal epibiotic bacteria were differently affected by atrazine treatments.

Isolation and Characterization of Potential Antibiotic-Producing Actinomycetes from Water and Soil Sediments of Different Regions of Nepal

Introduction. The actinomycetes are diversely distributed microorganisms in nature. The geographical diversity of Nepal is suitable for adaptation of various species of actinomycetes. The distribution of the actinomycetes is dependent upon the altitude and nature of the soil and water. Methods. A total of 22 water and soil samples were collected from different regions of Nepal and were processed. Different isolates were characterized by observing colony characteristics and microscopic characteristics. Screening of the antimicrobial property was based upon perpendicular line streaking and submerged-state fermentation for antibiotic production. Results. From the identification tool used, 12 were found to be Micromonospora, 9 were Nocardia, and 7 were Streptomyces. Out of total samples, 8 isolates of actinomycetes were tested effective against the tested bacteria by primary screening using the well diffusion method. Among the primarily screened, all isolates were subjected to submerged-state fermentation methods to produce crude extracts and 4 were found to be effective against the tested bacterial group. The actinomycetes identified from a water source showed better antimicrobial property towards the tested bacteria than the soil sample. Most isolates were found to be Micromonospora followed by Nocardia and Streptomyces with higher antimicrobial activities. Conclusion. The water source and soil sediments of Nepal provide suitable environments for actinomycetes towards obtaining a novel antimicrobial agent. The study of actinomycetes from various unexploited areas of Nepal is necessary. Thus, exploitation of various regions of Nepal for the discovery of an effective antimicrobial agent is helpful in providing a solution to the cost-effective therapy and action against antibiotic resistance.