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Ichthyofauna diversity acts as a bio-indicator and is playing a significant role in the sustainability of an aquatic environment. The present study explores the ichthyofauna assemblage in one of the largest wetlands of Bangladesh known as Asura beel located in Dinajpur district. Fortnightly fish samplings were done from November 2017 to October 2018 considering three seasons as winter,summer, and rainy. Fish biodiversity was assessed with their threatened status and analyzed seasonal abundance with the diversity indices. Findings revealed a total of 35 identified species of fish belonging to 7 orders, 17 families, and 26 genera. According to IUCN- Bangladesh 2015, the current research recorded 6 fish species as vulnerable (17%). While only 1 species is data deficient (3%), 6 species are endangered (17%), and the other 22 species are not threatened (63%). Among the fish species, Amblypharyngodon mola of Cypriniformes order contributed the highest abundance (12%). On the contrary, Ostreobrama cotio and Macrognathus armatus both represented the lowest abundance by contributing 0.35%. The survey also reported that the seasonal diversity indices and richness values did not vary significantly according to seasons although the number of catches was found higher in the winter season followedby summer and rainy seasons.

The main objectives of this study were to assess the diversity of diatom species and explain how physico-chemical factors and trophic levels interact with diatom assemblages. An assemblage of diatom communities in a riverine environment was assessed through forthright sampling for a period of 7 months from September 2019 to March 2020. Three sampling sites from the upstream, midstream and downstream parts of a river located in the northwest part of Bangladesh were selected for water quality analysis. A variety of multivariate data analyses were done to evaluate the environmental and biological data as well as to observe their interrelationships. A total of 7 genera of Diatom namely Nitzschia, Diatoma, Melosira, Synedra, Tabillaria, Navicula, and Fragillaria were recorded. Nitzschia was the most dominant genus compared to the other genus at downstream with an abundance of 1.92×103 cells/L while Tabillaria sp. was noted as a rare one with the lowest abundance of 0.37×103 cells/L at the midstream site. The interrelationship analysis clarified that water temperature positively altered the distribution of Melosira, Navicula, and Tabillaria while its abundance was less dependent on dissolved oxygen and pH. The results from a 2-dimensional Nonmetric Multidimensional Scaling (NMS) revealed the abundance of diatom at downstream was statistically higher than upstream and midstream. Hence, the study concluded that the diatom composition was very sensitive to the physico-chemical parameters according to water direction and could be used as a bio-indicator to assess the surface water quality. HIGHLIGHTS Diatom species composition was very sensitive to water quality indicators Diatom assemblages can be used as a bio-indicator to assess the water quality Diatom concentration was statistically higher at downstream compared to upstream and midstream GRAPHICAL ABSTRACT

This paper demonstrates a new algorithm for Electronic Opinion Analysis System (E-OASL) for university library where it can analyze the user opinion on library and categorized it in different classification such as positive, negative, neutral and suggestions. The system also shows the percentage of each classification as system output. Our proposed algorithm is based on hybrid approach of sentiment analysis where machine learning's rule-based classifier and lexicon approach's corpus datastore are utilized. We needed to collect around 1200 raw data from the different types of user who are using university library to build our algorithm. The system integrates MySQL database for faster and better data processing. The paper also shows the evaluation of the E-OASL which showed satisfactory result of effectiveness and efficiency of EOASL compare to manual opinion analysis approach.

Custom low power hardware for real-time network security and anomaly detection are in great demand, as these would allow for efficient security in battery-powered network devices. This paper presents a memristor based system for real-time intrusion detection, as well as an anomaly detection based on autoencoders. Intrusion detection is based on a single autoencoder, and the overall detection accuracy of this system is 92.91% with a malicious packet detection accuracy of 98.89%. The system described in this paper is also capable of using two autoencoders to perform anomaly detection using real-time online learning. Using this system, we show that anomalous data is flagged by the system, but over time the system stops flagging a particular datatype if its presence is abundant. Utilizing memristors in these designs allows us to present extreme low power systems for intrusion and anomaly detection, while sacrificing little accuracy.

Preliminary pharmacological studies were performed on the methanol extract of Bixa orellana L. (Bixaceae) leaves to investigate neuropharmacological, anticonvulsant, analgesic, antidiarrhoeal activity and effect on gastrointestinal motility. All studies were conducted in mice using doses of 125, 250 and 500 mg/kg of body weight. In the pentobarbitone-induced hypnosis test, the extract statistically reduced the time for the onset of sleep at 500 mg/kg dose and (dose-dependently) increased the total sleeping time at 250 and 500 mg/kg dose. A statistically significant decrease in locomotor activity was observed at all doses in the open-field and hole-cross tests. In the strychnine-induced anticonvulsant test, the extract increased the average survival time of the test animals (statistically significant at 250 and 500 mg/kg). The extract significantly and dose-dependently reduced the writhing reflex in the acetic acid-induced writhing test. Antidiarrhoeal activity was supported by a statistically significant decrease in the total number of stools (including wet stools) in castor oil-induced diarrhoea model. A statistically significant delay in the passage of charcoal meal was observed at 500 mg/kg in the gastrointestinal motility test. The extract was further evaluated in vitro for antioxidant and antibacterial activity. It revealed radical scavenging properties in the DPPH assay (IC(50)=22.36 microg/ml) and antibacterial activity against selected causative agents of diarrhoea and dysentery, including Shigella dysenteriae.