Systematics of Modern Benthic Foraminiferal Assemblages From the Deltaic Mangrove Ecosystem of Sundarbans

The contemporary intertidal foraminifera and estuarine environment information were collected from the four sites adjoining the deltaic mangrove environment in the Sundarbans. The marsh zones of the south-western coastal region of Bangladesh were examined for modern benthic foraminifera and to expound on the relationship of the foraminiferal assemblages with the environment. Due to high inaccessibility and remoteness, the taxonomic study of foraminifera and its depositional environment remains largely overlooked in the Sundarbans of Bangladesh. This study includes a detailed survey of depositional environment of these fluvio-deltaic to shallow marine sediments. The seventeen species belonging to fourteen genera representing nine families were recorded from surficial sediment of supratidal, intertidal, and dune environment of Kotka, Jamtala, Kochikhali, and Dimer char area. In the present study, these foraminiferal assemblages are characterized calcareous and agglutinated foraminifera. The Kotka beach is recognized as Nonionina assemblage zone, Jamtala beach designated as Ammonia assemblage zone, Kochikhali as Nonionina assemblage zone and Dimer char as Rosalina-Nonionina-Nonionella assemblage zone. The deposition of foraminifera is restricted to Sundarbans’ low to high marsh zone. J. Asiat. Soc. Bangladesh, Sci. 47(2): 121-136, December 2021

Factors Leading to Secondary School Dropout In Bangladesh: The Challenges to Meet the Sdg’s Targets

Bangladesh is regarded as a success story for rapid economic development and changes in social indicators that have taken place in the last couple of decades. Enrolment in education, especially women's education, has reached a desirable level. However, the dropout rate in secondary education is still a concern, which has not been reduced to the desired level. This research aims to understand better the undisclosed causes of dropout at secondary level schools. The primary data were collected from 790 former secondary school level students and 1580 parents/guardians, enabling in-depth and systematic analysis of the issue.. The method used in this study is quantitative with logit analysis. The study results showed that students’ perceptions on education, working experience, low socio-demographic status (SDS), family size, total number of siblings, food deficit, distance of the school, bullied by peers/teachers have a significant effect on increasing the probability of dropping out of school. Contrariwise, parents’ academic support, NGO membership of family members, mobility to the local power structure, and government’s social safety net programmes support are significant variables to reduce the probability of dropping out. The research reveals that financial problems are severely engaged to increase the dropout rate, and non-financial factors together aggressively play a catastrophic role and lead the academic life of the dropout student towards the end. The study suggests authorities for rapid response to reduce dropout, which leads Bangladesh to achieve SDGs targets and eventually become an upper middle-income country by 2041. J. Asiat. Soc. Bangladesh, Sci. 47(2): 173-190, December 2021

Incidence, Abundance and Damage of Papaya Mealybug In Southern Part of Bangladesh And Its Management

The papaya mealybug, Paracoccus marginatus Williams and Granara de Willink, is a small hemipteran that attacks several genera of host plants, including economically important tropical fruits and ornamentals. A study was carried out at farmers’ papaya garden and homestead areas of 8 locations viz., Dumki, Bouphal, Dashmina, Patuakhali, Mirjagonj, Amtali, Kalapara and Kuakata of Patuakhali and Barguna districts of Bangladesh to observe the incidence, abundance, and damage potential of papaya mealybug, Paracoccus marginatus (Williams and Granara de Willink) from March to June 2019. An experiment consisting of seven treatments following randomized complete block design (RCBD) with three replications was conducted for controlling papaya mealybugs at Patuakhali Science and Technology University (PSTU) campus during March to June 2019. Results revealed that among 8 locations, the highest incidence of P. marginatus was recorded in June, and the lowest was in April. The maximum abundance of P. marginatus on leaves and fruits of the papaya plant was observed at Kolapara, and the lowest was at Amtali. The highest percent infested plants (65%) per location, infested leaves/plant (97%), and infested fruits/plant (47%) was recorded in Kolapara, and the lowest percent infestations (31, 18, and 11%, respectively) were in Amtali. Among all treatments, the removal of infested leaves with petioles and application of Nitro 505EC @ 1 ml/L of water (T1) was the best approach for the management of papaya mealybugs. The removal of infested leaves with petioles + Biotap plus extra 95EC @ 0.2 g/L of water (T3) could be used as 2nd choice for controlling papaya mealybugs. The results concluded that removal of infested leaves and the application of Nitro 505 EC at the rate of 1 ml/L of water might be used to control the papaya mealybug. J. Asiat. Soc. Bangladesh, Sci. 47(2): 109-120, December 2021

Variability of Rainfall Over the Coastal Area In Bangladesh by Using Climate Model

The study attempt to understand the variability of rainfall by looking into the previous and future climate of the coastal area in Bangladesh from 1850 to 2100 by using the climate model (CMCC-CM- the Centro Euro-Mediterraneo Sui Cambiamenti Climatici Climate Model) of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). Rainfall data were collected from CMCC-CM by R programming for two GHGs emission scenarios (RCP 4.5 and RCP 8.5) referred to as ‘Representative Concentration Pathways (RCPs)’. The analysis has been conducted based on four seasons and an annual basis by plotting model data in MS Excel and R programming. The model shows that the average annual rainfall will increase from 1055.6 mm (during 1850-1900) to 1368.1mm (during 2051-2100) for RCP 4.5 while it will reach 1569.7mm (during 2050-2100) for RCP 8.5. Rainfall is also increasing for all seasons except winter. In winter season, the average rainfall will increase from 35.37mm (during 1850-1900) to 41.75mm (during 2051-2100) for RCP 4.5, where it will decrease from 35.37mm (during 1850-1900) to 22.55mm (during 2051-2100) for RCP 8.5 in the study area. The increasing and decreasing trend are more in high GHGs emission scenarios than in the medium, which will be alarming. Accordingly, this projection will be helpful to understand the adverse impacts of climatic elements and take short and long-term planning of decision-makers in that area. J. Asiat. Soc. Bangladesh, Sci. 47(2): 149-160, December 2021

Production of Microalgal Biomass at Different Growth Phases to Use as Biofuel Feedstock

The growth of microalgae under optimized conditions was determined for assessing their growth rate and biomass production. In this study, the growth of both green algae (Chlamydomonas noctigama and Chlorella vulgaris) and cyanobacteria (Anabaena variabilis and Nostoc spongiaeforme) was measured as optical density. Chlamydomonas noctigama and Chlorella vulgaris showed the doubling time of 9.5 and 8.0 hours, respectively, whereas Anabaena variabilis and Nostoc spongiaeforme showed the doubling time of 14.8 and 16.6 hours, respectively. All the species exhibited the highest growth in terms of biomass at the phase in between stationary and death phases. J. Asiat. Soc. Bangladesh, Sci. 47(2): 161-171, December 2021

A Comparative Study on Noise Pollution Levels In Dhanmondi Area, Dhaka: A Geospatial Analysis

Noise pollution has been recognized as one of the most vital environmental pollutions that affecting urban area’s quality of life. Sound levels at different points of the study area have been recorded and presented spatially by geostatistical analysis. A comparison has been made between the study area data in 2019 and that of 2021. In 2021 the noise level was significantly higher despite the Covid 19 pandemic. The comparative study showed that the noise level of the study area in 2021increased significantly. Noise level data in the sample points of the study area on Friday (holiday) were also collected and found that it was higher than that of even working days, especially in the evening. J. Asiat. Soc. Bangladesh, Sci. 47(2): 99-108, December 2021

Laboratory-Based Cytological and Biochemical Profile of Cerebrospinal Fluid for Children With Acute Bacterial Meningitis in Bangladesh

An attempt was made to analyze the cerebrospinal fluid (CSF) for a cytological and biochemical profile to identify etiological agents from children with suspected acute bacterial meningitis. The cerebrospinal fluid (CSF) samples from 371 suspected meningitis cases were examined, and the highest bacterial meningitis was found in 52(14.0%) cases in this study. Among a total of 371 samples of CSF, 272(73.3%) were crystal clear, 52(14.0%) were moderately turbid, 47(12.7%) highly turbid. The total leukocyte cell count of the CSF was proportionate to the turbidity. In the case of crystal clear CSF’s, total leukocyte counts (TLC) were normally ranging from <5 to 45 per mm3 with predominant lymphocytes. Moderately turbid fluid showed 46 to 500 cells per mm3 and highly turbid fluid showed from 501 to more than 10,00 cells/mm3. In the latter cases, differential counts demonstrated polymorphonuclear predominance. In addition, about 100% (52 cases) of positive and 12.5% (40/319) of negative cases had CSF protein concentration >100 mg/dL. CSF protein concentration greater than 100 mg/dl and sugar level below 40 mg/dl were considered as suspected bacterial meningitis in this study. Surprisingly, the C-Reactive Protein (CRP) values were found to be >40 mg/dL in both culturally positive and negative cases. Most of meningitis positive cases showed increased total cell counts as well as protein concentration, and decreased serum sugar concentrations. J. Asiat. Soc. Bangladesh, Sci. 47(2): 137-147, December 2021

Growth and Yield of Avicennia Officinalis (Baen) L. And Heritiera Fomes (Sundri) Buch. Ham. Plantations Established From Plus Tree Seeds in the Western Coastal Belt of Bangladesh

not available Asiat. Soc. Bangladesh, Sci. 46(2): 209-214, December 2020

Antagonistic Potentiality of Some Soil Fungi Against Six Fungal Pathogens Isolated From Cotton (Gossypium Hirsutum L.) Seeds

The antagonistic potentials of four soil filamentous fungi viz., Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tieghem and Trichoderma viride Pers. against six pathogens isolated from 14 varieties of cotton (Gossypium hirsutum L.) were evaluated by "dual culture colony interaction”, volatile and non-volatile metabolites. In dual culture colony interaction, out of four soil fungi, T. viride was found be the most effective to control the growth of the cotton pathogens. T. viride showed the highest growth inhibition against Curvularia lunata, Fusarium moniliforme, Mucor sp. and Rhizoctonia solani. On the other hand A. niger showed the highest growth inhibition against Fusarium nivale and A. fumigatus showed the maximum growth inhibition against C. gloeosporioides. The highest inhibition of radial growth of C. lunata, F. nivale and F. moniliforme was observed might be due to the secretion of volatile metabolites of T. viride whereas, the maximum inhibition of radial growth of C. gloeosporioides was observed because of the volatile metabolites of A. flavus. Mucor sp. and R. solani were inhibited due to the volatile metabolites of A. fumigatus. The greatest radial growth inhibition of C. lunata and F. moniliforme were noticed in case of T. viride owing to the effect of non-volatile metabolites. On the other hand, the radial growth of C. gloeosporioides and F. nivale were inhibited highest amount for the effect of non-volatile metabolites of A. niger, whereas highest growth inhibition of Mucor sp. and R. solani was observed due to the non-volatile effect of A. fumigatus. The present investigation suggests that the isolates of Aspergillus and Trichoderma may be further exploited as potential biocontrol agents against the fungal pathogens of cotton in field trial. Asiat. Soc. Bangladesh, Sci. 46(2): 143-153, December 2020

Genetic Characterization of Swamp Eel of Bangladesh Through Dna Barcoding and Rapd Techniques

The freshwater air-breathing swamp eel Monopterus spp. are native to the freshwater of Bangladesh and throughout the Indian subcontinent. To identify the different swamp eel species and to check the genetic diversity among them, a total of twelve swamp eel specimens were collected from four districts (Tangail, Bogura, Bagerhat and Sylhet) representing the four division of Bangladesh. The extracted DNA from twelve fish samples was amplified by the PCR technique for DNA barcoding and RAPD analysis. Among 12 specimens, 8 specimens showed a 95-100% similarity with M. cuchia species published in the NCBI GenBank database and BOLD system. The studied mct3 (collected from Tangail region), mcs1, mcs2 and mcs3 (collected from Sylhet region) specimens showed about 83% homology with Ophisternon sp. MFIV306-10 as per BLAST search; whereas BOLD private database showed 99% similarity with Ophisternon bengalense (Bengal eel). From the phylogenetic tree analysis, 8 samples were clustered with M. cuchia and 4 samples showed similarity with Ophisternon sp. MFIV306-10 and Ophisternon bengalense _ANGBF45828-19. In RAPD-PCR based analysis, it was found that the maximum genetic distance (1.6094) was observed between mcba2 and mcs3, while between mct1 and mct2, the minimum genetic distance was 0.000. A total of 192 bands, of which 35 were polymorphic with 17.88% polymorphisms among swamp eel species and the size of the amplified DNA fragments ranged from 250 to 1800 bp. The information on DNA barcoding and RAPD analysis help measure the genetic diversity among swamp eel species, ensure the reliability of the published taxonomic information, and initiate proper management programs to conserve these vulnerable species to meet future export demand. Asiat. Soc. Bangladesh, Sci. 46(2): 117-131, December 2020