University of Dhaka
  • Dhaka, Bangladesh
Recent publications
Background Neonatal cholestasis (NC) is a major cause of morbidity and mortality in young infants. This study examines the etiology of NC and its outcome during 2 years of follow-up at a tertiary referral center in Bangladesh. Results Out of 80 cholestatic infants, 60% had intrahepatic cholestasis with a mean age of onset of 12.4±2.8 days and a mean age of admission of 82.4±29.0 days. The remaining 40% were extrahepatic with a mean age of onset of 6.7±2.3 days and a mean age of admission of 94.6±50.4 days. Biliary atresia (BA), idiopathic neonatal hepatitis (INH), and TORCH (Toxoplasma, rubella, cytomegalovirus, and herpes simplex) infection except rubella were the most common causes. After receiving treatment, 46.2% of the cases improved, 23.8% deteriorated with morbidity, and 30% died. The majority of the children with INH, TORCH, choledochal cyst, hypothyroidism, galactosemia, and urinary tract infection (UTI) with sepsis were improved. Significant mortality was found in BA (56.6%), intrahepatic bile duct paucity (PIBD) (100%), and progressive familial intrahepatic cholestasis (PFIC) (100%) whereas the rest of BA (43.4%) live with persistent morbidity. Significant clinical improvement was observed in 37 (46.2%) cases of cholestasis evidenced by decreasing jaundice, change of color of urine from dark to normal color, change of stool color from pale to yellow, and gradual decrease in liver size from hepatomegaly state. In addition, decreasing median total bilirubin, direct bilirubin, alanine transaminase, gamma-glutamyl transferase, and alkaline phosphatase showed biochemical improvement at 2 years follow-up. The age of admission, etiology, and presence of ascites are the predictors of outcomes. Conclusion BA was the most common cause of extrahepatic while INH and TORCH infection were the most common cause of intrahepatic cholestasis. Majority of children with intrahepatic cholestasis improved but deteriorated with BA and genetic causes. Prompt referral and early diagnosis as well as the etiology of NC were the main determinants of the favorable outcome.
Background Tumor necrosis factor alpha (TNFA) is an important cytokine that influences multiple biological processes. It is one of the key mediators of acute and chronic systemic inflammatory reactions and plays a central role in several autoimmune diseases. A number of approved monoclonal antibodies (mAbs) are widely used to subside these autoimmune diseases. However, there is a high rate of non-responsiveness to treatments with these mAbs. Therefore, it is important to be able to predict responses of the patients in an individualistic manner to these therapeutic antibodies before administration. In the present study, we used in silico tools to explore the effects of missense variants in the respective epitopes of four therapeutic anti-TNFA mAbs—adalimumab (ADA), certolizumab pegol (CZP), golimumab (GLM), and infliximab (IFX)—on their interactions with TNFA. Results The binding affinities of CZP and ADA to corresponding epitopes appear to be reduced by four (TNFA R131Q , TNFA E135G , TNFA R138Q , and TNFA R138W ) and two (TNFA G66C and TNFA G66S ) variants, respectively. The binding of GLM and IFX appears to be affected by TNFA R141S and TNFA R138W , respectively. TNFA G66C and TNFA G66S may be associated with autoimmune diseases, whereas TNFA E135G , TNFA R138W , and TNFA R141S may be pathogenic per se. Conclusion These variants may contribute to the observed inter-individual variability in response to anti-TNFA mAbs treatments and be used as markers to predict responses, and thus optimize therapeutic benefits to the patients.
In this paper, the classical Rayleigh–Bénard convection model is considered and solved numerically for extremely large viscosity variations (i.e., up to $$10^{30}$$ 10 30 ) across the mantle at a high Rayleigh number. The Arrhenius form of viscosity is defined as a cut-off viscosity function. The effects of viscosity variation and viscous dissipation on convection with temperature-dependent viscosity and also temperature- and pressure-dependent viscosity are shown through the figures of temperature profiles and streamline contours. The values of Nusselt number and root mean square velocity indicate that the convection becomes significantly weak as viscosity variation and viscous dissipation are increased at a fixed pressure dependence parameter.
This study was considered realizing the immense application in petroleum, chemical and fuel industry of the conjugate effect of heat transfer and chemical reaction on the laminar fluid flow through a channel with several obstacles. Numerical simulation was conducted using the finite element method with the aid of COMSOL multi-physics software to relate the fluid flow pattern, heat and mass transfer, and the reaction rate to the modification of shape, number, and arrangement of the impediments alongside the change of spacing ratio, the initial velocity of fluid and temperature of the obstacles. The results of this investigation point out a number of interesting phenomenon such as circular objects cause most prominent decomposition of water and the decomposition is found to be oppositely symmetrical to spacing ratio. However, the rise of temperature amplify the decomposition process where the increase in initial velocity influences contrarily. Moreover, increasing the spacing ratio of the obstacles reduced thermal decomposition of the fluid.
The study empirically investigates selected macroeconomic determinants of non-performing loans (NPLs) for a panel of 8 South Asian Association for Regional Cooperation countries (Afghanistan, Bangladesh, Bhutan, India, Nepal, Maldives, Pakistan, and Sri Lanka), using annual data for the period 2008–2019. To examine the association, this study, primarily, conducted the OLS model, fixed effect estimates, and random effect estimates and, eventually, applied robust fixed effect estimates to resolve the problem of heteroscedasticity. The empirical findings confirmed the previous findings, indicating a significant positive association with the government budget balance and a significant inverse relationship with GDP, sovereign debt, inflation rate, and money supply. To reduce the aggregate NPLs in the South Asian Association for Regional Cooperation economy, the respective country’s government should identify the financial sector’s vulnerabilities and, thereby, emphasize boosting the economic growth, ensuring a moderate level of money supply along with inflation rate. The findings are useful for formulating macro-prudential along with fiscal policies to avoid the subsequent NPLs shock in South Asian Association for Regional Cooperation countries.
Background Pirin, a member of the cupin superfamily, is an iron-binding non-heme protein. It acts as a coregulator of several transcription factors, especially the members of NFκB transcription factor family. Based on the redox state of its iron cofactor, it can assume two different conformations and thereby act as a redox sensor inside the nucleus. Previous studies suggested that pirin may be associated with cancer, inflammatory diseases as well as COVID-19 severities. Hence, it is important to explore the pathogenicity of its missense variants. In this study, we used a number of in silico tools to investigate the effects of missense variants of pirin on its structure, stability, metal cofactor binding affinity and interactions with partner proteins. In addition, we used protein dynamics simulation to elucidate the effects of selected variants on its dynamics. Furthermore, we calculated the frequencies of haplotypes containing pirin missense variants across five major super-populations (African, Admixed American, East Asian, European and South Asian). Results Among a total of 153 missense variants of pirin, 45 were uniformly predicted to be pathogenic. Of these, seven variants can be considered for further experimental studies. Variants R59P and L116P were predicted to significantly destabilize and damage pirin structure, substantially reduce its affinity to its binding partners and alter pirin residue fluctuation profile via changing the flexibility of several key residues. Additionally, variants R59Q, F78V, G98D, V151D and L220P were found to impact pirin structure and function in multiple ways. As no haplotype was identified to be harboring more than one missense variant, further interrogation of the individual effects of these seven missense variants is highly recommended. Conclusions Pirin is involved in the transcriptional regulation of several genes and can play an important role in inflammatory responses. The variants predicted to be pathogenic in this study may thus contribute to a better understanding of the underlying molecular mechanisms of various inflammatory diseases. Future studies should be focused on clarifying if any of these variants can be used as disease biomarkers.
Recently metal organic frameworks (MOFs), already known as adsorbent materials, have gained increasing research interest in thermal energy storage and conversion. MOF-water working pairs have been envisaged to provide the next revolutionary advancement in the existing sorption-based thermal energy storage and conversion systems. Herein, a promising MOF for high water sorption, MIL-100(Fe), and its transition metal-doped (Ni 2+ and Co 2+) derivatives are produced following a green synthesis procedure. The synthesized materials were tested in water sorption measurements using a thermogravimetric technique. The experimentally obtained adsorption data were correlated with the Sun-Chakraborty adsorption isotherm model. As an example of thermal energy conversion, an adsorption chiller is considered, and hence cooling cycles were drawn using the sorption data. The cooling cycles revealed that the nickel-doped MIL-100(Fe) demonstrates the highest value of the specific cooling effect (450.79 kJ kg − 1) among the studied MOFs. Inverse gas chromatography technique was employed to investigate the surface free energy of the parent and doped MIL-100(Fe) MOFs. It was found that nickel-doped MIL-100(Fe) had the highest total surface free energy of 105.41 mJ m − 2. Surfaces' Lewis acid-base activities and the work of cohesion and adhesion (towards water molecules) were investigated. The surfaces' properties were correlated with the water adsorption isotherms, which can provide crucial information for developing optimal adsorbents targeting water as the adsorbate for an efficient and effective thermal energy storage and conversion system.
During a pandemic event like the present COVID-19, self-quarantine, mask-wearing, hygiene maintenance, isolation, forced quarantine, and social distancing are the most effective nonpharmaceutical measures to control the epidemic when the vaccination and proper treatments are absent. In this study, we proposed an epidemiological model based on the SEIR dynamics along with the two interventions defined as self-quarantine and forced quarantine by human behavior dynamics. We consider a disease spreading through a population where some people can choose the self-quarantine option of paying some costs and be safer than the remaining ones. The remaining ones act normally and send to forced quarantine by the government if they get infected and symptomatic. The government pays the forced quarantine costs for individuals, and the government has a budget limit to treat the infected ones. Each intervention derived from the so-called behavior model has a dynamical equation that accounts for a proper balance between the costs for each case, the total budget, and the risk of infection. We show that the infection peak cannot be reduced if the authority does not enforce a proactive (quantified by a higher sensitivity parameter) intervention. While comparing the impact of both self- and forced quarantine provisions, our results demonstrate that the latter is more influential to reduce the disease prevalence and the social efficiency deficit (a gap between social optimum payoff and equilibrium payoff).
We present a Hubbard U optimized density functional theory based study of band gap engineered doped SrTiO3 suitable for light sensitive applications. We tune the Hubbard U parameter Uopt to match the experimental direct band gap of SrTiO3. We benchmarked the DFT+Uopt derived density of states, band structure and optical properties with that of sophisticated Heyd–Scuseria–Ernzerhof (HSE06) hybrid functional simulations. The reliability of the DFT+U method is further tested in simulating stability of the cubic SrTiO3 from elastic tensor and density functional perturbation theory based phonon band structure calculations. Moreover, the DFT+Uopt simulated SrTiO3 Raman peaks are identified against the experimental observations found in existing literature. We red shift the energy band gap of SrTiO3 within the DFT+Uopt formalism from ultraviolet to visible range by incorporating different dopants such as Pt, S and Se which is consistent with recent HSE06 hybrid functional based simulations found elsewhere. The optical absorption simulations revealed steep absorption edges of doped SrTiO3 in the visible spectrum. Overall, the DFT+U approach successfully probed the potential of doped SrTiO3 in solar harvesting applications.
Climate change adaptation is currently an important community concern in developing countries like Bangladesh. The conceptualization of adaptation within the government system matters for the promotion of activities such as employment generation for local communities. The lesser the gap between government policy and the local community’s needs for adaptation the more effective outcomes are for ensuring policy success and promoting sustainable community livelihoods or vice versa. This interface between policy and community is important for climate change adaptation which is explored in this paper along with the findings of the research project, DEltas, vulnerability and climate change: Migration and Adaptation (DECCMA) conducted during 2014–2018 in Bangladesh, Ghana, India, and the United Kingdom. The data from Bangladesh was collected from 1384 survey respondents, 19 Focus Group Discussions (FGDs), 3 workshops, and 43 Key Informant Interviews (KIIs). The findings of the paper show that government adaptation activities mainly reflect the Reactive Approach of Limited Action (RALA) perspective rather than the Proactive Approach To Adaptation (PATA). The RALA perspective is characterized by piecemeal and top-down approaches to adaptation which fail to recognize a community conceptualization of climate change, policy perspectives for coping with local concerns, and governance approaches for effective adaptation. In response, the government needs to focus on the PATA in policy, programs, and projects with the governance approach implemented from the bottom-up or, in other words, from the local perspective. Community participation in decision-making processes is characteristic of this bottom-up governance model. Local community participation, consultation, and representation are essential parts of PATA in adaptation policy formulation and execution, providing important lessons for Bangladesh.
COVID-19 has emphasized that a precise prediction of a disease spreading is one of the most pressing and crucial issues from a social standpoint. Although an ordinary differential equation (ODE) approach has been well established, stochastic spreading features might be hard to capture accurately. Perhaps, the most important factors adding such stochasticity are the effect of the underlying networks indicating physical contacts among individuals. The multi-agent simulation (MAS) approach works effectively to quantify the stochasticity. We systematically investigate the stochastic features of epidemic spreading on homogeneous and heterogeneous networks. The study quantitatively elucidates that a strong microscopic locality observed in one- and two-dimensional regular graphs, such as ring and lattice, leads to wide stochastic deviations in the final epidemic size (FES). The ensemble average of FES observed in this case shows substantial discrepancies with the results of ODE based mean-field approach. Unlike the regular graphs, results on heterogeneous networks, such as Erdős-Rényi random or scale-free, show less stochastic variations in FES. Also, the ensemble average of FES in heterogeneous networks seems closer to that of the mean-field result. Although the use of spatial structure is common in epidemic modeling, such fundamental results have not been well-recognized in literature. The stochastic outcomes brought by our MAS approach may lead to some implications when the authority designs social provisions to mitigate a pandemic of un-experienced infectious disease like COVID-19.
In conventional preservation of hides and skins, the use of NaCl (50%) evolves enormous salinity and total dissolved solids (TDS) in soaking effluent during leather processing. Plant-based skins preservation is a sustainable solution in reducing salinity and TDS from leather industry to replace conventional curing. In this study, the application of Polygonum hydropiper-based dry powder paste over flesh side of goatskin following 10%, 10%, and 15% paste mixing with 5%, 10%, and 5% salt, respectively, was done with periodical monitoring of organoleptic properties, moisture content, hydrothermal stability, and bacterial load. As compared to conventional curing, these Phyto-based salt minimized curing formulations had preserved goatskin for 30 days, resulting in a maximum 81% and 52% salinity and TDS reduction, respectively, in soaking liquor. The preserved skins were processed into shoe-upper leather in the same manner, and the ultimately produced leather offered the equivalent physical qualities. SEM images corroborated the structural orientation of collagen fibers was more suited than leather produced from salt-preserved skins. The correlation analysis demonstrated strong interdependencies among goatskin preservation efficacy metrics, particularly moisture content and hydrothermal stability, with the highest correlation (r = −0.919). Phytochemicals like alkaloids, flavonoids, coumarin, quinones, terpenoids, tannin, and phlobatannin were present in P. hydropiper extracts. The acetonic and water extract of the examined plant demonstrated modest antibacterial efficacy (11 mm) against Staphylococcus aureus compared to chloramphenicol (27 mm). Therefore, P. hydropiper can be a potential curing agent with comparable leather strength while minimizing the environmental impact and endorsing sustainable developments of leather industry.
The OECD countries are failing to fulfil their obligation towards the implementation of the objectives of SDG 7 and SDG 13. The failure of OECD countries is major constraint concerning global progress on curbing GHG emissions and mitigation of climatic changes as it provides rationale for developing countries to avoid their commitments. Therefore, the major focus of COP26 was to explore policy options for sustainable transition of energy from fossil fuel to clean renewables. This study analyzes the impact of innovation in environmental technology along with various policy regimes on energy transition in OECD countries from 2000 to 2019. The driving factors of energy transition in OECD countries are analyzed, under moderation of environmental governance regimes. This objective is realized by constructing an Energy Transition Index that accounts for the movement along the energy ladder. This index is developed using the Energy Ladder Hypothesis. Using two-step system-GMM and segregating the sample across level of emissions, the results show that the regional authority augments the energy transition, while enforecement of the climate change laws shows mixed results. Based on the study outcomes, a policy framework is recommended for attaining the SDG objectives by realigning the climate change adaptation and mitigation policies.
The Karnaphuli River is one of the prime and most important streams in the southeastern part of Bangladesh. The favorable water current and the geographic location have rendered the Karnaphuly River estuary a suitable habitat and a breeding ground for diverse fish species. Reversely, this estuary has been polluted by discharges from many point and non-point sources due to its location in the catchment area of a heavily industrialized area, Chattagram port city. However, published research concerning the status of toxic and trace elements in some commercially important benthic and pelagic coastal fish species in Karnaphuli River estuary was not found in the existing literature. Therefore, it's an important field of study on the assessment of toxic and trace elements concentration in the commercially important benthic and pelagic coastal fish species and their health taxation in the Karnaphuli River Estuary. Energy dispersive X-ray fluorescence (ED-XRF) was used to quantify trace metal concentration in edible parts of the fish species. This study revealed that the rank of the trace metals concentration was as follows (mg/kg): Zn (37.1) > Mn (16.12) > V (11.16) > Cu (9.49) > Rb (5.62) > Pb (2.98) > Cr (1.59) > Co (1.17). The F-test showed that a significant difference at 95 % confidence level in the distribution pattern of trace metals concentration among the examined fish species in the study area. The metal pollution index (MPI) in the muscle of fishes were found to be in the following order: L. bata > P. monodon > T. cirratus > M. bleekeri > O. pabda > H. nehereus > L. calcarifer > P. argenteus > P. paradiseus > T. toli, and the MPIs for most of the benthic fish species were higher compared to the pelagic fishes. On the other hand, the examined fish species were significantly bio-accumulative with the highest bio-accumulation factor value for benthic species. The multivariate analysis identified that the sources of the trace metals were associated with anthropogenic activities. For the human health risk assessment concern, estimated daily intake, target hazard quotient and cancer-causing risk were estimated. The results for non-cancer hazardous index values were found to be lower than unity. On the other hand, the total cancer risk data ranging from 1.24E−05 to 1.70E−05 were fallen within the range for the threshold values (1.0E−06 to 1.0E−04). However, considering the suggested values set by the environmental and regulatory agencies, it has been recommended that no significant non-carcinogenic and cancer-causing health risk for humans was seen due to the consumption of the studied fish species.
The progress on Sustainable Development Goals (SDGs) needs constant updating and deepening to improve the design of pro-environmental policies. In this context, recent studies report various drivers of ecological footprint (EF) for better climate control; however, the impacts of financial risk (FNR) and external conflicts (EXF) on EF are not thoroughly investigated. Therefore, this research uncovers the role of financial risk and external conflicts in EF using the Environmental Kuznets Curve (EKC) based model. To this end, some advanced time series methods including the Augmented ARDL (AARDL) and Spectral causality tests are applied for the period from 1984 to 2017 in the context of India. The empirical estimates revealed cointegration among variables of the study. The findings uncovered that reducing financial risk mitigates EF levels and stimulates environmental quality. However, limiting external conflicts does not improve the quality of the environment because the EF levels expand due to a reduction in conflicts. The empirical evidence validated the EKC accounting for both financial risks and external conflicts. Population density is found to alleviate environmental deterioration. Moreover, external conflicts and financial risks Granger cause EF. Lastly, policies are directed to limit the financial risk for reducing the EF.
Data-driven analytics and artificial intelligence (AI) have become the most crucial aspects of today's industrial marketing management. Although many firms have embraced analytics and AI strategies, corresponding academic advances have been slow. This research investigates how industrial goods manufacturers sustain their competitive advantage in export markets, convincing buyers in a competitive data-rich business environment. The evidence has been taken from the RMG (readymade garment) industry, one of the largest manufacturing industries significantly attached to the export markets. Utilizing multi-phase research design, the study reveals that firms marketing analytics capability play a vital role in sensing, seizing, and reconfiguring the market, consequently leading to a sustained competitive advantage. The performance of sensing, seizing, and reconfiguring becomes higher for a firm when they adopt AI on the strength of the marketing analytics platform. These findings exhibit the latest avenue of exploration within marketing analytics and AI's academic research paradigm. Further, in practice, managers will be aware of the facts that create resilience in this specific industry context.
This paper focuses on a Gilpin–Ayala growth model with spatial diffusion and Neumann boundary condition to study single species population distribution. In our heterogeneous model, we assume that the diffusive spread of population is proportional to the gradient of population per unit resource, rather than the population density itself. We investigate global well-posedness of the mathematical model, determine conditions on harvesting rate for which non-trivial equilibrium states exist and examine their global stability. We also determine conditions on harvesting that leads to species extinction through global stability of the trivial solution. Additionally, for time periodic growth, resource, capacity and harvesting functions, we prove existence of time-periodic states with the same period. We also present numerical results on the nature of nonzero equilibrium states and their dependence on resource and capacity functions as well as on Gilpin–Ayala parameter θ. We conclude enhanced effects of diffusion for small θ which in particular disallows existence of nontrivial states even in some cases when intrinsic growth rate exceeds harvesting at some locations in space for which a logistic model allows for a nonzero equilibrium density.
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9,934 members
Kazi Matin Ahmed
  • Department of Geology
G M Golzar Hossain
  • Department of Chemistry
AHM Nurun Nabi
  • Department of Biochemistry and Molecular Biology
Syed Naimul Wadood
  • Department of Economics
Information
Address
Registrar Building, University of Dhaka, 1000, Dhaka, Bangladesh
Head of institution
Professor Dr. Mohammad Akhtaruzzaman, Vice Chancellor
Website
www.du.ac.bd
Phone
(880)-2-9670531
Fax
(880)-2-9667222