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Objectives This study was conducted to isolate, screening and purification of cellulase from bacteria present in sugar industry waste (molasses) and characterization by morphological and biochemical analysis. Results Based on experiments, three bacterial strains produced clear transparent zone into carboxymethyl cellulose (CMC) agar plate were identified as cellulase producing bacteria. Different culture parameters such as pH, temperature, incubation period, substrate concentration and carbon sources were optimized for enzyme production. According to the morphological and biochemical tests, the isolated strains were identified as Paenibacillus sp., Bacillus sp. and Aeromonas sp. The first strain Paenibacillus sp. showed high potentiality for maximum cellulase production (0.9 µmol ml −1  min −1 ) at pH 7.0 after 24 h of incubation at 40 °C in a medium containing 1.0% CMC. Then Paenibacillus sp. was selected for enzyme purification by ammonium sulfate precipitation, DEAE-cellulose and CM-cellulose column chromatography, respectively. In last step of purification, specific activity, recovery and purification fold were 2655 U/mg, 35.7% and 9.7, respectively. The molecular weight of the purified cellulase was found to be 67 kDa by SDS-PAGE, had an optimal pH and temperature at 7.0 and 40 °C. According to substrate specificity, the purified cellulase had high specificity on CMC substrate which indicated it to be an endo-β-1,4-glucanase.

Human parechovirus (HPeV) is widely recognized as a severe viral infection affecting infants and neonates. Belonging to the Picornaviridae family, HPeV is categorized into 19 distinct genotypes. Among them, HPeV-1 is the most prevalent genotype, primarily associated with respiratory and digestive symptoms. Considering HPeV’s role as a leading cause of life-threatening viral infections in infants and the lack of effective antiviral therapies, our focus centered on developing two multi-epitope vaccines, namely HPeV-Vax-1 and HPeV-Vax-2, using advanced immunoinformatic techniques. Multi-epitope vaccines have the advantage of protecting against various virus strains and may be preferable to live attenuated vaccines. Using the NCBI database, three viral protein sequences (VP0, VP1, and VP3) from six HPeV strains were collected to construct consensus protein sequences. Then the antigenicity, toxicity, allergenicity, and stability were analyzed after discovering T-cell and linear B-cell epitopes from the protein sequences. The fundamental structures of the vaccines were produced by fusing the selected epitopes with appropriate linkers and adjuvants. Comprehensive physicochemical, antigenic, allergic assays, and disulfide engineering demonstrated the effectiveness of the vaccines. Further refinement of secondary and tertiary models for both vaccines revealed promising interactions with toll-like receptor 4 (TLR4) in molecular docking, further confirmed by molecular dynamics simulation. In silico immunological modeling was employed to assess the vaccine’s capacity to stimulate an immune reaction. In silico immunological simulations were employed to evaluate the vaccines’ ability to trigger an immune response. Codon optimization and in silico cloning analyses showed that Escherichia coli (E . coli) was most likely the host for the candidate vaccines. Our findings suggest that these multi-epitope vaccines could be the potential HPeV vaccines and are recommended for further wet-lab investigation.

Purpose The study aims to search for potent cellulase producer from the gut of Gryllotalpa africana as well as to characterize and determine the effect of the purified enzyme on the cellulosic waste materials. Methods The potent cellulolytic strain was identified through morphological, biochemical, physiological, and molecular characterization like 16S rRNA and fatty acid methyl ester profile. After the optimization of cellulase production, the enzyme was purified through DEAE-Sepharose column chromatographic separation. The molecular weight of the purified enzyme was determined by SDS-PAGE analysis. The purified enzyme was characterized in terms of its activity and its effect on cotton fiber, and sawdust was also studied. Result The selected potent strain GAC 16.2 was identified as Acinetobacter junii that was capable to produce enhanced cellulase (112.38 ± 0.87 U/ml) at standardized optimum fermentation conditions. The molecular weight of the purified enzyme was determined as 55 kDa. The utmost activity of the purified enzyme was detected pH 7.0, temperature 50 °C, and in the presence of metal ions like Mg 2+ and Mn 2+ . The substantive degradation of cotton fiber and sawdust has been observed in a reasonably short period. Conclusion Purified cellulase from the selected isolate A. junii GAC16.2, a gut isolate of G. africana , has the potentiality to degrade cellulosic substances. This property can make the isolate a potent candidature for industrial application, as well as an effective biotechnological tool for environmental monitoring through cellulosic waste management.

Methylene blue (MB) is a textile dye that can be fatal to aquatic life, plants, and human health when discharged into the environment without treatment. A cheese whey-microbial fuel cell (CW-MFC) is a device that generates electricity from the degradation of cheese whey by microbial activity. The microbial activity of the CW-MFC during electricity production was able to decolorize MB. In this study, 50 ppm of MB was used to evaluate the decolorization capability of bacteria of the CW-MFC. A bacterial consortium present in the bioanode of the CW-MFC showed good MB decolorization in both the ex situ and in situ operations. Ex situ operation performed outside the CW-MFC reactor showed 92.2% MB decolorization within 18 h, while the in situ operation conducted inside the CW-MFC reactor showed 97.1% MB decolorization within the same timeframe. The maximum decolorization performance was achieved at pH 4 and 37 °C. The treated MB exhibited very little or no toxicity in the germination, rooting, and shooting of Oryza sativa compared to the untreated MB. Thus, the CW-MFC can be used as a promising technique to decolorize and remove the toxic effects of MB-contaminated wastewater, and the treated wastewater can be applicable for irrigation purposes.

The outcomes of ground response analysis (GRA) can significantly get affected by the variations of shallow soil properties. As the estimation of those properties are always associated with some inherent variabilities, it is quite important to consider those variabilities in the estimation of GRA. In this study, the effect of the variability associated with shear wave velocity (Vs) measurements on GRA is assessed for a site located in Kolkata. The variability in Vs is accounted through the statistical randomization. In the work, the parametric variations of standard deviation of Vs and inter-layer correlation coefficient, involved in the randomization process, are studied. In addition to that, the effect of intensity of input ground motion has also been investigated. Four different values of each parameter are considered in the analysis. In each case, 400 randomized profiles are analysed and a total of 4800 simulations are performed in the present study. The outcomes of GRA are presented in the form of transfer function (TF), spectral acceleration (SA) and PGA variation with depth. To quantify the variations for different adopted cases of parametric variations, the outcomes have also been quantified in the form of mean and standard deviations. The study reveals that the effect of standard deviation of Vs and intensity of input motion affect the GRA outcome substantially. In the study of the effect of standard deviation of Vs, TF exhibits higher standard deviations with a maximum value of ~ 3, whereas SA and PGA variations show a maximum value of ~ 0.45 and ~ 0.35, respectively. In case of intensity of input motion, the maximum values of standard deviation are observed to be ~ 3.5, 0.45 and 0.4 for TF, SA and PGA variations, respectively. Finally, the probability density functions and cumulative distribution functions of surface PGA variations are developed and proposed. To study the above, an equivalent linear ground response analysis program is developed in MATLAB environment along with the provisions of Vs randomization and repeated simulations of GRA.

Human coronaviruses like MERS CoV are known to utilize dipeptidyl peptidase 4 (DPP4), apart from angiotensin-converting enzyme 2(ACE2) as a potential co-receptor for viral cell entry. DPP4, the ubiquitous membrane-bound aminopeptidase, is closely associated with elevation of disease severity in comorbidities. In SARS-CoV-2, there is inadequate evidence for combination of spike protein variants with DPP4, and underlying adversity in COVID-19. To elucidate this mechanistic basis, we have investigated interaction of spike protein variants with DPP4 through molecular docking and simulation studies. The possible binding interactions between the receptor binding domain (RBD) of different spike variants of SARS-CoV-2 and DPP4 have been compared with interactions observed in the experimentally determined structure of the complex of MERS-CoV with DPP4. Comparative binding affinity confers that Delta-CoV-2: DPP4 shows close proximity with MERS-CoV:DPP4, as depicted from accessible surface area, radius of gyration and number of hydrogen bonding in the interface. Mutations in the delta variant, L452R and T478K directly participate in DPP4 interaction, enhancing DPP4 binding. E484K in alpha and gamma variants of spike protein is also found to interact with DPP4. Hence, DPP4 interaction with spike protein becomes more suitable due to mutation, especially due to L452R, T478K and E484K. Furthermore, perturbation in the nearby residues Y495, Q474 and Y489 is evident due to L452R, T478K and E484K, respectively. Virulent strains of spike protein are more susceptible to DPP4 interaction and are prone to be victimized in patients due to comorbidities. Our results will aid the rational optimization of DPP4 as a potential therapeutic target to manage COVID-19 disease severity.

Surface wave techniques are widely used to characterize a site based on shear wave velocity (Vs) or stiffness variation with depth. It utilizes the dispersion property of Rayleigh wave in a heterogeneous media. Dispersion curve is obtained from analyzing collected field test data and the final Vs profile is extracted from the inversion of the generated dispersion curve. The varying subsoil structures influence whether one or more Rayleigh modes will participate in the resulting wave propagation phenomenon. So, neglecting the higher mode participation may sometimes results in a completely different velocity profile than the actual existing one. In this paper, a detailed and comprehensive numerical study has been performed using finite element method for different types of soil profiles with different half-space impedances to assess how it affects the surface wave dispersion phenomenon. In addition to that, the effect of different data acquisition parameters on surface wave dispersion has also been studied.

Kolkata, capital of West Bengal, India, presently congested with moderate to high rise buildings, has undergone low to moderate damages due to past earthquakes. The city is situated on the world's largest delta island with soft thick alluvial soil layer. In this study, an attempt has been made to study ground response due to a number of past earthquakes, 1897 Shillong earthquake, 1964 Calcutta earthquake and 2011 Sikkim earthquake, for the purpose of preliminary microzonation of the Kolkata city. For this, synthetic ground motions have been generated at bedrock level by stochastic method. By using 1D wave propagation technique, the synthetic ground motion has been computed at surface level for 144 borehole locations in the city. Contours of PGA, PGV and PGD parameters in the city have been drawn for these three earthquakes. Response spectra for these three earthquakes have also been computed and an optimum response spectrum has been determined. A good correlation has been obtained with predicted ground motion at surface level of the city with the reported intensity and damages occurred in buildings of Kolkata during past earthquakes. The scenario of simulated ground motion for the past three earthquakes depicts that Kolkata city is very much prone to damages even due to moderate far and near source earthquakes.

This new work takes a comprehensive look at the quality control framework for statutory financial audit. Saha and Roy focus on identifying the different factors governing quality of audit and establish a comprehensive framework for quality control.

Executive Summary A business projects its financial performance through its financial statements. An audited financial statement is considered to be genuine and dependable by the stakeholders of the business. Therefore, statutory auditors should be self-regulating so that they can perform their professional role without being influenced by the management. The current regulatory framework for statutory auditors defines independence requirement for a statutory auditor in a professional engagement, points out circumstances that may create threats to independence and also proposes some measures to safeguard the same. However, in recent corporate accounting scandals, company’s failure led to devastating cost to the stakeholders, and audit failure was identified to be one of the causes behind them. Following investigations also sensed possible impairment of statutory auditors’ independence in those scams. In this backdrop, based on the existing literature on this subject, this article identifies variables influencing positively or negatively statutory auditors’ independence in their professional engagement. Opinions of statutory auditors and select other groups of respondents were collected. Most of the respondent groups believe that statutory auditors fail to detect irregularities in financial books due to their lack of independence and professional scepticism as was observed in this study. Several legal case decisions also support this finding. A long association between a statutory auditor and a client is one of the major reasons behind statutory auditors’ lack of independence. Opinions of respondents supported by applicable legal case decisions also proved that lax disciplinary measures and inadequate inspection framework caused audit failures in many recent cases. This study also analyses a significant difference of opinion among respondent groups and identifies the groups having a similar line of thought for each variable. One-way analysis of variance (ANOVA) and Tukey’s honestly significant difference (HSD) test were conducted, respectively, for these purposes. The result shows that significant differences exist among the respondent groups for most of the variables. Moreover, corporate executives have shown a significant difference of opinion from professional accountants, especially on the issue of statutory auditors’ negligence. While corporate executives believe statutory auditors are negligent in their duty, professional accountants oppose their views. Applicable legal case decisions also support such findings. Investors have shown similar views in line with academicians and students.