Real-world tailpipe emissions from autorickshaws (3-wheelers) under heterogeneous traffic conditions.

The current study aimed to measure real-world emissions of three-wheeled autorickshaws powered by CNG and parameters (such as speed, acceleration, air-fuel (A/F) ratio, and rpm) influencing 3-wheeler emission rates. Test vehicles manufactured under Bharat Standards BS-III and BS-IV were monitored for exhaust emissions in Delhi city using a portable exhaust emission measurement system (AVL Ditest Gas 1000). The average emission rates of CO, HC, and NO gases for on-road autorickshaws were found to be 0.015 ± 0.017, 0.003 ± 0.0017, and 0.007 ± 0.005 g/s, respectively. Further, the highest emission factor values of 3.98 g/km and 3.93 g/km were estimated for CO and HC+NO gases, respectively. These values were found to be 1.4-3.2 times higher than the respective BS emission norms (BS III-CO =1.25 g/km, HC+NO = 1.25 g/km; BS-IV-CO = 0.94 g/km and HC+NO = 0.94 g/km). In this study, it was observed that the driving pattern and emissions were affected by traffic characteristics, driver behavior (constant acceleration and deceleration), and vehicle characteristics. The air-fuel ratio (A/F) was found to correlate highly with emission rates, followed by acceleration/deceleration and speed. Further analysis found that more than 70% of the aggregated emissions were due to acceleration and deceleration, which contributed to nearly 70% of the travel time. This was followed by the breakdown of speed and emissions into different bins, which found that 20-30 kmph has a higher emission rate and 40-50 kmph bin has a lower emission rate.

Review on plastic wastes in marine environment - Biodegradation and biotechnological solutions.

The marine plastic pollution has drastic effect on marine species. The importance in environmental issues increases the demand to develop a significant technology which does not burden the marine environment or marine life forms. To mitigate the foreseen problems of micro and nanoplastic contamination, different biotechnological solutions has to be considered. Microbial communities exposed to plastic contaminated sites can adapt and form dense biofilms on the plastic surface and produce active catalytic enzymes. These enzymes can be able to degrade the synthetic polymers. In view of their high catalytic activity, microbial enzymes can be applicable for the degradation of synthetic polymers. This review highlights the toxicity of micro and nanoplastics on marine organisms, biodegradation of plastics and futuristic research needs to solve the issues of plastic pollution in marine environment.

Phenotypic identification & molecular detection of bla (ndm-1) gene in multidrug resistant Gram-negative bacilli in a tertiary care centre.

BACKGROUND & OBJECTIVES: Carbapenemase-producing Enterobacteriaceae isolates have been increasingly identified worldwide. Though molecular data regarding New Delhi metallo-beta-lactamase-1 (NDM-1) producers are available, data regarding their rate of infection in a hospital setting and percentage among different clinical isolates are scarce. Hence, this study was undertaken to determine the occurrence of bla NDM-1 gene among clinical isolates of multidrug resistant Gram-negative bacilli (MDRGNB) in a tertiary care centre in Bangalore, Karnataka, India. METHODS: A total of 74 MDRGNB isolates were studied. These were screened for MBL production by phenotypic assays such as double disk synergy test (DDST) and Modified Hodge's test (MHT). PCR was performed for the molecular detection of the gene and antibiograms were confirmed by automated bacteriology system. RESULTS: Of the 74 MDRGNB isolates, 34 were positive for bla NDM-1 gene. All isolates were resistant to aztreonam and two isolates were resistant to tigecycline. Complete resistance to the tested carbapenems was seen in 28 (82.35%) of the positive isolates whereas variable carbapenem resistance was seen in six (17.64%) of the positive clinical isolates. Of the total 34 PCR positive isolates, 33 (97.05%) NDM-1 producers were identified by DDST and 26 (76.47%) by MHT as producers of MBL. INTERPRETATION & CONCLUSIONS: A high percentage of plasmid encoded NDM was noted in MDRGNB. Phenotypic and molecular screening should be employed along with routine antimicrobial susceptibility testing to reflect the true number of metallo-beta-lactamase producers.