Sir Theagaraya College

This study applies two-dimensional correlation spectroscopy (2DCOS) and perturbation-correlation moving window (PCMW) 2DCOS to examine molecular alterations caused by cadmium (Cd) toxicity in Clarias batrachus fingerlings. Synchronous spectra revealed auto peaks near similar to 3048 and 2970 cm-1, linked to unsaturated fatty acids and methyl lipid groups. Asynchronous maps indicated variations in CH2 and CH3 fatty acids, suggesting altered membrane structure. Protein modifications were also observed, with transitions from alpha-helices to beta-turns reflecting instability. PCMW2DCOS highlighted Cd concentration-dependent effects: 0.8-1.9 ppm primarily disrupted lipid structures, while lower doses (0.4-1.2 ppm) signaled early protein changes. At higher levels (3.2-4.5 ppm), carbohydrate alterations became evident. These results emphasize the potential of PCMW2DCOS to detect subtle biomolecular responses to heavy metal stress on edible aquatic species. Additionally, Fourier-transform infrared (FTIR) spectroscopy coupled with machine learning was used to classify muscle tissues under Cd exposure. The PCA-LDA model achieved 96% accuracy with robust metrics, including an F score of 96% and MCC of 0.94, though minor misclassifications appeared in the confusion matrix. Support Vector Machine (SVM) models also performed strongly, with linear and polynomial kernels achieving 96% accuracy, while RBF and Sigmoid kernels were slightly lower at 91% and 87%. In conclusion, the integration of 2DCOS with FTIR and machine learning improved the detection of early biomolecular disruptions that are not visible in conventional one-dimensional FTIR. This approach provides new insight into Cd toxicity in edible fish species highlighting their utility in environmental toxicology and food safety monitoring. HIGHLIGHTS2DCOS spectra in the amide I region indicate a transition from alpha-helices to beta-turns, suggesting protein instability due to Cd exposure.PCMW2DCOS asynchronous spectral changes suggest phase-wise alterations in glycogen metabolismSVM models with linear and polynomial kernels demonstrated the highest classification performance, achieving an accuracy of 97%.

India is one of the world’s leading shrimp-producing countries. The shrimp hatchery industry also developed in parallel to this. Seed production is not in a constant manner due to various disease threats. Shrimp hatchery seed (Penaeus vannamei) production is depressed by various diseases, particularly caused by luminous bacteria (Vibrio harveyi), filamentous bacteria (Leucothrix mucor), and some viruses. Usage of various antibiotics becomes ineffective in many cases. It results in increases in the virulence of pathogens and, furthermore, is a cause for concern in promoting the transfer of antibiotic resistance to human pathogens. Usage of probiotics provides a solution to these problems. The microbial species composition in hatchery tanks by adding selected bacterial species to displace deleterious normal bacteria. The virulence of filamentous bacteria (Leucothrix mucor) is controlled during this experiment. In this study, it reveals that the probiotic not only controls the pathogenic bacteria (Leucothrix mucor), but also it improves the water quality and animal health.

India is the only country that has data on the past geomagnetic field (GMF) strength in the entire South Asia, therefore construction of new regional intensity secular variation curve is essential to describe the past Earth magnetic field behavior in this region. Two palaeo secular variation (PSV) curves for the last 3000 years are proposed; one for the whole Indian Subcontinent and the other for the Southern India using data respectively within 1600 km and 1000 km radius circles. The Subcontinent and the Southern India data are relocated to their geographically centered reference points (Karaundi village and Bangalore city respectively). All data were weighted based on the thermal intensity protocol, the number of samples per site and the type of studied materials. Selected data with weight (>= 6 and >= 8) were used to calculate the intensity PSV curves using the sliding window technique. The converted Virtual Axial Dipole Moment (VADM) PSV curves of both data sets are similar with respect to age, but values of the Southern India are little higher than those for the Indian Subcontinent with differences being somewhat conspicuous similar to 400 BCE and between 1100 and 1600 CE. Such difference can be due to (i) input data difference for the two curves and/or (ii) varying geomagnetic effects between the Indian Subcontinent and South India. The intensity PSV curve also indicates that the maximum PSV rate of change per century is observed between 900 CE and 1000 CE time window (similar to 8 mu T/century for 1600 km; 10 mu T/century for 1000 km radius circles). Intensity PSV predictions by global geomagnetic models (ARCH10k.1, CALS10k.2, SHAWQ2k and SHAWQ-Iron Age and ArchKalmag14k.r) for India do not reflect the regional intensity PSV pattern obtained in the current study and thus suggest that regional GMF curves are more meaningful rather than global models to describe regional/local variations. The converted VADM PSV curve trend of the Indian Subcontinent, considering the error in VADM and age, closely agree in short time spans with Central Asia (Uzbekistan), Western and Eastern Europe, and Mexico VADM PSV curve trends but shows no match at all with the VADM patterns of Eastern Asia (China, Japan and Korea), Central-Western Europe. The differences in regional VADMs behavior could be mainly due to variable non-dipolar contributions. The present results provide a good opportunity to describe some of the main features of the upper Holocene (0-3000 Yrs) GMF for the Indian Subcontinent and it needs further refinement as the present analysis is based on limited data.

In this study, we investigated the use of the green algae, Chlorella vulgaris, as an additional food source for larval development, survival rates, and growth performance in Penaeus vannamei nauplii. This research was carried out at a shrimp hatchery situated 50 km South of Chennai city. The experimental group was split into two subgroups. P. vannamei nauplii were provided with experimental diets for a duration of 10 days. The control diet included solely diatom (Chaetoceros calcitrans), whereas the experimental group was provided with Chlorella vulgaris and Chaetoceros calcitrans in alternating feedings. Both groups were also provided with algal feed and artificial feed two times daily. All additional parameters including water salinity (30‰), temperature (31±0.1℃), pH (7.9±1), alkalinity (124 mg/L), and hardness (4252±2) were maintained and probiotics were added for both the control and experimental groups. Water quality, feeding habits, and larval stage transformation were observed daily for up to 10 days until all larvae transitioned into post-larvae. The study's findings showed marginally improved survival rates in Penaeus vannamei.

The anticorrosion performance of the synthesized hydrogels was evaluated in 0.5 M HCl using gravimetric measurements at an inhibitor concentration of 0.5w%. Surface characterization through SEM (Scanning Electron Microscopy), EDX (Energy Dispersive X-Ray Spectrometer), and FTIR (FTIR- Fourier Transform Infra-Red) confirmed the formation of a stable corrosion-resistant coating on the metal surface, indicating strong interaction between the hydrogel and the substrate. Electrochemical analyses further verified that the hydrogels act as mixed-type inhibitors, suppressing both anodic metal dissolution and cathodic hydrogen evolution. Among the tested formulations, the poly(NCA-co-Am/NIPAM) hydrogel exhibited the highest inhibition efficiency of 85.13%, demonstrating its superior protective capability in acidic environments.