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In recent years, the extraction of groundwater (GW) in coastal aquifers has rendered the fragile aquifers more saline due to the sea water intrusion. Groundwater from the coastal aquifers of the Pudhucherry region were sampled to study the process of salinization. An integrated approach was adopted to identify the salinization process, by coordinating the results of borehole geophysics, rainfall pattern, water level variation, hydrochemical characters and multivariate statistical analysis. A total of 136 groundwater samples were collected during two different seasons, southwest monsoon (SWM) and northeast monsoon (NEM). The major cations and anions were analyzed adopting standard procedures. Resistivity and litholog indicate that the southeastern (SE) part of the study region has lower resistivity than in north. Based on electrical conductivity (EC) and total dissolved solids (TDS) values, most of the samples are potable, except for few samples from southeastern region. The study results indicated that higher values of Na, EC, K, SO4, Mg and Cl were observed during NEM, indicating leaching of salt into the aquifer and ion exchange process. The predominant hydrochemical facies of groundwater was Na-Cl and Ca–Mg–Cl type reflecting the saline water and the mixing process of saltwater and fresh groundwater, respectively. Though more number of samples with higher EC was noted in NEM, the results of PCA and correlation analysis indicate the predominance of leaching of salts and intense agricultural activities. The process of sea water intrusion was observed to be dominant during SWM.

This study considered the temporal variations in rainfall and water level patterns as governing factors, which influence the geochemical process of coastal aquifer around Pondicherry, South India. Rainfall and water level data were collected from 2006 to 2016, which showed that the amount of rainfall from 2006 to 2011 was higher than that of 2011 to 2016. To understand the geochemical process governing groundwater, samples were collected during 2006 (n = 54), followed by 2011 (n = 93), and during 2016 (n = 63) as part of continuous observation. The major ions and stable isotopes (δ18O and δD) were analyzed in the samples to determine the geochemical variations. The predominant types were noted as Na-HCO3 and Na-Cl; Ca-HCO3 and Ca-Mg-Cl; and Na-Cl and Ca-Mg-Cl in 2006, 2011, and 2016, respectively. Saturation states of sulfate and carbonate minerals were compared for the study periods and it indicates that the saturation index (SI) values were increased from 2006 to 2011, but decreased from 2011 to 2016. PHREEQC inverse modeling revealed the predominance for the dissolution and leaching of carbonate minerals during increased rainy periods, and the increase of halite saturation during lesser rainfall period. AQUACHEM mixing studies suggested that geochemical signatures of 2006 and 2011 were preserved in samples of 2016 in different proportions. Considering the major factors, the main processes prevailing in the study area were inferred to be dissolution and leaching during 2006~2011 years and seawater intrusion along with ion exchange during 2011~2016 years. In all these periods of study, anthropogenic impact was also identified in the groundwater samples. Hence, this study revealed that the rainfall and water level gave a significant variation in the geochemical process of groundwater in the coastal aquifer system.

Hydrogeochemical investigation was carried out in groundwater of Virudhunagar district, Tamil Nadu, India. Geologically the study area is occupied with Archaean, Charnockite, Unclassified Genesis and Pleistocene Laterite formations. A total of 72 groundwater samples were collected spatially during North East Monsoon (NEM) in 2019 based upon the coverage of geological formations. The collected samples were studied for different physio-chemical parameters like pH, TDS and EC, major cations (Ca, Mg, Na, K) and major anions (Cl, HCO3, SO4, PO4). EC and TDS ranges from 273 to 5869 mg/L and 194 to 4159 mg/L. The ionic dominance of the hydrochemical parameters follows in the order of Na > Ca > Mg > K and Cl > HCO3 > SO3 > PO4. The data represents two major hydrogeochemical facies of Ca-HCO3 and mixed Ca-Mg-Cl in the study region. The USSL classifications of samples signifies low alkali hazard and high to very high salinity hazard. The higher concentration of TDS and EC in the samples reflects the unsuitability of groundwater. According to the WHO drinking water quality standards and the value of SAR, RSC, Na% reflects the groundwater in the study region is more suitable for irrigation than drinking purpose. The statistical method also adopted to understand the major factors influencing the variation in hydrochemistry of the region. Weathering, leaching of salts and anthropogenic activities were identified to be the key governing factor in the varied groundwater chemistry of this region.

The irregular monsoonal rainfall and overexploitation of groundwater have resulted in the sharp decline of water resources in different parts across India. Various factors like geology, terrain morphology, hydrology, and hydrometeorology influence the recharge potentiality of a region. Application of remote sensing and geographical information system (GIS) tools might be effective in the delineation of groundwater recharge potential zones and help towards the sustainability of groundwater resources. In this study, it was attempted to identify the groundwater recharge potential zones in the Courtallam region located at Tamil Nadu state of South India by integrating multiple thematic layers involving lithology, geomorphology, land use/land cover, slope, lineament density, drainage density, and the spatial distribution of groundwater level and rainfall through weighted overlay analysis in Arc GIS. The recharge potential was compared with the electrical conductivity of groundwater for evaluating the water quality. It was characterized the groundwater recharge potential of the study area as very poor (8.7%), poor (32.5%), moderate (37%), good (16.3%), and very good (5.5%). one-third of this area has moderate groundwater recharge potentiality and the southeastern part of the study area with good quality of water is feasible for new bore-well construction.

Neuronal networks, especially those in the central nervous system (CNS), evolved to support extensive functional capabilities while ensuring stability. Several physiological “brakes” that maintain the stability of the neuronal networks in a healthy state quickly become a hinderance postinjury. These “brakes” include inhibition from the extracellular environment, intrinsic factors of neurons and the control of neuronal plasticity. There are distinct differences between the neuronal networks in the peripheral nervous system (PNS) and the CNS. Underpinning these differences is the trade-off between reduced functional capabilities with increased adaptability through the formation of new connections and new neurons. The PNS has “facilitators” that stimulate neuroregeneration and plasticity, while the CNS has “brakes” that limit them. By studying how these “facilitators” and “brakes” work and identifying the key processes and molecules involved, we can attempt to apply these theories to the neuronal networks of the CNS to increase its adaptability. The difference in adaptability between the CNS and PNS leads to a difference in neuroregenerative properties and plasticity. Plasticity ensures quick functional recovery of abilities in the short and medium term. Neuroregeneration involves synthesizing new neurons and connections, providing extra resources in the long term to replace those damaged by the injury, and achieving a lasting functional recovery. Therefore, by understanding the factors that affect neuroregeneration and plasticity, we can combine their advantages and develop rehabilitation techniques. Rehabilitation training methods, coordinated with pharmacological interventions and/or electrical stimulation, contributes to a precise, holistic treatment plan that achieves functional recovery from nervous system injuries. Furthermore, these techniques are not limited to limb movement, as other functions lost as a result of brain injury, such as speech, can also be recovered with an appropriate training program.

Olfaction is one of our 5 main qualitative sensory abilities. In this review, we have examined the physiology of olfaction from the olfactory receptor to the brain. Through analyzing the physiology of olfaction, we have found that the biochemistry of olfactory nerve stimulation is unique from that of other similar pathways. Upon receiving large amounts of input from the olfactory nerve, the olfactory bulb, followed by several layers of centrifugal and centripetal processing in the brain, has to sort the information from the input as well as integrate it with other inputs from the brain to develop a coherent understanding of the input. We then examined the implications of olfaction in the military, the practical applications of electronic noses and problems associated with injury to olfaction that could affect compensation and combat worthiness of a soldier following injury. In the military, olfaction can allow the army to perform at its best through 4 main methods, namely ensuring olfaction is consistent with other dimensions of perception (ensuring optimal olfaction ability in all soldiers in combat), understanding the impact of different common combat environments on the sense of smell, utilizing odor as a defense mechanism and using olfactory aids when necessary. Electronic noses are olfactory aids that have a large potential in the military ranging from saving lives through the detection of explosives to potential methods for improving combustion efficiency. There are several problems associated with injury to olfaction that should be considered when deciding on compensation and combat worthiness of the soldier following an injury.