Distribution and sources of organic matter in surface sediments of the eastern continental margin of India

The sources and distribution of Organic Matter (OM) in surface sediments of the eastern continental margin of India, including the region influenced by river discharge, were investigated using content, molar C:N ratios and stable isotopes of carbon and nitrogen. Despite relatively high water column integrated chlorophyll-a concentrations were found in the continental shelf than the slope; however, the lower Sediment Organic Carbon (SOC) was found in the former than the latter region suggesting that in situ production did not play significant role on preservation of SOC in the coastal Bay of Bengal. The broad range of δ13C of SOC (−23.2 to −16.7‰) suggests that OM is a broad mixture of terrestrial and marine OM. Relative contributions from terrestrial C3 and C4 plants and marine sources are quantified as 34%, 23% and 43%, respectively, indicating that dominant source of allochthonous OM (∼57%) in the coastal Bay of Bengal. Relatively higher contribution of OM from C4 plants was found in the sediments at off river Krishna indicating that this region received detritus of agricultural crops such as jowar, bajra and sugar cane, which are dominant in its drainage basin, during SW monsoon. This study revealed that relatively high OM preserved in the slope than shelf region along the coastal Bay of Bengal and the composition of OM is primarily controlled by the type of agricultural crops and vegetation in the drainage basin of the river

Effect of Integrated Nutrient Management Practices on Available Nutrient Status of Soil under Rice-Sorghum Cropping System in Clay Loamy Soils

A field experiment was conducted for two consecutive years 2020-2021 and 2021-2022 on clay loam soil at Agricultural College Farm, Bapatla to study the direct and residual effect of integrated use of organics and inorganics on soil nutrient status under rice-sorghum cropping system. The results revealed that at all the growth stages of rice, the highest available nitrogen, phosphorus and potassium were recorded with the application of 100% RDF + 25% N through GLM (T8) and this was on par with T9 (100% RDF + 12.5% N through FYM + 12.5% N through GLM), T3 (125% RDF through inorganic fertilizers) and T7 (100% RDF + 25% N through FYM, whereas the highest available sulphur was recorded in  100% RDF + 25% N through GLM (T8) and it was on par with T9 (100% RDF + 12.5% N through FYM + 12.5% N through GLM) and T7 (100% RDF + 25% N through FYM during 2020 and 2021.  In succeeding sorghum, significantly highest soil available N, P2O5, K2O and sulphur were recorded in T9 (100% RDF + 12.5% N through FYM + 12.5% N through GLM) and it was on par with T8 (100% RDF + 25% N through GLM) and T7 (100% RDF + 25% N through FYM) during both the years of study. Irrespective of the treatments applied to rice crop, the sub plot that received 100% RDF (S3) in rabi recorded significantly highest soil available nutrients at all stages of crop which was on par with 75% RDF (S2) except available sulphur whereas increased NPK levels from 75% RDF (S2) to 100% RDF(S3) did not show any significant difference and lowest was recorded in control (S1) during both the years of study, respectively

Sources, distribution and preservation of organic matter in a tropical estuary (Godavari, India)

Major sources and distribution of Organic Matter (OM) were examined in a tropical monsoonal estuary, the Godavari, using content and isotopic signatures in suspended particulate matter and surface sediments during no-discharge period. The lower (<10 km from the mouth) and upper (>10 km) estuaries have shown remarkably different features with reference to the sources, distribution and preservation of OM. The upper estuary is characterized by relatively high content of Particulate Organic Carbon (POC) and chlorophyll-a (Chl-a) and low suspended matter and sediment OC. In contrast, the lower estuary is characterized by relatively low content of particulate OC and Chl-a and high suspended matter and sediment OC. Our data and model results showed that suspended particulate OM is derived predominantly from freshwater phytoplankton in the upper (∼85%) and lower (∼60%) estuaries, with a minor contribution from estuarine phytoplankton (∼25%) and terrestrial C₃ plants (∼10%) in the lower estuary, during the study period. On the other hand, sediment OM in the upper and lower estuaries derived from both autochthonous and allochthonous sources with nearly equal contributions. Although relatively high in situ production was observed in the upper than the lower estuary, relatively low sediment OC was found in the former than the latter region, suggesting that strong influence of preservation conditions rather than surface biological production on OC accumulation in sediments. This is attributed to intense transformation of OM by heterotrophs in the upper than the lower estuary because of prevailing conducive conditions for degradation of OM in the upper estuary during the study period

Clinical and genetic aspects of generalized aggressive periodontitis in families of Tumkur district of Karnataka, India

Background: Aggressive periodontitis (AP) is a complex disease whose phenotype is determined by genetic and environmental influences on the affected individuals. About 45% of the adult population in India has periodontitis. In Tumkur district of Karnataka, India, consanguineous first cousin and uncle-niece marriages are common, with a high incidence of AP. These discrepancies in the expression of periodontal disease directed us to find genetic etiology with respect to the Tumkur population. The clinical and genetic aspects of AP from this area have been presented in this paper. Materials and Methods: A total of nine families were ascertained at the Department of Periodontics, Sri Siddhartha Dental College and Hospital (Sri Siddhartha University), Tumkur. The clinical and radiographic data were gathered according to 1999 Consensus Classification of Periodontal Diseases. Peripheral blood samples were collected for total genomic DNA isolation using a Wizard TM Genomic Purification Kit (Promega, USA). The homozygosity mapping was carried out in a large consanguineous family to map a novel locus using autosomal markers from the CHLC/Weber Human Screening Set 10 (Research Genetics Inc., USA) at Indian Institute of Sciences, Bangalore. Results: The pedigree analysis suggested that the disorder is segregating as an autosomal trait. The homozygosity mapping failed to identify a locus for generalized AP in the family. Conclusion: The disorder may not be segregating as an autosomal recessive trait and we could have been misled by consanguinity in the family. It could be a multifactorial trait, or it could be still segregating as an autosomal recessive trait, but the region of homozygosity could be small and we failed to detect it using microsatellite markers. Therefore, SNP-marker-based analysis is warranted in future

Preparation of Barium Titanate from Barite Ore of Andhra Pradesh

Barium titanate (BaTiO3) is an attractive material in the field of electro ceramics and microelectronics due to its better characteristics. It is having high dielectric constant and low loss characteristics and hence barium titanate is an excellent choice for many applications, such as capacitors, multilayer capacitors (MLCs) and energy storage devices. In the present study an attempt is made to prepare barium titanate from ore using reduction ,leaching ,precipitation and calcinations techniques. The material is giving higher dielectric constant compared to the synthetically prepared materials.</jats:p

Metal and Metal Oxide Based Advanced Ceramics for Electrochemical Biosensors-A Short Review

Identifying and quantifying the biological concentrations of certain biomolecules such as dopamine, glucose, tyrosine, and cholesterol, etc. has become the basis for medical diagnosis in the treatment of a number of related diseases. In most cases, the concentrations of these biomolecules in biofluids like blood acts as a biomarker and becomes crucial in the treatment of diseases. On the other hand, advanced ceramics refers to oxides (alumina, zirconia), non-oxides: (carbides, borides, nitrides, silicides), Composites (particulate reinforced combinations of oxides and non-oxides), etc. This review article discusses recent developments in the field of electrochemical sensors developed using metal and metal oxide based advanced ceramics with an emphasis on developments in the field over the past five years. The article presents the key results, important findings, and interesting chemistry of biosensing advanced ceramic based electrochemical biosensors for some important biomolecules such as acetaminophen, glucose, and dopamine, etc.</jats:p