BOBMEX: the Bay of Bengal monsoon experiment

The first observational experiment under the Indian Climate Research Programme, called the Bay of Bengal Monsoon Experiment (BOBMEX), was carried out during July-August 1999. BOBMEX was aimed at measurements of important variables of the atmosphere, ocean, and their interface to gain deeper insight into some of the processes that govern the variability of organized convection over the bay. Simultaneous time series observations were carried out in the northern and southern Bay of Bengal from ships and moored buoys. About 80 scientists from 15 different institutions in India collaborated during BOBMEX to make observations in most-hostile conditions of the raging monsoon. In this paper, the objectives and the design of BOBMEX are described and some initial results presented. During the BOBMEX field phase there were several active spells of convection over the bay, separated by weak spells. Observation with high-resolution radiosondes, launched for the first time over the northern bay, showed that the magnitudes of the convective available potential energy (CAPE) and the convective inhibition energy were comparable to those for the atmosphere over the west Pacific warm pool. CAPE decreased by 2-3 kJ kg-1 following convection, and recovered in a time period of 1-2 days. The surface wind speed was generally higher than 8 m s-1. The thermohaline structure as well as its time evolution during the BOBMEX field phase were found to be different in the northern bay than in the southern bay. Over both the regions, the SST decreased during rain events and increased in cloud-free conditions. Over the season as a whole, the upper-layer salinity decreased for the north bay and increased for the south bay. The variation in SST during 1999 was found to be of smaller amplitude than in 1998. Further analysis of the surface fluxes and currents is expected to give insight into the nature of coupling

The host range of Tobacco streak virus in India and transmission by thrips

Tobacco streak virus (TSV) recently caused an epidemic in peanut (= groundnut, Arachis hypogaea) crops in Andhra Pradesh, India. In the epidemic area TSV occurred in many widely distributed weeds of which Parthenium hysterophorus probably plays a major role in its spread by thrips. Three thrips species, Megalurothrips usitatus, Frankliniella schultzei and Scirtothrips dorsalis were vectors in the presence of infected pollen. Of crop species, Helianthus annuus (sunflower) and Tagetes patula (marigold) could act as sources of inoculum. In limited tests, the virus was not seed-transmitted in the peanut cultivar JL-24 or in the sunflower hybrids KBSH-41, -42, -44, and -50, MSFH-17 and ZSH-976. Strategies adopted to reduce the incidence of TSV are discussed

Three dimensional lithospheric structure of the western continental margin of India constrained from gravity modelling: implication for tectonic evolution

This paper describes a 3-D lithospheric density model of the Western Continental Margin of India (WCMI) based on forward modelling of gravity data derived from satellite altimetry over the ocean and surface measurements on the Indian peninsula. The model covers the north-eastern Arabian Sea and the western part of the Indian Peninsula and incorporates constraints from a wide variety of geophysical and geological information. Salient features of the density model include: (1) the Moho depth varying from 13 km below the oceanic crust to 46 km below the continental interior; (2) the lithosphere–asthenosphere boundary (LAB) located at depths between 70 km in the southwestern corner (under oceanic crust) and about 165 km below the continental region; (3) thickening of the crust under the Chagos–Laccadive and Laxmi Ridges and (4) a revised definition of the continent–ocean boundary. The 3-D density structure of the region enables us to propose an evolutionary model of the WCMI that revisits earlier views of passive rifting. The first stage of continental-scale rifting of Madagascar from India at about 90 Ma is marked by relatively small amounts of magmatism. A second episode of rifting and large-scale magmatism was possibly initiated around 70 Ma with the opening of the Gop Rift. Subsequently at around 68 Ma, the drifting away of the Seychelles and formation of the Laxmi Ridge was a consequence of the down-faulting of the northern margin. During this second episode of rifting, the northern part of the WCMI witnessed massive volcanism attributed to interaction with the Reunion hotspot at around 65 Ma. Subsequent stretching of the transitional crust between about 65 and 62 Ma formed the Laxmi Basin, the southward extension of the failed Gop Rift. As the interaction between plume and lithosphere continued, the Chagos–Laccadive Ridge was emplaced on the edge of the nascent oceanic crust/rifted continental margin in the south as the Indian Plate was moving northwards

Polymers imprinted with three REG1B peptides for electrochemical determination of Regenerating Protein 1B, a urinary biomarker for pancreatic ductal adenocarcinoma

Three peptides (each containing 13–18 amino acids) were synthesized and used as templates for molecular imprinting and epitope recognition of the Regenerating Protein 1B (REG1B), which is one of the urinary biomarkers for pancreatic ductal adenocarcinoma (PDAC). Poly(ethylene-co-vinyl alcohol)s were employed as the host for molecular imprinting of the peptides. Following their preparation, the molecularly imprinted polymers (MIP) were examined by cyclic voltammetry. The electrochemical responses of a screen-printed gold substrate coated with the MIP were measured at a working voltage of 300 mV (vs. Ag/AgCl); the entire protein and the peptides gave similar responses at concentrations of <1.0 pg⋅mL−1, with detection limits as low as 0.1 pg⋅mL−1. Urine samples from healthy and PDAC patients were then analyzed by using this modified gold electrode, and the results are in agreement with data obtained with ELISA

Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study

18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016

Modelling of coastal ocean environment for underwater surveillance

616-622Significance of ocean environment for underwater surveillance, namely for sonar systems, has been discussed in this paper. The passive as well as active sonar equations and the various parameters which are important for assessing sonar performance from environment point of view are highlighted. Some important published results which are available in the literature on the modelling of thermohaline structure of our coastal waters have been reviewed in this paper. Among 1-D mixed layer ocean models the model by Niiler and Kraus1 shows lesser deviations on Mixed Layer Depth (MLD) and Mixed Layer Temperature (MLT) when compared to the observations. The model given by Price et al 2 simulates the Sea Surface Temperature (SST) and the vertical profile of temperature. The comparison of simulated values with observations revealed that the diurnal variability of SST is well represented through this model but deviations are noticed in the thermocline zone. The 1-D ocean models are simple and easy to implement for operational purposes because they are computationally less intensive. However, it was found that these models accumulate more error for long-term simulation due to non-inclusion of advection processes which are important in coastal as well as open ocean conditions. The observed and predicted results of a 3-D model proposed by Blumberg and Mellor3, also known as Princeton Ocean Model (POM), showed a reasonable good comparison and this model could simulate successfully the Arabian Sea mini warm pool which is an important phenomenon that occurs in the south-eastern Arabian Sea before the onset of summer monsoon

Comparative study of wave parameters derived from spectral and zero-crossing methods

202-205Along wave records, collected in deep and shallow waters off Goa, West Coast of India, using ship-borne wave recorder, have been analysed following wave spectrum approach and zero-crossing method (Tucker/Draper method). Comparison of wave parameters obtained from both methods reveals that the significant wave heights (Hs) and zero-crossing periods (Tz) agree resonably well whereas the spectral width parameter (ϵ) and mean crest period (Tc) show some anomalies. Values of ϵ are higher and Tc lower for spectral approach compared to the zero-crossing method. It is envisaged that the use of spectral peak periods in place of Tz or Tc would be more appropriate for wave data sets containing predominant 'sea' and 'swell' components together

Analysis of Hindcasting wind waves and swell off Mangalore

21-25SMB method has been used for hindcasting waves and swell off Mangalore, Karnataka, India, during the SW monsoon of 1968 and 1969. Significant wave characteristics, both height and period, predicted by this method compare well with the recorded data. It is found that the fetch is not a continuous one. Two generating areas are encountered (from 74 to 70ᵒ E and 70 to 64ᵒ E). Waves generated between 64 and 70ᵒE play predominant role in forming the significant wave spectrum. During peak monsoon period waves generated beyond 64ᵒE also approach Mangalore Coast with significant periods of 10-12 sec. The effect of refraction especially for waves coming from SW and NW can not be neglected. A bottom friction factor f = 0.05 is found to be suitable for evaluating shallow water wave characteristics at this coast. Statistical relationships for obtaining shallow water significant wave height from deep water wave characteristics are presented