Influence of environmental forcings on the seasonality of dissolved oxygen and nutrients in the Bay of Bengal

Studies on seasonal variability of oxygen and nutrients during three seasons namely SW monsoon, fall intermonsoon and spring intermonsoon indicate influence of physical forcings on the distribution of these hydrochemical properties in the subsurface layer. In the open ocean the Minimum Oxygen Layer (MOL ≤10 mu Mol L-1) during the southwest monsoon and fall intermonsoon is mostly confined to the north of 11N due to the penetration of high salinity water in the deeper waters of the central Bay. During spring intermonsoon MOL is mostly confined to the northern region between 14 to 20N with a narrow band of suboxic waters (≤ 5 mu Mol L-1) around 19 to 20N. Along the western margin, the MOL occupies a larger area in the intermediate and deeper waters during the SW monsoon and fall intermonsoon with a thick layer of suboxic waters during the SW monsoon which gets reduced and confined to the northern region during fall intermonsoon. The core of suboxic waters seems to disappear during the spring intermonsoon. The displacement of the water mass to shallower depths under the influence of cold core eddies is the major mechanism supplying nutrients to the surface waters whereas stratification due to the immense runoff from major rivers in the north and the associated suspended load addition seems to be inhibiting the biological production through curtailment of light penetration in the northern Bay of Bengal during the southwest monsoon. Pockets of low oxygen contents are not associated with elevation in secondary nitrite levels suggesting that circulation of the water mass under the influence of seasonal currents and gyres and the geochemical processes play a significant role in regenerative processes and regulating the intensity of the MOL in the Bay of Bengal

Humic and fulvic acids in sediments of the Hooghly estuary and some coastal areas in the northern Bay of Bengal

16-20Humic substances separated from the sediments of the Hooghly estuary and some coastal stations, were studied. The major fraction of humic acids was extracted by 0.05 M alkali solution whereas the major fraction of fulvic acids required 0.5 M alkali solution. Humic acids were the major fraction in the riverine region whereas fulvic acids comprised the major fraction of humic substances in the estuarine region. Carbon to nitrogen ratio was characteristic of the allochthonous organic matter. Of the organic matter 40-69% was found to be associated with humic substances

Structural characteristics of marine sedimentary humic acids by CP/MAS C-13 NMR spectroscopy

Humic acids from sediments of different depositional environments have been studied by solid-state C-13 NMR and the results compared with the traditional wet chemical analysis. Results obtained are well in agreement with the previous literature reports that the carboxyl content measured by NMR correlated better with the total acidity, as well as with the carboxyl content obtained by wet chemical analysis after correction for amino acid carboxyl is made (following hydrolysis of peptide bonds). There is a large discrepancy between the NMR and wet chemical measurements of phenolics. NMR spectra was also indicative of branched paraffinic structures in the humic acids from the Arabian Sea; the humic acids of sediments from estuarine and coastal areas of the Bay of Bengal being dominated by carbohydrates and aromatic structures and to a lesser extent by paraffinic structures. These differences are attributed to their different biogeochemical origin.Les acides humiques de sédiments ont été étudiés dans différents environnements de dépôts par RMN du 13C (état solide) et les résultats ont été comparés avec les analyses chimiques traditionnelles en milieu liquide. Les données obtenues sont en accord avec la littérature, montrant une meilleure corrélation de la teneur en carboxyle mesurée par RMN avec l'acidité totale. Elle est également mieux corrélée avec la teneur en carboxyle obtenue par analyse chimique (milieu liquide), après correction des groupes carboxyle des amino-acides (par hydrolyse des liaisons peptidiques). Il y a une grande différence entre la RMN et les mesures chimiques en milieu liquide des phénols. Les spectres RMN sont également des indicateurs des structures ramifiées paraffiniques dans les acides humiques de la mer d'Arabie ; les acides humiques des sédiments estuarens et côtiers de la baie du Bengale sont dominés par les hydrates de carbone et les structures aromatiques, ainsi que, dans une moindre mesure, par les structures paraffiniques. Ces différences sont attribuées à une origine biogéochimique différente

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Not AvailableReproductive performance is one of the important factors for determining the economics of livestock production. Reproduction is a complex luxurious process affected by environmental factors and involves a series of physiological processes and supported by endocrine system through release of various hormones A sound knowledge of reproductive functioning in terms of interplay of hypothalamic, gonadotropic and gonadal hormones, with synergistic and antagonistic influences from other hormones and factors involved in the regulation of various reproductive stages, accurate oestrus detection, timely pregnancy diagnosis and early detection of non-conceived stock can be expected to lead to an improvement of the reproductive efficiency. The different phases of reproductive cycle and pregnancy are regulated by intricate sequential events and interactions between hypothalamic releasing hormones, hormones secreted from the pituitary and sex steroids secreted by the ovary. Lack of integration or synchronization or endocrine imbalances at any phase of the sequence may result in reproductive failure. This paper focuses on use of various hormones for detection of estrus and early pregnancy in livestockNot Availabl

Particulate organic carbon and particulate humic material in the Arabian Sea

5-9Variations in particulate organic carbon (POC) and particulate humic material (PHM) were studied in winter (February-March 1995) and intermonsoon (April-May 1994) seasons in the Arabian Sea. Higher levels of POC were found in the north than in the southeastern side of the Arabian Sea close to the coast caused by higher biological production as a consequence of winter overturning. The PHM showed significant aggregation between 100 and 200 m during winter and was negligibly low towards north and relatively more towards south indicating accumulation of humic material. In contrast, PHM occurred in north than in south in intermonsoon. The north south trends could be seen in POC and PHM along 64°E in the Arabian Sea. The POC levels were lower in the Central Arabian Sea in winter, than in intermonsoon, its concentration increasing slightly towards north in accordance with the microzooplakton and bacterial production. The abundance of PHM seems to be related to the intensity of biological activity, the nature of organic material and the spatial and temporal variations in biochemical conditions.</span

Enterolith with Enterocolic Fistula: The Diagnostic Approach

An enterolith is a mixed concretion formed in GIT, usually rare in humans. Primary enteroliths are formed in small bowel, typically within a diverticulum and secondary enteroliths in gallbladder. This case report highlights the presence of an enterocolic fistula; probably a postradiotherapy complication; and an enterolith without associated small bowel or colonic diverticuli. We have discussed the various diagnostic modalities used to reach a preoperative diagnosis of this rare condition. Imaging plays an important role in the detection and management of acquired gastrointestinal fistulas. The more routine use of cross-sectional imaging (especially computed tomography and magnetic resonance imaging) has altered the standard sequence of radiologic evaluation for possible fistulas, but fluoroscopic studies remain a valuable complement, especially for confirming and defining the anomalous communications