Empirical algorithm to estimate the average cosine of underwater light field at 490 nm

The average cosine of the underwater light field μ(λ), where λ is the wavelength, is an apparent optical property (AOP) that describes the angular distribution of radiance at a given point in water. Here, we present a simple algorithm to determine the average cosine at 490 nm, μ(490), which was developed using the measured optical parameters from the eastern Arabian Sea and coastal waters off Goa. The algorithm is validated using measured optical parameters. This algorithm, based on a single optical parameter, performed better compared with other empirical algorithms in determining the average cosine of underwater light field. The absorption coefficient at 490 nm, derived as an application of μ(490), compared well with the synthetic optical data and optical data measured from other regions.     

Malignant small cell tumour (Askin-Rosai) of the pericardium.

An Askin-Rosai tumour presenting as effusive constrictive pericarditis is reported. A 2-D echocardiogram was strongly suggestive of a primary pericardial tumour, and multiple pericardial and pleural aspiration failed to yield malignant cells. The final diagnosis was made at autopsy. Primary pericardial Askin-Rosai tumour has not to our knowledge been previously reported.     

Effect of Tidal Cycle on Escherichia coli Variability in a Tropical Estuary

A faecal indicator bacteria, Escherichia coli (E. coli), is widely used in monitoring health of estuaries, where tidal amplitude plays a critical role in its variability. Mahanadi estuary, formed at the mouth of a major tropical river Mahanadi, has large socio-economic importance. This anthropogenically stressed estuary remains understudied with respect to E. coli. Hence, this study addressed E. coli variability in Mahanadi estuary with novel sampling strategy that can be implemented at other tropical estuaries. The sampling strategy includes simultaneous measurements, at lesser-saline upper-estuary and higher-saline lower-estuary, over a tidal cycle. Although no significant variability of E. coli was observed between upper and lower-estuary, overall average count was higher during low tide and lower during high tide attributed to salinity fluctuations. Intermittent surpass of E. coli counts above recommended limits in Mahanadi estuary, indicated potential health risk, thus demands for frequent water quality monitoring and management strategies.