We have studied physiological parameters in a living cell using fluorescence lifetime imaging of endogenous chromophores. In this study, pH dependence of the fluorescence lifetime of flavin adenine dinucleotide (FAD), that is a significant cofactor exhibiting autofluorescence, has been investigated in buffer solution and in cells. The fluorescence lifetime of FAD remained unchanged with pH 5 to 9 in solution. However, the fluorescence lifetime in HeLa cells was found to decrease with increasing intracellular pH, suggesting that pH in a single cell can be estimated from the fluorescence lifetime imaging of FAD without adding exogenous fluorescent probes.

Coastal shrimp (Penaeus monodon) aquaculture in Bangladesh is mostly practiced in a special type of field/pond situated by the side of a river -called a Gher -that is used to cultivate rice in winter and shrimp in summer. Ghers of different sizes are managed in different ways. In order to understand the effects of Gher size and their corresponding management practices on the production and economic returns of shrimp farming, we conducted an on-farm study in three small (1À5 ha), three medium (6À10 ha) and three large (>10 ha) Ghers located in the coastal Southwest region of Bangladesh. The mean harvest weight of shrimp was similar in all Ghers, but survival rates were higher in the small (50%) and medium (37%) ones than in the large (18%) ones. The high mortality in the large units led to a production that was lower than one-half of that in the small Ghers (about 80 and 200 kg/ha, respectively). The total variable costs per unit area were similar in all Ghers, but the importance of different items varied with Gher size. In the small Ghers, there are relatively high investments on inputs and labor. This expenditure results in lower shrimp mortality and higher production, which in turn results in gross returns that are larger than the total costs -hence, a positive and high net return. In large Ghers, the fixed costs are larger than in the small ones simply because of the size of the pond. Variable costs include higher investments in postlarvae and labor than in small Ghers, and lower inputs applied only at pond preparation. This results in higher shrimp mortality and lower production, which in turn results in gross returns that are smaller than the total costs -hence, a negative or low net return. These findings have positive implications for the future policy formulation of coastal shrimp aquaculture in Bangladesh.

Topo-bathymetric surveys of stream channels and floodplains, along with their vegetation distributions, are difficult and expensive to quantify, but they are crucially important for balanced river management, addressing issues such as flood risk and ecosystem management. This study was conducted to demonstrate seasonal accuracy for the first time, appraising results of a novel cost-effective unmanned aerial vehicle (UAV)-borne topo-bathymetric light detection and ranging (lidar) used to examine the vegetated and gravel-bedded lower Asahi River, Japan. Compared with autumn, the winter findings were almost identical to those from ground-truth observations with outperformed accuracy ranging from around 2 to 12 cm of root-meansquare-error values. The results were compatible with the corresponding highresolution aerial image. During winter, the three-dimensional laser point clouds identified details of the submerged artificial infrastructure of the river and the continuous topography of underwater (shallower than or equal to 2.08 m depth) and overland areas. In comparison, the autumn's bathymetric performance was limited to a depth of 1.20 m and turbidity of 5.50 NTU because measurements were conducted after a flooding event. Furthermore, this study applied novel approaches for accurate land cover mapping and vegetation height assessment, which can be readily applied in future riverine vegetation appraisal studies. In conclusion, because the point cloud data can be useful as input and validation data in hydrodynamic-numerical models and riparian vegetation identification, lidar can be regarded as a technique to inform the management of clear-flowing and shallow streams with vegetated floodplains.

Eleven dead or sick birds submitted from farms in the year 2010 with a history of sudden death with respiratory and/or diarrhoeal signs were used for isolation and identification of Newcastle disease virus (NDV). All samples were subjected to routine necropsy. Pooled respiratory tissues were inoculated in embryonated chicken eggs and chicken embryo fibroblast (CEF) cell culture. The growth of NDV was confirmed by embryo mortality, cytopathic effects (CPE) in cell culture, haemagglutination (HA) and haemagglutination inhibition (HI) test. The presence of NDV was confirmed by reverse transcriptionpolymerase chain reaction (RT-PCR). At necropsy seven cases were tentatively diagnosed as Newcastle disease (ND). Out of seven ND-suspected samples, four yielded virus in both embryos and cell culture, while one was positive only in embryos, one only in cell culture and one sample was negative in both embryos and cell culture. RT-PCR successfully amplified a 766 bp fragment covering parts of Matrix and Fusion protein genes of NDV from the samples that were positive either in embryos or in cell culture. It is suggested that RT-PCR could be a rapid and sensitive tool for the detection of NDV.

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The poultry feed, meat and egg samples were collected from the major poultry raising areas of the country to know the presence of heavy metals especially arsenic (As), lead (Pb) and chromium (Cr). A total of 360 elemental samples for As, Pb and Cr were analyzed in the laboratory. The heavy metal contents (As, Pb & Cr) of all the tested samples were found positive. But, the levels were below the Maximum Permitted Concentration (MPC) in most cases. The layer and broiler ready feed samples found safe from those elements; On the other hand, the “Cr” and “Pb” content in 14% and 11% loose feed samples were 7-70 and 3 times respectively higher than that of MPC. Notes worthy, the egg samples were also found safe from those elements. Of the tested samples 14% broiler meat and 50% spent hen samples found slightly higher level of “As” and 4-6 times “Cr” respectively than the MPC. In conclusion, the poultry farmers are suggested to buy poultry feeds from the reputed feed company and discourage to use loose feeds. Moreover, feed marketing channel particularly loose feed marketing should be monitored properly by the regulatory authority. Asian Australas. J. Food Saf. Secur. 2018, 2(1), 1-5