Amino acid and fatty acid compositions and nutritional quality of muscle in the pomfret, Pampus punctatissimus

Plasmalogens, fatty acids and alkyl glyceryl ethers of marine and freshwater clams and mussels

Using polarization as an additional parameter apart from amplitude and phase in spatial filtering experiments offers additional advantages and possibilities. An S-waveplate that can convert a linearly polarized light into radially or azimuthally polarized light can also be used for isotropic edge enhancement. For anisotropic edge enhancement, introduction of a polarizer at the output was recommended and edge selection was done by orientation of the polarizer. But the full potential of the S-waveplate as a spatial filter has not been exploited so far. Unlike the standard amplitude and phase-based Fourier filters, which are independent to the state of polarization of the illuminating beam, the S-waveplate acts in a different way depending on the state of polarization. The edge selection does not need to be carried out by changing the orientation of the polarizer. With a fixed polarizer at the output, we show that either isotropic or anisotropic edge enhancement in any desired orientation can be performed by operating the same spatial filter setup in different illuminating polarization states.

Polarization-based spatial filtering for directional and nondirectional edge enhancement using an S-waveplate

Trace elements and POPs in two commercial shark species from Djibouti: Implications for human exposure.

The study aimed to evaluate the chemical composition and nutraceutical potential of two commercially significant edible bivalve mollusc species (Anadara broughtonii and Mactra chinensis). The edible parts (motor muscle, mantle and adductor) of these molluscs were analyzed for their proximate composition, collagen content, amino acid profile, chemical score and elemental constituents. Both molluscs had low fat content (2.43–6.91 g/100 g dry weight), and protein (55.36–68.01 g/100 g dry weight) and carbohydrates (11.36–20.37 g/100 g dry weight) were their main components. Total collagen content of the edible bivalve molluscs varied from 30.5 to 39 mg/g wet weight, accounting for approximately half of their total protein content. Among amino acids, glycine, glutamate, aspartic acid, alanine, leucine, lysine and arginine were present at high levels in the edible parts of both bivalve molluscs, while the major elements present were sodium, potassium, magnesium, calcium, iron, zinc and nickel. Having high-quality protein content, edible bivalve molluscs could be excellent sources of nutritive ingredients and, after further study, may find applications in nutricosmetics and functional foods.

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Nutritional composition and total collagen content of two commercially important edible bivalve molluscs from the Sea of Japan coast

A modified cyclic-path interferometer is employed for complete measurement of spatially varying birefringence. An expanded and collimated laser beam intercepted by a birefringent specimen is incident on a polarization-masked cube beam splitter, resulting in two mutually orthogonal polarization components propagating along clockwise and counterclockwise directions in the interferometer. These two wavefronts are made to interfere for four specific orientations of an analyzer. Suitable combinations of the interferograms result in determination of the direction of birefringence and its magnitude. Experimental results are presented.

Low-level birefringence measurement by cyclic-path polarization interferometer.

Lipid composition of the bivalve Pelecyora trigona indicated that the total lipid (0.9 ± 0.1%) contain 50 ± 8.4% phospholipid and 13.2 ± 3.5% cholesterol as major constituents. The ratio of phospholipid to cholesterol of P. trigona is 3.76. The fatty acid composition of total lipids revealed that saturated fatty acids constitute 56.15 ± 0.35% followed by polyunsaturated fatty acids (37.6 ± 1.83%) and monounsaturated fatty acids (10.25 ± 2.19%). Palmitic acid (C 16:0 ) was the major (43.5 ± 0.2%) saturated fatty acid. Among the polyunsaturated fatty acids, eicosapentaenoic acid C 20:5 (15.6 ± 0.00%) was present in significant amount.

Lipid composition of bivalve Pelecyora trigona

Total lipid was extracted from four organs of the turtle Aspidertes gangeticus namely liver, muscle, eye and brain. Lipids like phospholipid and cholesterol were estimated in the total lipids. Fatty acid compositions of the total lipids were also determined. A. gangeticus liver shows a much higher content of total lipid (11.2%) than in muscle (0.5%). Phospholipid content is more in brain (6.5%) and muscle (7.2%) than in liver (2.4%) and eye (1.5%). Cholesterol occurs in brain (12.6%), eye (7.6%) and muscle (6.1%). The phospholipid and cholesterol ratio is maximum in muscle (1.1), gradually lowering in liver (0.8), brain (0.5) and eye (0.2) in the proportions indicated. In turtle all the organs studied are rich in palmitic (C16:0) and stearic (C18:0) acids. The amount of saturated fatty acid is more or less in equal proportion in the organs like eye (36.7%) and liver (37.9%). Turtle muscle and liver are more rich in polyunsaturated fatty acids in comparison with the other organs. Liver is enriched in the monoenoic C18:1 acid (38.2%) that is relatively much less in brain (16.9%), eye (16.6%) and muscle (15.6%), respectively. Eicosapentaenoic acid (C20:5) is especially high in Aspideretes eye (12.9%). Arachidonic acid (C20:4) is present in all the tissues studied.

Lipid Profiles of Turtle (Aspideretes gangeticus ) Organs

We report a technique which provides the details of three dimensional phase profile of a transparent microscopic sample. The depth resolution achievable is of the order of nanometers. The physical dimensions of the sample are obtained from the numerically reconstructed phase of the object wave. The method involves digital holographic recording of interferograms produced by superposition of the object wave and the coherent reference wave. We sequentially record four different holograms by altering the phase differences between the object wave and the reference wave. To introduce different phase differences between the two interfering beams, we have made use of polarization phase shifting. Therefore, the configuration used is simple and provides accuracy as the phase is introduced by simply rotating a linear polarizer. Experimental results for a microhole etched on glass are presented.

Digital holomicroscopy for nanometer depth resolution

The aim of this study is to model edge enhancement effect in purely phase samples. A self compensating interferometer
similar to Sagnac’s, employed with a polarizing beam splitter where two counter propagating orthogonally polarized
mutually coherent beams are modulated by the phase shifts introduced by a phase sample. An afocal imaging system is
used to image the phase sample on the CCD so that one of the images is slightly defocused. Real-time subtraction of two
images results in intensity modulation of phase interfaces.

Sonali Chakraborty

Papers

Low-level birefringence measurement by cyclic-path polarization interferometer.

Lipid composition of bivalve Pelecyora trigona

Lipid Profiles of Turtle (Aspideretes gangeticus ) Organs

Digital holomicroscopy for nanometer depth resolution

Edge enhancement of phase objects using a cyclic-path polarization interferometer