Comparison of ocean color chlorophyll algorithms for IRS-P40CM sensor using in-situ data

In-situ chlorophyll concentration data and remote sensing reflectance (Rrs) measurements collected in -six different ship campaigns in the Arabian Sea were used to evaluate the accuracy, precision, and suitability of different ocean color chlorophyll algorithms for the Arabian Sea. The bio-optical data sets represent the typical range of biooptical conditions expected in this region and are composed of 47 stations encompassing chlorophyll concentration, between 0.072 and 5.90 mg m -3, with 43 observations in case I water and 4 observations in case I1 water. Six empirical chlorophyll algorithms [i.e. Aiken-C, POLDER-C, OCTS-C, Morel-3, Oceaa Chlorophyll-2 (OC2) and Ocean Chlorophyll-4 (OC4)] were selected for analysis on the Arabian Sea data set. Numerous statistical and graphical criterions were used to evaluate the performance of these algorithms. Among these six chlorophyll algorithms two chlorophyll algorithms (i.e. OC2 and OC4) performed well in the case I waters of the Arabian Sea. The OC2 algorithm, a modified cubic polynomial function which uses ratio of Rrs490 nm and Rrs555 nm (where, Rrs is remote sensing reflectance), performed well with r2=0.85; rms =0.15. The OC4 algorithm, a four-band (443, 490,510, 555 nm), maximum band ratio formulation was found best on the basis of statistical analysis results with r2=0.85 and rms=0.14. Both OC2 and OC4 algorithms failed to estimate chloróphyll in Trichodesmium dominated waters. The OC2 algorithm was preferred over OC4 algorithm for routine processing of the OCM data to generate chlorophyll-a images, as it uses a band ratio of 490/555 nm and atmospheric correction is more accurate in 490 nm compared to 443 nm band, which is used by OC4 algorithm

(2E)-1-(3,4-Dichloro­phen­yl)-3-(2-hy­droxy­phen­yl)prop-2-en-1-one

In the title compound, C15H10Cl2O2, the dihedral angle between the mean planes of the two benzene rings is 7.7 (6)°. The crystal packing is influenced by O—H⋯O hydrogen bonds, which form chains along [010]. Weak π–π stacking inter­actions [centroid–centroid distance = 3.6697 (13) Å] are observed, which may contribute to the crystal packing stability

N-(4-Bromo­phen­yl)-2-(4-chloro­phen­yl)acetamide

The title compound, C14H11BrClNO, consists of chloro­benzene and bromo­benzene units which are linked at either end of the N-methyl­propionamide group. The chloro­benzene unit [maximum deviation = 0.005 (4) Å] makes a dihedral angle of 68.21 (19)° with the bromo­benzene unit [maximum deviation = 0.012 (3) Å]. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into chains along [010]

Detection and monitoring of Trichodesmium blooms in the coastal waters off Saurashtra coast, India using IRS-P4 OCM data

Trichodesmium blooms have been observed in the coastal waters off Saurashtra coast, Gujarat, India using Indian Remote Sensing satellite IRS-P4 Ocean Colour Monitor (OCM) data. Bloom-forming features were identified using false colour composites of channels 8, 6 and 5 (865, 670, 555 nm). Several bloom features of Trichodesmium like spiral eddies, stripes, slicks and parallel bands were detected in satellite images during 29 April to 7 May 2002. A strong backscattering signal was observed in the near-infrared band of OCM data, indicating the surface manifestation of Trichodesmium bloom. The chlorophyll images have been analyzed during the bloom period; overestimation of pigments has been observed and the bloom patches appear darker. Subramaniam’s protocol for Trichodesmium bloom study has been evaluated utilizing IRS-P4 OCM data for the waters off Saurashtra coast and appeared to be relevant in detection by ocean color remote sensing. The in situ information confirmed the presence of the bloom as coastal waters turned dark brown in color with an appearance of sawdust spray

Conformational transitions of the sodium-dependent sugar transporter, vSGLT.

Sodium-dependent transporters couple the flow of Na+ ions down their electrochemical potential gradient to the uphill transport of various ligands. Many of these transporters share a common core structure composed of a five-helix inverted repeat and deliver their cargo utilizing an alternating-access mechanism. A detailed characterization of inward-facing conformations of the Na+-dependent sugar transporter from Vibrio parahaemolyticus (vSGLT) has previously been reported, but structural details on additional conformations and on how Na+ and ligand influence the equilibrium between other states remains unknown. Here, double electron-electron resonance spectroscopy, structural modeling, and molecular dynamics are utilized to deduce ligand-dependent equilibria shifts of vSGLT in micelles. In the absence and presence of saturating amounts of Na+, vSGLT favors an inward-facing conformation. Upon binding both Na+ and sugar, the equilibrium shifts toward either an outward-facing or occluded conformation. While Na+ alone does not stabilize the outward-facing state, gating charge calculations together with a kinetic model of transport suggest that the resting negative membrane potential of the cell, absent in detergent-solubilized samples, may stabilize vSGLT in an outward-open conformation where it is poised for binding external sugars. In total, these findings provide insights into ligand-induced conformational selection and delineate the transport cycle of vSGLT

N-(2,6-Dichloro­phen­yl)-2-(naphthalen-1-yl)acetamide

In the title compound, C18H13Cl2NO, the naphthalene ring system and the benzene ring form dihedral angles of 74.73 (13) and 62.53 (16)°, respectively, with the acetamide grouping [maximum deviation = 0.005 (3) Å]. The naphthalene ring system forms a dihedral angle of 75.14 (13)° with the benzene ring. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, forming C(4) chains propagating in [010]. The O atom also accepts two C—H⋯O inter­actions

(2E)-3-(3-Nitro­phen­yl)-1-[4-(piperidin-1-yl)phen­yl]prop-2-en-1-one

In the title compound, C20H20N2O3, the piperidine ring adopts a chair conformation and its mean plane forms dihedral angles of 19.63 (9) and 19.44 (9)°, respectively, with the benzene and the nitro-substituted benzene ring. The benzene and nitro-substituted benzene rings are almost coplanar and make a dihedral angle of 4.78 (8)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds into two-dimensional networks parallel to the ab plane. The crystal packing is further stabilized by π–π inter­actions [maximum centroid–centroid distance = 3.7807 (12) Å]

2-(4-Chloro­phen­yl)-6-meth­oxy­chroman-4-one

In the title mol­ecule, C16H13Cl O3, the two aromatic rings form a dihedral angle of 65.3 (1)°. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers, which are further packed into columns propagating in [100] by weak C—H⋯π inter­actions

Evolution of Fluctuation in relativistic heavy-ion collisions

We have studied the time evolution of the fluctuations in the net baryon number for different initial conditions and space time evolution scenarios. We observe that the fluctuations at the freeze-out depend crucially on the equation of state (EOS) of the system and for realistic EOS the initial fluctuation is substantially dissipated at the freeze-out stage. At SPS energies the fluctuations in net baryon number at the freeze-out stage for quark gluon plasma and hadronic initial state is close to the Poissonian noise for ideal as well as for EOS obtained by including heavier hadronic degrees of freedom. For EOS obtained from the parametrization of lattice QCD results the fluctuation is larger than Poissonian noise. It is also observed that at RHIC energies the fluctuations at the freeze-out point deviates from the Poissonian noise for ideal as well as realistic equation of state, indicating presence of dynamical fluctuations.Comment: 9 pages and 6 figures (Major modifications done