Efficacy of micro algae and cyanobacteria as a live feed for juveniles of shrimp Penaeus monodon

Growth performance and survival of giant tiger shrimp Penaeus monodon fed with five different micro algal diets as a live feed, was evaluated under laboratory condition. The experimental design consisted of feeding the juvenile with micro algal diets and cyanobacterial diets at the same concentrations. Fresh biomass of Chlorella sp., Tetraselmis sp., Isochrysis sp., Synechococcus sp. and Phormidium sp. were used as feed for shrimp P. monodon. Mean total length of shrimp was higher when fed with Chlorella sp. (4.8 cm) followed by Phormidium sp. (4.4 cm) and mean total weight was also higher in shrimp fed with Chlorella sp. (0.59 g) followed by Phormidium sp. (0.569 g). The survival rate of the shrimp was improved in shrimp fed Phormidium sp. (83.33%) and it was decreased in shrimp fed with Isochrysis sp. (36.67%). The shrimp that performed best had significantly more edible flesh (59.35%) (with Chlorella sp.) protein and lipid content (with Phormidium sp.) carbohydrate (with Tetraselmis sp.) Further more, water quality of the tank was better in shrimp fed with Chlorella sp. In general, the research of this study revealed that Chlorella sp. and Phormidium sp. could be used as a live feed for better growth of P. monodon.Key words: Penaeus monodon, micro algae, Synechococcus, Phormidium, Shrimp growth, Chlorella

A Markovian reliability analysis of electronic circuits

Call number: LD2668 .R4 1965 S95

A fully ab initio approach to inelastic atom-surface scattering

We introduce a universal and fully ab initio theory for inelastic scattering of any atom from any surface, and apply the theory to helium scattering from Nb(100). The key aspect making our approach universal is a direct first-principles evaluation of the scattering atom-electron vertex. By correcting misleading results from current state-of-the-art theories, this fully ab initio approach will be critical in guiding and interpreting experiments that adopt next-generation, non-destructive atomic beam scattering.Comment: 6 pages, 5 figure

Antimycobacterial activity of cyanobacterial species isolated from the coastal regions of Tamil Nadu

1165-1174The extract of Geitlerinema carotinosum CNP 4003 showed promising antimicrobial activity (100 and 1000 µg/disc/well) against E. coli ATCC 35218, S. aureus ATCC 25923, and M. smegmatis with inhibition zones of 6, 8, and 11 mm, respectively. In addition, the extract also exhibited cytotoxic activity (IC50 = 175 μg/ml) against mammalian (HepG2) liver cancer cell lines. Therefore, the crude extract was fractionated using column chromatography technique and the active fractions were identified. The active fractions tested against HepG2 cell line showed 95 % hemolytic activity at the concentration of 375 µg/ml with IC50 as 63 μg/ml. Further, the compounds in the active fractions were analyzed and the results indicated the presence of indoles, terpenes, and peptides. The chemical composition of the active fraction was analyzed by using gas chromatography-mass spectrometry (GC-MS). The potential antimycobacterial strain G. carotinosum CNP 4003 was confirmed by molecular characterization and the DNA sequence was deposited in the gene bank

Ab initio phonon coupling and optical response of hot electrons in plasmonic metals

Ultrafast laser measurements probe the nonequilibrium dynamics of excited electrons in metals with increasing temporal resolution. Electronic structure calculations can provide a detailed microscopic understanding of hot electron dynamics, but a parameter-free description of pump-probe measurements has not yet been possible, despite intensive research, because of the phenomenological treatment of electron-phonon interactions. We present ab initio predictions of the electron-temperature dependent heat capacities and electron-phonon coupling coefficients of plasmonic metals. We find substantial differences from free-electron and semiempirical estimates, especially in noble metals above transient electron temperatures of 2000 K, because of the previously neglected strong dependence of electron-phonon matrix elements on electron energy. We also present first-principles calculations of the electron-temperature dependent dielectric response of hot electrons in plasmonic metals, including direct interband and phonon-assisted intraband transitions, facilitating complete theoretical predictions of the time-resolved optical probe signatures in ultrafast laser experiments

Experimental and Ab Initio Ultrafast Carrier Dynamics in Plasmonic Nanoparticles

Ultrafast pump-probe measurements of plasmonic nanostructures probe the nonequilibrium behavior of excited carriers, which involves several competing effects obscured in typical empirical analyses. Here we present pump-probe measurements of plasmonic nanoparticles along with a complete theoretical description based on first-principles calculations of carrier dynamics and optical response, free of any fitting parameters. We account for detailed electronic-structure effects in the density of states, excited carrier distributions, electron-phonon coupling, and dielectric functions that allow us to avoid effective electron temperature approximations. Using this calculation method, we obtain excellent quantitative agreement with spectral and temporal features in transient-absorption measurements. In both our experiments and calculations, we identify the two major contributions of the initial response with distinct signatures: short-lived highly nonthermal excited carriers and longer-lived thermalizing carriers

Evaluation of classical precipitation descriptions for γ′′(Ni3Nb−D022) in Ni-base superalloys

The growth/coarsening kinetics of γ′′(Ni3Nb−D022) precipitates have been found by numerous researchers to show an apparent correspondence with the classical (Ostwald ripening) equation outlined by Lifshitz, Slyozov and (separately) Wagner for a diffusion controlled regime. Nevertheless, a significant disparity between the actual precipitate size distribution shape and that predicted by LSW is frequently observed in the interpretation of these results, the origin of which is unclear. Analysis of the literature indicates one likely cause for this deviation from LSW for γ′′ precipitates is the “encounter” phenomenon described by Davies et al. (Acta Metall 28(2):179–189, 1980) that is associated with secondary phases comprising a high volume fraction. Consequently, the distributions of both γ′′ precipitates described in the literature (Alloy 718) and measured in this research in Alloy 625 are analysed through employing the Lifshitz–Slyozov-Encounter-Modified (LSEM) formulation (created by Davies et al.). The results of the LSEM analysis show good far better agreement than LSW with experimental distributions after the application of a necessary correction for what is termed in this research as “directional encounter”. Moreover, the activation energy for γ′′ coarsening in Alloy 625 shows conformity with literature data once the effect of heterogeneous (on dislocations) precipitate nucleation at higher temperatures is accounted for

Protein complex directs hemoglobin-to-hemozoin formation in Plasmodium falciparum

Malaria parasites use hemoglobin (Hb) as a major nutrient source in the intraerythrocytic stage, during which heme is converted to hemozoin (Hz). The formation of Hz is essential for parasite survival, but to date, the underlying mechanisms of Hb degradation and Hz formation are poorly understood. We report the presence of a ∼200-kDa protein complex in the food vacuole that is required for Hb degradation and Hz formation. This complex contains several parasite proteins, including falcipain 2/2', plasmepsin II, plasmepsin IV, histo aspartic protease, and heme detoxification protein. The association of these proteins is evident from coimmunoprecipitation followed by mass spectrometry, coelution from a gel filtration column, cosedimentation on a glycerol gradient, and in vitro protein interaction analyses. To functionally characterize this complex, we developed an in vitro assay using two of the proteins present in the complex. Our results show that falcipain 2 and heme detoxification protein associate with each other to efficiently convert Hb to Hz. We also used this in vitro assay to elucidate the modes of action of chloroquine and artemisinin. Our results reveal that both chloroquine and artemisinin act during the heme polymerization step, and chloroquine also acts at the Hb degradation step. These results may have important implications in the development of previously undefined antimalarials