Structural, biochemical, and inhibition studies of cell wall formation in the unicellular marine coccolithophorid alga Hymenomonas carterae

The wall in the coccolith-bearing stage of the life cycle of the marine coccolithophorid alga, Hymenomonas carterae, consists of several ultrastructurally distinct units: (1) columnar material, (2) glue , (3) crystalline vesicles , (4) 2-3 layers of scales, (5) coccoliths, and (6) coccolithonets. A technique based on the use of a nonionic detergent (Triton X-100) was developed to isolate the cell wall from coccolith-bearing cells. This cell wall was characterized with respect to its spatial arrangement, degradation, and the in vitro assembly of some of its components. The approach was to carefully describe the wall ultrastructure, partially solubilize and isolate the component parts, and biochemically characterize them. Treatment with 10 M LiCl and 10 mM EDTA dissociated the cell wall into soluble and insoluble fractions (SF and ISF). Cytochemical studies using ruthenium red and catonized ferritin as well as qualitative biochemical analysis (including EDTA extraction, colorimetric sugar determinations, pectinase digestion, and uronic acid assay) strongly suggested the presence of pectin-like acidic polysaccharides in the columnar material, glue , the periphery of scales, and the distal surface of the coccoliths. Such tests also indicated that the wall is held together by hydrogen bonds, hydrophobic links, and primarily ionic interactions. Acidic polysaccharides of the cell wall were isolated. These molecules possess sedimentation coefficients of 1.55, 1.82, and 4.25. Polyacrylamide gel electrophoresis patterns of the EDTA soluble fraction of coccoliths along with self-assembly characteristics and ultrastructural evidence indicated that the polyanionic carbohydrate molecule with a sedimentation coefficient of 1.82 is a part of the coccolith. This molecule demonstrated a crystalline lattice structure with center to center spacing of 60-65 (ANGSTROM) and appeared to be a proper candidate for subunits of the small Golgi product, the coccolithosomes, which participate in the formation of the calcareous coccolith rim;Cell wall regeneration and kinetics of wall formation were monitored by light and electron microscopy following wall removal. Protoplasts were released after enzymatic treatment with macerozyme and cellulase. Electron microscopic observations revealed that the entire cell wall had reappeared within about 24 hours after removal of the cells from the enzyme mixture. Cell wall formation was inhibited by coumarin (1,2-benzopyrone) and 2,6-dichlorobenzonitrile (DBN). In H. carterae, both compounds reversibly inhibit wall formation as well as cytokinesis. Coumarin affected protoplasts more drastically than DBN, although, in the presence of DBN, cytokinesis completely stopped while nuclear division was unaffected. In contrast, the antimitotic effect of coumarin stopped nuclear division

Marijuana and Patents: The Complicated Relationship between Patent Rights and the Federal Criminalization of Marijuana

Difficult questions arise in the context of marijuana-related inventions, patent procurement, and patent enforcement. These questions are a subset of the contradictions in the law of marijuana, where the federal government prohibits marijuana use and yet many of the states legalize, regulate, and tax it. This federal prohibition could discourage research into the health effects of marijuana and makes it difficult for marijuana-related innovations to satisfy statutory patentability requirements. It also renders enforcement of marijuana patents questionable, making marijuana businesses and patent owners vulnerable to nonpracticing patent entities, sometimes called patent trolls

Optimization of flapping-wing micro aircrafts based on the kinematic parameters using genetic algorithm method

In this paper the optimization of kinematics, which has great influence in performance of flapping foil propulsion, is investigated. The purpose of optimization is to design a flapping-wing micro aircraft with appropriate kinematics and aerodynamics features, making the micro aircraft suitable for transportation over large distance with minimum energy consumption. On the point of optimal design, the pitch amplitude, wing reduced frequency and phase difference between plunging and pitching are considered as given parameters and consumed energy, generated thrust by wings and lost power are computed using the 2D quasi-steady aerodynamic model and multi-objective genetic algorithm. Based on the thrust optimization, the increase in pitch amplitude reduces the power consumption. In this case the lost power increases and the maximum thrust coefficient is computed of 2.43. Based on the power optimization, the results show that the increase in pitch amplitude leads to power consumption increase. Additionally, the minimum lost power obtained in this case is 23% at pitch amplitude of 25°, wing reduced frequency of 0.42 and phase angle difference between plunging and pitching of 77°. Furthermore, the wing reduced frequency can be estimated using regression with respect to pitch amplitude, because reduced frequency variations with pitch amplitude is approximately a linear function

Haar basis method to solve some inverse problems for two-dimensional parabolic and hyperbolic equations

A numerical method consists of combining Haar basis method and Tikhonov regularization method. We apply the method to solve some inverse problems for twodimensional parabolic and hyperbolic equations using noisy data. In this paper, a stable numerical solution of these problems is presented. This method uses a sensor located at a point inside the body and measures the u(x; y; t) at a point x = a; 0 < a < 1. We also show that the rate of convergence of the method is as exponential. Numerical results show that a good estimation on the unknown functions of the inverse problems can be obtained within a couple of minutes CPU time at Pentium IV-2.53 GHz PC.Publisher's Versio

Superconducting properties of doped blue phosphorene: Effects of non-adiabatic approach

We study the effects of Kohn anomalies on the superconducting properties in electron- and hole-doped cases of monolayer blue phosphorene, considering both adiabatic and non-adiabatic phonon dispersions using first-principles calculations. We show that the topology of the Fermi surface is crucial for the formation of Kohn anomalies of doped blue phosphorene. By using the anisotropic Eliashberg formalism, we further carefully consider the temperature dependence of the non-adiabatic phonon dispersions. In cases of low hole densities, strong electron-phonon coupling leads to a maximum critical temperature of $T_c=97$ K for superconductivity. In electron-doped regimes, on the other hand, a maximum superconducting critical temperature of $T_c=38$ K is reached at a doping level that includes a Lifshitz transition point. Furthermore, our results indicate that the most prominent component of electron-phonon coupling arises from the coupling between an in-plane (out-of-plane) deformation and in-plane (out-of-plane) electronic states of the electron (hole) type doping.Comment: 14 pages, 6 figures; supplementary is available upon reques