Varying parameterization of an ellipsoidal thin shell with FEM-based implementation

This article describes an algorithm developed for the finite element analysis of the stressstrain state of a shell that takes the shape of a triaxial ellipsoid with varying parameterization of its mid-surface. A quadrangular fragment of the shell mid-surface with nodal unknowns in the form of displacements and their first derivatives along the curvilinear coordinates was used as the discretization element.When approximating the displacements through the nodal values, two variants were considered. In the first variant, the known approximating functions were applied to each component of the displacement vector of the internal point of the finite element through the nodal values of the same component. In the second variant, the approximating expressions were used directly for the expression of the displacement vector of the internal point of the finite element through the vector unknowns of the nodal points. After the coordinate transformations, each component of the displacement vector of the internal point of the finite element was expressed through the nodal values of all components of the nodal unknowns. The approximating expressions of the required displacements of the internal point of the finite element also include the parameters of the curvilinear coordinate system used in the calculations.The high efficiency of the developed algorithm was confirmed by the results of the numerical experiments

Meroterpenoids from the Alga-Derived Fungi <i>Penicillium thomii</i> Maire and <i>Penicillium lividum</i> Westling

Ten new austalide meroterpenoids (<b>1</b>–<b>10</b>) were isolated from the alga-derived fungi <i>Penicillium thomii</i> KMM 4645 and <i>Penicillium lividum</i> KMM 4663. Their structures were elucidated by extensive spectroscopic analysis and by comparison with related known compounds. The absolute configurations of some of the metabolites were assigned by the modified Mosher’s method and CD data. Compounds <b>1</b>, <b>2</b>, <b>8</b>, and <b>9</b> were able to inhibit AP-1-dependent transcriptional activity in JB6 Cl41 cell lines at noncytotoxic concentrations. Austalides <b>1</b>–<b>5</b>, <b>8</b>, and <b>9</b> exhibited significant inhibitory activity against <i>endo</i>-1,3-β-d-glucanase from a crystalline stalk of the marine mollusk <i>Pseudocardium sachalinensis</i>

Late Ordovician trilobites from the Taimyr Peninsula, Arctic Russia

Ordovician trilobites from the important sequences of the Taimyr Peninsula, Arctic Russia have been poorly studied since the work by Balashova (1959, 1960). Newly collected and well-preserved specimens from Late Ordovician sections, along with the original collections of Balashova, form the basis of a reappraisal of 56 Upper Ordovician (Sandbian-Katian) trilobites. New species include Bronteopsis tenuirhachis, Dionide trigintasegmentata, Failleana superba, Pararemopleurides ornatissimus, Raymondella plastron, Robergia subtilis and R. nikolaiseni. Probable new species include: Stenopareia sp. aff. S. glaber, and Stygina sp. aff. S. latifrons. A new subgenus Bilobaspis of the monorakine genus Evenkaspis, and a new species, Evenkaspis (Bilobaspis) mirabilis, are proposed. Thoracic segments and pygidium are correctly associated for the first time with cephala of the hitherto poorly understood Taimyraspis. The genera Effnaspis and Yumenaspis are likely junior synonyms of Taimyraspis. A placement within the Ityophoridae is suggested for Taimyraspis, together with the closely related genera Ityophorus and Frognaspis. Comparison of Goldillaenoides taimyricus with Failleana suggests that these are also closely related. A provisional placement of the former in the Styginidae is adopted. Bronteopsis nannus Balashova could be a juvenile B. tenuirhachis, and is regarded as a nomen dubium. The genus Ceratevenkaspis dominates among the monorakines on Taimyr, while Monorakos itself has not been collected. Robergia nikolaiseni has a narrow cranidial border, which is also present in the type species of Robergia. Two biofacies are identified in the current collections. The first, the raphiophorid association, is widespread around low latitude Ordovician palaeocontinents, identifying marginal shelf sites; the association is not critical in defining palaeocontinents themselves. Inner shelf faunas of the monorakine-cheirurid-illaenid association have taxa that comprise a distinctive group with a strong link between Taimyr and the Ordovician Siberian craton. The trilobites described herein support reconstructions showing Taimyr peripheral to the Siberian craton during the Ordovician.