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Many achnanthoid diatoms were transferred from Achnanthes or Achnanthidium to new genera based on characteristics observed via scanning electron microscopy (SEM). In this study, we isolated and cultured two Korean freshwater achnanthoid diatoms (Bacillariophyceae), studied their morphological characteristics using SEM, and assessed their molecular characteristics by analysing the nuclear small subunit (SSU) and ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) genes. We emended the description of Lemnicola hungarica with regard to the spindly pore opening of the hymen and the internally convex occlusions of elongated pores on the mantle. In addition, we demonstrated that the valves of L. hungarica are occasionally biseriate to uniseriate towards the valve edge. A morphological comparison of Lemnicola strains and species showed that biseriate rows of areolae are no longer an essential characteristic for allocation to Lemnicola. Based on the SEM and molecular analysis results, we also established a new, small-celled monoraphid species, Lemnicola uniseriata sp. nov., which has elongated areolae occluded by radiately structured hymenes and an elliptic valve shape. The uniseriate areolae of L. uniseriata showed that Lemnicola includes both uniseriate and biseriate striae. Additionally, the results of SSU and rbcL sequence analyses provided strong evidence to support the recognition of L. uniseriata as a new species. [ABSTRACT FROM AUTHOR]

A new marine diatom species, Auricula weizhouensis sp. nov., was isolated from Weizhou Island, Guangxi, China, and the morphology was examined in detail. The frustule was symmetrical and quadrate, with four rounded angles. The valve was longitudinally reniform. The vegetative cells of A. weizhouensis were 28.9–35.0 μm in length and 22.2–28.9 μm in width. The mature cingulum was composed of five to six open bands. A large plate-like chloroplast was observed on the ventral side of the girdle. There were 5–7 poroids per 1 μm in a row along the median line. The number of radiate and biforked striae was 15–19 per 10 μm on the ventral margin and 21–31 per 10 μm on the dorsal margin. Striae were biseriate with two rows of areolae (12–14 areolae per 1 μm). Both sides of the double-sigmoid raphe canal had a longitudinal costa. Approximately 21–31 fibulae per 10 μm were arrayed in a row on each longitudinal costa. More importantly, A. weizhouensis and Auricula densestriata could be distinguished from other Auricula species by their characteristic concave ventral margin, and the ventral margin of A. weizhouensis was approximately straight in the middle, whereas that of A. densestriata was inflected. In addition, molecular data from partial SSU rDNA sequences showed that A. weizhouensis (strain WZ-1704-E8) belonged to the genus Auricula, with Auricula complexa (KX120684) as the nearest neighbour (4.58% p-distance). Therefore, both morphological and phylogenetic analyses supported A. weizhouensis as a new species. [ABSTRACT FROM AUTHOR]

Most of the existing digital fingerprint algorithms for vector maps are symmetric fingerprint algorithms, and merchants may frame a legitimate buyer. An asymmetric fingerprinting protocol utilizing homomorphic encryption is proposed. First, the buyer encrypts his fingerprint. Then, this encrypted fingerprint and the merchant’s fingerprint are embedded into an encrypted vector map by the merchant. Finally, the encrypted data with the fingerprints of both parties is distributed to buyers. The buyer can use his private key to decrypt the encrypted data and get the Non-encrypted data with the fingerprints. In this way, merchants can track illegal users without the buyer’s fingerprint. Experimental results show that after various attacks, fingerprints can still be detected correctly. [ABSTRACT FROM AUTHOR]