6 resultados para New left

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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A new species of Allocreadium, Allocreadium danjiangensis n. sp., is described from the intestine of several species of freshwater fish, including Abbottina rivularis (Basilewsky, 1855), Sarcocheilichthys nigripinnis nigripinns (Gunther, 1873), Gnathopogon argentatus (Sauvage et Dabry 1874), Opsariichthys uncirostris bidens (Gunther, 1873), and Erythroculter mongolicus mongolicus (Basilewsky, 1855) (Cyprinidae) from the Danjiangkou Reservoir in central China. The main morphological characters of the new species are as follows: vitelline follicles numerous, extending from the level of acetabulum to posterior extremity, distributed over both sides around the ceca; cirrus sac relatively large, developed, lying obliquely anterior to the acetabulum, extending from the level of the intestinal bifurcation to the central level of acetabulum, and overlapping left or right cecal; and ovary much smaller than testes, generally close to or even overlapping the anterior border of anterior testis. Observation by scanning electron microscopy shows only 2 kinds of tegumental formations, i.e., papillae and tubercles, instead of 3 types of tegumental formations, i.e., papillae, bosses, and minute sensor receptors observed on other species of the Allocreadiidae. The tegumental striations of the present species vary on the different parts of the body. In addition, a new structure, identified as the "groove" with a tonguelike tubercle, was observed on the inner wall of acetabulum.

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Two little-known nematode species of the genus Spinitectus Fourment, 1883, S. petrowi Belous, 1965 (prevalence 25%, intensity 1-8) and S. gigi Fujita, 1927 (prevalence 10%, intensity 2-3), were collected from the gastrointestinal tract of the yellow catfish, Pelteobagrus fulvidraco (Richardson), from Liangzihu Lake, Hubei Province, central China, in September of 2002. The light and scanning electron microscopical examination of this material, supplemented by a few museum specimens of S. gigi collected from the catfish Clarias fuscus (Lacepede) in southern China, made it possible to study in detail the morphology of these parasite species and to redescribe them. The first species, whose correct name is S. petrowi Belous, 1965, exhibits some morphological features (e.g., unusually short vestibule, shape of pseudolabia and of the left spicule) not found in most other congeners; a unique feature is the presence of peculiar pairs of transversely oriented peg-like cuticular spines with rounded ends on the ventral surface of the female tail. Spinitectus gigi was found to have 28-31 cuticular spines in the first ring, relatively long distances between the 2nd-7th rings of spines, and anterior rings divided into 2 sectors; the excretory pore is located at the level of the 4th ring of cuticular spines; males posses 4 pairs of preanal- and 6 pairs of postanal caudal papillae and a pair of small phasmids. Spinitectus bagri Wang, Wu et Yu, 1993 and S. wulingensis Yu et Wang, 1997 are considered junior synonyms of S. petrowi, whereas S. clariasi Ky, 1971, S. ophicephali Ky, 1971 and S. yuanjiangensis Wang, Wit et Yu, 1997 are regarded to be junior synonyms of S. gigi. Spinitectus petrowi was not previously reported from China.

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This work investigated analytically the band structure of photonic crystals (PCs) with alternate layers of left and right-handed materials in one-dimension. It was found that, under certain conditions, new peculiar band structures not seen in all right-handed material PCs appeared. We transformed the analytic dispersion relation into two cosine terms, and obtained an interesting band structure using the new form of dispersion equation. Conditions for obtaining such peculiar band structure were given. (c) 2005 Elsevier Ltd. All rights reserved.

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Microtransfer molding (muTM) is a kind of soft lithography for polymer micropatterning. In muTM, a liquid prepolymer(or concentrated polymer solution) is applied to the patterned surface of an elastomeric mold and then brought into the contact with a substrate. After prepolymer is cured thermally or by UV light, the elastomeric mold is peeled away. A pattern is left on the surface of the substrate. In this study, similar to300 nm lines and three-dimensional patterns of PMMA and epoxy on planar and/or non-planar substrates are realized.

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Six species belonging to two families of Hemichordata have previously been recorded in Chinese waters. This paper records the discovery and description of a new species of the genus Glandiceps found in Jiaozhou Bay, Qingdao, Shandong Province, named Glandiceps qingdaoensis. The new species has a long proboscis with dorsal and ventral grooves, a stomochord with a long vermiform process, a proboscis cavity with a dorsal median, right and left glomeruli, right and left glomeruli very large and encircling the stomochord, a proboscis skeleton in the cavity extends into the median posterior of the collar, a well-developed dorsal ventral muscular septum in the proboscis cavity dividing the cavity completely into two separate parts. The collar cord is without giant nerve roots. The trunk with four distinct regions that can be recognized externally: branchial-genital region, genital region, hepatic region, and intestinal region. The dorsal pharynx is large and the gill pores are small. The tongue bars are encircled by vesicles, and the first gonad commences at the level of the second or third gill slit.

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We studied the morphology of three rare haptorid ciliates, using live observation and silver impregnation: Apertospathula verruculifera n. sp., Longispatha elegans n. gen., n. sp., and Rhinothrix porculus (Penard, 1922) n. gen., n. comb. Simple ethanol fixation (50-70%, v/v) is recommended to reveal the ciliary pattern of "difficult" ciliates, such as R. porculus, by protargol impregnation. The three genera investigated have a distinct feature in common, viz., a lasso-shaped oral bulge and circumoral kinety, where the right half is slightly to distinctly longer than the left and the circumoral kinety is open ventrally. Thus, they are united in a new spathidiid family, the Apertospathulidae n. fam., which probably evolved from a Bryophyllum-like ancestor by partial reduction of the oral bulge and circumoral kinety. Apertospathula verruculifera has a wart-like process, the palpus dorsalis, at the anterior end of the dorsal brush. The right branch of the circumoral kinety is only slightly longer than the left one. Longispatha elegans has a straight oral bulge and circumoral kinety, the right branch of which extends to the posterior end of the body while the left branch ends in the anterior third of the body. Rhinothrix porculus, a curious ciliate with a snout-like dorsal elongation of the oral bulge, the palpus oralis, has a highly characteristic ciliary pattern: the oral pattern is as in Longispatha, but the bulge and circumoral kinety extend spirally to the posterior end of the body while the somatic kinetics course meridionally. This is achieved by inserting some shortened kinetics in the curves of the oral bulge.