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1.
A new moss species, Didymodon caboverdeanus J.A.Jiménez & M.J.Cano, from the Cape Verde archipelago is described and illustrated. It differs most saliently from other species of Didymodon Hedw. by the combination of the lanceolate leaves with obtuse and often cucullate leaf apices, recurved margins, the yellowish colour in KOH, costa ending below the apex, laminal cells with low papillae over the transverse walls, which reach the two adjacent cells, the presence of gemmae in the leaf axils, and a short and straight peristome.  相似文献   

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Four new species of Pelycidion P. Fischer in de Folin & Périer, 1873 are described from temperate Australia on the basis of shells: Pelycidion eukyrtos n. sp. from central Victoria, P. caperovertex n. sp. and P. kratycylindros n. sp. from southwest Australia and P. meizonarchei n. sp. from southern Tasmania. Two additional congeneric specimens are known from the region and discussed; one of these, from the Tasman Sea, is illustrated and likely represents a new species. Collectively, these specimens are the first members of the genus and family to be recorded from temperate Australia. A brief overview of the described species of Pelycidion is given.  相似文献   

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Bioassay-guided fractionation of the CHCl3 soluble portion of the roots of Panax japonicus C. A. Meyer var. major afforded an active fraction with inhibitory activity against baker’s yeast α-glucosidase with an IC50 value 1.02 mg/mL. Furthermore, the active fraction isolated contained three previously unreported polyacetylenes, designated panaxjapynes A–C, together with 11 other compounds, including four polyacetylenes, five phenolic compounds, a sesquiterpenoid, and a sterol glucoside. The structures of the compounds were elucidated by spectroscopic and chemical methods. Compared with the control acarbose (IC50 677.97 μM), six compounds were shown to be more potent α-glucosidase inhibitors with IC50 values in the range 22.21–217.68 μM.  相似文献   

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One infection method widely used by many gram-negative bacteria involves a protein nanomachine called the Type Three Secretion System (T3SS). The T3SS enables the transportation of bacterial “toxins” via a proteinaceous channel that directly links the cytosol of the bacteria and host cell. The channel from the bacteria is completed by a translocon pore formed by two proteins named the major and minor translocators. Prior to pore formation, the translocator proteins are bound to a small chaperone within the bacterial cytoplasm. This interaction is crucial to effective secretion. Here we investigated the specificity of the binding interfaces of the translocator–chaperone complexes from Pseudomonas aeruginosa via the selection of peptide and protein libraries based on its chaperone PcrH. Five libraries encompassing PcrH’s N-terminal and central α-helices were panned, using ribosome display, against both the major (PopB) and minor (PopD) translocator. Both translocators were shown to significantly enrich a similar pattern of WT and non-WT sequences from the libraries. This highlighted key similarities/differences between the interactions of the major and minor translocators with their chaperone. Moreover, as the enriched non-WT sequences were specific to each translocator, it would suggest that PcrH can be adapted to bind each translocator individually. The ability to evolve such proteins indicates that these molecules may provide promising anti-bacterial candidates.  相似文献   

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Introduction. Over the last years we have been engaged in studies of the South American Pottiaceae. Among the bryophyte specimens collected by us in central and northern Peru, some samples of a puzzling Pottiaceae were found. In this paper, we present our arguments for recognising these plants as a new species and its inclusion in Erythrophyllopsis Broth.

Key Results. It differs most saliently from other species of Erythrophyllopsis by the combination of its oblong-ovate to ovate-lanceolate leaves, with usually fragile apex, leaf margins papillose-crenulate from apex to lower third, sometimes erose or crenate, lamina unistratose, occasionally bistratose in patches, costa broad, usually ending below the apex, without dorsal stereids near the apex where they are replaced by cells similar to those of the lamina, and short and straight peristome teeth.

Conclusions. A new moss species, Erythrophyllopsis perlaticosta M.J.Cano & J.A.Jiménez, is described and illustrated from the Andean highlands in central and northern Peru. A revised identification key for the species of Erythrophyllopsis is also provided. This species grows in crevices or fissures of calcareous rocks or banks between 3050 and 4700?m. The principal distinctive characters that separate it from the nearest species of Erythrophyllopsis and related genera such as Bryoerythrophyllum P.C.Chen and Mironia R.H.Zander are discussed.  相似文献   


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Direct evidence of agriculture in Early Neolithic Portugal is almost non-existent, so there are very disparate estimates of the role played by agriculture during the period. Recent excavations at Cortiçóis, a newly discovered Early Neolithic site in central Portugal, revealed the first recognizable sickle implements and therefore relevant artefactual evidence of agricultural practices. These are typologically similar to Andalusian and Valencian sickles, reflecting a common technological tradition in southern Iberia during the period (c. 5600–4000 cal BC). Based on this fact, we summarize all available evidence for early agriculture in central Portugal and compare it with the Andalusian and Valencian records in order to tentatively present a model to be tested locally in future research.  相似文献   

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Résumé LeChrysosporium keratinophilum var.denticolum diffère du type par ses spores caténées et son habitat. La formation des aleuriospores a été particulièrement étudiée.
Summary Chrysosporium keratinophilum var.denticolum is distinct from the type by its catenate spores and its substrate. The genesis of the aleuriospores has been specially studied.
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Pristionchus fissidentatus n. sp., isolated from soil in Nepal, and P. elegans n. sp., isolated from Phelotrupes auratus (Coleoptera: Scarabaeidae) in Japan, are described. The two new species are recognized as basal within the genus and thus occupy an important position for macroevolutionary studies that center on the model P. pacificus. Pristionchus fissidentatus n. sp. is distinguished by its unique stegostomatal morphology: in the stenostomatous form, the right subventral ridge has three prominent cusps and the left subventral sector has, in addition to a plate with two cusps, a prominent denticle slightly left of ventral; in the eurystomatous form, the right subventral stegostomatal sector shows both a tooth and a ridge with several cusps. Diagnostic of P. elegans n. sp. is the structure of the stenostomatous cheilostom, which bulges medially and is underlain by a large vacuolated ring. No eurystomatous form has been observed in P. elegans n. sp. Reproductive modes of P. fissidentatus n. sp. and P. elegans n. sp. are hermaphroditic and gonochoristic, respectively. The additional isolation of P. fissidentatus n. sp. from soil and two species of scarab beetle on La Réunion Island in the Indian Ocean suggests a broad geographic range for this species.  相似文献   

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The present paper gives the results of the anthropological study of the human remains from the artificial cave of São Pedro do Estoril II (2300–2500 B.C.). These chalcolithic remains were fragmentary and incomplete, which made their analysis difficult.  相似文献   

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The ultrastructure of the mature spore in four Japanese species of the acrocarpous moss genus Ptychomitrium is presented. In all species the spores have a similar pattern: there is no recognisable aperture nor sporoderm polarity, exine and perine are poorly developed, cytoplasm only occasionally shows polarity, and plastids have a well developed inner membrane system. The presence of frequent intine protrusions is a remarkable feature of this genus. A multilaminar structure of the exine, already observed in Grimmia, occurs also in these species although here it is less pronounced. The significance of these features is discussed within these species, as well as in comparison to other taxa, especially the genus Grimmia.  相似文献   

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Abstract

Pictolejeunea levis, a new species of Lejeuneaceae found in N.E. Cuba, is described and illustrated. The species stands out within Pictolejeunea on account of its smooth leaf cells and the presence of ocelli on dorsal and ventral epidermal cells of the stem. Differences between this and the other four known species in the genus are discussed.  相似文献   

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A new species of Orthotrichum, O. dentatum T.Kiebacher & Lüth, is described from the European Alps. The new species belongs to the subgenus Pulchella (Schimp.) Vitt, section Diaphana Vent. Orthotrichum dentatum is similar to O. schimperi Hammar but differs from the latter in that it features a hairy calyptra, denticulate to dentate leaf apices and strongly keeled leaves. Orthotrichum dentatum grows as an epiphyte on a variety of deciduous trees. So far, the new species has only been found in Italy and Switzerland.  相似文献   

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The Caribbean island of Grenada furnishes the popular aphrodisiac drug Bois Bandé, which consists of the stem bark and the roots of Chione venosa (sw.) URBAN var. venosa (Rubiaceae), a native tree growing in the islands' rain forest. The phytochemical investigation of dichloromethane and methanolic-aqueous extracts of the bark and the roots yielded three acetophenone derivatives described for the first time in plants - ortho-hydroxy-acetophenone-azine (1), acetophenone-2-O-[beta-D-apiofuranosyl-(1'-->6')-O-beta-D-glucopyranoside] (2) and acetophenone-2-O-beta-D-glucopyranoside (3) - along with five known compounds, alpha-morroniside (4), sweroside (5), diderroside (6), daucosterol (7) and beta-sitosterol (8). Their structures were elucidated by 1D and 2D NMR analysis, UV-Vis and ESI-MS.  相似文献   

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