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P. E. J. DALEY 《Zoological Journal of the Linnean Society》1992,105(4):353-375
Detailed anatomical study of the solute Girvanicystis batheri from the Girvan starfish bed (Ashgill) has enabled the oral partition, hydropore, gonopore and the possible opening of a branchial slit to be identified. The distal part of the alimentary tract and the stomach were located in the posterior part of the head. Structures preserved as steinkernen are interpreted as a brain and left cranial nerve. The gross anatomy of G. batheri supports the hypothesis that it was a suspension feeder. Girvanicystis batheri is characterized by large plates on the dorsal surface of the head, 20 rings of the feeding arm and a nodular median plate on the ventral surface of the head. A new species of Girvanicystis, G. casteri , is described from the Sholeshook limestone (Ashgill) of South Wales. Girvanicystis casteri is distinguished from G. batheri in that the former has narrower head, a longer feeding arm and a spine on the median plate of the ventral surface of the head. Girvanicystis batheri has characters in common with the cornute Ceratocystis perneri , namely large plates of the skeleton of the head, right and left marginal flanges, opposite dorsal fore tail plates and alternate ventral fore tail plates, which suggest that G. batheri may also be a stem chordate. 相似文献
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A new species of murid rodent belonging to the ‘shrew‐mouse’ genus Archboldomys is described from Kalinga Province in northern Luzon Island, Philippines. This is the third known species of this endemic Philippine genus. The new species is distinguished from its congeners by consistent differences in adult body size, limb and tail proportions, coloration and texture of the pelage, and cranial and dental dimensions. Members of this genus are small, diurnal rodents that feed mainly on earthworms and other soil invertebrates, and occur in high elevation montane and mossy forests habitats. The new species may be restricted to the northern portion of the Cordillera Central, whereas its congeners occur in widely separated highland areas in other portions of Luzon. The fact that similar distribution patterns are seen for members of other endemic genera suggests that habitat vicariance may have shaped much of the diversification of murid rodents on Luzon. 相似文献
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Andrea Bennici 《Theoretical biology forum》2005,98(1):39-46
After evidencing the great importance of plants for animals and humans in consequence of the photosynthesis, several considerations on plant evolution are made. One of the peculiar characteristics of the plant is the sessile property, due especially to the cell wall. This factor, principally, strengthened by the photosynthetic process, determined the particular developmental pattern of the plant, which is characterized by the continuous formation of new organs. The plant immobility, although negative for its survival, has been, in great part, overcome by the acquisition of the capacity of adaptation (plasticity) to the environmental stresses and changes, and the establishment of more adapted genotypes. This capacity to react to the external signals induced Trewavas to speak of "plant intelligence". The plant movement incapacity and the evolution of the sexual reproduction system were strongly correlated. In this context, the evolution of the flower in the Angiosperms has been particularly important to allow the male gamete to fertilize the immobile female gamete. Moreover, the formation of fruit and seed greatly improved the dispersal and conservation of the progeny in the environment. With the flower, mechanisms to favour the outcrossing among different individuals appeared, which are essential to increase the genetic variability and, then, the plant evolution itself. Although the Angiosperms seem highly evolved, the plant evolution is not surely finished, because many reported morpho-physiological processes may be still considered susceptible of further improvement. In the last years the relationships among humans, plants and environment are becoming closer and closer. This is due to the use of the DNA recombinant techniques with the aim to modify artificially plant characters. Therefore, the risk of a plant evolution strongly directed towards practical or commercial objectives, or "an artificial evolution", may be hypothesized. 相似文献
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Franco Andreone Luca Bartolozzi Giovanni Boano Ferdinando Boero Marco?A. Bologna Mauro Bon Nicola Bressi Massimo Capula Achille Casale Maurizio Casiraghi Giorgio Chiozzi Massimo Delfino Giuliano Doria Antonio Durante Marco Ferrari Spartaco Gippoliti Michele Lanzinger Leonardo Latella Nicola Maio Carla Marangoni Stefano Mazzotti Alessandro Minelli Giuseppe Muscio Paola Nicolosi Telmo Pievani Edoardo Razzetti Giorgio Sabella Marco Valle Vincenzo Vomero Alberto Zilli 《ZooKeys》2014,(456):139-146
The Italian natural history museums are facing a critical situation, due to the progressive loss of scientific relevance, decreasing economic investments, and scarcity of personnel. This is extremely alarming, especially for ensuring the long-term preservation of the precious collections they host. Moreover, a commitment in fieldwork to increase scientific collections and concurrent taxonomic research are rarely considered priorities, while most of the activities are addressed to public events with political payoffs, such as exhibits, didactic meetings, expositions, and talks. This is possibly due to the absence of a national museum that would have better steered research activities and overall concepts for collection management. We here propose that Italian natural history museums collaborate to instate a “metamuseum”, by establishing a reciprocal interaction network aimed at sharing budgetary and technical resources, which would assure better coordination of common long-term goals and scientific activities. 相似文献
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U. Bässler 《Biological cybernetics》1976,24(1):47-49
In inactive stick insects ramp-wise stretching of the femoral chordotonal organ excites the slow extensor tibiae motoneuron. In active animals the same stimulus decreases the firing rate of this motoneuron. The time-course of increased and decreased activity of this motoneuron can be seen with triangular stimulation.Supported by the Deutsche Forschungsgemeinschaft 相似文献
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Carex subcapitata X.F.Jin,C.Z.Zheng&B.Y.Ding,a new species of Cyperaceae from Zhejiang,China,is described and illustrated.It is related to C.grandiligulata K kenth.in having lateral culms,narrow leaves,spikelets androgynous,1-2arising from each node,but d 相似文献
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Abstract Rhododendron liboense,a new species of the Ericaceae from Libo County,Guizhou,Chi-na,is described and illustrated.This species is related to R.huianum Fang in having inflorescence terminal,corolla pink,broadly campanulate,ovary densely white glan 相似文献
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Peliosanthes pachystachya W.H.Chen&Y.M.Shui,a new species of Liliaceae from L chun County,SE Yunnan,is described and illustrated.The new species is similar to P.sinica Wang&Tang in the stolon with internodes ca.18cm long,but different by leaves9-13-nerved 相似文献
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The endogean carabid Typhlocharis zaballosi n. sp., belonging to the T. gomezi group, is described and illustrated. The work provides diagnostic characters, in particular the structure of male and female genitalia, affinities to putative relatives and some remarks on its ecology and distribution. A key for the identification of all known species of the T. gomezi species group are provided. Some remarks on the external microsculpture of the last abdominal sternum “belt” of T. carinata Serrano & Aguiar 2006, T. quarta Pérez-González & Zaballos 2013, T. crespoi Serrano & Aguiar 2007 and T. zaballosi n. sp. are given. An overall revision of the presence/absence of this structure in the genus is provided and its taxonomic relevance is also discussed. 相似文献
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Arenaria dawuensis A. J. Li&Q. Ban,a new species of the Caryophyllaceae from Dawu County,Sichuan,China,is described and illustrated. It is related to A. fimbriata(E. Pritz. )Mattf. in having fusiform roots,cymose inflorescence,two linear styles,but differ 相似文献
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Igor M. Sokolov 《ZooKeys》2013,(352):51-92
One new genus and eight new species of anilline carabids are described from southern Mexico. The new genus, Zapotecanillus
gen. n., is established for Z. oaxacanus (type species) sp. n., Z. nanus
sp. n., Z. iviei
sp. n., Z. ixtlanus
sp. n., Z. montanus
sp. n., and Z. kavanaughi
sp. n. from the Sierra Madre de Oaxaca, Z. pecki
sp. n. from the Sierra Madre del Sur, and Z. longinoi
sp. n. from the Sierra Madre de Chiapas. A taxonomic key for all described species of Zapotecanillus and a cladistic analysis, based on morphological data, are provided. Morphological, behavioral and biogeographical aspects of the speciation in the genus obtained from the resulting cladogram are discussed. 相似文献
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McPherson T 《Filaria journal》2003,2(1):1-5
BACKGROUND: Hygiene and skin care are effective and important interventions in the management of lymphoedema secondary to lymphatic filariasis. We analyzed the impact on the quality of life that education and introduction of a designated nurse had on lymphoedema patients in a community that was endemic for lymphatic filariasis. METHODS: Patients' life quality was assessed using a Dermatology Life Quality Index (DLQI) questionnaire. At the same time they received education on appropriate hygiene, skin care techniques and simple exercises that encourage lymph drainage. A designated nurse was provided with educational materials and treatments. The DLQI life quality measure was repeated one year later. RESULTS: The DLQI improved for all patients and reported acute attacks were reduced. A paired t-test showed the improvement in DLQI to be highly significant (P = < 0.0001). CONCLUSIONS: A nurse-led service combined with patient education in communities endemic for lymphatic filariasis is an effective intervention in improving the quality of life of patients with lymphoedema. 相似文献
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Wm. Wayt Thomas 《Brittonia》1984,36(3):244-247
A new species,Simaba cavalcantei, is described and illustrated. It is considered to be intermediate between sectionsGrandiflorae andFloribundae and is distinguished from potentially sympatric species in a key to the species occurring north of the Amazon River. 相似文献
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G.R. Julião M.E.C. Amaral G.W. Fernandes E.G. Oliveira 《Biodiversity and Conservation》2004,13(11):2055-2066
The aim of this study was to (i) measure differences in species richness between edge habitats versus interior habitats, or more precisely the edge effect, and (ii) test the species–area relationship for gall-forming insects in natural forest patches in a Brazilian floodplain (Pantanal of Mato Grosso do Sul). These patches are regionally known as capões, basically composed of woody vegetation. Twenty-seven patches were surveyed. In each patch two transects were conducted for gall sampling. One transect encircled the patches while the other was conducted in the interior of the patch, totaling 54h of sampling. Host plant and galling insect species composition differed quite characteristically between the edge and the interior of patches, but galling insect richness did not. When insect gall richness was expressed as the ratio between insect gall and host plant richness (gall per plant ratio), a weak species–area relationship was found. Our results suggest that the number of galling insects per individual plant is not affected by the size of the patch. Despite these results, the natural forest patches found in this region seem well suited for long-term studies addressing species–area relationships. With regard to herbivorous insects, these studies should be combined with research on host plant dynamics during flooding and dry seasons. 相似文献
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Hepatitis C virus (HCV) is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma. There is no vaccine available for HCV, and almost half of patients cannot be cured using standard combination therapy. Thus, new anti-HCV strategies and drugs are urgently needed. Here, the gene encoding a new α-helical peptide, Hp1090, was screened from the venomous gland cDNA library of the scorpion Heterometrus petersii. Structural analysis showed that Hp1090 is an amphipathic α-helical peptide. In vitro HCV RNA inhibitory assays indicated that Hp1090 peptide inhibited HCV infection with an IC50 of 7.62 μg/ml (5.0 μM), whereas Hp1035 peptide, showing high homology to Hp1090, exhibited no anti-HCV activity. Hp1090 acted as a viricide against HCV particles in vitro and prevented the initiation of HCV infection. Furthermore, this peptide interacted with HCV particles directly and rapidly permeabilized phospholipid membranes. Collectively, it seems that Hp1090 is virocidal for HCV in vitro, directly interacting with the viral membrane and decreasing the virus infectivity. These results suggest that Hp1090 could be considered an anti-HCV lead compound with virocidal mechanism that offers a potential therapeutic approach to HCV infection. Our work opens a new avenue for antiviral drug discovery in natural scorpion venom. 相似文献
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Glover AG Källström B Smith CR Dahlgren TG 《Proceedings. Biological sciences / The Royal Society》2005,272(1581):2587-2592
We describe a new species of the remarkable whalebone-eating siboglinid worm genus, Osedax, from a whale carcass in the shallow north Atlantic, west of Sweden. Previously only recorded from deep-sea (1500-3000m) whale-falls in the northeast Pacific, this is the first species of Osedax known from a shelf-depth whale-fall, and the first from the Atlantic Ocean. The new species, Osedax mucofloris sp. n. is abundant on the bones of an experimentally implanted Minke whale carcass (Balaenoptera acutorostrata) at 125m depth in the shallow North Sea. O. mucofloris can be cultured on bones maintained in aquaria. The presence of O. mucofloris in the shallow North Sea and northeast Pacific suggests global distribution on whale-falls for the Osedax clade. Molecular evidence from mitochondrial cytochrome oxidase 1 (CO1) and 18S rRNA sequences suggests that O. mucofloris has high dispersal rates, and provides support for the idea of whale-falls acting as 'stepping-stones' for the global dispersal of siboglinid annelids over ecological and evolutionary time. 相似文献
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Karnyothrips cyathomorphus
sp. n. (Phlaeothripidae: Phlaeothripinae) is described as a new apterous species in the genus Karnyothrips Watson 1923, and it represents the fourth species of the genus to be recorded from China. A key to the Chinese species is given. 相似文献