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The insect orders Megaloptera and Neuroptera are closely related members of the superorder Neuropterida, a relict lineage of holometabolous insects that also includes the Raphidoptera. Megaloptera, composed of the families Sialidae and Corydalidae (including subfamilies Chauliodinae and Corydalinae), has fully aquatic larvae that occur in a wide variety of lotic and lentic habitats, including temporary streams. In total, 2 of 17 families of Neuroptera have aquatic larvae: Nevrorthidae live in the benthos of fast-flowing streams and Sisyridae reside on freshwater sponges. A third family of Neuroptera, Osmylidae, contains some water-dependent species that reside under leaves and rocks along the margins of waterbodies. We recognize 328 extant, described species of Megaloptera (composed of 116 species of Chauliodinae, 131 species of Corydalinae, and 81 species of Sialidae) and 73 species of aquatic Neuroptera (composed of 12 species of Nevrorthidae and 61 species of Sisyridae). Additionally, we estimate that 45 species of Osmylidae are water-dependent, although the ecology of this group is poorly understood. Chauliodinae and Corydalidae are both found in the New World, the Oriental region, and South Africa, but are absent from Europe, the Middle East, Central Asia, tropical Africa, and boreal regions. Chauliodinae is quite speciose in Australia, whereas Corydalinae is absent. Sialidae is most speciose in temperate regions, and is absent from tropical Africa and portions of the Oriental region. Sisyridae and Osmylidae are nearly cosmopolitan, but the relict family Nevrorthidae is limited to Japan, the Mediterranean, and Australia. The discovery of many new species in recent years, particularly among Corydalidae in the Neotropics and China, suggests that our knowledge of aquatic neuropterid diversity is far from complete. Guest editors: E. V. Balian, C. Lévêque, H. Segers and K. Martens Freshwater Animal Diversity Assessment  相似文献   

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Cheng MC  Lin CH  Lin HJ  Yu YP  Wu SH 《Glycobiology》2004,14(2):147-155
Alpha-(2 --> 8)/alpha(2 --> 9) alternatively linked polysialic acid (PSA) can be identified by controlled hydrolysis followed by the analysis with capillary electrophoresis (CE). Due to the different stability of alpha(2 --> 8) and alpha(2 --> 9) linkages in acidic hydrolysis, oligosialic acids (OSAs) from the hydrolysis of alpha(2 --> 8)/alpha(2 --> 9) OSA/PSA could be classified into two groups in the CE profile. The group with an odd numerical degree of polymerization (DP) had two peaks in the CE profile, and the other group, with even number of DP, showed one peak. Each alternating alpha(2 --> 8)/alpha(2 --> 9) linked OSA contains two isomers: one starts with the alpha(2 --> 8) linkage from the nonreducing end and the other starts with the alpha(2 --> 9) linkage from the nonreducing end. Trimers and tetramers were isolated by using a Mono Q column with an HPLC system. The two trimer isomers are alpha(2 --> 8)/alpha(2 --> 9) and alpha(2 --> 9)/alpha(2 --> 8) linkages and only showed partial separation by CE. After lactonization, sialidase hydrolysis, and alkaline treatment, the two trimer isomers could be separated and identified by CE analysis, but only the alpha(2 --> 8)/alpha(2 --> 9) trimer could be converted to the dilactone in glacial acetic acid. The two tetramer isomers could be converted to four monolactones and three dilactones. These lactonized species could be identified on the basis of several principles in sialidase hydrolysis and lactonization. In conclusion, regioselectivity on the lactonization of oligosialic acids proceeds under several principles: (1) Lactonization takes place more easily in the alpha(2 --> 8) linkage than in the alpha(2 --> 9) linkage; (2) all of the positions of alpha(2 --> 8) linkages in alpha(2 --> 8)/alpha(2 --> 9) alternatively linked OSA can be lactonized regardless of external or internal carboxyl groups involved; and (3) for the site of alpha(2 --> 9) linkage, only internal carboxyl groups can be lactonized.  相似文献   

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The “Megalosaur” remains from Saint-Agnant (Charente-Maritime, France), reported as early as 1881 by Boissellier, are here described and figured for the first time. These bones, as well as a few additional specimens from the nearby locality of Soubise, belong in fact to an indeterminate sauropod. The stratigraphical position of these remains unambiguously indicates an infra-Cenomanian age. However, the presence in this area of continental deposits with Purbeckian and Wealden facies does not allow to decide between an earliest or late Early Cretaceous age.  相似文献   

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The large canid of Vallonnet cave belongs to Xenocyon lycaonoides. Its remains are similar to the Xenocyon from Untermassfeld in Germany. X. Lycaonoides, and evoluated form of the Xenocyon genus, is characteristic of the second half of the Lower Pleistocene. The genus Xenocyon may be the ancestor of both Cuon and Lycaon.  相似文献   

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Epidemiological studies corroborate a correlation between pesticide use and Parkinson's disease (PD). Thiocarbamate and dithiocarbamate pesticides are widely used and produce neurotoxicity in the peripheral nervous system. Recent evidence from rodent studies suggests that these compounds also cause dopaminergic (DAergic) dysfunction and altered protein processing, two hallmarks of PD. However, DAergic neurotoxicity has yet to be documented. We assessed DAergic dysfunction in Caenorhabditis elegans (C. elegans) to investigate the ability of thiocarbamate pesticides to induce DAergic neurodegeneration. Acute treatment with either S‐ethyl N,N‐dipropylthiocarbamate (EPTC), molinate, or a common reactive intermediate of dithiocarbamate and thiocarbamate metabolism, S‐methyl‐N,N‐diethylthiocarbamate (MeDETC), to gradual loss of DAergic cell morphology and structure over the course of 6 days in worms expressing green fluorescent protein (GFP) under a DAergic cell specific promoter. HPLC analysis revealed decreased DA content in the worms immediately following exposure to MeDETC, EPTC, and molinate. In addition, worms treated with the three test compounds showed a drastic loss of DAergic‐dependent behavior over a time course similar to changes in DAergic cell morphology. Alterations in the DAergic system were specific, as loss of cell structure and neurotransmitter content was not observed in cholinergic, glutamatergic, or GABAergic systems. Overall, our data suggest that thiocarbamate pesticides promote neurodegeneration and DAergic cell dysfunction in C. elegans, and may be an environmental risk factor for PD.  相似文献   

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A series of twelve novel diamminetetrakis(carboxylato)platinum(IV) and 18 novel bis(carboxylato)dichlorido(ethane‐1,2‐diamine)platinum(IV) complexes with mixed axial carboxylato ligands was synthesized and characterized by multinuclear 1H‐, 13C‐, 15N‐, and 195Pt‐NMR spectroscopy. Their cytotoxic potential was evaluated (by MTT assay) against three human cancer cell lines derived from ovarian teratocarcinoma (CH1/PA‐1), lung (A549), and colon carcinoma (SW480). In the cisplatin‐sensitive CH1/PA‐1 cancer cell line, diamminetetrakis(carboxylato)platinum(IV) complexes showed IC50 values in the low micromolar range, whereas, for the most lipophilic compounds of the bis(carboxylato)dichlorido(ethane‐1,2‐diamine)platinum(IV) series, IC50 values in the nanomolar range were found.  相似文献   

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The reaction between cimetidine in a methanolic solution of KOH and a dichloromethane solution of PPh3AuCl affords a new compound with formula [L-Au-PPh3] (I) (L = 2-(N-methyl-N′-cyano-N″-ethylguanidino)thiolate), the thiolato ligand resulting from cleavage of one of the thioether bonds of cimetidine. (I) has been characterized by elemental analysis, infrared, and 1H and 13C NMR spectroscopy. Single crystal x-ray structure determination shows that the gold atom is linearly coordinated by a phosphine ligand (Au-P 2.258(1) Å) and by an S atom (Au-S 2.282(1) Å) of the thiolato ligand. Crystal data: triclinic, space group P with a = 8.848(1), b = 11.343(3), c = 12.107(3)Å, = 87.63(1), β = 85.24(1), γ = 79.89(1)°, R = 0.024 for 3673 reflections with I > 3 δ (I).  相似文献   

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Chinese tallow (Triadica sebifera, also known as Sapium sebiferum) is an important oil seed crop in its native China but has become a noxious invasive species in USA. This review covers 601 publications since 1946. To date, grape (var. conferticarpa), chicken claw (var. laxiarpa), long claw, and mixed types are recognized within the species with 77 compounds isolated from various tissues. Some of the known 13 tetracyclic diterpenoids or phorbols showed pro-inflammatory and skin irritant activities or antibacterial and antiviral activities. In contrast, leaf extracts of T. sebifera showed analgesic and anti-inflammatory activities in animal models. Tallow leaves have been used to treated bacterial infections in birds and fish in China and also showed molluscicidal activities. Seed fats and oils have a long history of uses in China. The seed aril has been used to produce Chinese tallow cocoa butter equivalent since the late 1980s, but product quality and cost need improvement. The kernel oil showed promising potential for biodiesel production. In USA, the plantings were well developed before the mid-1900s since it introduced in 1772. The tree spread quickly in the southeastern USA due to its high fertility, fast growth and broad adaptability, lack of natural enemies, increasing habitat fragmentation, disturbance events like hurricanes, and selection and development of superior high-seed yield cultivars/clones. It is now considered as one of the worst invasive species in the area. Its conventional herbicide, biological, and mechanical control methods are costly, and either largely ineffective or not environmental friendly.  相似文献   

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Miscanthus and Saccharum are closely related perennial C4 grasses. Miscanthus has recently attracted interest as a non-food crop for energy and fibre production. However, molecular genetic tools for the selection of new Miscanthus genotypes and study of its genetic resources are limited. We have identified six chloroplast (plastid) marker loci,containing both microsatellites (cpSSRs) and single nucleotide polymorphisms (SNPs) and developed primers to amplify and sequence these regions. The primers were designed using the complete chloroplast genome sequence of sugarcane and were tested on a collection of 164 Miscanthus genotypes and 14 related species of the subfamily Panicoideae. The cpSSR markers were highly polymorphic, with the number of alleles ranging from 10 to 16 per locus. Within the six cpSSR marker loci, the hybrid M. ×giganteus exhibits virtually no cpDNA variation compared with its putative parents M. sinensis and M. sacchariflorus. These SNP markers enable the differentiation of most Miscanthus species and detect infraspecific variation suitable for defining cytoplasmic genepools of Miscanthus for breeding purposes.  相似文献   

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