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1.
Combes C. and Nassi H. 1977. Metacercarial dispersion and intracellular parasitism in a strigeid trematode. International Journal for Parasitology7: 501–503. The life cycle of Apatemon graciliformis Szidat, 1928 (Trematoda, Strigeidae), a parasite of Biorrphalaria glabrata in Guadeloupe, involves a novel mode of transmission, experimentally demonstrated, between the second intermediate host and the definitive host. The furcocercariae penetrate gravid females of the ovoviviparous fish, Poecilia reticulata, and develop into metacercariae in vitelline vesicles of the embryos where they encyst a short time before parturition. The young guppies are born infected with 1–3 metacercariae. It is considered that young infected fish are more prone to predation by the definitive host, thereby increasing the probability of the cycle being completed. Domestic ducks have been experimentally infected with these metacercariae. If cercariae penetrate non-gravid P. reticulata, they enter the oocytes; this represents a phase of intracellular parasitism. 相似文献
2.
Summary Papain was able to catalyze the one-step synthesis of Gly-Gly-PheNH2, from N-unprotected amino acid derivatives. Maximum synthetic activity was obtained for a pH value of 6.5 and for a ]PheNH2]/[Gly-GlyOEt] ratio of 6. The presence of an organic cosolvent, such as ethylene glycol, influenced the synthetic activity. Synthetic yield was higher than 65% for a 12.5 M cosolvent concentration. 相似文献
3.
Alexis Dereeper Romain Guyot Christine Tranchant-Dubreuil François Anthony Xavier Argout Fabien de Bellis Marie-Christine Combes Frederick Gavory Alexandre de Kochko Dave Kudrna Thierry Leroy Julie Poulain Myriam Rondeau Xiang Song Rod Wing Philippe Lashermes 《Plant molecular biology》2013,83(3):177-189
Coffee is one of the world’s most important agricultural commodities. Coffee belongs to the Rubiaceae family in the euasterid I clade of dicotyledonous plants, to which the Solanaceae family also belongs. Two bacterial artificial chromosome (BAC) libraries of a homozygous doubled haploid plant of Coffea canephora were constructed using two enzymes, HindIII and BstYI. A total of 134,827 high quality BAC-end sequences (BESs) were generated from the 73,728 clones of the two libraries, and 131,412 BESs were conserved for further analysis after elimination of chloroplast and mitochondrial sequences. This corresponded to almost 13 % of the estimated size of the C. canephora genome. 6.7 % of BESs contained simple sequence repeats, the most abundant (47.8 %) being mononucleotide motifs. These sequences allow the development of numerous useful marker sites. Potential transposable elements (TEs) represented 11.9 % of the full length BESs. A difference was observed between the BstYI and HindIII libraries (14.9 vs. 8.8 %). Analysis of BESs against known coding sequences of TEs indicated that 11.9 % of the genome corresponded to known repeat sequences, like for other flowering plants. The number of genes in the coffee genome was estimated at 41,973 which is probably overestimated. Comparative genome mapping revealed that microsynteny was higher between coffee and grapevine than between coffee and tomato or Arabidopsis. BESs constitute valuable resources for the first genome wide survey of coffee and provide new insights into the composition and evolution of the coffee genome. 相似文献
4.
Stanislav Sobolevsky Izabela Sitko Remi Tachet des Combes Bartosz Hawelka Juan Murillo Arias Carlo Ratti 《PloS one》2016,11(2)
Scientific studies of society increasingly rely on digital traces produced by various aspects of human activity. In this paper, we exploit a relatively unexplored source of data–anonymized records of bank card transactions collected in Spain by a big European bank, and propose a new classification scheme of cities based on the economic behavior of their residents. First, we study how individual spending behavior is qualitatively and quantitatively affected by various factors such as customer’s age, gender, and size of his/her home city. We show that, similar to other socioeconomic urban quantities, individual spending activity exhibits a statistically significant superlinear scaling with city size. With respect to the general trends, we quantify the distinctive signature of each city in terms of residents’ spending behavior, independently from the effects of scale and demographic heterogeneity. Based on the comparison of city signatures, we build a novel classification of cities across Spain in three categories. That classification exhibits a substantial stability over different city definitions and connects with a meaningful socioeconomic interpretation. Furthermore, it corresponds with the ability of cities to attract foreign visitors, which is a particularly remarkable finding given that the classification was based exclusively on the behavioral patterns of city residents. This highlights the far-reaching applicability of the presented classification approach and its ability to discover patterns that go beyond the quantities directly involved in it. 相似文献
5.
Patterns of Root Colonization in Epacridaceous Plants Collected from Different Sites 总被引:2,自引:0,他引:2
Root colonization was studied in ten species of the Epacridaceaeat three sites in Victoria by morphological and cross-inoculationexperiments. The sites and genera chosen were Cranbourne [Epacrisimpressa Labill. andLeucopogon ericoides(Smith) R. Br.] andRye [L. parviflorus(Andrews) Lindley] on the Mornington Peninsula,and the Grampians[Astroloma conostephioides(Sond.) Benth.,A.humifusum(Cav.) R. Br.,A pinifolium(R. Br.) Benth,Brachylomadaphnoides(Smith) Benth.,E. impressa, E. impressavar.grandifloraBenth.andStyphelia adscendensR. Br.] in western Victoria. For morphologicalstudies, samples of roots from each species at each site werecleared and stained and examined microscopically. For cross-inoculationstudies, cuttings from each site were struck in potting mediuminoculated with soil from the same and other sites. The ericoidmycorrhizae in the roots of plants found at or grown in Cranbourneand Rye soils were similar. Both were significantly differentfrom the internal hyphae found in the roots of plants foundat or grown in Grampians soils, which were three times largerin diameter and formed dense coils which filled the host celland invaded adjacent epidermal cells. This suggests that morethan one fungus is involved in the relationships, that the MorningtonPeninsula sites had a different fungus from the Grampians siteand that host specificity is low. Vesicular structures werealso found commonly on plants at the Grampians site, in contrastwith other sites. Epacridaceae; root; fungus; mycorrhiza; morphology; inoculation 相似文献
6.
Tchuem Tchuenté LA Southgate VR Combes C Jourdane J 《Parasitology today (Personal ed.)》1996,12(6):231-236
Previously assumed to be monogamous, the mating system of schistosomes has been the subject of some debate since recent findings have shown that change of mate can occur among these parasites. Here, Louis-Albert Tchuem Tchuenté, Vaughan R. Southgate, Claude Combes and Joseph Jourdane review progress made in the understanding of the mating behaviour of schistosomes, and highlight the importance of mating systems in the dynamics of natural transmission of schistosomiasis. 相似文献
7.
Jouy-Avantin F Combes C Lumley H Miskovsky JC Moné H 《The Journal of parasitology》1999,85(2):376-379
This paper reports on the discovery of dicrocoelid eggs in a coprolite collected in an archeological layer dated earlier than 550,000 yr BP (before present) from the Caune de l'Arago cave (Tautavel, Pyrénées-Orientales, France). It is the first trematode egg finding in an isolated coprolite from the Middle Pleistocene context. 相似文献
8.
Noir S Patheyron S Combes MC Lashermes P Chalhoub B 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(1):225-230
In order to promote genome research on coffee trees, one of the most important tropical crops, a bacterial artificial chromosome (BAC) library of the coffee allotetraploid species, Coffea arabica, was constructed. The variety IAPAR 59, which is widely distributed in Latin America and exhibits a fair level of resistance to several pathogens, was chosen. High-efficiency BAC cloning of the high molecular weight genomic DNA partially digested by HindIII was achieved. In total, the library contains 88,813 clones with an average insert size of 130 kb, and represents approximately eight C. arabica dihaploid genome equivalents. One original feature of this library is that it can be divided into four sublibraries with mean insert sizes of 96, 130, 183 and 210 kb. Characterisation of the library showed that less than 4.5% of the clones contained organelle DNA. Furthermore, this library is representative and shows good genome coverage, as established by hybridisation screening of high-density filters using a number of nuclear probes distributed across the allotetraploid genome. This Arabica BAC library, the first large-insert DNA library so far constructed for the genus Coffea, is well-suited for many applications in genome research, including physical mapping, map-based cloning, functional and comparative genomics as well as polyploid genome analyses.Communicated by J.W. Snape 相似文献
9.
Interspecific triploid hybrid plants between the tetraploid species Coffea arabica L. and the diploid species C. canephora P. were backcrossed to C. arabica. Although characterised by a low production and an important fruit dropping, all attempted crosses (ie, 6) generated BC(1) progenies. Flow cytometric analysis of the nuclear DNA content revealed that most of the BC1 individuals were nearly tetraploid. Among the male gametes produced by the interspecific triploid hybrids, those presenting a high number of chromosomes appeared strongly favoured. Only pollen mother cells having nearly 22 chromosomes were effective, the others leading to deficient endosperm and fruit dropping. Molecular markers (ie, microsatellite and AFLP) combined with evaluations of morphological characteristics and resistance to leaf rust were applied to verify the occurrence of gene transfer from C. canephora into C. arabica, and to estimate the amount of introgression present in BC(1) individuals. The results reveal a strong deficiency in the C. canephroa alleles indicating a severe counter-selection against the introgression of genetic material from C. canephora into C. arabica by way of triploid hybrids. However, introgressants displaying desirable traits such as a high resistance to leaf rust were obtained. The low level of introgression could be an advantage by facilitating the recovery of the recurrent parent and possibly reducing the number of required backcrosses. On the other hand, this could be a limitation when attempting the transfer of a complex trait or several simply inherited traits. 相似文献
10.