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Heavy metal residues in birds of Lake Nakuru, Kenya 总被引:1,自引:0,他引:1
Jim K. Kairu 《African Journal of Ecology》1996,34(4):397-400
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The effectiveness of immigrants as agents of gene flow was investigated in a laboratory model, using mutant marker strains of the flour beetle, Tribolium castaneum (Herbst).We show that immigrants had an advantage over residents. The proportion of hybrid offspring (PHO), resulting from immigrant mating with residents, was higher than expected from their frequency in the parental population. This advantage was observed regardless of immigrant sex and immigrant strain. The advantage seems to result from immigrant mating advantage (although not a rare-male phenomenon) and not from better survival of hybrid offspring. However, hybrid offspring seem to be more resistant to sporozoan infection, resulting in higher PHO in sporozoan-infected cultures. 相似文献
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Shamayim T. Ramírez-Puebla Luis E. Servín-Garcidue?as Berenice Jiménez-Marín Luis M. Bola?os Mónica Rosenblueth Julio Martínez Marco Antonio Rogel Ernesto Orme?o-Orrillo Esperanza Martínez-Romero 《Applied and environmental microbiology》2013,79(1):2-9
Animal guts and plant roots have absorption roles for nutrient uptake and converge in harboring large, complex, and dynamic groups of microbes that participate in degradation or modification of nutrients and other substances. Gut and root bacteria regulate host gene expression, provide metabolic capabilities, essential nutrients, and protection against pathogens, and seem to share evolutionary trends. 相似文献
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Bhisma K. Patel James B. Thomson Victor Jiménez Klaus Eckart Fritz Fxkstein 《Nucleosides, nucleotides & nucleic acids》2013,32(7-9):1443-1446
Abstract The hydrolytic stability of oligoribonucleotides containing 2′- amino nucleophile is due to poor leaving characteristic of 5′-nucleoside, replacement of 5′-leaving group by thio or amino results in considerable instability towards hydrolysis. 相似文献
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Marvin J. Núñez Alejandro E. Ardiles Morena L. Martínez David Torres-Romero Ignacio A. Jiménez Isabel L. Bazzocchi 《Phytochemistry letters》2012,5(2):244-248
Three new triterpenoids, including two rare D:B-friedobaccharanes (leonatriol, 1 and leonatriolone, 2) and a 2,3-seco-2,24-epoxy-3,24-olide-D:A-friedooleanane (cassinolide, 3) were isolated from the root bark of Cassine xylocarpa and Celastrus vulcanicola, collected in El Salvador. Their stereostructures were elucidated on the basis of spectroscopic analyses, mainly 1D and 2D NMR techniques, spectrometric analyses, and comparison with data reported in the literature. The absolute configuration of 1 and 2 were determined by the application of the Riguera ester procedure and biogenetic considerations. The possible biogenetic pathway for cassinolide (3) is also discussed. 相似文献
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Esther Jiménez Susana Delgado Antonio Maldonado Rebeca Arroyo Mar Albújar Natalia García Manel Jariod Leonides Fernández Adolfo Gómez Juan M Rodríguez 《BMC microbiology》2008,8(1):143
Background
Breast milk is an important source of staphylococci and other bacterial groups to the infant gut. The objective of this work was to analyse the bacterial diversity in feces of breast-fed infants and to compare it with that of formula-fed ones. A total of 23 women and their respective infants (16 breast-fed and 7 formula-fed) participated in the study. The 16 women and their infants provided a sample of breast milk and feces, respectively, at days 7, 14, and 35. The samples were plated onto different culture media. Staphylococcal and enterococcal isolates were submitted to genetic profiling and to a characterization scheme, including detection of potential virulence traits and sensitivity to antibiotics. 相似文献9.
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Synthesis, processing, and secretion of recombinant human factor VIII expressed in mammalian cells 总被引:12,自引:0,他引:12
The synthesis, processing, and secretion of factor VIII expressed from heterologous genes introduced into Chinese hamster ovary cells has been studied. The results show factor VIII to be synthesized as a primary translation product of approximately 230 kDa that can be detected in the lumen of the endoplasmic reticulum. In this compartment, the majority of the factor VIII is in a complex with a resident protein of the endoplasmic reticulum, binding protein, and may never appear in the medium. Some factor VIII transits the endoplasmic reticulum to the Golgi apparatus, where it is cleaved to generate the mature heavy and light chains. In the absence of von Willebrand factor in the medium, the secreted heavy and light chains are unassociated and subsequently degraded. In the presence of von Willebrand factor in the medium, the heavy and light chains are secreted as a stable complex and activity accumulates linearly with time. The utilization and complexity of asparagine-linked carbohydrate present on the secreted recombinant-derived factor VIII and human plasma-derived factor VIII were compared and found to be very similar. In both cases, the asparagine-linked carbohydrate moieties on the heavy chain are primarily of the hybrid or complex-type. In contrast, the factor VIII from both sources contains a high-mannose type of asparagine-linked carbohydrate on the light chain. 相似文献