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1.
Ivo Strecker 《Visual Anthropology: Published in cooperation with the Commission on Visual Anthropology》2013,26(3-4):207-227
As the anthropological theory of politeness has put it, people have universally two kinds of social want. They wish to be close to others, liked and accepted, but they also want some distance, freedom from imposition and respect of mutual difference. These wants, which one may also call basic human rights, are however often violated, and images play an important role in this. Images are ultimately generated in the human mind and may find verbal as well as written and pictorial representation. Tyler [1978] has proposed a typology of mental images based on criteria of conscious control, completeness, abstraction, media and autonomy. These criteria also prove useful when probing into prototypical usages of intrusive imagery such as cursing, blessing, magic, witchcraft and the evil eye. Also the criteria help one understand the subtle process by which imagery can lead to the articulation and even discovery of peoples’ selves. Ethnographic discourse has always been to a large extent about images, but until recently the ethnographer stood between his or her audience and the people of whom he or she was speaking or writing. Now, as sound recordings, film and video have arrived, this allows for richer varieties of cooperation where the non‐literate counterparts of the ethnographer can make more expressive and coherent contributions than before. Also it seems that in the face of suppression people welcome the new media as a support in their ongoing battle for a recognition of their cultural and social worthiness. 相似文献
2.
Gerard Strecker Jean-Michel Wieruszeski Jean-Claude Michalski Jean Montreuil 《Glycoconjugate journal》1988,5(4):385-396
The structure of a new nonasaccharide isolated from human milk has been investigated. By using methylation analysis, FAB-MS and1H-and13C-NMR spectroscopy as basic methods of structural investigation, this oligosaccharide was identified as VI2--Fuc,V4-Fuc,III3--Fuc-p-lacto-n-hexaose: Fuc1-2Gal1-3[Fuc1-4]GlcNAc1-3Gal1-4[Fuc1-3]GlcNAc1-3Gal1-4Glc.Abbreviations COSY
correlation spectroscope
- DP
degree of polymerisation
- FAB-MS
fast atom bombardment-mass spectrometry
- HPLC
high performance liquid chromatography
- NMR
nuclear magnetic resonance
- GLC
gas-liquid chromatography 相似文献
3.
Sabine Lhernould Yannis Karamanos Sylvain Bourgerie Gerard Strecker Raymond Julien Henri Morvan 《Glycoconjugate journal》1992,9(4):191-197
We have previously isolated mannoside and xylomannoside oligosaccharides with one or two terminal reducingN-acetylglucosamine residues from the extracellular medium of white campion (Silene alba) suspension culture. We have now demonstrated the presence of peptide-N
4-(N-acetylglucosaminyl)asparagine amidase (PNGase) activity in cell extracts as well in the culture medium that could explain the production of those compounds. An additional xylomannoside, (GlcNAc)Man3(Xyl)GlcNAc(Fuc)GlcNAc, was characterized, and1H- and13C-NMR assignments for the oligosaccharide Man3(Xyl)GlcNAc(Fuc)GlcNAc were obtained using homonuclear and heteronuclear spectroscopy (COSY).Abbreviations Endo
endo--N-acetylglucosaminidase
- Fuc
fucose
- GlcNAc
N-acetylglucosamine
- Man
mannose
- NMR
nuclear magnetic resonance
- PNGase
peptide-N
4-(N-acetylglucosaminyl)asparagine amidase
- Xyl
xylose 相似文献
4.
T Baussant G Strecker J M Wieruszeski J Montreuil J C Michalski 《European journal of biochemistry》1986,159(2):381-385
An endo-N-acetyl-beta-D-glucosaminidase active towards oligosaccharides with a reducing terminal [bis(N-acetylglucosamine)]residue has been characterized in rat liver. The primary structure of its reaction products was determined using high-resolution 1H-NMR spectroscopy. The enzyme is predominantly located in the lysosomal fraction, presents a maximum of activity at pH 3.5 and is completely inactive towards conjugated glycans, i.e. glycoproteins and glycopeptides as well as on glycoasparagines. These results support the existence of a new pathway for the degradation of glycoprotein glycans inside the lysosome. In particular, this enzymic activity may be the origin of oligosaccharides bearing a single terminal reducing N-acetylglucosamine residue which are excreted in the urine of patients with various exoglycosidase deficiencies. 相似文献
5.
J C Michalski J Montreuil G Strecker H van Halbeek L Dorland J F Vliegenthart B Cartigny J P Farriaux 《European journal of biochemistry》1983,132(2):375-381
Initial-rate measurements were made of the reduction of pyridine-3-aldehyde and p-carboxybenzaldehyde by NADPH catalyzed by pig liver aldehyde reductase I. The initial velocity analysis and product inhibition data suggest that aldehyde reductase I obeys a compulsory-order mechanism with pyridine-3-aldehyde as substrate but follows a partially random-order pathway with p-carboxybenzaldehyde. The partially random-order pathway would be operative only at high concentrations of p-carboxybenzaldehyde. In both cases, aldehydes and the corresponding alcohol substrates inhibit the enzyme at high concentration. Abortive ternary complexes are shown to be formed with pyridine-3-aldehyde and with p-carboxybenzaldehyde. Dissociation of the coenzyme from the abortive ternary complex seems only to be observed with p-carboxybenzaldehyde. This study suggests overall that an enzyme kinetic mechanism may be different, depending on whether specific interactions can occur between certain amino acid residue(s) of the protein active site and substrates. Finally, the mechanism of the inhibition of pyridine-3-aldehyde reduction by diacid derivatives is discussed. 相似文献
6.
Carbonic anhydrase in the animal kingdom 总被引:1,自引:0,他引:1
T H Maren 《Federation proceedings》1967,26(4):1097-1103
7.
European Journal of Wildlife Research - Bei 30 Birkhühnern wurde nach kontrolliert durchgeführter Trinkwasservaccination gegen Newcastle Disease (ND) (Erstimpfung mit Hitchner B1,... 相似文献
8.
The broad diversity of neutral and sialylated oligosaccharides derived from human salivary mucins. 总被引:3,自引:0,他引:3
A Klein C Carnoy J M Wieruszeski G Strecker A M Strang H van Halbeek P Roussel G Lamblin 《Biochemistry》1992,31(26):6152-6165
Mucin glycopeptides were prepared from the salivary mucins of 20 healthy donors with blood group O. The carbohydrate chains of the high-molecular-weight mucins were released by alkaline borohydride treatment. Neutral and monosialylated oligosaccharide-alditols were purified by ion-exchange chromatography, gel filtration, and HPLC. The structures of the oligosaccharide-alditols were determined by high-resolution 1H-NMR spectroscopy in combination with fast atom bombardment mass spectrometry and methylation analysis. Thirty-seven oligosaccharide-alditols were characterized and illustrate the extreme diversity of the salivary mucins carbohydrate chains. This diversity might represent a mosaic of bacterial adhesion sites and be involved in the early events of the nonimmune defense of the oral cavity. Among these 37 oligosaccharide-alditols, 31 have not been previously described in human saliva and five of these are novel structures: [formula: see text] 相似文献
9.
Eduardo Moreno-Jiménez Fernando T. Maestre Maren Flagmeier Emilio Guirado Miguel Berdugo Felipe Bastida Marina Dacal Paloma Díaz-Martínez Raúl Ochoa-Hueso César Plaza Matthias C. Rillig Thomas W. Crowther Manuel Delgado-Baquerizo 《Global Change Biology》2023,29(2):522-532
Soil micronutrients are capital for the delivery of ecosystem functioning and food provision worldwide. Yet, despite their importance, the global biogeography and ecological drivers of soil micronutrients remain virtually unknown, limiting our capacity to anticipate abrupt unexpected changes in soil micronutrients in the face of climate change. Here, we analyzed >1300 topsoil samples to examine the global distribution of six metallic micronutrients (Cu, Fe, Mn, Zn, Co and Ni) across all continents, climates and vegetation types. We found that warmer arid and tropical ecosystems, present in the least developed countries, sustain the lowest contents of multiple soil micronutrients. We further provide evidence that temperature increases may potentially result in abrupt and simultaneous reductions in the content of multiple soil micronutrients when a temperature threshold of 12–14°C is crossed, which may be occurring on 3% of the planet over the next century. Altogether, our findings provide fundamental understanding of the global distribution of soil micronutrients, with direct implications for the maintenance of ecosystem functioning, rangeland management and food production in the warmest and poorest regions of the planet. 相似文献
10.
Maren Preuss Pilar Díaz-Tapia Heroen Verbruggen Giuseppe C. Zuccarello 《Journal of phycology》2023,59(5):950-962
Parasitic red algae are an interesting system for investigating the genetic changes that occur in parasites. These parasites have evolved independently multiple times within the red algae. The functional loss of plastid genomes can be investigated in these multiple independent examples, and fine-scale patterns may be discerned. The only plastid genomes from red algal parasites known so far are highly reduced and missing almost all photosynthetic genes. Our study assembled and annotated plastid genomes from the parasites Janczewskia tasmanica and its two Laurencia host species (Laurencia elata and one unidentified Laurencia sp. A25) from Australia and Janczewskia verruciformis, its host species (Laurencia catarinensis), and the closest known free-living relative (Laurencia obtusa) from the Canary Islands (Spain). For the first time we show parasitic red algal plastid genomes that are similar in size and gene content to free-living host species without any gene loss or genome reduction. The only exception was two pseudogenes (moeB and ycf46) found in the plastid genome of both isolates of J. tasmanica, indicating potential for future loss of these genes. Further comparative analyses with the three highly reduced plastid genomes showed possible gene loss patterns, in which photosynthetic gene categories were lost followed by other gene categories. Phylogenetic analyses did not confirm monophyly of Janczewskia, and the genus was subsumed into Laurencia. Further investigations will determine if any convergent small-scale patterns of gene loss exist in parasitic red algae and how these are applicable to other parasitic systems. 相似文献