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21.
Alan Rumsey 《The Australian journal of anthropology》2006,17(1):47-69
One of the leading challenges for contemporary anthropology is to try to contribute to an understanding of the interaction between indigenous and exogenous socio‐cultural orders, especially at the frontiers of globalisation. Here I review three recent attempts to do so: (1) a model of structural transformation as developed by Marshall Sahlins; (2) a model of articulation as developed by James Clifford; (3) a model of ‘adoption’ proposed by Joel Robbins. As a test case for these models, I consider them in relation to some recent developments in local segmentary politics and verbal art in the Ku Waru region of Highland New Guinea. I show that all three models are in certain respects inadequate for understanding those developments, and offer some proposals as to what kinds of theory might be more adequate to the task. 相似文献
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When expressed in Escherichia coli, a truncated form of phytochrome (oat PHYA AP3 residues 464-1129) self associates to form a series of products ranging in size from monomers to aggregates of greater than 20 subunits. When these same phytochrome sequences are coexpressed with the chaperonins GroEL and GroES, the truncated phytochrome migrates as a native-like dimer in size exclusion chromatography and no higher-order aggregates were detected. GroEL and GroES inhibition of phytochrome aggregation in E. coli presumably occurs via the suppression of folding pathways leading to incorrectly folded phytochrome. 相似文献
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Alan B Oelkers Erick J Schutte David R Tyler 《Photochemical & photobiological sciences》2008,7(2):228-234
The photochemistry of the [(CpR)Mo(CO)(3)](2) molecules, where CpR = eta(5)-C(5)H(4)(CH(2))(2)C(O)NCH(3)(CH(2))(n)CH(3) (n = 3, 8, 13, and 18), was examined using femtosecond pump-probe transient absorption spectroscopy. The goal of this study was to investigate the importance of radical size and mass on the dynamics and efficiency of geminate radical-radical recombination. The femtosecond results demonstrated the lack of any size/mass dependence of the recombination efficiency. This finding contrasts with results from a prior study that did find a size/mass dependence using a steady-state photochemical technique. To explain these conflicting results, it is proposed that the femtosecond pump-probe results are a measurement of the efficiency of primary geminate recombination whereas the steady-state method results are a measurement of the sum of primary and secondary geminate recombination efficiencies. The size/mass dependence is evident in the latter because secondary geminate recombination is a slower diffusive recombination process and therefore depends on the steric properties of the radicals. Although the existence of primary and secondary recombination channels is often taken for granted, experimental differentiation of primary and secondary caging has proven to be difficult because it is not possible for a single experimental technique to span the entire timescale for recombination of a radical cage pair and adequately resolve these recombination pathways. 相似文献
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Alan C. L. Yu 《PloS one》2010,5(8)
Variation is a ubiquitous feature of speech. Listeners must take into account context-induced variation to recover the interlocutor''s intended message. When listeners fail to normalize for context-induced variation properly, deviant percepts become seeds for new perceptual and production norms. In question is how deviant percepts accumulate in a systematic fashion to give rise to sound change (i.e., new pronunciation norms) within a given speech community. The present study investigated subjects'' classification of /s/ and // before /a/ or /u/ spoken by a male or a female voice. Building on modern cognitive theories of autism-spectrum condition, which see variation in autism-spectrum condition in terms of individual differences in cognitive processing style, we established a significant correlation between individuals'' normalization for phonetic context (i.e., whether the following vowel is /a/ or /u/) and talker voice variation (i.e., whether the talker is male or female) in speech and their “autistic” traits, as measured by the Autism Spectrum Quotient (AQ). In particular, our mixed-effect logistic regression models show that women with low AQ (i.e., the least “autistic”) do not normalize for phonetic coarticulation as much as men and high AQ women. This study provides first direct evidence that variability in human''s ability to compensate for context-induced variations in speech perceptually is governed by the individual''s sex and cognitive processing style. These findings lend support to the hypothesis that the systematic infusion of new linguistic variants (i.e., the deviant percepts) originate from a sub-segment of the speech community that consistently under-compensates for contextual variation in speech. 相似文献
26.
The particulate enzyme fraction from pig aorta was treated with Triton X-100 or Nonidet P-40 to yield a soluble enzyme preparation. This solubilized enzyme catalyzed the transfer of mannose from GDP-[14C]mannose, but not from [14C]mannosyl-phosphoryl-polyprenol, to G1cNAc-G1cNAc-pyrophosphoryl-polyprenol to form the trisaccharide-lipid, Man-β-GlcNAc-GlcNAc-pyrophosphoryl-polyprenol. The trisaccharide-lipid formed in these reactions was isolated by solvent fractionation and was subjected to mild acid hydrolysis to release the [14C]trisaccharide. Essentially all of the radioactivity was released from this trisaccharide as mannose upon treatment with β-mannosidase while α-mannosidase had no effect. 相似文献
27.
Alan G. Clews 《CMAJ》1980,123(7):692-693
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The light-induced free-radical signal of Photosystem II (observed after illumination at 77 °K) has been studied in chloroplasts as a function of the oxidation-reduction potential established prior to freezing. The intensity of the light-induced signal is unchanged in the potential region of +590 mV to +760 mV. At higher potential (+850 mV), there is a 30% decrease in signal intensity. The light-induced signal decreases to zero in the low-potential region, with a midpoint potential of +475 mV. These results are considered in terms of a Photosystem II reaction-center complex in which the light-induced free-radical signal arises from the oxidized form of the reaction-center chlorophyll, and this chlorophyll molecule is capable of being reduced at liquid-nitrogen temperature by a secondary electron donor which has a midpoint oxidation-reduction potential of +475 mV. 相似文献