12,132 research outputs found
Reflections on Edward Said’s Legacy: Orientalism, Cosmopolitanism, and Enlightenment
How are we to understand Edward Said's critique of the imbrication of knowledge and colonial power in light of his own education at elite universities such as Princeton and Harvard? Is Said's own path through elite colonial schooling in the Middle East and the exclusive schools of the United States a context for understanding the origins of his arguments in Orientalism? Yu uses the tension in Said's own commitment to a cosmopolitan ideal of knowledge to explore the contradictions within the legacies of the Enlightenment and European colonialism.Comment faut-il comprendre la critique qu’Edward Said formule sur l’imbrication du savoir et de l’influence coloniale quand on sait qu’il fut lui-même issu de milieux universitaires élitistes comme ceux de Princeton et de Harvard ? Le fait que Said a reçu son instruction au Moyen-Orient dans le réseau scolaire colonial réservé à l’élite et qu’il a fréquenté aux États-Unis de prestigieux établissements d’enseignement permet-il d’expliquer les origines de sa pensée sur l’orientalisme ? Dans sa poursuite d’un idéal cosmopolite du savoir, Said exprime une tension qu’exploite Henry Yu pour faire ressortir les contradictions contenues dans l’héritage du Siècle des lumières et du colonialisme européen
RELATIVE EFFECTIVENESS OF USDA'S NONPRICE EXPORT PROMOTION INSTRUMENTS
The USDA'Â’s Foreign Agricultural Service funds three types of activities to promote agricultural exports: consumer promotion, technical assistance, and trade servicing. These "instruments" are analyzed using an adaptation of Muth's model. Results indicate that consumer promotion always increases the derived demand for the U.S. agricultural commodity, but that under certain conditions technical assistance and trade servicing can have a perverse effect. Applying the model to cotton promotion in Japan, the results suggest that, owing to cotton's modest share of retail value, the current emphasis on consumer promotion may be misplaced. Specifically, it appears that producer returns can be enhanced by emphasizing technical assistance projects that save on the marketing input.Agricultural and Food Policy, International Relations/Trade,
Equilibrium Properties of Mouse-Torpedo Acetylcholine Receptor Hybrids Expressed in Xenopus Oocytes
This study used messenger RNA encoding each subunit (α, β, γ
and δ) of the nicotinic acetylcholine (ACh) receptor from mouse BC3H-1 cells and from Torpedo electric organ. The mRNA was synthesized in vitro by transcription with SP6 polymerase from cDNA clones. All 16 possible combinations that include one mRNA for each of α, β, γ and δ were injected into oocytes. After allowing 2-8 d for translation and assembly, we assayed each oocyte for (a) receptor assembly, measured by the binding of [^125]α-bungarotoxin to the oocyte surface, and (b) ACh-induced conductance, measured under voltage clamp at various membrane potentials. All combinations yielded detectable
assembly (30-fold range among different combinations) and ACh-induced
conductances (>1,000-fold range at 1 µM). On double-logarithmic coordinates, the dose-response relations all had a slope near 2 for low concentrations of ACh. Data were corrected for variations in efficiency of translation among identically injected oocytes by expressing ACh-induced conductance per femtomole
of α-bungarotoxin-binding sites. Five combinations were tested for d-tubocurarine
inhibition by the dose-ratio method; the apparent dissociation
constant ranged from 0.08 to 0.27 µM. Matched responses and geometric
means are used for describing the effects of changing a particular subunit
(mouse vs. Torpedo) while maintaining the identity of the other subunits. A
dramatic subunit-specific effect is that of the β subunit on voltage sensitivity of
the response: g_ACh(-90 mV)/g_Ach(+30 mV) is always at least 1, but this ratio
increases by an average of 3.5-fold if β_M replaces β_T. Also, combinations
including γ_T or δ_M usually produce greater receptor assembly than combinations
including the homologous subunit from the other species. Finally, E_ACh is
defined as the concentration of ACh inducing 1 µS/fmol at -60 mV; E_ACh is
consistently lower for α_m. We conclude that receptor assembly, voltage sensitivity,
and E_ACh are governed by different properties
Functional expression of the yeast alpha-factor receptor in Xenopus oocytes
The STE2 gene of the yeast Saccharomyces cerevisiae encodes a 431- residue polypeptide that has been shown by chemical cross-linking and genetic studies to be a component of the receptor for the peptide mating pheromone, alpha-factor. To demonstrate directly that the ligand binding site of the alpha-factor receptor is comprised solely of the STE2 gene product, the STE2 protein was expressed in Xenopus oocytes. Oocytes microinjected with synthetic STE2 mRNA displayed specific surface binding for 35S-labeled alpha-factor (up to 40 sites/micron2/ng RNA). Oocytes injected with either STE2 antisense RNA or heterologous receptor mRNA (nicotinic acetylcholine receptor alpha, beta, gamma, and delta subunit mRNAs) showed no binding activity (indistinguishable from uninjected control oocytes). The apparent KD (7 nM) of the alpha-factor binding sites expressed on the oocyte surface, determined by competition binding studies, agreed with the values reported for intact yeast cells and yeast plasma membrane fractions. These findings demonstrate that the STE2 gene product is the only yeast polypeptide required for biogenesis of a functional alpha-factor receptor. Electrophysiological measurements indicated that the membrane conductance of oocytes injected with STE2 mRNA, or with both STE2 and GPA1 (encoding a yeast G protein alpha-subunit) mRNAs, did not change and was not affected by pheromone binding. Thus, the alpha-factor receptor, like mammalian G protein-coupled receptors, apparently lacks activity as an intrinsic or ligand-gated ion channel. This report is the first instance in which a membrane-bound receptor from a unicellular eukaryote has been expressed in a vertebrate cell
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