ALBERT

Notes: The paper gives a simple representation of how oligopoly affects the general theory of international trade. Three points are emphasized: the simplicity of trade under oligopoly in the Ricardian model; the equations describing the general equilibrium of a world economy with any number of goods, countries, and factors under oligopolistic conditions and an integrated world market; and a complete description of the solution of a Mill–Ricardo–Cournot model with oligopoly in one sector and perfect competition in the other.

Notes: Considers cooperative negotiation tactic use in early stages of business-to-business buyer-seller relationships. Specifically, it addresses a serious gap in the study of individual difference effects on cooperative negotiation, an area that has received little academic attention. In doing so, insight is provided on an area that marketing researchers say needs attention now. We conduct a study where subjects take the role of a salesperson. They make offers, or respond to buyers' offers, to negotiate. Subjects indicate what offers they would make, or what counteroffers they would respond with. Results support the notion that individual differences in intrinsic motivation (operationalized as autonomy causality orientation) affect the use of cooperative offers, but do not affect counteroffers, due possibly to reciprocation.

Notes: Abstract The relative stability of body weight over the long term and under a variety of environmental conditions that alter short-term energy intake and expenditure provides strong evidence for the regulation of body energy content. The lipostatic theory of energy balance regulation proposed 40 years ago that circulating factors, generated in proportion to body fat stores, acted as signals to the brain, eliciting changes in energy intake and expenditure. The discovery of leptin and its receptors has now provided a molecular basis for this theory. Leptin functions as much more than an adipocyte-derived signal of lipid stores, however. Although suppression of food intake is an important centrally mediated effect of leptin, considerable evidence indicates that leptin also functions both directly and indirectly, via the brain, to orchestrate complex metabolic changes in a number of organs and tissues, altering nutrient flux to favor energy expenditure over energy storage.

Notes: The advantage of magnetic resonance sounding (MRS) as compared to other classical geophysical methods is in its water selective approach and reduced ambiguity in determination of subsurface free water content and hydraulic properties of the media due to the nuclear magnetic resonance (NMR) principle applied. Two case examples are used to explain how hydrogeological parameters are obtained from an MRS survey. The first case example in Delft (the Netherlands) is a multiaquifer system characterized by large signal to noise ratio (S/N = 73), with a 24 m thick, shallow sand aquifer, confined by a 15 m thick clay layer. For the shallow aquifer, a very good match between MRS and borehole data was obtained with regard to effective porosity nc∼28% and specific drainage Sd∼20%. The MRS interpretation at the level deeper than 39 m was disturbed by signal attenuation in the low resistivity (∼10 Ωm) media. The second case of Serowe (Botswana) shows a fractured sandstone aquifer where hydrogeological parameters are well defined at depth 〉74 m below ground surface despite quite a low S/N = 0.9 ratio, thanks to the negligible signal attenuation in the resistive environment. Finally, capabilities and limitations of the MRS technology are reviewed and discussed. MRS can contribute to subsurface hydrostratigraphy description, hydrogeological system parameterization, and improvement of well siting. The main limitations are survey dependence upon the value of the S/N ratio, signal attenuation in electrically conductive environments, nonuniformity of magnetic field, and some instrumental limitations. At locations sufficiently resistive to disregard the signal attenuation problems, the MRS S/N ratio determines how successfully MRS data can be acquired. Both signal and noise vary spatially; therefore, world scale maps providing guidelines on spatial variability of signal and noise are presented and their importance with respect to the MRS survey results is discussed. The noise varies also temporally; therefore, its diurnal and seasonal variability impact upon the MRS survey is covered as well.

Notes: We present a method to calibrate empirically the demand parameters in a merger simulation model by using brand-level profit margin data. While the approach can be generalized, we develop these ideas within a particular framework - the PCAIDS (proportionality-calibrated AIDS) model. We show that the brand-level margins effectively define product "nests" (products that are especially close substitutes) and substantially increase the flexibility of PCAIDS for modeling critical own- and cross-price elasticities. The model is particularly valuable for transactions at the wholesale level (where scanner data do not exist) and for geographic markets that span national borders (where comparable data may not be available), since other methods to derive elasticities, particularly those based on econometric estimation, may not be possible or may not be reliable.

Notes: The present study, undertaken as a continuation of an earlier study on quantitative trait loci (QTL) analysis of grain protein content (GPC) in bread wheat (Prasad et al. 1999), includes the following: (1) identification of an additional molecular marker associated with GPC; (2) development of near-isogenic lines (NILs) for high GPC; and (3) the use of three sets of NILs (a total of 10 NILs) to validate the two available markers linked with QTL for GPC. A total of 114 sequence-tagged microsatellite site (STMS) primer pairs (that were not used in the previous study) were used for detection of polymorphism between the two parents (PH132, with high GPC; WL711, with low GPC) of a mapping population of 100 recombinant inbred lines (RILs). A total of 95 primer pairs gave amplification products, of which only 30 detected reproducible polymorphism between the parental genotypes. Bulked segregant analysis was conducted using these 30 primers on two bulks (each comprising eight RILs) representing the two extremes of the normal distribution. A solitary primer pair (WMC415) showed association with GPC, which was further confirmed through selective genotyping. Subsequently, 100 RILs were genotyped. A single-marker linear regression analysis showed significant association between the marker WMC415 and GPC, thus identifying a quantitative trait locus (designated as QGpcccsu-5A1), which explained 6.21% of the variation for GPC among the RILs. The above STMS marker, together with the STMS marker (WMC41) identified earlier, explains approximately 25% of the variation for GPC. In order to conduct validation of the above two available markers, 10 NILs were developed for high GPC using two genotypes (WL711 and HD2329) with low GPC as recipient parents and another two genotypes (PH132 and PH133) with high GPC as donor parents. NIL 2233 (with 11.7% GPC), derived from HD2329, when tried with WMC41 gave a characteristic amplification profile similar to that of its donor parent PH132, and NIL 2215 (with 11.9% GPC) derived from WL711, when tried with WMC415 gave an amplification profile that resembled its donor parent PH133. The remaining eight NILs with high GPC gave patterns similar to those of their corresponding recipient parents with both the markers, suggesting that either the QTL, other than those associated with the above markers, were actually transferred from the donor parents and contributed to high GPC in these NILs or that recombination had occurred between the markers identified and the corresponding QTL. Thus, the marker validation conducted using NILs, while demonstrating the utility of these two microsatellite markers for use in marker-assisted selection in plant breeding, also suggested that many more QTL exist that would need to be identified using closely linked molecular markers.

Notes: ABSTRACTS: FORTY-FIRST ANNUAL CONFERENCE OF THE WESTERN ECONOMIC ASSOCIATION