Single-Element and Competitive Metal Mobility Measured with Column Infiltration and Batch Tests

The distribution coefficient, K-d, is often used to quantify heavy metal mobility in soils. Batch sorption or column infiltration tests may be used to measure K-d. The latter are closer to natural soil conditions, but are difficult to conduct in clays. This difficulty can be overcome by using a laboratory centrifuge. An acceleration of 2600 gravities was applied to columns of London Clay, an Eocene clay sub-stratum, and Cu, Ni, and Zn mobility was measured in centrifuge infiltration tests, both as single elements and in dual competition. Single-element K-d values were also obtained from batch sorption tests, and the results from the two techniques were compared. It was found that K-d values obtained by batch tests vary considerably depending on the metal concentration, while infiltration tests provided a single K-d value for each metal. This was typically in the lower end of the range of the batch test K-d values. For both tests, the order of mobility was Ni > Zn > Cu. Metals became more mobile in competition than when in single-element systems: Ni K-d decreased 3.3 times and Zn K-d 3.4 times when they competed with Cu, while Cu decreased only 1.2 times when in competition with either Ni or Zn. Our study showed that competitive sorption between metals increases the mobility of those metals less strongly bound more than it increases the mobility of more strongly bound metals.

Right-wing authoritarianism, social dominance orientation and prejudice against threatening and competitive ethnic groups

This research rests on the assumption that individual differences approaches to prejudice benefit from all integration of intergroup factors. Following Duckitt (2001), we assumed that two prominent individual differences variables, right-wing authoritarianism (RWA) and social dominance orientation (SDO), would differentially predict majority members' levels of ethnic prejudice depending on specific factors of the intergroup context: RWA as all index of motivational concerns about social cohesion, stability and security should drive prejudice against outgroups perceived as socially threatening, and SDO as an index of concerns about ingroup superiority and dominance should predict prejudice against outgroups perceived as potential competitors for power-status. Across two studies (Ns = 82, 176), using between-participants and within-participants experimental designs, the effects of RWA on prejudice were particularly powerful when the outgroup was manipulated to be socially threatening, but the effects of SDO on prejudice appeared not to increase when the outgroup was manipulated to be competitive. In Study 2, presenting the outgroup as having low status also increased the effect of RWA, but not the effect of SDO. These results support the differential prediction assumption for RWA, but not for SDO. Implications for the conceptualisation of RWA and SDO are discussed. Copyright (C) 2008 John Wiley & Sons, Ltd.

Increasing Returns and Competitive Equilibrium--The Content and Development of Marshall's Theory

This paper reviews Alfred Marshall's attempts to reconcile increasing returns and competition from the early economic writings to the later editions of his Principles. It is shown that while Marshall's final solution to the problem involved naming external economies the cause of increasing returns in a regime of competition , both the life cycle of the firm and internal economies remained necessary to his argument. Their function was to give some operation al content to the elusive concept of external economies.

Phase I study of GSK461364, a specific and competitive Polo-like Kinase 1 (PLK1) inhibitor in patients with advanced solid malignancies.

Purpose: GSK461364 is an ATP-competitive inhibitor of polo-like kinase 1 (Plk1). A phase I study of two schedules of intravenous GSK461364 was conducted. Experimental Design: GSK461364 was administered in escalating doses to patients with solid malignancies by two schedules, either on days 1, 8, and 15 of 28-day cycles (schedule A) or on days 1, 2, 8, 9, 15, and 16 of 28-day cycles (schedule B). Assessments included pharmacokinetic and pharmacodynamic profiles, as well as marker expression studies in pretreatment tumor biopsies. Results: Forty patients received GSK461364: 23 patients in schedule A and 17 in schedule B. Dose-limiting toxicities (DLT) in schedule A at 300 mg (2 of 7 patients) and 225 mg (1 of 8 patients) cohorts included grade 4 neutropenia and/or grade 3–4 thrombocytopenia. In schedule B, DLTs of grade 4 pulmonary emboli and grade 4 neutropenia occurred at 7 or more days at 100 mg dose level. Venous thrombotic emboli (VTE) and myelosuppression were the most common grade 3–4, drug-related events. Pharmacokinetic data indicated that AUC (area under the curve) and C max (maximum concentration) were proportional across doses, with a half-life of 9 to 13 hours. Pharmacodynamic studies in circulating tumor cells revealed an increase in phosphorylated histone H3 (pHH3) following drug administration. A best response of prolonged stable disease of more than 16 weeks occurred in 6 (15%) patients, including 4 esophageal cancer patients. Those with prolonged stable disease had greater expression of Ki-67, pHH3, and Plk1 in archived tumor biopsies. Conclusions: The final recommended phase II dose for GSK461364 was 225 mg administered intravenously in schedule A. Because of the high incidence (20%) of VTE, for further clinical evaluation, GSK461364 should involve coadministration of prophylactic anticoagulation.