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Abstract  

The purpose of this study was to investigate the effects of competition between cobalt, europium and strontium for isosaccharinate, gluconate and picolinate. Systems where results indicated that competitive effects were significant have been identified. Thermodynamic calculations were performed for each system for comparison with the experimental results. Some exceptions may be due to precipitation of some species, or presence of species not in databases, or formation of mixed-metal complexes, or sorption to the solid phase(s). In some of the experiments, the complexity of the systems studied caused difficulty in identifying consistent trends. By concentrating on the results for simpler systems (i.e. for solubilities in the presence and absence of organic complexants and with just one competing metal ion), the evidence for competition effects has been investigated. Evidence for solubility enhancement due to organic ligands was apparent in the data for the systems Co with gluconate and Eu with isosaccharinate and gluconate. Of these above cases, the systems in which the effects of the competing ion are consistent with competition were limited to the cases of Eu with isosaccharinate and Sr as the competing ion, and Eu with gluconate and either Co or Sr as the competing ion.

Restricted access
Evolution, Mind and Behaviour
Authors:
Andrew Watt
,
Deiniol Skillicorn
,
Jediah Clark
,
Rachel Evans
,
Paul Hewlett
, and
Nick Perham

Background

Heterosexual men and women differ in their sensitivity to cues indicating material status. This dissociation has been explained by appealing to sexual selection processes that encourage women to evaluate men on the basis of their material status but could perhaps be explained by sex differences in contextual attention, or, associative representations.

Method

In Experiment 1, heterosexual women rated the attractiveness of an opposite sex model in 4 conditions; (1) attractive context, (2) attractive context with implied ownership, (3) unattractive context, and (4) unattractive context with ownership implied. A second experiment used a fictitious stockbroker learning task (with both men and women) in 2 biconditional discriminations to measure contextual attention (stage 1) and then to explore the structure of contextual representation (stage 2) using a transfer of occasion setting test.

Results

In Experiment 1, females increased ratings in attractive contexts, both when context ownership was implied and when it was not. In the first stage of Experiment 2, men and women were equally sensitive to contextual cues. In stage 2, women’s learning was impaired when a stimulus previously used as a target was employed as a context (they showed transfer of occasions setting), men showed no such difference.

Conclusions

Sex differences in sensitivity to cues indicating material status may reflect how men and women tend to encode the relationships between background/context stimuli and target stimuli. Women automatically attend to the background and modulate the value of targets using a hierarchical form of representation, whilst men represent background-target associations configurally.

Open access