Influence of roasting conditions on health-related compounds in different nuts.

Due to their health-beneficial ingredients the consumption of nuts can contribute to a healthy diet. The composition of hazelnuts, almonds, macadamia nuts, pistachios and walnuts regarding health-promoting and potentially harmful compounds was examined before and after roasting under different time and temperature conditions. Fatty acid compositions were not affected by roasting. Malondialdehyde increased with higher roasting temperatures (17-fold in walnuts). Levels of tocopherol isomers were reduced after roasting (α-T: 38%, ß-T: 40%, γ-T: 70%) and hydrophilic antioxidant capacity decreased significantly in hazelnuts (1.4-fold), macadamia nuts (1.7-fold) and walnuts (3.7-fold). Increasing roasting temperatures supported the formation of significant amounts of acrylamide only in almonds (1220 µg kg(-1)). In general, nuts roasted at low/middle temperatures (120-160°C) exhibited best sensory properties. Therefore, desired sensory quality along with a favourable healthy nut composition may be achieved by roasting over a low to medium temperature range.

Evidence for the application of rules in Pavlovian electrodermal conditioning with humans.

Two Pavlovian SCR conditioning experiments investigated interference effects in sequential training of positive and negative patterning discriminations in humans. In Experiment 1, positive patterning (A-, B-, AB+) was trained in Phase 1, immediately followed by a negative patterning schedule (C+, D+, CD-). We predicted that human participants would learn a specific numerosity rule in positive patterning, which interferes with the subsequent negative patterning schedule. In Experiment 2, negative patterning (C+, D+, CD-) was trained in Phase 1, followed by a positive patterning schedule (A-, B-, AB+) in Phase 2. Because human participants would learn an abstract 'separate-versus-together'- or 'opposite'-rule to solve the negative patterning discrimination in Phase 1, there should be less interference in positive patterning in Phase 2 where the separate/together-rule could be applied, too. In both experiments, the initial patterning discriminations were acquired successfully. In Experiment 1, human participants totally failed to solve the Phase 2 discrimination, while in Experiment 2 appropriate response differentiation developed in Phase 2. Thus, without pre-experience human participants seem to utilize a specific numerosity-rule in positive patterning and a separate/together-rule in negative patterning.

What is learned in patterning discriminations? Further tests of configural accounts of associative learning in human electrodermal conditioning.

Two Pavlovian SCR conditioning experiments investigated positive and negative patterning discriminations in humans by means of transfer tests. In Experiment 1, positive patterning (A-,B-,AB+) was trained interleaved with non-reinforced presentations of an additional stimulus (C-). Then responding to new compounds consisting of either already trained elements (AC,BC) or new elements (DE) was examined. In Experiment 2, negative patterning (A+,B+,AB-) was trained interleaved with reinforced presentations of an additional stimulus (C+). Again, we examined responding to new compounds consisting of either already trained elements (AC,BC) or new elements (DE). In both experiments the initial patterning discrimination was solved successfully. The response patterns to the test compounds in both experiments were in contradiction to configural accounts of associative learning. In positive patterning human participants seemed to utilize 'number' or some other abstract feature in preference to available concrete stimuli. In negative patterning the abstract dimension of 'separate-versus-together' or 'opposite' was used.

Inhibition of human ether à go-go potassium channels by Ca(2+)/calmodulin.

Intracellular Ca(2+) inhibits voltage-gated potassium channels of the ether à go-go (EAG) family. To identify the underlying molecular mechanism, we expressed the human version hEAG1 in Xenopus oocytes. The channels lost Ca(2+) sensitivity when measured in cell-free membrane patches. However, Ca(2+) sensitivity could be restored by application of recombinant calmodulin (CaM). In the presence of CaM, half inhibition of hEAG1 channels was obtained in 100 nM Ca(2+). Overlay assays using labelled CaM and glutathione S-transferase (GST) fusion fragments of hEAG1 demonstrated direct binding of CaM to a C-terminal domain (hEAG1 amino acids 673-770). Point mutations within this section revealed a novel CaM-binding domain putatively forming an amphipathic helix with both sides being important for binding. The binding of CaM to hEAG1 is, in contrast to Ca(2+)-activated potassium channels, Ca(2+) dependent, with an apparent K(D) of 480 nM. Co-expression experiments of wild-type and mutant channels revealed that the binding of one CaM molecule per channel complex is sufficient for channel inhibition.

Is causal induction based on causal power? Critique of Cheng (1997).

The authors empirically evaluate P. W. Cheng's (1997) power PC theory of causal induction. They reanalyze some published data taken to support the theory and show instead that the data are at variance with it. Then, they report 6 experiments in which participants evaluated the causal relationship between a fictitious chemical and DNA mutations. The power PC theory assumes that participants' estimates are based on the causal power p of a potential cause, where p is the contingency between the cause and the effect normalized by the base rate of the effect. Three of the experiments used a procedure in which causal information was presented trial by trial. For these experiments, the power PC theory was contrasted with the predictions of the probabilistic contrast model and the Rescorla-Wagner theory. For the remaining 3 experiments, a summary presentation format was employed to which only the probabilistic contrast model and the power PC theory are applicable. The power PC theory was unequivocally contradicted by the results obtained in these experiments, whereas the other 2 theories proved to be satisfactory.