The effects of context on item-based directed forgetting were assessed. Study words were presented against different background pictures and were followed by a cue to remember (R) or forget (F) the target item. The effects of incidental and intentional encoding of context on recognition of the study words were examined in Experiments 1 and 2. Recognition memory for the picture contexts was assessed in Experiments 3a and 3b. Recognition was greater for R-cued compared to F-cued targets, demonstrating an effect of directed forgetting. In contrast, no directed forgetting effect was seen for the background pictures. An effect of context-dependent recognition was seen in Experiments 1 and 2, such that the hit rate and the false-alarm rate were greater for items tested in an old compared to a novel context. An effect of context-dependent discrimination was also observed in Experiment 2 as the hit rate was greater for targets shown in their same old study context compared to a different old context. The effects of context and directed forgetting did not interact. The results are consistent with Malmberg and Shiffrin's (Journal of Experimental Psychology: Learning, Memory, and Cognition, 31, 322-336, 2005) Bone-shot^context storage hypothesis that assumes that a fixed amount of context is stored in the first 1 to 2 s of the presentation of the study item. The effects of context are independent of item-based directed forgetting because context is encoded prior to the R or F cue, and the differential processing of target information that gives rise to the directed forgetting effect occurs after the cue.
Peptoids are versatile peptidomimetic molecules with wide‐ranging applications from drug discovery to materials science. An understanding of peptoid sequence features that contribute to both their three‐dimensional structures and their interactions with lipids will expand functions of peptoids in varied fields. Furthermore, these topics capture the enthusiasm of undergraduate students who prepare and study diverse peptoids in laboratory coursework and/or in faculty led research. Here, we present the synthesis and study of 21 peptoids with varied functionality, including 19 tripeptoids and 2 longer oligomers. We observed differences in fluorescence spectral features for 10 of the tripeptoids that correlated with peptoid flexibility and relative positioning of chromophores. Interactions of representative peptoids with sonicated glycerophospholipid vesicles were also evaluated using fluorescence spectroscopy. We observed evidence of conformational changes effected by lipids for select peptoids. We also summarize our experiences engaging students in peptoid‐based projects to advance both research and undergraduate educational objectives in parallel.
Firstly, to determine a satisfactory animal model for induction of intrarenal calcification, a study of four previously described animal models of intrarenal calcification was carried out which showed that intraperitoneal injection of 10% calcium gluconate into female Sprague-Dawley rats was most effective. We then investigated the hypothesis that dietary supplementation with essential fatty acids could reduce the intrarenal calcification developing as a result of intraperitoneal calcium injection. Using a combination of fish oil and evening primrose oil, we demonstrated a significant difference in renal parenchymal calcification, which was 940 +/- 240 micrograms Ca/g dry weight renal parenchyma in unsupplemented animals and 320-370 +/- 55-65 micrograms Ca/g dry weight renal parenchyma in supplemented animals (means +/- SEM, P < 0.005). It was also demonstrated that there was synergism between eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA): dietary supplementation with a combined oil preparation containing 27 mg/ml EPA and 67 mg/ml GLA mixed as 2% with food was as effective as oils containing either 400 mg/ml EPA or 80 mg/ml GLA mixed as 4% of food.
<p>The synthesis and fluorescence spectroscopy studies of 21 peptoids,</p>
<p>including 19 new tripeptoids, are described. Insight into sequence features that influence biophysical properties in the presence and absence of unilamellar lipid vesicles is provided. Concomitantly, we highlight the educational value of training undergraduates in multidisciplinary research using peptoid science.</p>
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