The aim of this work was to test the hypothesis that motor fluency should help the integration of the components of the trace and therefore its re-construction. In the encoding phase of each of the ...three experiments we conducted, a word to be remembered appeared colored in blue or purple. Participants had to read these words aloud and, at the same time, execute a gesture in their ipsilateral (fluent gesture) or contralateral space (non-fluent gesture), according to the color of the word. The aim of the first experiment was to show that the words associated with a fluent gesture during the encoding phase were more easily recognized than those associated with a non-fluent gesture. The results obtained supported the hypothesis. In the second experiment, our objective was to show that the fluency of a gesture performed during encoding in order to associate a word with a color can facilitate the integration of the word with its color. Here again, the results obtained supported the hypothesis. While in Experiment
2
we tested the effect of motor fluency during encoding on word-color integration, the objective of Experiment
3
was to show that motor fluency was integrated in the word-color trace and contributed to the re-construction of the trace. The results obtained supported the hypothesis. Taken together, these findings lead us to believe that traces are not only traces of the processes that gave rise to them, but also traces of the way in which the processes took place.
Neural correlates of responses to emotionally valenced olfactory, visual, and auditory stimuli were examined using positron emission tomography. Twelve volunteers were scanned using the water bolus ...method. For each sensory modality, regional cerebral blood flow (rCBF) during presentation of both pleasant and unpleasant stimuli was compared with that measured during presentation of neutral stimuli. During the emotionally valenced conditions, subjects performed forced-choice pleasant and unpleasant judgments. During the neutral conditions, subjects were asked to select at random one of a two key-press buttons. All stimulations were synchronized with inspiration, using an airflow olfactometer, to present the same number of stimuli for each sensory modality. A no-stimulation control condition was also performed in which no stimulus was presented. For all three sensory modalities, emotionally valenced stimuli led to increased rCBF in the orbitofrontal cortex, the temporal pole, and the superior frontal gyrus, in the left hemisphere. Emotionally valenced olfactory and visual but not auditory stimuli produced additional rCBF increases in the hypothalamus and the subcallosal gyrus. Only emotionally valenced olfactory stimuli induced bilateral rCBF increases in the amygdala. These findings suggest that pleasant and unpleasant emotional judgments recruit the same core network in the left hemisphere, regardless of the sensory modality. This core network is activated in addition to a number of circuits that are specific to individual sensory modalities. Finally, the data suggest a superior potency of emotionally valenced olfactory over visual and auditory stimuli in activating the amygdala.
One very well-known memory phenomenon is the observation that if a specific item seems to be different or rare in any way from other items present in the same encoding context, this item is likely to ...be remembered more accurately. This phenomenon, named the von Restorff effect or the isolation effect, has been known since 1933 and been considered today as one of the possible ways to create distinctiveness. The aim of this article is to report that the current debate concerning its non-emergence in implicit memory tasks is directly due to a theoretical disagreement about the nature of human memory. In this paper, we conclude that non-abstractive global-matching models can provide an effective theoretical framework for the study of the distinctiveness effect with isolation both in implicit and explicit memory tasks.
Un phénomène particulièrement avéré en mémoire est l’observation même que si un élément spécifique semble être différent ou rare d’une certaine manière des autres éléments présents dans le même contexte d’encodage, cet élément est susceptible d’être mieux rappelé. Ce phénomène, appelé l’effet von Restorff ou l’effet d’isolation, est connu depuis 1933, est considéré aujourd’hui comme l’un des méthodes possibles pour créer la distinctivité. Le but de cet article est de soutenir que le débat actuel concernant la non-émergence de l’effet de distinctivité dans les tâches de mémoire implicite est directement du au désaccord théorique sur la nature et l’organisation de la mémoire humaine. Dans cet article, nous soutenons que les modèles d’appariement global non abstractifs peuvent fournir un cadre théorique pertinent pour étudier l’effet de distinctivité et l’isolation à la fois dans les tâches de mémoire implicite et explicite.
LAF389 is a synthetic analogue of bengamides, a class of marine natural products that produce inhibitory effects on tumor growth in vitro and in vivo. A proteomics-based approach has been used to ...identify signaling pathways affected by bengamides. LAF389 treatment of cells resulted in altered mobility of a subset of proteins on two-dimensional gel electrophoresis. Detailed analysis of one of the proteins, 14-3-3gamma, showed that bengamide treatment resulted in retention of the amino-terminal methionine, suggesting that bengamides directly or indirectly inhibited methionine aminopeptidases (MetAps). Both known MetAps are inhibited by LAF389. Short interfering RNA suppression of MetAp2 also altered amino-terminal processing of 14-3-3gamma. A high resolution structure of human MetAp2 co-crystallized with a bengamide shows that the compound binds in a manner that mimics peptide substrates. Additionally, the structure reveals that three key hydroxyl groups on the inhibitor coordinate the di-cobalt center in the enzyme active site.
The structural chemistry and biological activity of the bengamide class of compounds have been further characterized. Extracts prepared from recollected Jaspis cf. coriacea from five sites in Fiji ...were pooled. Six new bengamides, M (7b), N (8a), O (8b), P (9a), Q (9b), and R (10), were identified, accompanied by the known bengamides A (1a), B (1b), E (3a), F (3b), Y (5), Z (6), L (7a), G (11a), H (11b), and I (12). The structures of the new compounds were determined from spectroscopic data, and some were additionally confirmed by semisynthesis. Cytotoxicity screening data were obtained from the NCI-DTP 60 cell screen for bengamides A, B, and P. Bengamides A and B were more potent than bengamide P, with average IC(50) values of 0.046, 0.011, and 2.70 FM, respectively. The in vitro antitumor activity against MDA-MB-435 human mammary carcinoma was also determined for natural bengamides A, B, E, F, P, M, O, and Z and for synthetic samples of B and O. The best activity was observed for the natural bengamides A (IC(50) = 1 nM) and O (IC(50) = 0.3 nM).
Bengamide B, a novel sponge-derived marine natural product with broad spectrum antitumor activity, was not suitable for further preclinical development because of its difficult synthesis and very ...poor water solubility. Bengamide B produced a 31% T/C at its solubility-limited maximum intravenous dose of 33 micromol/kg in MDA-MB-435 breast carcinoma implanted subcutaneously as a xenograft in nude mice. Compound 8a, a bengamide B analogue with three structural changes (t-Bu alkene substituent, unsubstituted lactam nitrogen, and inverted lactam 5'-myristoyloxy group), was as potent as bengamide B in vitro and more efficacious than bengamide B in vivo. A series of ester-modified analogues based on 8a were synthesized and tested in vitro and in vivo (MDA-MB-435). The cyclohexyl- and phenethyl-substituted esters, 8c and 8g, respectively, had in vitro and in vivo activities similar to that of 8a and enhanced water solubility (ca. 1 mg/mL). Consequently, 8c and 8g were tested in the MDA-MB-435 xenograft model at 100 micromol/kg and produced 29% and 57% tumor regression, respectively.
Total syntheses of bengamides B and E Kinder, Jr, F R; Wattanasin, S; Versace, R W ...
Journal of organic chemistry,
03/2001, Letnik:
66, Številka:
6
Journal Article
Recenzirano
Total syntheses of the cytotoxic marine natural products bengamides B and E are described. Both bengamides are prepared via amide coupling of a protected polyhydroxylated lactone intermediate 9 with ...a suitably substituted aminocaprolactam intermediate. Lactone 9 is prepared in five steps from commercially available alpha-D-glucoheptonic gamma-lactone. The key reactions are a selective deprotection of a 1,2-acetonide in the presence of a 1,3-acetonide and an (E)-selective olefination of an unstable aldehyde using a gem-dichromium reagent. The bengamide B lactam intermediate 10 is prepared in seven steps from commercially available (5R)-5-hydroxy-L-lysine (12). The desired S-configuration at the gamma-OH lactam position is established using the Mitsunobu reaction.
Several studies have shown that adults can memorize an audio-visual association in response to an incidental presentation. Moreover, a motor experience of the letter-shape promotes letter knowledge ...and reading acquisition.
In order to develop optimal learning designs for children, we evaluate the effect of the implicit learning of grapho-phonemic correspondences on decoding abilities (study 1). The action performed on the letter-shape in this type of learning was then also investigated with regard to the emergence of multisensory knowledge (study 2).
A paradigm inspired by studies conducted with adults was tested in 5-year-old children (study 1). A classical design pre-test/learning/post-test was used in the study 2. During the learning, the child was asked to explore the letter shape. An incidental presentation of the corresponding sound was simultaneously proposed to the child.
Results indicated that (1) implicit learning was efficient on the discrimination of grapho-phonemic correspondences in young children and (2) the motor action amplified audio-visual integration within a single memory trace.
These results are discussed in the light of knowledge emergence in long-term memory and the benefit of an implicit training at the beginning of reading acquisition.
Certaines études ont montré qu’une association audio-visuelle peut être intégrée grâce à une présentation incidente chez l’adulte. De plus, l’expérience motrice de la forme des lettres favoriserait la connaissance des lettres et l’apprentissage de la lecture.
Afin de créer des situations optimales d’apprentissage chez l’enfant, l’étude 1 vise à évaluer l’effet d’un apprentissage implicite aux correspondances graphèmes-phonèmes sur les capacités de décodage. La seconde étude a pour objectif de déterminer le rôle de l’action sur la forme de la lettre dans un tel dispositif sur l’émergence de connaissances multi-sensorielles.
Un paradigme inspiré des études conduites chez les adultes est testé avec des enfants de 5 ans (étude 1). Un protocole classique pré-test/apprentissage/post-test est mis en œuvre dans l’étude 2. Dans l’apprentissage, il est demandé à l’enfant d’explorer la forme de la lettre. Une présentation incidente du son correspondant est proposée simultanément par l’enfant.
Les résultats indiquent que (1) un apprentissage implicite est efficace sur la discrimination des correspondances grapho-phonémiques chez les jeunes enfants et (2) l’action motrice amplifie l’intégration audio-visuelle en une trace unique en mémoire.
Ces résultats sont discutés au regard de l’émergence des connaissances en mémoire à long terme et de l’intérêt d’un apprentissage implicite au début de l’apprentissage de la lecture.
Peripheral papillary adenomas of the lung are uncommon neoplasms (only ten cases have been described so far in the English literature) composed predominantly of type-II pneumocytes and generally ...considered benign. We describe here two additional cases of this lung tumor. In both cases histological examination revealed an encapsulated papillary neoplasm with invasion of the capsule and, in one case, invasion of the adjacent alveoli and visceral pleura too. The proliferative index (Ki67) was less than 2% and the epithelial cells were positive for cytokeratins, surfactant apoproteins (SP), and nuclear thyroid transcription factor-1 (TTF- 1). Ultrastructurally, the epithelial cells showed the characteristic surface microvilli and cytoplasmic lamellar inclusions of type-II cells. Review of the literature has revealed two other cases of peripheral papillary adenoma of type-II pneumocytes with infiltrative features. Thus, we propose replacing the term peripheral papillary adenoma with peripheral papillary tumor of undetermined malignant potential.
PDF
