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941.
Associations between certain odors and for instance health effects may lead to positive or negative attitudes toward these odors. However, in experiments we conducted using the Implicit Association Test (IAT), we encountered attitudes even to odor "words." The IAT is based on the principle that reaction times measuring the association between words from a target dimension (in this case, odor vs. a neutral reference category) and an attribute dimension (i.e., positive or negative words) reflect the attitude to the target, where attitude-congruent associations between target and attribute are reflected by shorter reaction times. In a first experiment, we found distinctly positive attitudes to the concept odor in a student sample, which was replicated in a second experiment. In the main experiment, subjects in the aromatherapy group, who prefer using scented consumer products for relaxation purposes, showed a significantly more positive attitude toward odor words in the IAT than a control group, who did not have such a preference. The fact that results from the implicit test were not always associated with explicitly stated attitudes toward the odor words attests to the fact that the IAT measures the attitude of interest in a different way. As such, the IAT has added value in circumstances where explicit tests can be biased. 相似文献
942.
Sculpin are small-bodied fish that exhibit limited mobility. These fish may therefore be an ideal choice as sentinel species
in environmental effects monitoring as they may be more reflective of ambient local conditions than are the large-bodied,
more wide-ranging species historically used in monitoring programs. This study quantified the spatial and temporal density
and distributional patterns of the slimy sculpin (Cottus cognatus) population in Catamaran Brook, New Brunswick, with the aim of gaining a better understanding of their response to natural
environmental variability. We predicted that sculpin densities would follow a longitudinal temperature gradient from headwater
to mouth and would be highly sensitive to fluctuations in stream flow and substrate disturbance. Electrofishing surveys conducted
twice per year from 1991 to 1998 revealed significant differences in sculpin density between years, reaches, and habitats,
but not between seasons. The highest sculpin densities were found in those reaches with the coolest summer water temperature.
The Middle reach in Catamaran Brook annually supported the highest sculpin density, followed by the headwater or Upper reach
and then by the two lowermost reaches: Gorge and Lower. Stochastic events also influenced population dynamics. A mid-winter
ice break-up (1996) and its associated flood and ice scour caused the greatest disturbance of the sculpin population, resulting
in a significant density decline and a shift in the population age structure. A bedload movement experiment conducted to further
assess sculpins’ response to substrate stability identified greater bed stability in the Upper and Middle reaches of the brook
than in the Lower reach. The pattern of sculpin distribution observed in this study is consistent with the idea that distribution
and abundance of sculpin are significantly influenced by stream temperature but also, in part, by stream bed stability. 相似文献
943.
Ruiz L Sánchez B Ruas-Madiedo P de Los Reyes-Gavilán CG Margolles A 《FEMS microbiology letters》2007,274(2):316-322
Bifidobacterium animalis ssp. lactis is a probiotic frequently used as adjunct culture in fermented dairy products. In order to ensure its proper function at the intestinal level, this bacterium has to be tolerant to physiological concentrations of bile. This study examined the influence of bile on the fatty acid composition and the membrane characteristics of B. animalis IPLA 4549 and its mutant with acquired resistance to bile, B. animalis 4549dOx. Bile adaptation triggers in B. animalis 4549dOx a decrease in membrane fluidity and in the protein : phospholipid ratio, as well as a shift in the fatty acid composition of the cell. Remarkably, the presence of bile in the growth medium induced similar changes in both B. animalis cells. Furthermore, transmission electron microscopy analysis showed that bile promotes a severe distortion of the cell surface. This study provides new insights of the action of bile on the cell envelope of bifidobacteria. 相似文献
944.
The immature stages oí Hemilucilia segmentaria (Fabricius, 1805) (Diptera: Calliphoridae) are described. Egg morphology and structures such as the cephalopharyngeal skeleton, anterior and posterior spiracles, and the dorsal spines between the prothorax and mesothorax from first, second and third instar larvae are characterized, using light and scanning electron microscopy. This species is abundant in Neotropical forests and, because of its necrophagous behavior, is of substantial medico-legal importance for estimating the postmortem interval in criminal investigations. Information presented herein may be useful to differentiate among eggs and larvae of closely related species and to supplement the database for blowfly identification. 相似文献
945.
946.
Through bioinformatics and experimental approaches, we have assigned the first biochemical property to a predicted protein product in the human genome as a new 14-3-3 binding protein. 14-3-3 client proteins represent a diverse group of regulatory molecules that often function as signaling integrators in response to various environmental cues and include proteins such as Bad and Foxo. Using 14-3-3 as a probe in a yeast two-hybrid screen, we identified a novel 14-3-3 binding protein with unknown function, initially designated as clone 546. Confocal microscopy revealed that clone 546 localized to the nucleus of mammalian cells. Additional studies show that the gene encoding clone 546 is expressed in many human tissues, including the thymus, as well as a number of cancer cell lines. The interaction of clone 546 with 14-3-3 was confirmed in mammalian cells. Interestingly, this interaction was markedly enhanced by the expression of activated Akt/PKB, suggesting a phosphorylation dependent event. Mutational analysis was carried out to identify Ser479 as the predominant residue that mediates the clone 546/14-3-3 association. Phosphorylation of Ser479 by AKT/PKB further supports a critical role for Akt/PKB in regulation of the clone 546/14-3-3 interaction. On the basis of these findings, we named this undefined protein FAKTS: Fourteen-three-three associated AKT Substrate. 相似文献
947.
948.
High sensitivity of human centrin 2 toward radiolytical oxidation: C-terminal tyrosinyl residue as the main target 总被引:1,自引:0,他引:1
Blouquit Y Duchambon P Brun E Marco S Rusconi F Sicard-Roselli C 《Free radical biology & medicine》2007,43(2):216-228
Centrins are calcium-binding proteins that play a significant role in the maintenance of the centrosomal organization, mainly in the continuity between centrosome and microtubular network. Recent data showed that centrosome duplication abnormalities, like overduplication for example, could be due to hydrogen peroxide, suggesting an important impact of oxidative stress. To challenge this hypothesis, we performed one-electron oxidation experiments with human centrin 2, starting from azide radicals. Our results first revealed several intermolecular cross-links generating dimers, tetramers, hexamers, and higher molecular mass species. Dimers result from covalent bond linking the C-terminal tyrosines of each monomer. Second, the methionyl residue at position 19 was oxidized on the monomeric centrin. Further, electron microscopy experiments on centrin 2 showed a preexisting hexameric organization that was stabilized by covalent bonds as a result of irradiation. Overall, these results show that centrin 2 is highly sensitive to ionizing radiation, which could have important consequences on its biological functions. 相似文献
949.
950.