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81.
[Correction Notice: An erratum for this article was reported in Vol 7(4) of Emotion (see record 2007-17748-022). The image printed for Figure 3 was incorrect. The correct image is provided in the erratum.] Previous studies indicate that the encoding of new facial identities in memory is influenced by the type of expression displayed by the faces. In the current study, the authors investigated whether or not this influence requires attention to be explicitly directed toward the affective meaning of facial expressions. In a first experiment, the authors found that facial identity was better recognized when the faces were initially encountered with a happy rather than an angry expression, even when attention was oriented toward facial features other than expression. Using the Remember/Know/Guess paradigm in a second experiment, the authors found that the influence of facial expressions on the conscious recollection of facial identity was even more pronounced when participants' attention was not directed toward expressions. It is suggested that the affective meaning of facial expressions automatically modulates the encoding of facial identity in memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
82.
In this paper, we describe a complete system for mission planning and execution for multiple robots in natural terrain. We report on experiments with a system for autonomously driving two vehicles based on complex mission specifications. We show that the system is able to plan local paths in obstacle fields based on sensor data, to plan and update global paths to goals based on frequent obstacle map updates, and to modify mission execution, e.g., the assignment and ordering of the goals, based on the updated paths to the goals.Two recently developed sensors are used for obstacle detection: a high-speed laser range finder, and a video-rate stereo system. An updated version of a dynamic path planner, D*, is used for on-line computation of routes. A new mission planning and execution-monitoring tool, GRAMMPS, is used for managing the allocation and ordering of goals between vehicles.We report on experiments conducted in an outdoor test site with two HMMWVs. Implementation details and performance analysis, including failure modes, are described based on a series of twelve experiments, each over 1/2 km distance with up to nine goals.The work reported here includes a number of results not previously published, including the use of a real-time stereo machine and a high-performance laser range finder, and the use of the GRAMMPS planning system.  相似文献   
83.
The structure of the thermostable triosephosphate isomerase (TIM) from Bacillus stearothermophilus complexed with the competitive inhibitor 2-phosphoglycolate was determined by X-ray crystallography to a resolution of 2.8 A. The structure was solved by molecular replacement using XPLOR. Twofold averaging and solvent flattening was applied to improve the quality of the map. Active sites in both the subunits are occupied by the inhibitor and the flexible loop adopts the "closed" conformation in either subunit. The crystallographic R-factor is 17.6% with good geometry. The two subunits have an RMS deviation of 0.29 A for 248 C alpha atoms and have average temperature factors of 18.9 and 15.9 A2, respectively. In both subunits, the active site Lys 10 adopts an unusual phi, psi combination. A comparison between the six known thermophilic and mesophilic TIM structures was conducted in order to understand the higher stability of B. stearothermophilus TIM. Although the ratio Arg/(Arg+Lys) is higher in B. stearothermophilus TIM, the structure comparisons do not directly correlate this higher ratio to the better stability of the B. stearothermophilus enzyme. A higher number of prolines contributes to the higher stability of B. stearothermophilus TIM. Analysis of the known TIM sequences points out that the replacement of a structurally crucial asparagine by a histidine at the interface of monomers, thus avoiding the risk of deamidation and thereby introducing a negative charge at the interface, may be one of the factors for adaptability at higher temperatures in the TIM family. Analysis of buried cavities and the areas lining these cavities also contributes to the greater thermal stability of the B. stearothermophilus enzyme. However, the most outstanding result of the structure comparisons appears to point to the hydrophobic stabilization of dimer formation by burying the largest amount of hydrophobic surface area in B. stearothermophilus TIM compared to all five other known TIM structures.  相似文献   
84.
Conjugated linoleic acids (CLAs) consist of a series of positional and geometrical isomers of linoleic acid. CLA have been reported to beneficially affect cardiovascular risk factors in animal models. In order to assess the role of individual CLA isomers on lipoprotein cholesterol concentration, 30 hamsters were fed for 12 weeks an hyperlipidic diet containing pure cis-9,trans-11 CLA (c9,t11) or pure trans-10, cis-12 CLA (t10,c12) isomers given alone or as a mixture. Plasma total cholesterol, LDL and HDL cholesterol concentrations were significantly lower in the c9,t11 CLA isomer fed hamsters relative to the Control group, with the most substantially effect on LDL cholesterol (−56%; P < 0.05). Plasma triacylglycerol concentrations did not differ significantly regarding those two groups. Plasma cholesterol parameters showed a tendency to decrease in the t10,c12 CLA isomer and CLA mixture fed hamsters compared with the Control group, but differences were not significant. For the first time, the atherogenic fraction of small dense LDL was investigated. Plasma small dense LDL cholesterol concentration was lower in the c9,t11 CLA relative to Control, while the t10,c12 and CLA mixture groups showed only a non significant tendency to decrease. Taken together, these data indicate that feeding rumenic acid (c9,t11 CLA) may beneficially affect lipoprotein profile in hamster fed a cholesterol- and lipid-enriched semi-purified diet, when t10,c12 CLA isomer or CLA mixture would be less active.  相似文献   
85.
The aim of this study was to investigate the potential fire performance of alcohol resistant foams using a new additive developed by DuPont. The main intention of the new additive is to allow a lower amount of polysaccharide in the formulation of AFFF/AR concentrates thereby reducing their viscosity. A comparative study was performed using two similar formulations of AFFF/AR-concentrates, one traditional concentrate (designated F1) and a novel concentrate (designated F2), which contains the new additive and half the traditional amount of polysaccharide. The study, performed at SP Fire Technology, comprised small scale fire tests in combination with a series of additional tests aimed to provide detailed information about expansion and drainage characteristics, foam spread properties, the influence of heat exposure and vapour suppression capability.The study confirms the desired reduction of the viscosity of an AFFF/AR foam concentrate, using a lower amount of polysaccharide in its formulation, while with the use of the new additive, the fire performance has the potential to be similar or even better than a traditional AFFF/AR foam.  相似文献   
86.
It has been suggested that patients with schizophrenia experience a distorted sense of continuity of self across time. However, temporal aspects of self-processing have received little empirical attention in schizophrenia. In this study, the authors investigated schizophrenic patients' ability to generate specific mental images of their personal past and future. Results showed that patients recalled fewer specific past events than did healthy controls and were even more impaired in generating specific future events. These deficits were associated with positive symptoms but were not associated with negative symptoms or with performances on verbal fluency tasks. It is suggested that schizophrenic patients' failures to project themselves into specific past and future episodes might be related to difficulties in retrieving contextual details from memory, as well as disturbance of the sense of subjective time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
87.
This paper presents the results of field trials of a prototype lunar rover traveling over natural terrain under safeguarded teleoperation control. Both the rover and the safeguarding approach have been used in previous work. The original contributions of this paper are the development and integration of a laser hazard detection system, and extensive field testing of the overall system. The laser system, which complements an existing stereo vision system, is based on a line-scanning laser ranger viewing the area 1 meter in front of the rover. The laser system has demonstrated excellent performance: zero misses and few false alarms operating at 4 Hz. The overall safeguarding system guided the rover 43 km over lunar analogue terrain with 0.8 failures per kilometer.  相似文献   
88.
In situ capping has recently emerged as a remedial method for contaminated sediments and involves placing a layer of clean material at the sediment-water interface. The biogeochemical response of native sediment following capping, as well as the redoxenvironmentsthatdevelopwithinthe cap, are currently unknown. Column experiments were performed using voltammetric microelectrodes to characterize spatial and temporal distributions of biogeochemical processes in capped sediments under stagnant and upflow conditions. Oxygen penetration into sand caps extended only a few centimeters, thus maintaining underlying sediment anaerobic. Chemical species indicative of heterotrophic organic matter degradation (Mn2+, Fe2+, organic--FeIII(aq), FexSy(aq), sigmaH2S) were observed in stratified zones below the oxic layer. The majority of the overlying cap was subject to iron-reducing conditions under stagnant flow, while upflow conditions led to a compression of the redox zones toward the cap-water interface. Controls confirmed that sediment capping induced an upward, vertical shift of biogeochemical processes into the overlying cap, with redox stratification conserved. The redox conditions within the cap, specifically the predominance of iron reduction, should allow for reductive contaminant attenuation processes to extend into the overlying cap. These findings improve our understanding of the dynamics of biogeochemical processes following capping of contaminated sediments.  相似文献   
89.
An inverse, free‐radical emulsion polymerization technique was designed for the preparation of copolymers of acrylamide and sodium acrylate modified with low amounts (<0.5 mol %) of a series of amphiphilic comonomers, the isooctylphenoxy–poly(oxyethylene)(n) methacrylates (1 ≤ n ≤ 12). The products of the reaction were hydrophobically modified water‐soluble polymers (HMWSPs) of high molecular weight encapsulated within water droplets dispersed in an organic medium. Kinetic studies showed that the full‐conversion samples were rather homogeneous in composition because of the specificity of the process. A mechanistic scheme is proposed that accounts for the incorporation level of the amphiphilic comonomer as a function of its hydrophile–lipophile balance and the nature of the redox initiator (hydrophilic or lipophilic). The rheological properties of the HMWSPs in aqueous solutions were investigated as a function of the comonomer content and the nature of the initiator with steady‐flow experiments. The thickening properties were directly correlated to the conditions of synthesis and were optimal when the initiator and the amphiphilic comonomer were located in two distinct phases. A maximum in viscosity was observed for a hydrophobe content of about 0.3 mol %. An examination of the viscosity as a function of the shear rate and time showed that these solutions had all the characteristics of associating polymers. The complex rheological behavior was the result of the balance between interchain and intrachain hydrophobic liaisons and the kinetics of disorganization and reorganization of the network structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1418–1430, 2002; DOI 10.1002/app.10337  相似文献   
90.
Effects of cassava variety on chemical composition and consumer acceptability of gari were investigated. Three traditional cassava varieties Bonoua 2, Yace and Yavo as well as four improved cassava varieties Bocou 1, Bocou 2, Bocou 3 and TMS (2) 1425 were evaluated. All the varieties had appreciable high value of carbohydrates ranged from 86.6% (TMS (2) 1425) to 90.89% (Bonoua 2). TMS (2) 1425 had the lowest reducing sugar value (0.22%) while Bocou 3 had the highest reducing sugar value (0.38%). Studied gari exhibited low value of hydrogen cyanide with the lowest value found in Bocou 1 (1.53 mg per 100 g). Total fibre value varied to 2.88% (Yace) to 2.28% (Bocou 2). Gari of Bocou 1 and Bocou 3 were the most appreciated. These gari had fairly sweet taste, were fairly bright and contained few impurities. This study demonstrated that cassava variety influenced the chemical composition and consumer acceptability of gari.  相似文献   
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