The availability and salience of object attributes under haptic exploration, with and without vision, were assessed by 2 tasks in which Ss sorted objects that varied factorially in size, shape, texture, and hardness. In the directed-discrimination task, Ss were instructed to sort along a particular dimension. Although levels on all dimensions were easily discriminated, shape was relatively less so for haptic explorers without vision, as was hardness for those using vision and haptics. Size was least discriminable for both groups. In the free-sorting task, Ss were to sort objects by similarity. Three groups used haptic exploration only; these were differentiated by the experimenters' definition of object similarity: unbiased haptics, haptically biased haptics, haptics plus visual imagery. A 4th group used vision as well as haptics, with instructions like those of the unbiased haptics group. Results support the contention that the haptic and visual systems have distinct encoding pathways, with haptics oriented toward the encoding of substance rather the shape. This may reflect a direct influence of haptic exploratory procedures. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
Under the hypothesis that cardioprotective agents might benefit from synergism between antiarrhythmic activity and antioxidant properties, a small series of mexiletine analogues were coupled with the 2,2,5,5-tetramethylpyrroline moiety, known for its antioxidant effect, in order to obtain dual-acting drugs potentially useful in the protection of the heart against post-ischemic reperfusion injury. The pyrroline derivatives reported herein were found to be more potent as antiarrhythmic agents than mexiletine and displayed antioxidant activity. The most interesting tetramethylpyrroline congener, a tert-butyl-substituted analogue, was at least 100 times more active as an antiarrhythmic than mexiletine. 相似文献
The potential cardiovascular benefit of virgin olive oil (VOO) is widely recognized. However, the use of VOO at very high cooking temperatures makes these oils poorly suited for many Asian dishes. The use of tea seed oil (TSO) is increasing in Thailand, with TSO having a higher smoke point than VOO. The current study examines the effects of daily TSO intake in healthy adults. In a randomized, single-blind crossover design, 12 men consumed for 3 weeks 40 g day−1 of food prepared with either TSO or VOO as a cooking oil. Plasma lipids, thiobarbituric acid reactive substances (TBARS), and oxidant defense enzyme activities are measured before and after each 3-week intervention period. Gas chromatography analysis of TSO and VOO demonstrates that both oils are equally high in monounsaturated fatty acid. The dietary incorporation of TSO and VOO for three weeks reduces low-density lipoprotein cholesterol (LDL-C) concentrations by 15% and 13%, respectively; with total cholesterol (TC) levels lowered by 10% in both groups. No significant changes in TBARS or antioxidant enzyme activity is observed. These results support the concept that Thai TSO can be utilized as a suitable and healthy alternative oil for high-temperature cooking in many Thai and Asian diets. Practical Applications: Tea seed oil from Camellia oleifera grown in Thailand has been recently reported to favorably lower lipid profiles in hamsters fed a high-fat diet in a manner similar to feeding refined olive oil or grapeseed oil. A pilot crossover trial is conducted to compare the effects of three weeks of daily intake of either TSO or VOO in healthy human adults. Consumption of both oils produced significant reductions in TC and LDL-C. Thai TSO leads to favorable lipid profiles and is a reasonable choice for many Thai and Asian food recipes. 相似文献
In this study, microcrystalline cellulose (MCC) was chemically modified with 3-(aminopropyl)triethoxysilane and added to epoxy to improve chemical, thermal and dynamic-mechanical characteristics of the composites. The composites were manufactured aided by sonication with 1.0%, 2.5%, or 5.0% wt/wt of untreated MCC or amino-functionalized MCC (MCC-Si). The epoxy/MCC-Si composites showed a decrease in the ─OH band by Fourier-transform infrared spectroscopy, and X-ray diffraction analysis indicated better dispersion. The incorporation of MCC-Si in epoxy resin decreased the heat of reaction, increased activation energy values (Ea) and pre-exponential factor (A), and did not affect thermal degradation. All conversion degree (α) versus temperature curves for the composites showed a sigmoidal shape. MCC-Si composites showed better dynamic-mechanical properties than the MCC counterparts, and the functionalization effect was evidenced in storage modulus (E') and loss modulus (E"). At 2.5% wt/wt of MCC-Si content an increase of 119% in E' at the glassy region, 127% in E' at the rubbery region and 173% in E" was observed compared to the neat resin, whereas the Tg barely changed among samples. Good adhesion between the amino-functionalized MCC and the epoxy matrix was observed at the fracture surface, evidencing that surface modification of MCC improves their chemical interaction. 相似文献
Reactivity data related to processes in which molecular receptors promote the reaction of two simultaneously complexed reactants have been surveyed and analyzed in terms of effective molarity (EM). Methods and criteria for the calculation of reliable EM's have been highlighted. Extension of a previous extrathermodynamic treatment of intramolecular reactions of bifunctional chains to the intracomplex reactions of the ternary complexes involved in two-substrate catalyzed reactions has provided a sound framework for a comparative analysis of reactivity and catalytic efficiency in structurally diverse and apparently unrelated systems. 相似文献
Remote sensing of invasive species is a critical component of conservation and management efforts, but reliable methods for the detection of invaders have not been widely established. In Hawaiian forests, we recently found that invasive trees often have hyperspectral signatures unique from that of native trees, but mapping based on spectral reflectance properties alone is confounded by issues of canopy senescence and mortality, intra- and inter-canopy gaps and shadowing, and terrain variability. We deployed a new hybrid airborne system combining the Carnegie Airborne Observatory (CAO) small-footprint light detection and ranging (LiDAR) system with the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) to map the three-dimensional spectral and structural properties of Hawaiian forests. The CAO-AVIRIS systems and data were fully integrated using in-flight and post-flight fusion techniques, facilitating an analysis of forest canopy properties to determine the presence and abundance of three highly invasive tree species in Hawaiian rainforests.
The LiDAR sub-system was used to model forest canopy height and top-of-canopy surfaces; these structural data allowed for automated masking of forest gaps, intra- and inter-canopy shadows, and minimum vegetation height in the AVIRIS images. The remaining sunlit canopy spectra were analyzed using spatially-constrained spectral mixture analysis. The results of the combined LiDAR-spectroscopic analysis highlighted the location and fractional abundance of each invasive tree species throughout the rainforest sites. Field validation studies demonstrated < 6.8% and < 18.6% error rates in the detection of invasive tree species at 7 m2 and 2 m2 minimum canopy cover thresholds. Our results show that full integration of imaging spectroscopy and LiDAR measurements provides enormous flexibility and analytical potential for studies of terrestrial ecosystems and the species contained within them. 相似文献
Heavy metal removal from industrial wastewaters has been intensively studied, since it is well known that they can cause severe problems to human health and aquatic life, even at very low concentrations. In this work, it was demonstrated that electrodeposition in fluidized bed electrode (FBE) can be efficiently employed to remove metal ions from solution, avoid contamination, and recover the metal. Copper electrodeposition from diluted solutions was efficiently performed using a membraneless FBE. The average current efficiency (ACE), average energy consumption (AEC), and space–time yield (AY) was optimized taking into account the operational and process variables. It was noted that for all response variables studied, the raise of supporting electrolyte concentration (Cs) contributed to improvements in the process. The operational conditions current (I) and bed expansion (E) determined the values of CE, Y, and EC under activated control, but the initial copper concentration (C0) determined how long the electrodeposition process will work under activated or mass transfer control, thus affecting the average values of CE, Y, and EC. Considering C0 of 500 mg L?1, copper can be optimally recovered with ACE >60 %, AY >38 kg h?1 m?3, and AEC <4.0 kWh kg?1 by applying the lowest I and the highest levels of E and Cs. It was concluded that the electrochemical technology using a membraneless FBE reactor is economically competitive and be applied for the treatment of wastewaters contaminated with copper or other metals. 相似文献
Silver-based products have been proven to be effective in retarding and preventing bacterial growth since ancient times. In the field of restorative dentistry, the use of silver ions/nanoparticles has been explored to counteract bacterial infections, as silver can destroy bacterial cell walls by reacting with membrane proteins. However, it is also cytotoxic towards eukaryotic cells, which are capable of internalizing nanoparticles. In this work, we investigated the biological effects of Chitlac-nAg, a colloidal system based on a modified chitosan (Chitlac), administered for 24–48?h to a co-culture of primary human gingival fibroblasts and Streptococcus mitis in the presence of saliva, developed to mimic the microenvironment of the oral cavity. We sought to determine its efficiency to combat oral hygiene-related diseases without affecting eukaryotic cells. Cytotoxicity, reactive oxygen species production, apoptosis induction, nanoparticles uptake, and lysosome and autophagosome metabolism were evaluated. In vitro results show that Chitlac-nAg does not exert cytotoxic effects on human gingival fibroblasts, which seem to survive through a homoeostasis mechanism involving autophagy. That suggests that the novel biomaterial Chitlac-nAg could be a promising tool in the field of dentistry. 相似文献
Brain-computer interface (BCI) systems aim to enable interaction with other people and the environment without muscular activation by the exploitation of changes in brain signals due to the execution of cognitive tasks. In this context, the visual P300 potential appears suited to control smart homes through BCI spellers. The aim of this work is to evaluate whether the widely used character-speller is more sustainable than an icon-based one, designed to operate smart home environment or to communicate moods and needs. Nine subjects with neurodegenerative diseases and no BCI experience used both speller types in a real smart home environment. User experience during BCI tasks was evaluated recording concurrent physiological signals. Usability was assessed for each speller type immediately after use. Classification accuracy was lower for the icon-speller, which was also more attention demanding. However, in subjective evaluations, the effect of a real feedback partially counterbalanced the difficulty in BCI use. PRACTITIONER SUMMARY: Since inclusive BCIs require to consider interface sustainability, we evaluated different ergonomic aspects of the interaction of disabled users with a character-speller (goal: word spelling) and an icon-speller (goal: operating a real smart home). We found the first one as more sustainable in terms of accuracy and cognitive effort. 相似文献