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81.
The forthcoming home environment will comprise numerous computationally enhanced artifacts that are autonomous, but interconnected via an invisible web of network-based services. The approach presented in this paper is to enable end users to make their own applications by linking such artifacts, which are treated as reusable components. A key requirement to achieve this is the availability of editing tools that meet the needs of different classes of users. A tool of this kind designed for end users is presented in this paper, together with the outcome of user evaluation sessions.  相似文献   
82.
The behavior of fluoroquinolone antibacterial agents (FQs) during mechanical-biological wastewater treatment was studied by mass flow analysis. In addition, the fate of FQs in agricultural soils after sludge application was investigated. Concentrations of FQs in filtered wastewater (raw sewage, primary, secondary, and tertiary effluents) were determined using solid-phase extraction with mixed phase cation exchange disk cartridges and reversed-phase liquid chromatography with fluorescence detection. FQs in suspended solids, sewage sludge (raw, excess, and anaerobically digested sludge), and sludge-treated soils were determined as described for the aqueous samples but preceded by accelerated solvent extraction. Wastewater treatment resulted in a reduction of the FQ mass flow of 88-92%, mainly due to sorption on sewage sludge. A sludge-wastewater partition coefficient (log Kd approximately 4) was calculated in the activated sludge reactors with a hydraulic residence time of about 8 h. No significant removal of FQs occurred under methanogenic conditions of the sludge digesters. These results suggest sewage sludge as the main reservoir of FQ residues and outline the importance of sludge management strategies to determine whether most of the human-excreted FQs enter the environment. Field experiments of sludge-application to agricultural land confirmed the long-term persistence of trace amounts of FQs in sludge-treated soils and indicated a limited mobility of FQs into the subsoil.  相似文献   
83.
The structures and stabilities of cyclic DNA octamers of different sequences have been studied by NMR and CD spectroscopy and by restrained molecular dynamics. At low oligonucleotide concentrations, some of these molecules form stable monomeric structures consisting of a short stem of two base pairs connected by two mini-loops of two residues. To our knowledge, these dumbbell-like structures are the smallest observed to date. The relative stabilities of these cyclic dumbbells have been established by studying their melting transitions. Dumbbells made up purely of GC stems are more stable than those consisting purely of AT base pairs. The order of the base pairs closing the loops also has an important effect on the stabilities of these structures. The NMR data indicate that there are significant differences between the solution structures of dumbbells with G-C base pairs in the stem compared to those with A-T base pairs. In the case of dumbbells with G-C base pairs, the residues in the stem form a short segment of a BDNA helix stabilized by two Watson-Crick base pairs. In contrast, in the case of d, the stem is formed by two A-T base pairs with the glycosidic angles of the adenine bases in a syn conformation, most probably forming Hoogsteen base pairs. Although the conformations of the loop residues are not very well defined, the thymine residues at the first position of the loop are observed to fold back into the minor groove of the stem.  相似文献   
84.
The effects of the operating conditions, the initial concentrations of marine diesel fuel (MDF) and the coexisting Pb in the soil, and the ethylene diamine tetra acetic salt (EDTA) in solution on MDF removal by sodium dodecyl sulfate (SDS) washing were extensively investigated with the aim of optimizing the process parameters and determining the MDF removal efficiency by SDS under different contamination conditions. The experimental results from batch tests indicated that the majority of MDF was removed by SDS in the first 2?h, and its optimal pH was nearly neutral. Increasing the SDS concentration linearly increased the MDF removal efficiency. At a given SDS concentration, the removal efficiency was dependent on the existing forms of MDF in soils, and the free phase of MDF was found to be more easily removed than the adsorbed phase. MDF removal by SDS was significantly reduced by the coexisting Pb in soils, which likely forms a complexation with SDS and thereby enhances the partitioning of MDF in the soil by the re-adsorption of released MDF onto the hydrophobic tails of the adsorbed SDS. EDTA alone, or with SDS, could remove MDF, but the remaining MDF in the contaminated soil after EDTA washing became more difficult to be removed by SDS. Therefore, the EDTA washing followed by SDS washing is not recommended for MDF removal.  相似文献   
85.
Grey parrots (Psittacus erithacus) learn referential English labels when they view and interact with 2 humans who model vocal labeling and who demonstrate referentiality and functionality of a label (I. M. Pepperberg, 1990a). To test if both trainers are necessary, the authors contrasted 2-trainer modeling with training by 1 human who presented targeted labels to a bird in concert with appropriate items, who asked questions, and who would reward attempts at the label with the item. The bird was also tutored by either 1 or 2 interactive humans in conjunction with a conspecific who already used referential labels. Referential labels were learned from multiple live tutors but not a single trainer. Presence of a conspecific enhanced learning compared with single-trainer sessions but did not affect acquisition in 2-human sessions. Specific aspects of paired tutoring seem critical for acquiring referential vocal labels. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
86.
Studies of university–industry collaboration remain subject to important limitations due to the shortage of empirical data and a lack of consistency in that obtained to date. This article puts into practice a set of universities Third Mission indicators in a regional innovation system. Selected indicators previously compiled from literature were reorganized and pre-tested. We have undertaken two face-to-face surveys of 737 firms and 765 heads of research teams, respectively. The results test the validation of indicators and provide a complex map of university–industry linkages as well as some observations on the flexibility needed to address this issue.  相似文献   
87.
Responds to C. A. Heflinger's (1987) critique of the present authors (1986) by reiterating their concern for the principle of autonomy. The present authors note that all patients were fully informed about the research plan and their right to withdraw. Nonetheless, the ethical criticism offered by Heflinger regarding randomization cannot be entirely dismissed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
88.
89.
Meta-analyses were performed on 25 comparative Minnesota Multiphasic Personality Inventory (MMPI) and MMPI-2 studies of 1,428 male African Americans versus 2,837 male European Americans, 12 studies of 1,053 female African Americans versus 1,470 female European Americans, and 13 studies of 500 male Latino Americans and 1,345 male European Americans. Aggregate effect sizes suggest higher scores for ethnic minority groups than for European Americans on some MMPI/MMPI-2 scales and lower scores on others. However, none of the aggregate effect sizes suggest substantive differences from either a statistical or clinical perspective. The MMPI and MMPI-2 apparently do not unfairly portray African Americans and Latinos as pathological. Effect sizes across studies generally did not vary as a function of sociodemographic variables, research setting, or use of the MMPI versus MMPI-2. It is recommended that additional between- and within-ethnic groups psychopathology research continue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
90.
ABSTRACT

A mathematical model of simultaneous mass, heat and momentum transfer for two-phase flow of a gas and a solid/liquid slurry was developed. The model was applied to calculation of the drying process of coal-water slurry droplets in a gas medium in a steady one-dimensional flow. The model was based on the well-known two-stage drying process for slurry droplets. After the first period of drying, in which the evaporation rate is controlled by the gas phase resistance, the evaporating liquid diffuses through the porous shell (crust) and then, by convection, into the gas medium. Inside the dry external crust of the drop, a wet central core forms, which shrinks as evaporation proceeds. The temperature of the slurry droplet rises. The process ends when the temperature of the dry outer crust reaches the coal ignition temperature in the case of combustion or when the moisture of the particle reaches the final required moisture. The developed model was based on one-dimensional balance equations of mass, energy and momentum for the liquid/solid and gas phases. The system of governing equations was represented by first-order differential equations and solved simultaneously. The numerical solution of the governing equations was obtained using Gear's method. The model permitted calculation  相似文献   
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