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511.
Fernando Elizalde-Ramírez Iris A. Martínez-Salazar Yasmín Á. Ríos-Solís 《Applied Artificial Intelligence》2019,33(5):440-461
Users of public transit networks require tools that generate travel plans to traverse them. The main issue is that public transit networks are time and space dependent. Travel plans depend on the current location of users and transit units, along with a set of user preferences and time restrictions. In this work, we propose the design and development of artificial intelligence (AI) planning models for engineering travel plans for such networks. The proposed models consider temporal actions, bus locations, and user preferences as constraints, to restrict the set of travel plans generated. Our approach decouples model design from algorithm construction, providing a greater level of flexibility and richness of solutions. We also introduce an integer linear programming formulation, and a fast preprocessing procedure, to evaluate the quality of the solutions returned by the proposed planning models. Experimental results show that AI planning models can efficiently generate close to optimal solutions. Furthermore, our analysis identifies user preferences as the most critical factor that increases solution complexity for planning models. 相似文献
512.
513.
Mercerisation changes the fine structure, morphology and conformation of cotton cellulose chains (cellulose I to cellulose II), resulting in a variation in fibre strength and lustre as well as adsorption properties. Recently it has been shown that mercerisation also changes the electrokinetic behaviour of cotton. The aim of the work presented here is to study the behaviour in unmercerised and mercerised cotton. The zeta potential of cotton fibres was measured by the streaming current method, using an EKA electrokinetic analyser. The relationships between zeta potential and the pH of a potassium chloride solution on the one hand and the point of zero charge (PZC) on the other, determined by titration with a cationic surfactant (cetylpyridinium chloride), were investigated. 相似文献
514.
Dr. Grégory Coué Dr. Iris Hermanns Dr. Ronald E. Unger Prof. C. James Kirkpatrick Prof. Johan F. J. Engbersen 《ChemMedChem》2013,8(11):1787-1794
A poly(amidoamine) with disulfide linkages in the main chain and 4‐hydroxybutyl and ω‐carboxy‐PEG groups (9:1 ratio) as side chains was prepared by Michael addition polymerization of cystamine bisacrylamide with 4‐hydroxybutylamine and ω‐carboxy‐PEG‐amine. To develop therapeutic protein formulations for improved delivery of antigen via the intranasal route, nanoparticles were prepared from this polymer by self‐assembly with p24 or ovalbumin as the model proteins and CpG as the adjuvant. The nanoparticles incorporated the antigens and adjuvant from the feed solution with high efficiency (~90 %) and have sizes of 112 and 169 nm, respectively, with low positive surface charge (~+2 mV). Formulations of the nanoparticles were shown to be nontoxic and stable for at least 10 days at room temperature. Their capacity to pass through epithelial and endothelial cell layers was evaluated in vitro by using a respiratory mucosa‐like barrier model in which monolayers of NCI H441 respiratory epithelial cells and ISO‐HAS‐1 endothelial cells were co‐cultured on both sides of a transwell filter membrane. It was shown that p24 incorporated in the nanoparticles was transported with >140 % greater efficiency through the two contact‐inhibited layers than p24 in its free form, whereas incorporation of ovalbumin in the nanoparticles leads to a 40 % decrease in transport efficiency relative to the free antigen. 相似文献
515.
Andriy E. Yaroshchuk Volker Ribitsch 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2000,80(1-3):203-214
Nanofiltration (NF) is a relatively new membrane process suitable for the separation of solutes of close molecular weight. The rejection mechanisms of nanofiltration membranes have not been reliably identified, yet. The electrostatic repulsion of coions by fixed membrane charge (Donnan exclusion) is considered one of most probable rejection mechanisms. However, practically no direct information on the electrochemical and/or electrokinetic properties of NF membranes is available. The interpretation of conventional electrochemical and/or electrokinetic measurements with NF membranes is complicated by their multilayer structure. Under linear conditions only average membrane transport properties can be obtained from steady-state measurements. Information on the properties of constituent layers can be obtained from non-steady-state and/or non-linear measurements, alone. In this paper the opportunities offered by non-steady-state techniques are explored. Volume flows and changes in solute concentration cannot usually be observed at sufficiently short times when the system is still far away from steady state. Therefore the only suitable response is electrical. It is not immediate due to the concentrational polarisation of boundaries between membrane constituent layers. The theory of transient membrane potential, transient filtration potential and low-frequency electrical impedance is briefly presented. The suitability of various non-steady state techniques for the determination of transport and accumulation properties of constituent layers of NF membranes is discussed and compared with available experimental data on transient membrane potential. It is concluded that each of techniques has its advantages and drawbacks. Therefore, the application of several techniques to the same system is desirable for the minimisation of systematic errors. 相似文献
516.
Iris Steitz Callum Kingwell Robert J. Paxton Manfred Ayasse 《Journal of chemical ecology》2018,44(9):827-837
Chemical communication is crucial for the maintenance of colony organization in eusocial insects and chemical signals are known to mediate important aspects of their social life, including the regulation of reproduction. Sociality is therefore hypothesized to be accompanied by an increase in the complexity of chemical communication. However, little is known about the evolution of odor signals at the transition from solitary living to eusociality. Halictid bees are especially suitable models to study this question as they exhibit considerable variability in social behavior. Here we investigated whether the dissimilarities in cuticle chemical signals in females of different castes and life stages reflect the level of social complexity across halictid bee species. Our hypothesis was that species with a higher social behavior ergo obligate eusocial species possess a more distinct chemical profile between castes or female life stages. We analyzed cuticular chemical profiles of foundresses, breeding females and workers of ancestrally solitary species, facultative and obligate eusocial halictid species. We also tested whether social complexity was associated with a higher investment in chemical signals. Our results revealed higher chemical dissimilarity between castes in obligate than in facultative eusocial species, especially regarding macrocyclic lactones, which were the single common compound class overproduced in queens compared with workers. Chemical dissimilarities were independent of differences in ovarian status in obligate eusocial species but were dependent on ovarian status in facultative eusocial species, which we discuss in an evolutionary framework. 相似文献
517.
Katja Schladitz Aila Särkkä† Iris Pavenstädt‡ Otto Haferkamp‡ & Torsten Mattfeldt‡ 《Journal of microscopy》2003,211(2):137-153
We studied the point processes of intramembranous particles of mitochondrial membranes from HeLa cells using the freeze fracture technique. Three groups – under normal conditions, after exposition with rotenone, and after exposition with sodium acid – were compared. First, we used several summary statistics in order to study the two‐dimensional point patterns of intramembranous particles within each group. Then, we compared the patterns in different groups by bootstrap tests using the K‐function and the nearest neighbour distance function G(r). Estimation of the G‐function provided significant results but no significant differences between groups were found using the classical K‐function; estimation of G(r) should therefore not be omitted when studying observed planar point patterns. 相似文献
518.
Sad and anxious feelings are known to increase in the immediate postpartum period, whereas studies on new mothers' other emotional qualities such as anger are scarce. In laboratory studies, attachment security was found to be associated with effective emotion regulation in challenging situations. This study investigated attachment representations of experiences with parents and of current experiences with the partner as predictors of sad, anxious, and angry feelings across the transition to motherhood. Seventy-seven pregnant women in their third trimester were administered the Adult Attachment Interview and the Current Relationship Interview. The Differential Emotions Scale was given in pregnancy and at the infant's ages of 2 weeks, 2, 4, and 6 months, asking both mothers and fathers about maternal emotional experience. Sadness and anxiety increased 2 weeks postpartum and returned to below baseline over the following months, while anger did not change. Contrary to mothers with an insecure representation of their couple relationship, those with a secure representation reported and displayed increased sadness and anxiety 2 weeks after giving birth, from which they quickly recovered. For mothers secure in their representation of past attachment relationships with parents, an increase of low-level anger emerged 4 months postpartum, which did not occur in insecure participants and receded quickly. It can be concluded that secure representations of current and past attachment relationships help new mothers express and recover from negative emotions. These findings further elucidate the associations between attachment status and emotion regulation while adding a couple perspective. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
519.
Two experiments examined how sensory acuity affects age differences in susceptibility to interference in the reading-with-distraction task. In both experiments, older and younger adults read texts in an italic font and were required to ignore distractor words in an upright font. Experiment 1 examined whether the age-related increase in distractibility can be simulated in younger adults by reducing their visual acuity. Experiment 2 investigated whether the age differences in distractibility disappear if visual acuity is equated across all participants in both age groups. Both experiments showed that an impairment in visual acuity leads to increased interference in the reading-with-distraction task. However, older adults were much more impaired by the distractor material than younger adults with reduced visual acuity (Experiment 1). The age differences in the reading-with-distraction task persisted when visual acuity was equated between older and younger adults (Experiment 2). We conclude that the age-related increase in susceptibility to interference in the reading-with-distraction task is not solely due to perceptual deficits of older adults but arises from a deficit in higher cognitive processes such as inhibitory attention. Nevertheless, sensory acuity has to be taken into account as a potential confounding factor in perceptually demanding visual attention tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
520.
Hans Gross Iris Keitel Burkhard Costisella 《Advanced Synthesis \u0026amp; Catalysis》1978,320(2):255-260
Synthesis of 3-Substituted 7,8-Dimethyl-1,5-dihydro-2,4-benzdithiepines 7,8-Dimethyl-1,5-dihydro-2,4-benzdithiepines substituted in 3-position are available from the dithiol 1 and aldehydes or acetales. By chlorination of the dithiepin 6 the 3-chloro-dithiepin 3 is formed, which was not available in pure state, but can be transformed in situ with N- or C-nucleophiles into the respective 2 -derivatives. By oxidation of 6 using chloramin T and subsequent reaction with methanol the 3-methoxy derivative 4 is formed via the S-tosyliminocompound 5 . 相似文献