The role of drug expectancy in the control of human drug seeking.

Human drug seeking may be goal directed in the sense that it is mediated by a mental representation of the drug or habitual in the sense that it is elicited by drug-paired cues directly. To test these 2 accounts, the authors assessed whether a drug-paired stimulus (S+) would transfer control to an independently trained drug-seeking response. Smokers were trained on an instrumental discrimination that established a tobacco S+ in Experiment 1 and a tobacco and a money S+ in Experiment 2 that elicited an expectancy of their respective outcomes. Participants then learned 2 new instrumental responses, 1 for each outcome, in the absence of these stimuli. Finally, in the transfer test, each S+ was found to augment performance of the new instrumental response that was trained with the same outcome. This outcome-specific transfer effect indicates that drug-paired stimuli controlled human drug seeking via a representation or expectation of the drug rather than through a direct stimulus-response association. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A top-down event-driven approach for concurrent activity recognition

In this paper a framework for automatic online workflow recognition in industrial environments where the issue of concurrent activities rises, is presented. The framework consists of three main parts: The first part is devoted to detecting activity in specific Regions of Interest (ROIs) of the video sequence. This is effected by separating each frame into ROIs and representing the resulting subimages through feature vectors. By observing these vectors we can determine when there is action in a particular ROI. The second part of the framework lies in examining whether the detected activity corresponds to a workflow related event. This is accomplished by HMM modeling. Finally, the third part employs a string matching based technique to confirm the validity of the observed sequence of events or correct any detection or classification errors. This last step also addresses a top down approach by informing lower system levels (such as image representation or object tracking) about the errors committed. The performance of the proposed approach is thoroughly evaluated under real-life complex visual workflow understanding scenarios, in an industrial plant. The obtained results are compared and discussed.     

Elastic Properties of UHMWPE-SWCNT Nanocomposites’ Fiber: An Experimental, Theoretic, and Molecular Dynamics Evaluation

Ultrahigh molecular weight polyethylene (PE) filaments were reinforced with 2 wt.% of single-walled carbon nanotubes (SWCNTs). The solution spinning method was used to produce both neat and reinforced PE filaments. Tensile tests and strain hardening through repeated loading-unloading cycles of the filaments revealed a spectacular contribution of the SWCNTs in enhancing the elastic properties, e.g., strength and modulus. The theoretic strength and modulus of the reinforced PE were predicted using the shear lag model and micromechanics-based model, respectively, and verifying with experimental results. It was observed that the predicted strength and modulus were comparable only with those obtained after strain hardening. In the next step, a molecular dynamic simulation was conducted by simulating a unit cell containing a SWCNT surrounded by PE matrix subjected to uniaxial tensile strain. The strength and modulus of the simulated structure showed an agreement, to certain extent, with experimental observations of strain-hardened nanocomposites.     

Identification of the Female-Produced Sex Pheromone of Tischeria ekebladella, an Oak Leafmining Moth

The native leafmining moth Tischeria ekebladella (Lepidoptera: Tischeriidae) feeds on oaks and recently has become a pest of silviculture and urban green areas in central Europe. The behavioral responses of male moths to hexane extracts of whole bodies of calling females or males were tested under laboratory conditions. Only extracts of females elicited responses from males. Analysis of extracts by coupled gas chromatography/electroantennographic detection revealed the presence of two electroantennogram-active peaks. Structure elucidation of these compounds, by gas-chromatography/mass spectrometry and independent synthesis revealed them to be (3Z,6Z,9Z)-tricosa-3,6,9-triene and (3Z,6Z,9Z,19Z)-tricosa-3,6,9,19-tetraene. While the triene was present in both sexes, the tetraene was female-specific. The latter is a new structure for a pheromone component of Lepidoptera and a novel natural product. Field trapping tests, carried out in a mixed oak forest near Budapest (Hungary), using synthetic compounds applied to rubber dispensers, showed that the tetraene per se elicited catches of males in large numbers. When the triene was added to the tetraene in a ratio of 1:1, there was no increase in trap catch; the triene alone did not elicit catches of males. For monitoring this insect, the tetraene, applied to rubber dispensers at a dose of 300?μg, is a potent sex attractant.     

Prediction and uncertainty in human Pavlovian to instrumental transfer.

Attentional capture and behavioral control by conditioned stimuli have been dissociated in animals. The current study assessed this dissociation in humans. Participants were trained on a Pavlovian schedule in which 3 visual stimuli, A, B, and C, predicted the occurrence of an aversive noise with 90%, 50%, or 10% probability, respectively. Participants then went on to separate instrumental training in which a key-press response canceled the aversive noise with a .5 probability on a variable interval schedule. Finally, in the transfer phase, the 3 Pavlovian stimuli were presented in this instrumental schedule and were no longer differentially predictive of the outcome. Observing times and gaze dwell time indexed attention to these stimuli in both training and transfer. Aware participants acquired veridical outcome expectancies in training—that is, A > B > C, and these expectancies persisted into transfer. Most important, the transfer effect accorded with these expectancies, A > B > C. By contrast, observing times accorded with uncertainty—that is, they showed B > A = C during training, and B     

Kinetic study of high pressure microbial and enzyme inactivation and selection of pasteurisation conditions for Valencia Orange Juice

Keeping quality of fresh orange juice is highly dependent on pectinolytic enzyme activity and the growth of spoilage microorganisms. The inactivation kinetics of indigenous pectin methylesterase (PME) and of the two more pressure resistant species of spoilage lactic acid bacteria (LAB) Lactobacillus plantarum and L. brevis in freshly squeezed Valencia orange juice under high hydrostatic pressure (100–500 MPa) combined with moderate temperature (20–40 °C) was investigated. PME inactivation followed first order kinetics with a residual PME activity (15%) at all pressure–temperature combinations used. The values of activation energy and activation volume were estimated at each pressure and at each temperature, respectively. Values of 90 kJ/mol and ?30 mL/mol at reference pressure of 300 MPa and reference temperature of 35 °C were estimated respectively. The corresponding z_T and z_P values of LAB inactivation were also estimated at all conditions tested. Values of 19.5 °C and 95 MPa at reference pressure of 300 MPa and reference temperature of 30 °C were estimated respectively for L. plantarum, while the corresponding values for L. brevis were 40 °C and 82 MPa, respectively, at the same reference conditions. Pressure and temperature were found to act synergistically both for PME and LAB inactivation. The PME and LAB inactivation rate constants were expressed as functions of the temperature and pressure process conditions. These functions allow the determination of the pressure/temperature conditions that achieve the target enzyme and microbial inactivation at a selected processing time. The process conditions of 350 MPa at 35 °C for 2 min are proposed as effective for Valencia orange juice cold pasteurisation.     

Quantitative quality tests for frozen fish: Soluble protein and free fatty acid content as quality criteria for hake (Merluccius capensis) stored at −18°C

Hake fillets and mince were frozen and stored at ?18°C in four different tests. Samples were periodically withdrawn and analysed for total protein, protein soluble in aqueous salt solution, free fatty acid content and texture. Highly significant correlations were found between the texture and both the ratio of protein soluble in aqueous salt solution to total protein and the free fatty acid content. These correlations led to the formulation of quantitative quality criteria based on protein soluble in aqueous salt solution and free fatty acid content for frozen hake stored at ?18°C.     

Virtualised e-Learning on the IRMOS real-time Cloud

This paper presents the real-time virtualised Cloud infrastructure that was developed in the context of the IRMOS European Project. The paper shows how different concepts, such as real-time scheduling, QoS-aware network protocols, and methodologies for stochastic modelling and run-time provisioning were practically combined to provide strong performance guarantees to soft real-time interactive applications in a virtualised environment. The efficiency of the IRMOS Cloud is demonstrated by two real interactive e-Learning applications, an e-Learning mobile content delivery application and a Virtual World e-Learning application.     

Topic modelling of clickthrough data in image search

In this paper we explore the benefits of latent variable modelling of clickthrough data in the domain of image retrieval. Clicks in image search logs are regarded as implicit relevance judgements that express both user intent and important relations between selected documents. We posit that clickthrough data contains hidden topics and can be used to infer a lower dimensional latent space that can be subsequently employed to improve various aspects of the retrieval system. We use a subset of a clickthrough corpus from the image search portal of a news agency to evaluate several popular latent variable models in terms of their ability to model topics underlying queries. We demonstrate that latent variable modelling reveals underlying structure in clickthrough data and our results show that computing document similarities in the latent space improves retrieval effectiveness compared to computing similarities in the original query space. These results are compared with baselines using visual and textual features. We show performance substantially better than the visual baseline, which indicates that content-based image retrieval systems that do not exploit query logs could improve recall and precision by taking this historical data into account.     

A secure framework exploiting content guided and automated algorithms for real time video searching

This paper presents an architecture that allows End Users, via the services of Search Engines, to search, in a secure and efficient way, the video content belonging to Content Providers. The search can be accomplished with any searching scheme that the Search Engines wish to provide, as long as certain security constraints are met. However we propose specific algorithms that demonstrate an efficient way to search video data without sacrificing security effectiveness of the system. The search is completed without the End Users or Search Engines needing to purchase the premium content beforehand, and without the Content Providers needing to purchase the search technology. The business motivation of this technique is to assist End Users to purchase content best suiting their requirements—they are offered search results only, not actual content. The objective is to face the problem caused by the current segregation between content ownership and video processing technology ownership. To face this segregation, we present an architecture that guarantees security of Content Provider’s data and Search Engine’s technology and we also present two innovative algorithms that make real time video searching a feasible process. Particularly these algorithms (a) organize video content into a graph based hierarchical structure and (b) perform content guided, non interactive and real time search by exploiting the graph based video structures. The proposed algorithms are incorporated in the presented architecture under the given security constraints. Experimental results and comparisons with conventional techniques are presented to demonstrate the outperformance of the proposed algorithms.