Induction of parasitoid attracting synomone in brussels sprouts plants by feeding ofPieris brassicae larvae: Role of mechanical damage and herbivore elicitor

Induction of plant defense in response to herbivory includes the emission of synomones that attract the natural enemies of herbivores. We investigated whether mechanical damage to Brussels sprouts leaves (Brassica oleracea var.gemmifera) is sufficient to obtain attraction of the parasitoidCotesia glomerata or whether feeding byPieris brassicae caterpillars elicits the release of synomones not produced by mechanically damaged leaves. The response of the parasitoidCotesia glomerata to different types of simulated herbivory was observed. Flight-chamber dual-choice tests showed that mechanically damaged cabbage leaves were less attractive than herbivore-damaged leaves and mechanically damaged leaves treated with larval regurgitant. Chemical analysis of the headspace of undamaged, artificially damaged, caterpillar-infested, and caterpillar regurgitant-treated leaves showed that the plant responds to damage with an increased release of volatiles. Greenleaf volatiles and several terpenoids are the major components of cabbage leaf headspace. Terpenoids are emitted in analogous amounts in all treatments, including undamaged leaves. On the other hand, if the plant is infested by caterpillars or if caterpillar regurgitant is applied to damaged leaves, the emission of green-leaf volatiles is highly enhanced. Our data are in contrast with the induction of more specific synomones in other plant species, such as Lima bean and corn.     

Impairments in theory of mind shortly after traumatic brain injury and at 1-year follow-up.

Most studies into acquired theory of mind (ToM) deficits assessed patients once, long after the onset of brain injury. As a result, the time course of acquired ToM impairments is largely unknown. The present study examined whether ToM impairments following traumatic brain injury (TBI) recover, remain stable, or worsen over time. Because of the alleged association between ToM and social communication, ToM impairments may deteriorate because of changes in patients' social environment following injury. ToM ability and executive functioning were assessed shortly after injury and at 1-year follow-up. Compared with the orthopedic control group, the TBI group was impaired on ToM and executive functioning tasks at both assessments. Furthermore, the ToM impairments in the TBI group remained stable over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of the geometry in a 3D flow-focusing device

We present a numerical and experimental study on a non-planar three-dimensional design of a microfluidic flow-focusing device for the well-controlled generation of monodisperse micron-sized droplets. Three relevant geometric parameters were identified: the distance between the inner inlet channel and the outlet channel, the width of the outlet channel, and its length. Simulation data extracted from a full parameter study and finite element simulations yielded four optimum designs that were then fabricated using soft lithography techniques. Under the predicted operating conditions, micro-droplets of a size of \({\sim}1\,\upmu \text {m}\) in diameter are obtained from a channel \(50\,\upmu \text {m}\) in width. This work represents an important breakthrough in the practical use of flow-focusing devices delivering a ratio of constriction to droplet size of 50 times, with the advantage of reduced clogging of the micro-channel, greatly improving the control and reliability of the device.     

Mapping queries to the Linking Open Data cloud: A case study using DBpedia

We introduce the task of mapping search engine queries to DBpedia, a major linking hub in the Linking Open Data cloud. We propose and compare various methods for addressing this task, using a mixture of information retrieval and machine learning techniques. Specifically, we present a supervised machine learning-based method to determine which concepts are intended by a user issuing a query. The concepts are obtained from an ontology and may be used to provide contextual information, related concepts, or navigational suggestions to the user submitting the query. Our approach first ranks candidate concepts using a language modeling for information retrieval framework. We then extract query, concept, and search-history feature vectors for these concepts. Using manual annotations we inform a machine learning algorithm that learns how to select concepts from the candidates given an input query. Simply performing a lexical match between the queries and concepts is found to perform poorly and so does using retrieval alone, i.e., omitting the concept selection stage. Our proposed method significantly improves upon these baselines and we find that support vector machines are able to achieve the best performance out of the machine learning algorithms evaluated.     

Asymptotic solutions for turbulent mass transfer augmented by a first order chemical reaction

We present asymptotic solutions for turbulent mass transfer in a smooth conduit at high Schmidt number in the presence of a first-order chemical reaction in the fluid. Far-field solutions are derived for a case dominated by (1) mass transfer at the wall and (2) the first-order chemical reaction. An approximate solution is derived for the regime where both are important. The solutions are in good agreement with numerical solutions and with the literature. At high Damköhler numbers the system is governed by a reaction–diffusion equation and the observed increase in mass transfer coefficient is caused by thinning of the mass transfer boundary layer due to the fast chemical reaction in the fluid. We present closed-form far-field solutions for Dirichlet, Neumann and Robin boundary conditions and comment on grid resolution requirements to accurately resolve the mass transfer boundary layer. The solution strategy presented can be straightforwardly extended to non-linear wall- and bulk-reactions.     

Wikipedia workload analysis for decentralized hosting

We study an access trace containing a sample of Wikipedia’s traffic over a 107-day period aiming to identify appropriate replication and distribution strategies in a fully decentralized hosting environment. We perform a global analysis of the whole trace, and a detailed analysis of the requests directed to the English edition of Wikipedia. In our study, we classify client requests and examine aspects such as the number of read and save operations, significant load variations and requests for nonexisting pages. We also review proposed decentralized wiki architectures and discuss how they would handle Wikipedia’s workload. We conclude that decentralized architectures must focus on applying techniques to efficiently handle read operations while maintaining consistency and dealing with typical issues on decentralized systems such as churn, unbalanced loads and malicious participating nodes.     

Identified versus introjected approach and introjected avoidance motivations in school and in sports: The limited benefits of self-worth strivings.

On the basis of self-determination theory (Ryan & Deci, 2000), the authors examined whether 2 different types of introjected motivation—an avoidant type aimed at avoiding low self-worth and an approach type aimed at attaining high self-worth—are both associated with a less positive pattern of correlates relative to identified motivation—acting because one identifies with the value of the action. Two studies focusing on the academic and sports domains (N = 1,222) showed that children and adolescents differentiated between the 2 types of introjected motivation. Although introjected avoidance motivation was associated with a more negative pattern of affective and performance correlates than was introjected approach motivation, identified motivation was associated with a much more positive pattern of correlates than both types of introjected motivation. Furthermore, being high on introjected approach motivation did not yield any benefits even when combined with high identified motivation. Results suggest that past findings portraying introjected motivation as being less desirable than identified motivation cannot be ascribed to the avoidance component of introjected motivation. Findings are consistent with the view that even an approach-oriented introjected motivation has very limited benefits when compared with identified motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of perspective effects and accelerations in perceived three-dimensional structure-from-motion.

It has been suggested that perceived three-dimensional (3D) structure-from-motion can be accounted for by a 2-frame orthographic approximation of the flow field. This study investigated the extent to which higher order cues (perspective and acceleration) are used in addition to first-order flow. Participants matched the 3D dihedral angle of a hinged plane (probe) defined by multiple-depth cues to one defined by motion only, for stimulus sizes of 8 and 33°, using perspective and orthographic projection. The results show that perspective effects can be important even for relatively small stimuli (8°) and that accelerations contribute to perceived shape. In all conditions, large biases were found. These are well accounted for by a model in which all relevant flow measurements (first-order, perspective, and acceleration) are used together with estimates of the noise in each. The model has no built-in bias toward particular 3D shapes. Instead, the visual system may act as an optimal estimator of 3D structure-from motion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioural responses to neighbourhood reputations

Most research on the effect of neighbourhood reputations focuses on the influence on attitudes and behaviour of non-residents. Much less attention is paid to the possible effects of a poor neighbourhood reputation on behaviour of residents. In order to get a better understanding of the effect of neighbourhoods on its residents (the so-called neighbourhood effects) and the role of neighbourhoods in the urban housing market, it is necessary to fill this gap. The aim of this paper is to review the literature on the reputation of places and to give an overview of possible behavioural responses of residents to negative neighbourhood reputations. The paper develops a model of behavioural responses of residents based on Hirschman’s ‘Exit, Voice and Loyalty’ framework. Three basic responses are central to the discussion of the literature: leaving the neighbourhood, attempting to improve the neighbourhood through neighbourhood participation, and (dis)investing in social contacts within the neighbourhood.