The effect of linguistic and visual salience in visual world studies

Research using the visual world paradigm has demonstrated that visual input has a rapid effect on language interpretation tasks such as reference resolution and, conversely, that linguistic material-including verbs, prepositions and adjectives-can influence fixations to potential referents. More recent research has started to explore how this effect of linguistic input on fixations is mediated by properties of the visual stimulus, in particular by visual salience. In the present study we further explored the role of salience in the visual world paradigm manipulating language-driven salience and visual salience. Specifically, we tested how linguistic salience (i.e., the greater accessibility of linguistically introduced entities) and visual salience (bottom-up attention grabbing visual aspects) interact. We recorded participants' eye-movements during a MapTask, asking them to look from landmark to landmark displayed upon a map while hearing direction-giving instructions. The landmarks were of comparable size and color, except in the Visual Salience condition, in which one landmark had been made more visually salient. In the Linguistic Salience conditions, the instructions included references to an object not on the map. Response times and fixations were recorded. Visual Salience influenced the time course of fixations at both the beginning and the end of the trial but did not show a significant effect on response times. Linguistic Salience reduced response times and increased fixations to landmarks when they were associated to a Linguistic Salient entity not present itself on the map. When the target landmark was both visually and linguistically salient, it was fixated longer, but fixations were quicker when the target item was linguistically salient only. Our results suggest that the two types of salience work in parallel and that linguistic salience affects fixations even when the entity is not visually present. © 2014 Cavicchio, Melcher and Poesio

Optimizing the order of taxon addition in phylogenetic tree construction using genetic algorithm

Abstract. Phylogenetics has gained in public favor for the analysis of DNA sequence data as molecular biology has advanced. Among a number of algorithms for phylogenetics, the fastDNAml is considered to have reasonable computational cost and performance. However, it has a defect that its performance is likely to be significantly affected by the order of taxon addition. In this paper, we propose a genetic algorithm for optimizing the order of taxon addition in the fastDNAml. Experimental results show that the fastDNAml with the optimized order of taxon addition constructs more probable evolutionary trees in terms of the maximum likelihood.

Expression of costimulatory molecules in the bovine corpus luteum

BACKGROUND: Bovine luteal parenchymal cells express class II major histocompatibility complex (MHC) molecules and stimulate class II MHC-dependent activation of T cells in vitro. The ability of a class II MHC-expressing cell type to elicit a response from T cells in vivo is also dependent on expression of costimulatory molecules by the antigen presenting cell and delivery of a costimulatory signal to the T cell. Whether bovine luteal parenchymal cells express costimulatory molecules and can deliver the costimulatory signal is currently unknown. METHODS: Bovine luteal tissue was collected during the early (day 5; day of estrus = day 0), mid (day 11–12), or late (day 18) luteal phase of the estrous cycle, and at 0, 0.5, 1, 4, 12 or 24 hours following administration of PGF2alpha to cows on day 10 of the estrous cycle. Northern analysis was used to measure CD80 or CD86 mRNA concentrations in luteal tissue samples. Mixed luteal parenchymal cell cultures and purified luteal endothelial cell cultures were prepared, and real-time RT-PCR was used to examine the presence of CD80 and CD86 mRNA in each culture type. Monoclonal antibodies to CD80 and CD86 were added to a mixed luteal parenchymal cell-T cell co-culture in vitro T cell proliferation assay to assess the functional significance of costimulatory molecules on activation of T lymphocytes by luteal parenchymal cells. RESULTS: Northern analysis revealed CD80 and CD86 mRNAs in luteal tissue, with greatest steady-state concentrations at midcycle. CD80 and CD86 mRNAs were detected in mixed luteal parenchymal cell cultures, but only slight amounts of CD80 (and not CD86) mRNA were detected in cultures of luteal endothelial cells. Luteinizing hormone, PGF2alpha and TNF-alpha were without effect on concentrations of CD80 or CD86 mRNA in mixed luteal parenchymal cells cultures. Anti-CD80 or anti-CD86 monoclonal antibodies inhibited T cell proliferation in the in vitro T cell proliferation assay. CONCLUSION: It can be concluded from this study that parenchymal cells within the bovine CL express functional costimulatory molecules that facilitate interactions between with T cells, and these components of the antigen presentation pathway are expressed maximally in the midcycle CL

Fine-grain Study: initial results

Purpose of the study: Auditory percept resulting from stimulation with continuous intensity growth (\u201cfine-grain\u201d) at single stimulation electrodes was analysed. Starting from 0 qu up to the loudest acceptable presentation level (LAPL), stimulation intensity was continuously increased with 1 qu per second (1qu~nano Coulomb). Stimuli were presented in three runs: two continuous growth stimulations at rates of 40 and 80Hz, as well as a growth using larger steps (~1-1.5qu).During the delivery of the stimuli, the threshold of electrical elicitation of the stapedius reflex (eSRT) was monitored and the evoked compound action potentials (ECAPs) were recorded. Materials and Methods used: In earlier analysis of the continuous stimulation growth with larger with different charge steps (44Hz vs 80Hz) a difference in LAPL was observed: Lutz et al [2015] showed that the LAPL was considerably smaller for larger charges steps (at 44Hz) compared to 80Hz (~18qu versus ~21qu respectively ). It remained unsolved whether the stimulation frequency and/or the step size are influencing factors. Additionally it was not investigated if the stapedius reflex is influenced by the varying stimuli. Continuous growth stimuli were presented on all stimulating electrodes; and non-continuous stimuli were presented on three representative electrodes in the apical / middle / basal region. Recordings were performed on n=12 cooperative pediatric cochlear implant recipients aged 6 to 10 years at the Audiology Dept. of the University of Milano. Results: Determination of ECAP parameters (threshold and amplitude growth with respect to the stimulation intensity) was considerably faster using the fine-grain stimuli (compare to Lutz et al.). Identification of neural responses was easier for the fine-grain stimuli due to the higher resolution of stimulation intensities. The eSRT varied according to the different LAPLs reached;the analysis of the correlation is done regarding of the correlation between eSRT and LAPL for the different stimuli is presented. Conclusion: Information about the obtained loudest acceptable presentation limit and the elicitation of the eSRT stapedius reflex provide further insights about the nature of the electrically evoked auditory percept in children. Our results support the use of objective measures such as the variation of stimulation intensity and continuous growth to assess the change in auditory percept . Besides these findings, our study confirmed the suitability of the fine-grain stimulation paradigm for a paediatric population. References: Lutz et al [2015] Conference on Implantable Auditory Prostheses: Influence of the Recording Electrode on the ECAP Threshold using a Novel fine-grain Recording Paradigm

Enclosed but safe? Monitoring of heavy metals in zoos

Present work reports about the monitoring of heavy metals in different species housed in zoos. Starting from 2009 a collaboration with Falconara and Pistoia zoos started to monitor the level of heavy metals in animals that died because of natural causes or pathologies. Tissue samples were collected during necropsies, when all information concerning health status of the animal were also registered. Samples were analysed with ICP-OES technique and data were correlated to health status, age and any other information available on the animal. Obtained data underline a reduced exposure to heavy metal, that is not strange given the position of the zoo far from main street or any other potential source of pollution. Some particular cases are also revised. The project can be considered as a starting point for the definition of background values for heavy metals in different wildlife species, which can help in identifying possible risky exposure in free wildlife