A Field Theory Model With a New Lorentz-Invariant Energy Scale

A framework is proposed that allows to write down field theories with a new energy scale while explicitly preserving Lorentz invariance and without spoiling the features of standard quantum field theory which allow quick calculations of scattering amplitudes. If the invariant energy is set to the Planck scale, these deformed field theories could serve to model quantum gravity phenomenology. The proposal is based on the idea, appearing for example in Deformed Special Relativity, that momentum space could be curved rather than flat. This idea is implemented by introducing a fifth dimension and imposing an extra constraint on physical field configurations in addition to the mass shell constraint. It is shown that a deformed interacting scalar field theory is unitary. Also, a deformed version of QED is argued to give scattering amplitudes that reproduce the usual ones in the leading order. Possibilities for experimental signatures are discussed, but more work on the framework's consistency and interpretation is necessary to make concrete predictions.Comment: 20 page

Accessibility of referent information influences sentence planning : An eye-tracking study

Acknowledgments We thank Phoebe Ye and Gouming Martens for help with data collection for Experiment 1 and 2, respectively. This research was supported by the European Research Council for the ERC Starting Grant (206198) to YC.Peer reviewedPublisher PD

Encoding actions and verbs : Tracking the timecourse of relational encoding during message and sentence formulation

Many thanks to Annelies van Wijngaarden and student assistants from the Psychology of Language Department (in particular Esther Kroese, Marloes Graauwmans, and Ilse Wagemakers) for help with data collection and processing, and Tess Forest and Antje Meyer for helpful discussions.Peer reviewedPostprin

Direct experimental observation of binary agglomerates in complex plasmas

A defocusing imaging technique has been used as a diagnostic to identify binary agglomerates (dimers) in complex plasmas. Quasi-two-dimensional plasma crystal consisting of monodisperse spheres and binary agglomerates has been created where the agglomerated particles levitate just below the spherical particles without forming vertical pairs. Unlike spherical particles, the defocused images of binary agglomerates show distinct, stationary/periodically rotating interference fringe patterns. The results can be of fundamental importance for future experiments on complex plasmas

Modeling the functional genomics of autism using human neurons.

Human neural progenitors from a variety of sources present new opportunities to model aspects of human neuropsychiatric disease in vitro. Such in vitro models provide the advantages of a human genetic background combined with rapid and easy manipulation, making them highly useful adjuncts to animal models. Here, we examined whether a human neuronal culture system could be utilized to assess the transcriptional program involved in human neural differentiation and to model some of the molecular features of a neurodevelopmental disorder, such as autism. Primary normal human neuronal progenitors (NHNPs) were differentiated into a post-mitotic neuronal state through addition of specific growth factors and whole-genome gene expression was examined throughout a time course of neuronal differentiation. After 4 weeks of differentiation, a significant number of genes associated with autism spectrum disorders (ASDs) are either induced or repressed. This includes the ASD susceptibility gene neurexin 1, which showed a distinct pattern from neurexin 3 in vitro, and which we validated in vivo in fetal human brain. Using weighted gene co-expression network analysis, we visualized the network structure of transcriptional regulation, demonstrating via this unbiased analysis that a significant number of ASD candidate genes are coordinately regulated during the differentiation process. As NHNPs are genetically tractable and manipulable, they can be used to study both the effects of mutations in multiple ASD candidate genes on neuronal differentiation and gene expression in combination with the effects of potential therapeutic molecules. These data also provide a step towards better understanding of the signaling pathways disrupted in ASD

Planning to speak in L1 and L2

Many thanks to Annelies van Wijngarden, Caitlin Decupyer, and student assistants in the Psychology of Language Department (Esther Kroese, Marloes Gauwamans, Jessica Aguilar Diaz, Ilse Wagemakers) for invaluable help during data collection and processing.Peer reviewedPostprin

Assessing priming for prosodic representations : Speaking rate, intonational phrase boundaries, and pitch accenting

We thank Candice Stanfield, Ashley Frost, and Ashley Devereux for their assistance with data collection and coding. This work was supported in part by National Institutes of Health Grant R01 DC008774 and by the James S. McDonnell Foundation.Peer reviewedPostprin

Word order affects the time course of sentence formulation in Tzeltal

The scope of planning during sentence formulation is known to be flexible, as it can be influenced by speakers' communicative goals and language production pressures (among other factors). Two eye-tracked picture description experiments tested whether the time course of formulation is also modulated by grammatical structure and thus whether differences in linear word order across languages affect the breadth and order of conceptual and linguistic encoding operations. Native speakers of Tzeltal [a primarily verb–object–subject (VOS) language] and Dutch [a subject–verb–object (SVO) language] described pictures of transitive events. Analyses compared speakers' choice of sentence structure across events with more accessible and less accessible characters as well as the time course of formulation for sentences with different word orders. Character accessibility influenced subject selection in both languages in subject-initial and subject-final sentences, ruling against a radically incremental formulation process. In Tzeltal, subject-initial word orders were preferred over verb-initial orders when event characters had matching animacy features, suggesting a possible role for similarity-based interference in influencing word order choice. Time course analyses revealed a strong effect of sentence structure on formulation: In subject-initial sentences, in both Tzeltal and Dutch, event characters were largely fixated sequentially, while in verb-initial sentences in Tzeltal, relational information received priority over encoding of either character during the earliest stages of formulation. The results show a tight parallelism between grammatical structure and the order of encoding operations carried out during sentence formulation

Ecological Interactions Between Metals and Microbes

Analyses of chromium resistant microbes. Culturable xylene-degrading and chromate-resistant microbes were obtained from chronically cocontaminated soil using a microcosm enrichment technique, and shown to correlate to dominant soil populations using culture independent techniques. The soil microbial community proved able to mount a respiratory response to addition of xylene in the presence of chromate. The majority of isolates belonged to the ubiquitous but poorly studied high %G+C Gram positive genus Arthrobacter, and exhibited considerable genotypic and phenotypic variability. Phenotypic assays uncovered a wide variation in the levels of chromate resistance, even between very closely related strains. Primers designed against conserved motifs in the known chrA chromate efflux gene failed to detect similar sequences among the chromate resistant Arthrobacter isolates obtained through enrichment

Ecological Interactions Between Metals and Microbes That Impact Bioremediation

Previous work showed the correlation between bacterial biomass, population structure and the amount of lead, chromium and aromatic compounds present along a 21.6 m transect in which the concentrations of both heavy metals (Pb and Cr) and aromatic compounds varied 2-3 orders of magnitude. This work suggested that (a) biomass level was better correlated to the level of biodegradable organic C than the level of heavy metals, (b) microbial community composition differed between highly contaminated soils and uncontaminated ones, and (c) substantial microbial activity was found even in the highly contaminated soils. One confounding factor in these analyses was that the contaminated soils contained Pb, Cr, and aromatic hydrocarbons. Therefore, it was difficult to determine which factors were most important in the shifts of microbial community composition. Therefore, experiments were conducted in microcosms in which individual factors could be systematically varied. In this case, soils were used from the Seymour, IN site which had low levels of contamination, and the microbial community had little chance to adapt to heavy metals or aromatic compounds