CoolMoves

Current Virtual Reality (VR) systems are bereft of stylization and embellishment of the user's motion - concepts that have been well explored in animations for games and movies. We present CooIMoves, a system for expressive and accentuated full-body motion synthesis of a user's virtual avatar in real-time, from the limited input cues afforded by current consumer-grade VR systems, specifically headset and hand positions. We make use of existing motion capture databases as a template motion repository to draw from. We match similar spatio-temporal motions present in the database and then interpolate between them using a weighted distance metric. Joint prediction probability is then used to temporally smooth the synthesized motion, using human motion dynamics as a prior. This allows our system to work well even with very sparse motion databases (e.g., with only 3-5 motions per action). We validate our system with four experiments: a technical evaluation of our quantitative pose reconstruction and three additional user studies to evaluate the motion quality, embodiment and agency.

Light-activated signaling in DNA-encoded sender-receiver architectures

Collective decision making by living cells is facilitated by exchange of diffusible signals where sender cells release a chemical signal that is interpreted by receiver cells. Biologists have started to unravel the underlying physicochemical determinants that control the effective communication distance using genetically modified cells. However, living systems are inherently challenging to manipulate and study systematically and quantitatively. Therefore, the development of generic and tunable abiotic mimics featuring compartmentalized signaling is highly desirable. Here, by adapting a previously reported artificial cell-cell communication system, we engineer DNA-encoded sender-receiver architectures, where protein-polymer microcapsules act as cell mimics and molecular communication occurs through diffusive DNA signals. We prepare spatial distributions of sender and receiver protocells using a microfluidic trapping array, and setup a signaling gradient from a single sender cell using light, which activates surrounding receivers through DNA strand displacement. Our systematic analysis reveals how the effective signal range of a single sender is determined by various factors including the density and permeability of receivers, extracellular signal degradation, signal consumption and catalytic regeneration. In addition, we construct a three-population configuration where two sender cells are embedded in a dense array of receivers that implement Boolean logic and investigate spatial integration of non-identical input cues. The results advance our understanding of diffusion-based sender-receiver topologies and present a strategy for constructing spatially controlled chemical communication systems that have the potential to reconstitute collective cellular behavior.

Simultaneous effects of inflectional paradigms and classes in processing of Serbian verbs

In this paper we show that the processing of inflected verb forms is simultaneously influenced by the distributional properties of their inflectional paradigm (all the inflected forms of the given verb) and also by their inflectional class (all the verbs that conjugate in the same manner). Thus, we generalize a finding that was previously observed with nouns. We demonstrate that a divergence of the frequency distribution within inflectional paradigm from the frequency distribution within inflectional class (operationalized as Relative entropy between the two frequency distributions) is detrimental to processing. We present the results of a visual lexical decision experiment and the results of a simulation that was ran in the Naive Discriminative Reader, a simple computational model based on basic learning principles. We show that Relative entropy between an inflectional paradigm and an inflectional class predicts both empirically observed and simulated processing latencies. By doing so, we add to the body of research that investigates processing effects of information theory based descriptions of language. We also demonstrate that the effect of Relative entropy on the processing of morphology can arise as a consequence of the principles of discriminative learning in a system that maps input cues to outcomes, with no specification of morphology per se.

Phosphatases Generate Signal Specificity Downstream of Ssp1 Kinase in Fission Yeast

ABSTRACT AMPK-related protein kinases (ARKs) coordinate cell growth, proliferation, and migration with environmental status. It is unclear how specific ARKs are activated at specific times. In the fission yeast Schizosaccharomyces pombe, the CaMKK-like protein kinase Ssp1 promotes cell cycle progression by activating the ARK Cdr2 according to cell growth signals. Here, we demonstrate that Ssp1 activates a second ARK, Ssp2/AMPKα, for cell proliferation in low environmental glucose. Ssp1 activates these two related targets by the same biochemical mechanism: direct phosphorylation of a conserved residue in the activation loop (Cdr2-T166 and Ssp2-T189). Despite a shared upstream kinase and similar phosphorylation sites, Cdr2 and Ssp2 have distinct regulatory input cues and distinct functional outputs. We investigated this specificity and found that distinct protein phosphatases counteract Ssp1 activity toward its different substrates. We identified the PP6 family phosphatase Ppe1 as the primary phosphatase for Ssp2-T189 dephosphorylation. The phosphatase inhibitor Sds23 acts upstream of PP6 to regulate Ssp2-T189 phosphorylation in a manner that depends on energy but not on the intact AMPK heterotrimer. In contrast, Cdr2-T166 phosphorylation is regulated by protein phosphatase 2A but not by the Sds23-PP6 pathway. Thus, our study provides a phosphatase-driven mechanism to induce specific physiological responses downstream of a master protein kinase.

Learnability

The study of natural language learnability is necessarily multidisciplinary. Its aim is to devise and evaluate possible psychological mechanisms by which a system bounded by the cognitive capabilities and linguistic exposure of a young child might be able to arrive at rich knowledge of an adult human language. The abstract formal models that launched this discipline have over the years become increasingly responsive to theoretical linguistic discoveries about the properties of natural language grammars, many embracing parameter theory in particular as a systemization of the ways in which grammars may differ. The concept of grammar acquisition as the setting of parameters has inspired a number of recent learning models, whose details are compared and contrasted here. But it has not swept away all learnability problems, as it has become clear that the input cues needed to trigger the correct parameter settings are often ambiguous or opaque.

Context, as well as inputs, shape decisions, but are people aware of it?

Even if people are experts at understanding how various input cues landed them at a particular decision (something the authors refer to as cue utilization), they may still fail to appreciate how context influences the weight given to those input variables. We review evidence suggesting that people are unaware of contextual influences on their decisions.

Testing an Adaptationist Theory of Trait Covariation: Relative Bargaining Power as a Common Calibrator of an Interpersonal Syndrome

This article provides the first test of an adaptationist ‘common calibration’ theory to explain the origins of trait covariation, which holds that (i) personality traits are often facultatively calibrated in response to cues that ancestrally predicted the reproductive payoffs of different trait levels and (ii) distinct traits that are calibrated on the basis of common input cues will exhibit consistent patterns of covariation. This theory is applied to explain the covariation within a ‘personality syndrome’ encompassing various interpersonal trait dimensions (e.g. extraversion, emotionality and attachment styles). Specifically, it is hypothesized that these traits are inter–correlated because each is calibrated in response to relative bargaining power (RBP)—a joint function of one's ability to benefit others and harm others. Path analyses from a correlational study compellingly supported this theoretical model: Objective and self–perceived measures of RBP–enhancing phenotypic features (physical attractiveness and physical strength) influenced an internal regulatory variable indexing RBP (i.e. self–perceived RBP), which in turn had robust effects on each of the focal personality traits. Moreover, in support of the theory's core postulate, controlling for self–perceived RBP greatly reduced the covariation within the interpersonal syndrome. These novel findings illustrate the promise of an evolutionary psychological approach to elucidating trait covariation. Copyright © 2013 John Wiley & Sons, Ltd.

The role of age of onset and input in early child bilingualism in Greek and Dutch

ABSTRACTThe focus of this study is the acquisition of grammatical gender in Greek and Dutch by bilingual children whose other language is English. Although grammatical gender languages share the property of noun classification in terms of grammatical gender, there are important differences between the languages under investigation here in terms of both the morphological cues for gender marking available to the child and the developmental path followed by monolingual children. Dutch offers limited input cues for grammatical gender, but Greek shows consistent and regular patterns of morphological gender marking on all members of the nominal paradigm. This difference is associated with the precocious pattern of gender acquisition in Greek and the attested delay in monolingual Dutch development. We explore the development of gender in Dutch and Greek with the aim of disentangling input from age of onset effects in bilingual children who vary in the age of first exposure to Dutch or Greek. Our findings suggest that although bilingual Greek children encounter fewer difficulties in gender acquisition compared to bilingual Dutch children, amount of input constitutes a predictive factor for the pattern attested in both cases. Age of onset effects could be partly responsible for differences between simultaneous and successive bilinguals in Greek, but this is clearly not the case for Dutch. Our findings are also addressed from the more general perspective of the status of “early” and “late” phenomena in monolingual acquisition and the advantages of investigating these from the bilingual perspective.

Widening the field: The process of language acquisition

Evans & Levinson (E&L) argue against Universal Grammar on the basis of language diversity. A related and fundamental issue is whether the language input provides sufficient information for a child to acquire it. I briefly discuss the more integrated approaches to language acquisition which focus on the mechanisms, and research showing that input cues provide valuable information for the language learner.

TRANSFER AND TRANSITION IN THE SLA OF ASPECT

Previous studies have shown that it is particularly difficult for second language (L2) learners to overcome the effects of transfer when they need to unlearn specific aspects of the native language in the absence of explicit input that indicates which properties of the first language (L1) are ruled out by the L2 grammar (Inagaki, 2001; Westergaard, 2003; White, 1991a, 1991b). The present study focuses on the effects of transfer in the domain of aspectual semantics through an investigation of the interpretation of the present progressive in L2 English and the imperfective marker te-iru in L2 Japanese and examines whether L2 learners can rule out interpretations available in the L1 but not in the L2. Japanese learners of English (n = 101), English native-speaker controls (n = 23), English learners of Japanese (n = 31), and Japanese native-speaker controls (n = 33) completed an interpretation task in English or Japanese. The results show that the L2 Japanese learners were more successful than the L2 English learners in both acquiring the semantics of the imperfective in the L2 and ruling out interpretations available only in the L1. It is proposed that successful unlearning depends on both the grammatical complexity of the semantic target in the L2 and the transparency of the input cues available to the learner.