Positivity of the English language

Over the last million years, human language has emerged and evolved as a fundamental instrument of social communication and semiotic representation. People use language in part to convey emotional information, leading to the central and contingent questions: (1) What is the emotional spectrum of natural language? and (2) Are natural languages neutrally, positively, or negatively biased? Here, we report that the human-perceived positivity of over 10,000 of the most frequently used English words exhibits a clear positive bias. More deeply, we characterize and quantify distributions of word positivity for four large and distinct corpora, demonstrating that their form is broadly invariant with respect to frequency of word use.Comment: Manuscript: 9 pages, 3 tables, 5 figures; Supplementary Information: 12 pages, 3 tables, 8 figure

Septin filaments exhibit a dynamic, paired organization that is conserved from yeast to mammals

© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Journal of Cell Biology 193 (2011): 1065-1081, doi:10.1083/jcb.201012143.The septins are conserved, GTP-binding proteins important for cytokinesis, membrane compartmentalization, and exocytosis. However, it is unknown how septins are arranged within higher-order structures in cells. To determine the organization of septins in live cells, we developed a polarized fluorescence microscopy system to monitor the orientation of GFP dipole moments with high spatial and temporal resolution. When GFP was fused to septins, the arrangement of GFP dipoles reflected the underlying septin organization. We demonstrated in a filamentous fungus, a budding yeast, and a mammalian epithelial cell line that septin proteins were organized in an identical highly ordered fashion. Fluorescence anisotropy measurements indicated that septin filaments organized into pairs within live cells, just as has been observed in vitro. Additional support for the formation of pairs came from the observation of paired filaments at the cortex of cells using electron microscopy. Furthermore, we found that highly ordered septin structures exchanged subunits and rapidly rearranged. We conclude that septins assemble into dynamic, paired filaments in vivo and that this organization is conserved from yeast to mammals.This work was supported by the National Science Foundation under grant No. MCB-0719126 to A.S. Gladfelter, the National Institute of Biomedical Imaging and Bioengineering under grant No. EB002583 to R. Oldenbourg, a Drexel CURE grant from the State of Pennsylvania Tobacco Settlement Fund, and National Institute of Neurological Disorders and Stroke grant NS48090- 06A to E.T. Spiliotis

Evolutionary games on graphs

Game theory is one of the key paradigms behind many scientific disciplines from biology to behavioral sciences to economics. In its evolutionary form and especially when the interacting agents are linked in a specific social network the underlying solution concepts and methods are very similar to those applied in non-equilibrium statistical physics. This review gives a tutorial-type overview of the field for physicists. The first three sections introduce the necessary background in classical and evolutionary game theory from the basic definitions to the most important results. The fourth section surveys the topological complications implied by non-mean-field-type social network structures in general. The last three sections discuss in detail the dynamic behavior of three prominent classes of models: the Prisoner's Dilemma, the Rock-Scissors-Paper game, and Competing Associations. The major theme of the review is in what sense and how the graph structure of interactions can modify and enrich the picture of long term behavioral patterns emerging in evolutionary games.Comment: Review, final version, 133 pages, 65 figure

“Till the muddle in my mind have cleared awa”: can we help shape policy using systems modelling?

This paper considers how some well-documented deficiencies of mental models make it difficult to create effective policies, and suggests that systems modelling can begin to address this issue. To illustrate the argument three short cases are presented. These relate to specific domains but demonstrate how systems modelling can illuminate different general phenomena: effects on labour costs (unintended consequences and feedback); fishery management (accumulation and non-linearity) and child protection (worldviews and sense-making). Six levers for increasing the use of systems modelling in the policy arena are then discussed. The paper closes by emphasising the opportunities for systems modellers in the Anthropocene Era

Elevations of intracellular calcium reflect normal voltage-dependent behavior, and not constitutive activity, of voltage-dependent calcium channels in gastrointestinal and vascular smooth muscle

In smooth muscle, the gating of dihydropyridine-sensitive Ca2+ channels may either be stochastic and voltage dependent or coordinated among channels and constitutively active. Each form of gating has been proposed to be largely responsible for Ca2+ influx and determining the bulk average cytoplasmic Ca2+ concentration. Here, the contribution of voltage-dependent and constitutively active channel behavior to Ca2+ signaling has been studied in voltage-clamped single vascular and gastrointestinal smooth muscle cells using wide-field epifluorescence with near simultaneous total internal reflection fluorescence microscopy. Depolarization (−70 to +10 mV) activated a dihydropyridine-sensitive voltage-dependent Ca2+ current (ICa) and evoked a rise in [Ca2+] in each of the subplasma membrane space and bulk cytoplasm. In various regions of the bulk cytoplasm the [Ca2+] increase ([Ca2+]c) was approximately uniform, whereas that of the subplasma membrane space ([Ca2+]PM) had a wide range of amplitudes and time courses. The variations that occurred in the subplasma membrane space presumably reflected an uneven distribution of active Ca2+ channels (clusters) across the sarcolemma, and their activation appeared consistent with normal voltage-dependent behavior. Indeed, in the present study, dihydropyridine-sensitive Ca2+ channels were not normally constitutively active. The repetitive localized [Ca2+]PM rises (“persistent Ca2+ sparklets”) that characterize constitutively active channels were observed rarely (2 of 306 cells). Neither did dihydropyridine-sensitive constitutively active Ca2+ channels regulate the bulk average [Ca2+]c. A dihydropyridine blocker of Ca2+ channels, nimodipine, which blocked ICa and accompanying [Ca2+]c rise, reduced neither the resting bulk average [Ca2+]c (at −70 mV) nor the rise in [Ca2+]c, which accompanied an increased electrochemical driving force on the ion by hyperpolarization (−130 mV). Activation of protein kinase C with indolactam-V did not induce constitutive channel activity. Thus, although voltage-dependent Ca2+ channels appear clustered in certain regions of the plasma membrane, constitutive activity is unlikely to play a major role in [Ca2+]c regulation. The stochastic, voltage-dependent activity of the channel provides the major mechanism to generate rises in [Ca2+]

Perceptual Advantage of Animal Facial Attractiveness: Evidence From b-CFS and Binocular Rivalry

© Copyright © 2020 Shang, Liu, Yang, Wang, Zheng, Chen and Liu. Research has shown that attractive human faces enjoy an advantage in both conscious and preconscious processing. Here we examined whether this preference for attractiveness is exclusive to human faces by measuring participants’ sensitivity to the attractiveness of cat and tiger faces. Experiment 1 measured the time taken to break continuous flash suppression (b-CFS), whereas Experiment 2 measured the dominant time in binocular rivalry (BR). The results showed that attractive cat faces were detected more quickly (Experiment 1) and dominated for longer time in visual awareness (Experiment 2). However, no effect of attractiveness was found for tiger faces in Experiment 1, while attractive tiger faces also dominated for longer time in visual awareness in Experiment 2. The results provide first evidence that the preference for attractive animal faces can be shown involuntarily or without apparent conscious control. The findings suggest that human preference for facial attractiveness may contain an aesthetic element rather than being a purely adaptive means for mate choice

Hsp104-Dependent Remodeling of Prion Complexes Mediates Protein-Only Inheritance

Inheritance of phenotypic traits depends on two key events: replication of the determinant of that trait and partitioning of these copies between mother and daughter cells. Although these processes are well understood for nucleic acid–based genes, the mechanisms by which protein-only or prion-based genetic elements direct phenotypic inheritance are poorly understood. Here, we report a process crucial for inheritance of the Saccharomyces cerevisiae prion [PSI(+)], a self-replicating conformer of the Sup35 protein. By tightly controlling expression of a Sup35-GFP fusion, we directly observe remodeling of existing Sup35([PSI+]) complexes in vivo. This dynamic change in Sup35([PSI+]) is lost when the molecular chaperone Hsp104, a factor essential for propagation of all yeast prions, is functionally impaired. The loss of Sup35([PSI+]) remodeling by Hsp104 decreases the mobility of these complexes in the cytosol, creates a segregation bias that limits their transmission to daughter cells, and consequently diminishes the efficiency of conversion of newly made Sup35 to the prion form. Our observations resolve several seemingly conflicting reports on the mechanism of Hsp104 action and point to a single Hsp104-dependent event in prion propagation

Serrano (Sano) Functions with the Planar Cell Polarity Genes to Control Tracheal Tube Length

Epithelial tubes are the functional units of many organs, and proper tube geometry is crucial for organ function. Here, we characterize serrano (sano), a novel cytoplasmic protein that is apically enriched in several tube-forming epithelia in Drosophila, including the tracheal system. Loss of sano results in elongated tracheae, whereas Sano overexpression causes shortened tracheae with reduced apical boundaries. Sano overexpression during larval and pupal stages causes planar cell polarity (PCP) defects in several adult tissues. In Sano-overexpressing pupal wing cells, core PCP proteins are mislocalized and prehairs are misoriented; sano loss or overexpression in the eye disrupts ommatidial polarity and rotation. Importantly, Sano binds the PCP regulator Dishevelled (Dsh), and loss or ectopic expression of many known PCP proteins in the trachea gives rise to similar defects observed with loss or gain of sano, revealing a previously unrecognized role for PCP pathway components in tube size control