Erratum: Noise-induced transition in human reaction times

We thank Kenneth H Norwich (University of Toronto, Canada) for his help and support in the derivation of equations (10) and (11).The human reaction/response time can be defined as the time elapsed from the onset of stimulus presentation until a response occurs in many sensory and cognitive processes. A reaction time model based on Piéron’s law is investigated. The model shows a noise-induced transition in the moments of reaction time distributions due to the presence of strong additive noise. The model also demonstrates that reaction times do not follow fluctuation scaling between the mean and the variance but follow a generalized version between the skewness and the kurtosis. The results indicate that noise-induced transitions in the moments govern fluctuations in sensory–motor transformations and open an insight into the macroscopic effects of noise in human perception and action. The conditions that lead to extreme reaction times are discussed based on the transfer of information in neurons

On the structure of symmetric self-dual Lie algebras

A finite-dimensional Lie algebra is called (symmetric) self-dual, if it possesses an invariant nondegenerate (symmetric) bilinear form. Symmetric self-dual Lie algebras have been studied by Medina and Revoy, who have proven a very useful theorem about their structure. In this paper we prove a refinement of their theorem which has wide applicability in Conformal Field Theory, where symmetric self-dual Lie algebras start to play an important role due to the fact that they are precisely the Lie algebras which admit a Sugawara construction. We also prove a few corollaries which are important in Conformal Field Theory. (This paper provides mathematical details of results used, but only sketched, in the companion paper hep-th/9506151.)Comment: 19 pages, .dvi.uu (needs AMSFonts 2.1+

Lorentzian Lie n-algebras

We classify Lie n-algebras possessing an invariant lorentzian inner product.Comment: 10 pages (V2: more details on Section 3 and a new lemma. V3: typos corrected

Commentary: Piéron's law is not just an artifact of the response mechanism

A commentary on Piéron's law is not just an artifact of the response mechanism by Donkin, C., and van Maanen, L. (2014). J. Math. Psychol. 62–63, 22–32. doi: 10.1016/j.jmp.2014.09.006

Advances in modern mental chronometry

Mental chronometry encompasses all aspects of time processing in the nervous system and constitutes a standard tool in many disciplines including theoretical and experimental psychology and human neuroscience. Mental chronometry has represented a fundamental approach to elucidate the time course of many cognitive phenomena and their underlying neural circuits over more than a century. Nowadays, mental chronometry continues evolving and expanding our knowledge, and our understanding of the temporal organization of the brain in combination with different neuroscience techniques and advanced methods in mathematical analysis. In research on mental chronometry, human reaction/responses times (RT) play a central role. Together with RTs, other topics in mental chronometry include vocal, manual and saccadic latencies, subjective time, psychological time, interval timing, time perception, internal clock, time production, time representation, time discrimination, time illusion, temporal summation, temporal integration, temporal judgment, redundant signals effect, perceptual, decision and motor time, etc. It is worth noting that there have been well over 37,000 full-length journal papers published in the last decade on a variety of topics related to simple and choice RTs, etc. This amounts to approximately 3800 papers per year, or roughly 10 papers per day (source: PubMed, similarly Thomson Reuters Web of Science). There are comprehensive reviews that deal extensively with the history of mental chronometry, experimental methods and paradigms, stochastic models, etc. as well as its relationship to other psychological and physiological variables, neuroscience methods and clinical applications

Reassessment of miRNA variant (isomiRs) composition by small RNA sequencing

IsomiRs, sequence variants of maturemicroRNAs, are usually detected and quantified using high-throughput sequencing. Many examples of their biological relevance have been reported, but sequencing artifacts identified as artificial variants might bias biological inference and therefore need to be ideally avoided. We conducted a comprehensive evaluation of 10 different small RNA sequencing protocols, exploring both a theoretically isomiR-free pool of synthetic miRNAs and HEK293T cells. We calculated that, with the exception of two protocols, less than 5% of miRNA reads can be attributed to library preparation artifacts. Randomizedend adapter protocols showed superior accuracy, with 40% of true biological isomiRs. Nevertheless, we demonstrate concordance across protocols for selected miRNAs in non-templated uridyl additions. Notably, NTA-U calling and isomiR target prediction can be inaccurate when using protocols with poor single-nucleotide resolution. Our results highlight the relevance of protocol choice for biological isomiRs detection and annotation, which has key potential implications for biomedical applications

Transgenerational and within-generation plasticity shape thermal performance curves

Thermal performance curves (TPCs) compute the effects of temperature on the performance of ectotherms and are frequently used to predict the effect of environmental conditions and currently, climate change, on organismal vulnerability and sensitivity. Using Drosophila melanogaster as an animal model, we examined how different thermal environments affected the shape of the performance curve and their parameters. We measured the climbing speed as a measure of locomotor performance in adult flies and tested the ontogenetic and transgenerational effects of thermal environment on TPC shape. Parents and offspring were reared at 28 ± 0ºC (28C), 28 ± 4ºC (28V), and 30 ± 0ºC (30C). We found that both, environmental thermal variability (28V) and high temperature (30C) experienced during early ontogeny shaped the fruit fly TPC sensitivity. Flies reared at variable thermal environments shifted the TPC to the right and increased heat tolerance. Flies held at high and constant temperature exhibited lower maximum performance than flies reared at the variable thermal environment. Furthermore, these effects were extended to the next generation. The parental thermal environment had a significative effect on TPC and its parameters. Indeed, flies reared at 28V whose parents were held at a high and constant temperature (30C) had a lower heat tolerance than F1 of flies reared at 28C or 28V. Also, offspring of flies reared at variable thermal environment (28V) reached the maximum performance at a higher temperature than offspring of flies reared at 28C or 30C. Consequently, since TPC parameters are not fixed, we suggest cautiousness when using TPCs to predict the impact of climate change on natural populations.Fil: Cavieres Parada, Grisel Beatriz. Pontificia Universidad Católica de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Alruiz, José M.. Pontificia Universidad Católica de Chile; ChileFil: Medina, Nadia R.. Pontificia Universidad Católica de Chile; ChileFil: Bogdanovich, José M.. Pontificia Universidad Católica de Chile; ChileFil: Bozinovic, Francisco. Pontificia Universidad Católica de Chile; Chil

Sistema de predicció de pictogrames per una aplicació de CAA basada en pictogrames

En aquest projecte hem construït un sistema de compansió (compressió-expansió) que expandeix llenguatge telegràfic (frases únicament amb paraules de contingut sense reflexió) en frases de llenguatge natural en català i castellà, en el context d'un programari de Comunicació Augmentativa i Alternativa (CAA). El sistema ha estat dissenyat per millorar la comunicació dels usuaris de CAA, que normalment tenen deficiències motores o de parla greus i que utilitzen mètodes de comunicació basats en pictogrames en la seva vida diària. No obstant això, també pot ser vist com una eina per donar suport a l'alfabetització d'aquests usuaris i a la rehabilitació de transtorns del llenguatge. El sistema de compressió i expansió té dos components principals: una analitzador de dependències sintàctico-semàntic en el qual es basa el nostre predictor i un generador que construeix la frase final. Aquest document explica el desenvolupament d'aquest projecte.In this project we have built a compansion (compression-expansion) system that expands telegraphic language (utterances with only uninflected content words) into natural language sentences in Catalan and in Spanish, in the context of an Augmentative and Alternative Communication (AAC) software. The system has been designed to improve the communication of AAC users, who usually have severe speech or motor impairments and use pictogram-based communication methods in their daily life. However, it can also be seen as a potential tool to support literacy for these users and to help in the field of language rehabilitation. The compansion system has two main components: a syntactic-semantic dependency parser, in which our predictor is based and a generator that constructs the final sentence. This document explains the development of this project.En este proyecto hemos construodo un sistema de compansión (compresión-expresión) que expande lenguaje telegráfico (frases únicamente con palabras de contenido sin reflexión) en frases de lenguaje natural en catalán y castellano, en el contexto de un programa de Comunicación Aumentativa y Alternativa (CAA). El sistema ha estado diseñado para mejorar la comunicación de los usuarios de CAA, que normalmente tienen deficiencias motoras o de habla graves i que utilizan métodos de comunicación basados en pictogramas durante su vida diaria. No obstante, también puede ser visto como una herramienta para dar soporte a la alfabetización de estos usuarios y a la rehabilitación de trastornos del lenguaje. El sistema de compresión y expansión tiene dos componentes principales: un analizador de dependencias sintáctico-semántico en el cual se basa nuestro predictor y un generador que construye la frase final. Este documento explica el desarrollo de este proyecto

Postnatal changes in rhodamine-123 stained mitochondrial populations are sensitive to protein synthesis inhibitors but mimicked in vitro by atp

AbstractThe incubation of term fetus mitochondria with ATP mimicked in vitro the increase in the respiratory control index and in the percentage of the rhodamine-123-low fluorescence population that occurred in vivo immediately after birth, suggesting that both phenomena are closely associated. The administration of streptomycin inhibited the increase in the percentage of the low fluorescence population that occurred immediately after birth, while the administration of cycloheximide even reversed these changes. These results suggest that the in vivo interconversion between mitochondrial forms depends on both cytosolic and mitochondrial protein synthesis