2,443 research outputs found
Environmental and genetic influences on neurocognitive development: the importance of multiple methodologies and time-dependent intervention
Genetic mutations and environmental factors dynamically influence gene expression and developmental trajectories at the neural, cognitive, and behavioral levels. The examples in this article cover different periods of neurocognitive development—early childhood, adolescence, and adulthood—and focus on studies in which researchers have used a variety of methodologies to illustrate the early effects of socioeconomic status and stress on brain function, as well as how allelic differences explain why some individuals respond to intervention and others do not. These studies highlight how similar behaviors can be driven by different underlying neural processes and show how a neurocomputational model of early development can account for neurodevelopmental syndromes, such as autism spectrum disorders, with novel implications for intervention. Finally, these studies illustrate the importance of the timing of environmental and genetic factors on development, consistent with our view that phenotypes are emergent, not predetermined
Classifying the Arithmetical Complexity of Teaching Models
This paper classifies the complexity of various teaching models by their
position in the arithmetical hierarchy. In particular, we determine the
arithmetical complexity of the index sets of the following classes: (1) the
class of uniformly r.e. families with finite teaching dimension, and (2) the
class of uniformly r.e. families with finite positive recursive teaching
dimension witnessed by a uniformly r.e. teaching sequence. We also derive the
arithmetical complexity of several other decision problems in teaching, such as
the problem of deciding, given an effective coding of all uniformly r.e. families, any such that
, any and , whether or not the
teaching dimension of with respect to is upper bounded
by .Comment: 15 pages in International Conference on Algorithmic Learning Theory,
201
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The development of the passé composé in lower-intermediate learners of French as a second language
In this study we tracked the development of the passe compose in second-language learners of French whose first language is English. Although the passe compose is a highly used tense among native speakers of French and it appears to present particular difficulty for first-language English speakers, its second-language development has been surprisingly under-researched. In order to trace developmental patterns of the passe compose we obtained a corpus of obligatory context use of this tense by 30 Year-12 (lower-intermediate) students at two time points six months apart and analysed the data both quantitatively and qualitatively. Our findings suggest that these students used remarkably few memorized formulas, that they passed through five distinct stages in their acquisition of the passe compose, that those early stages were characterized by transfer errors, and that the presence of the auxiliary, whether correct or incorrect, formed a crucial stage in the development of the tense. Theoretical explanations for the findings are presented together with some tentative pedagogical implications
Evaluating surface radiation fluxes observed from satellites in the southeastern Pacific Ocean
Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 45 (2018): 2404-2412, doi:10.1002/2017GL076805.This study is focused on evaluation of current satellite and reanalysis estimates of surface radiative fluxes in a climatically important region. It uses unique observations from the STRATUS Ocean Reference Station buoy in a region of persistent marine stratus clouds 1,500 km off northern Chile during 2000–2012. The study shows that current satellite estimates are in better agreement with buoy observations than model outputs at a daily time scale and that satellite data depict well the observed annual cycle in both shortwave and longwave surface radiative fluxes. Also, buoy and satellite estimates do not show any significant trend over the period of overlap or any interannual variability. This verifies the stability and reliability of the satellite data and should make them useful to examine El Niño–Southern Oscillation variability influences on surface radiative fluxes at the STRATUS site for longer periods for which satellite record is available.National Oceanic and Atmospheric Administration Grant Number: NA14OAR4320158;
NASA Grant Numbers: NNX13AC12G, NNX08AN40A2018-08-2
WCRP surface radiation budget shortwave data product description, version 1.1
Shortwave radiative fluxes which reach the Earth's surface are key elements that influence both atmospheric and oceanic circulation. The World Climate Research Program has established the Surface Radiation Budget climatology project with the ultimate goal of determining the various components of the surface radiation budget from satellite data on a global scale. This report describes the first global product that is being produced and archived as part of that effort. The interested user can obtain the monthly global data sets free of charge using e-mail procedures
The use of ICT in the assessment of modern languages: the English context and European viewpoints
The ever increasing explosion of highly attractive multimedia resources on offer has boosted the use of information and communication technology (ICT) in the teaching and learning of modern languages. The use of ICT to assess languages is less frequent, however, although online testing is starting to develop. This paper examines the national context for the assessment of modern foreign language proficiency in England, outlines the kinds of assessment currently available and the development of electronic forms of assessment and compares the above with the survey results of a European Union (EU) funded project on current good practice in online assessment of languages in other European countries. The findings indicate that speaking is inadequately served by online testing as tests currently focus primarily on receptive language skills. The implications for future successful online testing include the incorporation of interactive skills and effective formative feedback
Critical behavior in a cross-situational lexicon learning scenario
The associationist account for early word-learning is based on the
co-occurrence between objects and words. Here we examine the performance of a
simple associative learning algorithm for acquiring the referents of words in a
cross-situational scenario affected by noise produced by out-of-context words.
We find a critical value of the noise parameter above which learning
is impossible. We use finite-size scaling to show that the sharpness of the
transition persists across a region of order about ,
where is the number of learning trials, as well as to obtain the
learning error (scaling function) in the critical region. In addition, we show
that the distribution of durations of periods when the learning error is zero
is a power law with exponent -3/2 at the critical point
Multi-Technique Analysis of Precipitable Water Vapor Estimates in the sub-Sahel West Africa
Precipitable water vapor (PWV) is an important climate parameter indicative
of available moisture in the atmosphere, it is also an important greenhouse
gas. Observations of precipitable water vapor in sub-Sahel West Africa are
almost non-existent. Several Aerosol Robotic Network (AERONET) sites have been
established across West Africa, and observations from four of them, namely,
Ilorin (4.34o E, 8.32o N), Cinzana (5.93o W, 13.28o N), Banizoumbou (2.67o E,
13.54o N) and Dakar (16.96o W, 14.39o N) are being used in this study. Data
spanning the period from 2004 to 2014 have been selected, they include
conventional humidity parameters, remotely sensed aerosol and precipitable
water information and numerical model outputs. Since in Africa, only
conventional information on humidity parameters is available, it is important
to utilize the unique observations from the AERONET network to calibrate
empirical formulas frequently used to estimate precipitable water vapor from
humidity measurements. An empirical formula of the form PWV=aT_d+b where T_d is
the surface dew point temperature, a and b are constants, was fitted to the
data and is proposed as applicable to the climatic condition of the sub-Sahel.
Moreover, we have also used the AERONET information to evaluate the
capabilities of well-established numerical weather prediction (NWP) models such
as ERA Interim Reanalysis, NCEP-DOE Reanalysis II and NCEP-CFSR, to estimate
precipitable water vapor in the sub-Sahel West Africa, it was found that the
models tend to overestimate the amount of precipitable water at the selected
sites by about 25 %
Links that speak: The global language network and its association with global fame
International audienceLanguages vary enormously in global importance because of historical, demographic, political, and technological forces. However , beyond simple measures of population and economic power, there has been no rigorous quantitative way to define the global influence of languages. Here we use the structure of the networks connecting multilingual speakers and translated texts, as expressed in book translations, multiple language editions of Wikipedia, and Twitter, to provide a concept of language importance that goes beyond simple economic or demographic measures. We find that the structure of these three global language networks (GLNs) is centered on English as a global hub and around a handful of intermediate hub languages, which include Spanish, German, French, Russian, Portuguese, and Chinese. We validate the measure of a language's centrality in the three GLNs by showing that it exhibits a strong correlation with two independent measures of the number of famous people born in the countries associated with that language. These results suggest that the position of a language in the GLN contributes to the visibility of its speakers and the global popularity of the cultural content they produce. networks | languages | culture | digital humanities | fam
The Emerging Scholarly Brain
It is now a commonplace observation that human society is becoming a coherent
super-organism, and that the information infrastructure forms its emerging
brain. Perhaps, as the underlying technologies are likely to become billions of
times more powerful than those we have today, we could say that we are now
building the lizard brain for the future organism.Comment: to appear in Future Professional Communication in Astronomy-II
(FPCA-II) editors A. Heck and A. Accomazz
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