8,902 research outputs found
Spousal Concordance in Academic Achievements and Intelligence and Family-Based Association Studies Identified Novel Loci Associated with Intelligence.
Assortative Mating, the tendency for mate selection to occur on the basis of similar traits, plays an essential role in understanding the genetic variation on academic achievements and intelligence (IQ). It is an important mechanism explaining spousal concordance. We used principal component analysis (PCA) for spousal correlation. There is a significant positive correlation between spouses by the new variable PC1 (correlation coefficient=0.515, p\u3c0.0001). We further research the genetic factor that affects IQ by using the same data. We performed a low density genome-wide association (GWA) analysis with a family-based association test to identify genetic variants that associated with intelligence as measured by WAIS full-score IQ (FSIQ). NTM at 11q25 (rs411280, p=0.000764) and NR3C2 at 4q31.23 (rs3846329, p=0.000675) were 2 novel genes that haven\u27t been associated with IQ from other studies. This study may serve as a resource for replication in other populations and a foundation for future investigations
Inception vs Completion: Comparing the Effects of Two Treatments on the Acquisition of le
This study aims to explore the effects of two instructional treatments on adult English-speaking Chinese learners’ learning of the Chinese particle le. Previous studies reveal that adult English-speaking Chinese learners’ performance on le structures is subject to the influence of the time grammar of English. Drawing upon Input Processing theory, English-speaking Chinese learners’ performance on le structures correlates to their awareness of the syntactic uniqueness of le, and the awareness may vary according to the way le is introduced. That is, the influence of time grammar on learners may be either strengthened or weakened depending on how learners’ attention is directed at the stage of input. In this sense, this study hypothesizes that the time-analysis based (completion-oriented) instruction will differ from the fact-analysis based (inception-oriented) instruction in effects on English-speaking Chinese learners’ learning of the Chinese particle le. Specifically, learners exposed to the inception-oriented treatment will develop processing strategies that are less subject to time grammar. Relatively, learners exposed to the completion-oriented treatment will be more susceptible to the influence of time grammar transfer in the processing of le structures. An experiment was conducted to compare the effects of the two instructional treatments, and the results of the experiment support the conclusion that the instructional treatments caused differences the two groups’ performances
A Finite Time Analysis of Two Time-Scale Actor Critic Methods
Actor-critic (AC) methods have exhibited great empirical success compared
with other reinforcement learning algorithms, where the actor uses the policy
gradient to improve the learning policy and the critic uses temporal difference
learning to estimate the policy gradient. Under the two time-scale learning
rate schedule, the asymptotic convergence of AC has been well studied in the
literature. However, the non-asymptotic convergence and finite sample
complexity of actor-critic methods are largely open. In this work, we provide a
non-asymptotic analysis for two time-scale actor-critic methods under
non-i.i.d. setting. We prove that the actor-critic method is guaranteed to find
a first-order stationary point (i.e., ) of the non-concave performance function
, with sample
complexity. To the best of our knowledge, this is the first work providing
finite-time analysis and sample complexity bound for two time-scale
actor-critic methods.Comment: 45 page
Advanced DSP Techniques for High-Capacity and Energy-Efficient Optical Fiber Communications
The rapid proliferation of the Internet has been driving communication networks closer and closer to their limits, while available bandwidth is disappearing due to an ever-increasing network load. Over the past decade, optical fiber communication technology has increased per fiber data rate from 10 Tb/s to exceeding 10 Pb/s. The major explosion came after the maturity of coherent detection and advanced digital signal processing (DSP). DSP has played a critical role in accommodating channel impairments mitigation, enabling advanced modulation formats for spectral efficiency transmission and realizing flexible bandwidth. This book aims to explore novel, advanced DSP techniques to enable multi-Tb/s/channel optical transmission to address pressing bandwidth and power-efficiency demands. It provides state-of-the-art advances and future perspectives of DSP as well
Energy cascade in the Garrett-Munk spectrum of internal gravity waves
We study the spectral energy transfer due to wave-triad interactions in the
Garrett-Munk spectrum of internal gravity waves (IGWs) based on a numerical
evaluation of the collision integral in the wave kinetic equation. Our
numerical evaluation builds on the reduction of the collision integral on the
resonant manifold for a horizontally isotropic spectrum. We directly evaluate
the downscale energy flux available for ocean mixing, whose value is in close
agreement with the empirical finescale parameterization. We further decompose
the energy transfer into contributions from different mechanisms, including
local interactions and three types of nonlocal interactions, namely parametric
subharmonic instability (PSI), elastic scattering (ES) and induced diffusion
(ID). Through analysis on the role of each type of interaction, we resolve two
long-standing paradoxes regarding the mechanism for forward cascade in
frequency and zero ID flux for GM76 spectrum. In addition, our analysis
estimates the contribution of each mechanism to the energy transfer in each
spectral direction, and reveals new understanding of the importance of local
interactions and ES in the energy transfer
Modelling Stochastic Star Formation History of Dwarf Galaxies in GRUMPY
We investigate the impact of bursty star formation on several galaxy scaling
relations of dwarf galaxies using the galaxy formation model.
While this model reproduces the star formation rate (SFR)-stellar mass, stellar
mass-gas mass, and stellar mass-metallicity relations, the scatter of these
relations in the original model is smaller than observed. We explore the
effects of additional stochasticity of SFR on the scaling relations using a
model that reproduces the level of SFR burstiness in high-resolution zoom-in
simulations. The additional SFR stochasticity increases the scatter in the
SFR-stellar mass relation to a level similar to that exhibited by most nearby
dwarf galaxies. The most extreme observed starbursting dwarfs, however, require
higher levels of SFR stochasticity. We find that bursty star formation
increases the scatter in the colour-magnitude distribution (CMD) for brighter
dwarf galaxies to the observed level, but not for fainter ones
for which scatter remains significantly smaller than observed. This is due to
the predominant old stellar populations in these faint model galaxies and their
generally declining SFR over the past 10 Gyrs, rather than quenching caused by
reionization. We examine the possibility that the colour scatter is due to
scatter in metallicity, but show that the level of scatter required leads to an
overestimation of scatter in the metallicity-mass relation. This illustrates
that the scatter of observed scaling relations in the dwarf galaxy regime
represents a powerful constraint on the properties of their star formation.Comment: 14 pages, 8 figures, submitted to MNRA
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