1,506 research outputs found
Accounting for Population Structure in Gene-by-Environment Interactions in Genome-Wide Association Studies Using Mixed Models.
Although genome-wide association studies (GWASs) have discovered numerous novel genetic variants associated with many complex traits and diseases, those genetic variants typically explain only a small fraction of phenotypic variance. Factors that account for phenotypic variance include environmental factors and gene-by-environment interactions (GEIs). Recently, several studies have conducted genome-wide gene-by-environment association analyses and demonstrated important roles of GEIs in complex traits. One of the main challenges in these association studies is to control effects of population structure that may cause spurious associations. Many studies have analyzed how population structure influences statistics of genetic variants and developed several statistical approaches to correct for population structure. However, the impact of population structure on GEI statistics in GWASs has not been extensively studied and nor have there been methods designed to correct for population structure on GEI statistics. In this paper, we show both analytically and empirically that population structure may cause spurious GEIs and use both simulation and two GWAS datasets to support our finding. We propose a statistical approach based on mixed models to account for population structure on GEI statistics. We find that our approach effectively controls population structure on statistics for GEIs as well as for genetic variants
Self-organization and phase transition in financial markets with multiple choices
Market confidence is essential for successful investing. By incorporating
multi-market into the evolutionary minority game, we investigate the effects of
investor beliefs on the evolution of collective behaviors and asset prices.
When there exists another investment opportunity, market confidence, including
overconfidence and under-confidence, is not always good or bad for investment.
The roles of market confidence is closely related to market impact. For low
market impact, overconfidence in a particular asset makes an investor become
insensitive to losses and a delayed strategy adjustment leads to a decline in
wealth, and thereafter, one's runaway from the market. For high market impact,
under-confidence in a particular asset makes an investor over-sensitive to
losses and one's too frequent strategy adjustment leads to a large fluctuation
in asset prices, and thereafter, a decrease in the number of agents. At an
intermediate market impact, the phase transition occurs. No matter what the
market impact is, an equilibrium between different markets exists, which is
reflected in the occurrence of similar price fluctuations in different markets.
A theoretical analysis indicates that such an equilibrium results from the
coupled effects of strategy updating and shift in investment. The runaway of
the agents trading a specific asset will lead to a decline in the asset price
volatility and such a decline will be inhibited by the clustering of the
strategies. A uniform strategy distribution will lead to a large fluctuation in
asset prices and such a fluctuation will be suppressed by the decrease in the
number of agents in the market. A functional relationship between the price
fluctuations and the numbers of agents is found
Aquabis(5-butylpyridine-2-carboxylato)zinc monohydrate
In the title complex, [Zn(C10H12NO2)2(H2O)]·H2O, the ZnII ion is coordinated by two N and two O atoms from two 5-n-butylpyridine-2-carboxylato ligands and one O atom from a water molecule in a distorted square-pyramidal geometry. In the crystal, intermolecular O—H⋯O hydrogen bonds link molecules into a two-dimensional supramolecular structure parallel to (001)
Detecting extreme-mass-ratio inspirals for space-borne detectors with deep learning
One of the primary objectives for space-borne gravitational wave detectors is
the detection of extreme-mass-ratio inspirals (EMRIs). This undertaking poses a
substantial challenge because of the complex and long EMRI signals, further
complicated by their inherently faint signal. In this research, we introduce a
2-layer Convolutional Neural Network (CNN) approach to detect EMRI signals for
space-borne detectors. Our method employs the Q-transform for data
preprocessing, effectively preserving EMRI signal characteristics while
minimizing data size. By harnessing the robust capabilities of CNNs, we can
reliably distinguish EMRI signals from noise, particularly when the
signal-to-noise~(SNR) ratio reaches 50, a benchmark considered a ``golden''
EMRI. At the meantime, we incorporate time-delay interferometry (TDI) to ensure
practical utility. We assess our model's performance using a 0.5-year dataset,
achieving a true positive rate~(TPR) of 94.2\% at a 1\% false positive
rate~(FPR) across various signal-to-noise ratio form 50-100, with 91\% TPR and
1\% FPR at an SNR of 50. This study underscores the promise of incorporating
deep learning methods to advance EMRI data analysis, potentially leading to
rapid EMRI signal detection.Comment: 12 pages, 8 figures, 2 table
The detection, extraction and parameter estimation of extreme-mass-ratio inspirals with deep learning
One of the primary goals of space-borne gravitational wave detectors is to
detect and analyze extreme-mass-ratio inspirals (EMRIs). This endeavor presents
a significant challenge due to the complex and lengthy EMRI signals, further
compounded by their inherently faint nature. In this letter, we introduce a
2-layer Convolutional Neural Network (CNN) approach to detect EMRI signals for
space-borne detectors, achieving a true positive rate (TPR) of 96.9 % at a 1 %
false positive rate (FPR) for signal-to-noise ratio (SNR) from 50 to 100.
Especially, the key intrinsic parameters of EMRIs such as mass and spin of the
supermassive black hole (SMBH) and the initial eccentricity of the orbit can be
inferred directly by employing a VGG network. The mass and spin of the SMBH can
be determined at 99 % and 92 % respectively. This will greatly reduce the
parameter spaces and computing cost for the following Bayesian parameter
estimation. Our model also has a low dependency on the accuracy of the waveform
model. This study underscores the potential of deep learning methods in EMRI
data analysis, enabling the rapid detection of EMRI signals and efficient
parameter estimation .Comment: 6 pages, 5 figure
Characterizing and Predicting Early Reviewers for Effective Product Marketing on E-Commerce Websites
Online reviews have become an important source of information for users before making an informed purchase decision. Early reviews of a product tend to have a high impact on the subsequent product sales. In this paper, we take the initiative to study the behavior characteristics of early reviewers through their posted reviews on two real-world large e-commerce platforms, i.e., Amazon and Yelp. In specific, we divide product lifetime into three consecutive stages, namely early, majority and laggards. A user who has posted a review in the early stage is considered as an early reviewer. We quantitatively characterize early reviewers based on their rating behaviors, the helpfulness scores received from others and the correlation of their reviews with product popularity. We have found that (1) an early reviewer tends to assign a higher average rating score; and (2) an early reviewer tends to post more helpful reviews. Our analysis of product reviews also indicates that early reviewers' ratings and their received helpfulness scores are likely to influence product popularity. By viewing review posting process as a multiplayer competition game, we propose a novel margin-based embedding model for early reviewer prediction. Extensive experiments on two different e-commerce datasets have shown that our proposed approach outperforms a number of competitive baselines
A generalized public goods game with coupling of individual ability and project benefit
Facing a heavy task, any single person can only make a limited contribution
and team cooperation is needed. As one enjoys the benefit of the public goods,
the potential benefits of the project are not always maximized and may be
partly wasted. By incorporating individual ability and project benefit into the
original public goods game, we study the coupling effect of the four
parameters, the upper limit of individual contribution, the upper limit of
individual benefit, the needed project cost and the upper limit of project
benefit on the evolution of cooperation. Coevolving with the individual-level
group size preferences, an increase in the upper limit of individual benefit
promotes cooperation while an increase in the upper limit of individual
contribution inhibits cooperation. The coupling of the upper limit of
individual contribution and the needed project cost determines the critical
point of the upper limit of project benefit, where the equilibrium frequency of
cooperators reaches its highest level. Above the critical point, an increase in
the upper limit of project benefit inhibits cooperation. The evolution of
cooperation is closely related to the preferred group-size distribution. A
functional relation between the frequency of cooperators and the dominant group
size is found
Incorporating social role theory into topic models for social media content analysis
In this paper, we explore the idea of social role theory (SRT) and propose a novel regularized topic model which incorporates SRT into the generative process of social media content. We assume that a user can play multiple social roles, and each social role serves to fulfil different duties and is associated with a role-driven distribution over latent topics. In particular, we focus on social roles corresponding to the most common social activities on social networks. Our model is instantiated on microblogs, i.e., Twitter and community question-answering (cQA), i.e., Yahoo! Answers, where social roles on Twitter include "originators" and "propagators", and roles on cQA are "askers" and "answerers". Both explicit and implicit interactions between users are taken into account and modeled as regularization factors. To evaluate the performance of our proposed method, we have conducted extensive experiments on two Twitter datasets and two cQA datasets. Furthermore, we also consider multi-role modeling for scientific papers where an author's research expertise area is considered as a social role. A novel application of detecting users' research interests through topical keyword labeling based on the results of our multi-role model has been presented. The evaluation results have shown the feasibility and effectiveness of our model
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