77 research outputs found
Model-driven CT reconstruction algorithm for nano-resolution X-ray phase contrast imaging
The low-density imaging performance of a zone plate based nano-resolution
hard X-ray computed tomography (CT) system can be significantly improved by
incorporating a grating-based Lau interferometer. Due to the diffraction,
however, the acquired nano-resolution phase signal may suffer splitting
problem, which impedes the direct reconstruction of phase contrast CT (nPCT)
images. To overcome, a new model-driven nPCT image reconstruction algorithm is
developed in this study. In it, the diffraction procedure is mathematically
modeled into a matrix B, from which the projections without signal splitting
can be generated invertedly. Furthermore, a penalized weighed least-square
model with total variation (PWLS-TV) is employed to denoise these projections,
from which nPCT images with high accuracy are directly reconstructed. Numerical
and physical experiments demonstrate that this new algorithm is able to work
with phase projections having any splitting distances. Results also reveal that
nPCT images with higher signal-to-noise-ratio (SNR) would be reconstructed from
projections with larger signal splittings. In conclusion, a novel model-driven
nPCT image reconstruction algorithm with high accuracy and robustness is
verified for the Lau interferometer based hard X-ray nano-resolution phase
contrast imaging
Distinguishing communal narcissism from agentic narcissism: A behavior genetics analysis on the agency-communion model of narcissism
This article examined the genetic and environmental bases of the newly proposed agency communion model of narcissism. The model distinguishes between agentic narcissism and communal narcissism. The sample comprised 304 pairs of twins. Genes explained 47% and 25% of the variance in agentic and communal narcissism, respectively; shared environments contributed 0% and 15%, respectively, to agentic and communal narcissism, with non-shared environments accounting for the remaining portions. Although some common genes and environments influenced agentic and communal narcissism simultaneously, most genetic (68%) and environmental (94%) influences on agentic and communal narcissism were unique. These findings provide novel evidence for the theoretical plausibility of communal narcissism as well as its relatedness to and distinctiveness from agentic narcissism, supporting the agency communion narcissism model. (C) 2014 Elsevier Inc. All rights reserved
Focused ultrasound-mediated brain genome editing.
Gene editing in the brain has been challenging because of the restricted transport imposed by the blood-brain barrier (BBB). Current approaches mainly rely on local injection to bypass the BBB. However, such administration is highly invasive and not amenable to treating certain delicate regions of the brain. We demonstrate a safe and effective gene editing technique by using focused ultrasound (FUS) to transiently open the BBB for the transport of intravenously delivered CRISPR/Cas9 machinery to the brain
Implicit Consumer Animosity: A Primary Validation
The present study validated implicit animosity as a unique determinant of consumer behavior in the context of Chinese animosity toward Japan. The Implicit Association Test (IAT) was employed to measure implicit Chinese animosity toward Japan. The results showed that (a) implicit animosity was distinct from consumer ethnocentrism; (b) implicit animosity was significantly correlated with war animosity, but not with economic animosity; and (c) implicit animosity exerted negative impacts on purchase intention, independent of explicit animosity, consumer ethnocentrism, and product judgment. Taken together, these findings provide initial evidence of discriminant, convergent, and predictive validity for implicit animosity, highlighting the importance of taking implicit animosity into account in future animosity research
A behavioral genetic study of intrapersonal and interpersonal dimensions of narcissism.
Narcissism, characterized by grandiose self-image and entitled feelings to others, has been increasingly prevalent in the past decades. This study examined genetic and environmental bases of two dimensions of narcissism: intrapersonal grandiosity and interpersonal entitlement. A total of 304 pairs of twins from Beijing, China completed the Narcissistic Grandiosity Scale and the Psychological Entitlement Scale. Both grandiosity (23%) and entitlement (35%) were found to be moderately heritable, while simultaneously showing considerable non-shared environmental influences. Moreover, the genetic and environmental influences on the two dimensions were mostly unique (92-93%), with few genetic and environmental effects in common (7-8%). The two dimensions of narcissism, intrapersonal grandiosity and interpersonal entitlement, are heritable and largely independent of each other in terms of their genetic and environmental sources. These findings extend our understanding of the heritability of narcissism on the one hand. On the other hand, the study demonstrates the rationale for distinguishing between intrapersonal and interpersonal dimensions of narcissism, and possibly personality in general as well
Differential item functioning of the Rosenberg Self-Esteem Scale in the US and China: Measurement bias matters
Using an item-response theory-based approach (i.e. likelihood ratio test with an iterative procedure), we examined the equivalence of the Rosenberg Self-Esteem Scale (RSES) in a sample of US and Chinese college students. Results from the differential item functioning (DIF) analysis showed that the RSES was not fully equivalent at the item level, as well as at the scale level. The two cultural groups did not use the scale comparably, with the US students showing more extreme responses than the Chinese students. Moreover, we evaluated the practical impact of DIF and found that cultural differences in average self-esteem scores disappeared after the DIF was taken into account. In the present study, we discuss the implications of our findings for cross-cultural research and provide suggestions for future studies using the RSES in China
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