Entropy fluctuation formulas of fermionic Gaussian states

We study the statistical behaviour of quantum entanglement in bipartite systems over fermionic Gaussian states as measured by von Neumann entropy. The formulas of average von Neumann entropy with and without particle number constrains have been recently obtained, whereas the main results of this work are the exact yet explicit formulas of variances for both cases. For the latter case of no particle number constrain, the results resolve a recent conjecture on the corresponding variance. Different than existing methods in computing variances over other generic state models, the key ingredient in proving the results of this work relies on a new simplification framework. The framework consists of a set of new tools in simplifying finite summations of what we refer to as dummy summation and re-summation techniques. As a byproduct, the proposed framework leads to various new transformation formulas of hypergeometric functions.Comment: 64 pages, 3 figure

Saikosaponins induced hepatotoxicity in mice via lipid metabolism dysregulation and oxidative stress: a proteomic study

Background Radix Bupleuri (RB) has been popularly used for treating many liver diseases such as chronic hepatic inflammation and viral Hepatitis in China. Increasing clinical and experimental evidence indicates the potential hepatotoxicity of RB or prescriptions containing RB. Recently, Saikosaponins (SS) have been identified as major bioactive compounds isolated from RB, which may be also responsible for RB-induced liver injury. Methods Serum AST, ALT and LDH levels were determined to evaluate SS-induced liver injury in mice. Serum and liver total triglyceride and cholesterol were used to indicate lipid metabolism homeostasis. Liver ROS, GSH, MDA and iNOS were used to examine the oxidative stress level after SS administration. Western blot was used to detect CYP2E1 expression. A 8-Plex iTRAQ Labeling Coupled with 2D LC - MS/MS technique was applied to analyze the protein expression profiles in livers of mice administered with different doses of SS for different time periods. Gene ontology analysis, cluster and enrichment analysis were employed to elucidate potential mechanism involved. HepG2 cells were used to identify our findings in vitro. Results SS dose- and time-dependently induced liver injury in mice, indicated by increased serum AST, ALT and LDH levels. According to proteomic analysis, 487 differentially expressed proteins were identified in mice administrated with different dose of SS for different time periods. Altered proteins were enriched in pathways such as lipid metabolism, protein metabolism, macro molecular transportation, cytoskeleton structure and response to stress. SS enhanced CYP2E1 expression in a time and dose dependent manner, and induced oxidative stress both in vivo and in vitro. Conclusion Our results identified hepatotoxicity and established dose-time course-liver toxicity relationship in mice model of SS administration and suggested potential mechanisms, including impaired lipid and protein metabolism and oxidative stress. The current study provides experimental evidence for clinical safe use of RB, and also new insights into understanding the mechanism by which SS and RB induced liver injury

Automatic 3D tooth segmentation using convolutional neural networks in harmonic parameter space

Automatic segmentation of 3D tooth models into individual teeth is an important step in orthodontic CAD systems. 3D tooth segmentation is a mesh instance segmentation task. Complex geometric features on the surface of 3D tooth models often lead to failure of tooth boundary detection, so it is difficult to achieve automatic and accurate segmentation by traditional mesh segmentation methods. We propose a novel solution to address this problem. We map a 3D tooth model isomorphically to a 2D harmonic parameter space and convert it into an image. This allows us to use a CNN to learn a highly robust image segmentation model to achieve automated and accurate segmentation of 3D tooth models. Finally, we map the image segmentation mask back to the 3D tooth model and refine the segmentation result using an improved Fuzzy Clustering-and-Cuts algorithm. Our method has been incorporated into an orthodontic CAD system, and performs well in practice

PRODUCTION AND PERCEPTUAL ANALYSIS OF SPEECH PRODUCED IN NOISE

When exposed to noise, speakers modify the way they speak, possibly in an effort to maintain intelligible communication. These modifications are collectively referred to as the Lombard effect. The work described in this thesis compares speech production changes induced by noise with various spectral and temporal characteristics, and explores the perceptual consequence of these changes. The thesis consists of a series of experimental studies, which involve the analysis of speech corpora collected under different noise conditions, with and without a communicative task. Intelligibility is also measured and predicted using a computer model. The first study concerns the acoustic and phonetic consequences of N-talker “babble” noise on sentence production for a range of values of N from 1 (competing talker) to “infinity” (speech-shaped noise). The effect of noise on speech production increased with N and noise level, both of which act to increase the energetic masking effect of the noise. In a background of stationary noise, noise-induced speech was always more intelligible than speech produced in quiet, and the gain in intelligibility increased with N and noise level, suggesting that talkers modify their productions to ameliorate energetic masking at the ears of the listener. The effect of low- and high-pass filtered noise on speech production was also examined to address the issue of whether speakers can compensate for energetic masking by actively shifting their spectral energy to regions least affected by the noise. Little evidence was found that speakers are able to modify their speech production to take advantage of those spectral regions clear of noise. To evaluate the origin of the increased intelligibility of Lombard speech, the fundamental frequency and spectral tilt of speech produced in quiet were artificially manipulated to match those of speech produced in speech-shaped noise. A perceptual evaluation showed that spectral flattening made a larger contribution to Lombard speech intelligibility, but failed to find an influence of an increase in fundamental frequency. A computational modeling study indicated that durational changes could also play an important role in increasing intelligibility. These findings suggest that speech modifications which reallocate energy in time and frequency to introduce more “glimpses” of clean speech in the presence of noise are able to contribute to speech intelligibility. An analysis of the effect of noise on speech production requires material recorded while undertaking realistic tasks. The effect of a communication factor was explored using conversational speech collected in the presence of maskers with differing degrees of energetic and informational masking potential. The size of speech production changes was found to scale with the energetic masking potential of background noise, extending the findings with read speech to a communicative task. In addition, relative to the non-communicative task, speakers exploited temporal planning to reduce the amount of overlap with a modulated background noise, an effect which was stronger when the noise contained intelligible speech. In conclusion, the strategies used by talkers to promote successful speech communication under various noise conditions reported in this thesis could enable spoken output applications such as dialogue systems to adapt to communicational environment

Active hearing, active speaking

A static view of the world permeates most research in speech and hearing. In this idealised situation, sources don’t move and neither do listeners; the acoustic environment doesn’t change; and speakers speak without any effect of auditory input from their own voice or other speakers. Corpora for speech research and most behavioural tasks have grown to reflect the static viewpoint. Yet it is clear that speech and hearing takes place in a world where none of the static assumptions hold, or at least not for long. The dynamic view complicates traditional signal processing approaches, and renders conventional evaluation processes unrepeatable since the observer’s dynamics influence the signals received at the ears. However, the dynamic viewpoint also provides many opportunities for active processes to exploit. Some of these, such as the use of head movements to resolve front-back confusions, are well-known, while others exist solely as hypotheses. This paper reviews known and potential benefits of active processes in both hearing and speech production, and goes on to describe two recent studies which demonstrate the value of such processes. The first shows how dynamic cues can be used to estimate distance in an acoustic environment. The second demonstrates that the changes in speech production which take place when other speakers are active result in increased glimpsing opportunities at the ear of the interlocutor

Development and Utilization of Multifunctional Polymeric Scaffolds for the Regulation of Physical Cellular Microenvironments

Polymeric biomaterials exhibit excellent physicochemical characteristics as a scaffold for cell and tissue engineering applications. Chemical modification of the polymers has been the primary mode of functionalization to enhance biocompatibility and regulate cellular behaviors such as cell adhesion, proliferation, differentiation, and maturation. Due to the complexity of the in vivo cellular microenvironments, however, chemical functionalization alone is usually insufficient to develop functionally mature cells/tissues. Therefore, the multifunctional polymeric scaffolds that enable electrical, mechanical, and/or magnetic stimulation to the cells, have gained research interest in the past decade. Such multifunctional scaffolds are often combined with exogenous stimuli to further enhance the tissue and cell behaviors by dynamically controlling the microenvironments of the cells. Significantly improved cell proliferation and differentiation, as well as tissue functionalities, are frequently observed by applying extrinsic physical stimuli on functional polymeric scaffold systems. In this regard, the present paper discusses the current state-of-the-art functionalized polymeric scaffolds, with an emphasis on electrospun fibers, that modulate the physical cell niche to direct cellular behaviors and subsequent functional tissue development. We will also highlight the incorporation of the extrinsic stimuli to augment or activate the functionalized polymeric scaffold system to dynamically stimulate the cells

Development and Utilization of Multifunctional Polymeric Scaffolds for the Regulation of Physical Cellular Microenvironments.

Polymeric biomaterials exhibit excellent physicochemical characteristics as a scaffold for cell and tissue engineering applications. Chemical modification of the polymers has been the primary mode of functionalization to enhance biocompatibility and regulate cellular behaviors such as cell adhesion, proliferation, differentiation, and maturation. Due to the complexity of the in vivo cellular microenvironments, however, chemical functionalization alone is usually insufficient to develop functionally mature cells/tissues. Therefore, the multifunctional polymeric scaffolds that enable electrical, mechanical, and/or magnetic stimulation to the cells, have gained research interest in the past decade. Such multifunctional scaffolds are often combined with exogenous stimuli to further enhance the tissue and cell behaviors by dynamically controlling the microenvironments of the cells. Significantly improved cell proliferation and differentiation, as well as tissue functionalities, are frequently observed by applying extrinsic physical stimuli on functional polymeric scaffold systems. In this regard, the present paper discusses the current state-of-the-art functionalized polymeric scaffolds, with an emphasis on electrospun fibers, that modulate the physical cell niche to direct cellular behaviors and subsequent functional tissue development. We will also highlight the incorporation of the extrinsic stimuli to augment or activate the functionalized polymeric scaffold system to dynamically stimulate the cells