190 results match your criteria: "School of Mathematics and Computational Science[Affiliation]"

Background: Ultrasound is considered a reliable, widely available, non-invasive, and inexpensive imaging technique for assessing and detecting the development phases of cancer; both in vivo and ex vivo, and for understanding the effects on cell cycle and viability after ultrasound treatment.

Methods: Based on the topological continuity characteristics, and that adjacent points or areas represent similar features, we propose a topological penalized convex objective function of sparse coding, to recognize similar cell phases.

Results: This method introduces new features using a deep learning method of sparse coding with topological continuity characteristics.

View Article and Find Full Text PDF

Self-Assembly of Asymmetrically Interacting ABC Star Triblock Copolymer Melts.

J Phys Chem B

November 2015

Hunan Key Laboratory for Computation and Simulation in Science and Engineering, School of Mathematics and Computational Science, Xiangtan University, Hunan 411105, China.

The phase behavior of asymmetrically interacting ABC star triblock copolymer melts is investigated by the self-consistent field theory (SCFT). Motivated by the experimental systems, in this study, we focus on the systems in which the Flory-Huggins interaction parameters satisfy χAC > χ BC ≈ χAB. Using various initialization strategies, a large number of periodic structures have been obtained in our calculations.

View Article and Find Full Text PDF

Is high high-density lipoprotein cholesterol beneficial for premature coronary heart disease? A meta-analysis.

Eur J Prev Cardiol

May 2016

Cardiovascular Medicine Department, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, Guangzhou, China

Aims: To clarify the association between premature coronary heart disease of patients ≤55 years and high-density lipoprotein cholesterol (HDL-C) plasma levels.

Methods: Searches were performed between 2002 and 2013 using PubMed, Web of Science, Science Direct, and Google Scholar. The original articles selected published premature coronary heart disease diagnosed by World Health Organization criteria or via angiograph both in males and females ≤55 years and with plasma HDL-C levels in both the case and control groups.

View Article and Find Full Text PDF

A Dietary Intervention in Urban African Americans: Results of the "Five Plus Nuts and Beans" Randomized Trial.

Am J Prev Med

January 2016

Department of Medicine, The Johns Hopkins School of Medicine, Baltimore, Maryland; Johns Hopkins Center to Eliminate Cardiovascular Health Disparities, Johns Hopkins School of Medicine, Baltimore, Maryland; The Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, Maryland; Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.

Introduction: Unhealthy diets, often low in potassium, likely contribute to racial disparities in blood pressure. We tested the effectiveness of providing weekly dietary advice, assistance with selection of higher potassium grocery items, and a $30 per week food allowance on blood pressure and other outcomes in African American adults with hypertension.

Design: We conducted an 8-week RCT with two parallel arms between May 2012 and November 2013.

View Article and Find Full Text PDF

High speed BLASTN: an accelerated MegaBLAST search tool.

Nucleic Acids Res

September 2015

Guangdong Province Key Laboratory of Computational Science, School of Mathematics and Computational Science, Sun Yat-sen University, Guangzhou 510275, P. R. China Department of Mathematics, Syracuse University, Syracuse, NY 13244, USA

Sequence alignment is a long standing problem in bioinformatics. The Basic Local Alignment Search Tool (BLAST) is one of the most popular and fundamental alignment tools. The explosive growth of biological sequences calls for speedup of sequence alignment tools such as BLAST.

View Article and Find Full Text PDF

Division time-based amplifiers for stochastic gene expression.

Mol Biosyst

September 2015

School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.

While cell-to-cell variability is a phenotypic consequence of gene expression noise, sources of this noise may be complex - apart from intrinsic sources such as the random birth/death of mRNA and stochastic switching between promoter states, there are also extrinsic sources of noise such as cell division where division times are either constant or random. However, how this time-based division affects gene expression as well as how it contributes to cell-to-cell variability remains unexplored. Using a computational model combined with experimental data, we show that the cell-cycle length defined as the difference between two sequential division times can significantly impact the expression dynamics.

View Article and Find Full Text PDF

Roles of factorial noise in inducing bimodal gene expression.

Phys Rev E Stat Nonlin Soft Matter Phys

June 2015

Guangdong Province Key Laboratory of Computational Science, School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.

Some gene regulatory systems can exhibit bimodal distributions of mRNA or protein although the deterministic counterparts are monostable. This noise-induced bimodality is an interesting phenomenon and has important biological implications, but it is unclear how different sources of expression noise (each source creates so-called factorial noise that is defined as a component of the total noise) contribute separately to this stochastic bimodality. Here we consider a minimal model of gene regulation, which is monostable in the deterministic case.

View Article and Find Full Text PDF

Azathioprine plus corticosteroid treatment in Chinese patients with neuromyelitis optica.

J Clin Neurosci

July 2015

Department of Neurology, Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, Guangdong 510630, China. Electronic address:

We investigated the efficacy of azathioprine (AZA) plus long-term low dose corticosteroids in Chinese patients with neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD) at the Center for Demyelinating Diseases, South China. We prospectively enrolled patients between June 2010 and June 2014. Annualized relapse rate (ARR), expanded disability status scale (EDSS) score and modified Rankin Scale (mRS) were analyzed retrospectively.

View Article and Find Full Text PDF

The effect of body-mind relaxation meditation induction on major depressive disorder: A resting-state fMRI study.

J Affect Disord

September 2015

Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia. Electronic address:

Background: Meditation has been increasingly evaluated as an important complementary therapeutic tool for the treatment of depression. The present study employed resting-state functional magnetic resonance imaging (rs-fMRI) to examine the effect of body-mind relaxation meditation induction (BMRMI) on the brain activity of depressed patients and to investigate possible mechanisms of action for this complex intervention.

Method: 21 major depressive disorder patients (MDDs) and 24 age and gender-matched healthy controls (HCs) received rs-fMRI scans at baseline and after listening to a selection of audio designed to induce body-mind relaxation meditation.

View Article and Find Full Text PDF

Effects of promoter leakage on dynamics of gene expression.

BMC Syst Biol

March 2015

Guangdong Province Key Laboratory of Computational Science, School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou, 510275, PR China.

Background: Quantitative analysis of simple molecular networks is an important step forward understanding fundamental intracellular processes. As network motifs occurring recurrently in complex biological networks, gene auto-regulatory circuits have been extensively studied but gene expression dynamics remain to be fully understood, e.g.

View Article and Find Full Text PDF

Autism spectrum disorders (ASD) comprise a heterogeneous group of neurodevelopmental disorders that have strong heritability. To better understand the heritable factors in twins with clinically diagnosed ASD and to discuss the relationship between social impairments and genetic and environmental factors. In last 13 years, over 12,000 cases of ASD were diagnosed in the children's development and behavior center, the authors review 37 pairs of these twins, in each pair, and at least 1 twin had been diagnosed with an ASD, and found that the concordance rate was 80% [95% confidence interval (CI) 51.

View Article and Find Full Text PDF

Modified momentum exchange method for fluid-particle interactions in the lattice Boltzmann method.

Phys Rev E Stat Nonlin Soft Matter Phys

March 2015

College of Engineering, Shantou University, Shantou, P.R. China 515063.

In this paper, a modified momentum exchange method for fluid-particle interactions is proposed based on the finite-volume lattice Boltzmann method. The idea of the improvement is to remove the restriction that the boundary points must be set as the midpoints of the grid lines or the intersection of the grid lines with the solid boundaries. The particle surface is represented by a set of arc (area) elements, and the interior fluid is used which the geometric conservation law is naturally satisfied.

View Article and Find Full Text PDF

An exploitation-competition system with negative effect of prey on its predator.

Math Biosci

May 2015

School of Mathematics and Computational Science, Sun Yat-sen University, Guangzhou 510275, PR China. Electronic address:

This paper considers an exploitation-competition system in which exploitation is the dominant interaction when the prey is at low density, while competition is dominant when the prey is at high density due to its negative effect on the predator. The two-species system is characterized by differential equations, which are the combination of Lotka-Volterra competitive and predator-prey models. Global dynamics of the model demonstrate some basic properties of exploitation-competition systems: (i) When the growth rate of prey is extremely small, the prey cannot promote the growth of predator.

View Article and Find Full Text PDF

There is no general consensus on possible factors associated with microalbuminuria in hypertensive patients nor any reported study about this issue in Chinese patients. To examine this issues, 944 hypertensive patients were enrolled in a study based on a cross-sectional survey conducted in Southern China. Multivariate regression analyses were performed to identify the factors related with the presence of microalbuminuria and urinary excretion of albumin.

View Article and Find Full Text PDF

Dynamical analysis of mCAT2 gene models with CTN-RNA nuclear retention.

Phys Biol

January 2015

School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.

As an experimentally well-studied nuclear-retained RNA, CTN-RNA plays a significant role in many aspects of mouse cationic amino acid transporter 2 (mCAT2) gene expression, but relevant dynamical mechanisms have not been completely clarified. Here we first show that CTN-RNA nuclear retention can not only reduce pre-mCAT2 RNA noise but also mediate its coding partner noise. Then, by collecting experimental observations, we conjecture a heterodimer formed by two proteins, p54(nrb) and PSP1, named p54(nrb)-PSP1, by which CTN-RNA can positively regulate the expression of nuclear mCAT2 RNA.

View Article and Find Full Text PDF

Persistence of pollination mutualisms in the presence of ants.

Bull Math Biol

January 2015

School of Mathematics and Computational Science, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China.

This paper considers plant-pollinator-ant systems in which the plant-pollinator interaction is mutualistic but ants have both positive and negative effects on plants. The ants also interfere with pollinators by preventing them from accessing plants. While a Beddington-DeAngelis (BD) formula can describe the plant-pollinator interaction, the formula is extended in this paper to characterize the pollination mutualism under the ant interference.

View Article and Find Full Text PDF

Feedback-induced counterintuitive correlations of gene expression noise with bursting kinetics.

Phys Rev E Stat Nonlin Soft Matter Phys

November 2014

Guangdong Province Key Laboratory of Computational Science, School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, Peoples' Republic of China.

Previous studies showed that a higher frequency of bursting results in lower expression noise whereas a larger size of bursting leads to higher expression noise. Here, we show counterintuitive correlations of expression noise with bursting kinetics due to the effect of feedback. Specifically, in the case of increasing the negative feedback strength but keeping the mean expression fixed, both the mean burst frequency and the mean burst size are invariant if the off-switching rate decreases, but expression noise is reduced; or the mean burst frequency is invariant and the burst size decreases if the transcription rate increases, but expression noise is amplified.

View Article and Find Full Text PDF

Pathway-based analysis tools for complex diseases: a review.

Genomics Proteomics Bioinformatics

October 2014

Institute for Medical Systems Biology, and Department of Medical Statistics and Epidemiology, School of Public Health, Guangdong Medical College, Dongguan 523808, China; Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China; Department of Statistical Sciences, School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, China. Electronic address:

Genetic studies are traditionally based on single-gene analysis. The use of these analyses can pose tremendous challenges for elucidating complicated genetic interplays involved in complex human diseases. Modern pathway-based analysis provides a technique, which allows a comprehensive understanding of the molecular mechanisms underlying complex diseases.

View Article and Find Full Text PDF

Population dynamics of intraguild predation in a lattice gas system.

Math Biosci

January 2015

School of Mathematics and Computational Science, Sun Yat-sen University, Guangzhou 510275, PR China. Electronic address:

In the system of intraguild predation (IGP) we are concerned with, species that are in a predator-prey relationship, also compete for shared resources (space or food). While several models have been established to characterize IGP, mechanisms by which IG prey and IG predator can coexist in IGP systems with spatial competition, have not been shown. This paper considers an IGP model, which is derived from reactions on lattice and has a form similar to that of Lotka-Volterra equations.

View Article and Find Full Text PDF

On power idealization filter topologies of lattice implication algebras.

ScientificWorldJournal

June 2015

School of Mathematics and Computational Science, Xiangtan University, Xiangtan 411105, China ; Department of Mathematics and Computational Science, Hunan University of Science and Engineering, Yongzhou 425100, China.

The aim of this paper is to introduce power idealization filter topologies with respect to filter topologies and power ideals of lattice implication algebras, and to investigate some properties of power idealization filter topological spaces and their quotient spaces.

View Article and Find Full Text PDF

This paper deals with the numerical analysis of nonlinear Black-Scholes equation with transaction costs. An unconditionally stable and monotone splitting method, ensuring positive numerical solution and avoiding unstable oscillations, is proposed. This numerical method is based on the LOD-Backward Euler method which allows us to solve the discrete equation explicitly.

View Article and Find Full Text PDF

Reinitiation enhances reliable transcriptional responses in eukaryotes.

J R Soc Interface

August 2014

FIRST, Aihara Innovative Mathematical Modelling Project, Japan Science and Technology Agency, Tokyo, Japan Institute of Industrial Science, The University of Tokyo, Tokyo, Japan Key Laboratory of Systems Biology, Chinese Academy of Sciences, Shanghai, People's Republic of China

Gene transcription is a noisy process carried out by the transcription machinery recruited to the promoter. Noise reduction is a fundamental requirement for reliable transcriptional responses which in turn are crucial for signal transduction. Compared with the relatively simple transcription initiation in prokaryotes, eukaryotic transcription is more complex partially owing to its additional reinitiation mechanism.

View Article and Find Full Text PDF

Ideal regularization for learning kernels from labels.

Neural Netw

August 2014

Department of Mathematics, Syracuse University, Syracuse, NY 13244, USA. Electronic address:

In this paper, we propose a new form of regularization that is able to utilize the label information of a data set for learning kernels. The proposed regularization, referred to as ideal regularization, is a linear function of the kernel matrix to be learned. The ideal regularization allows us to develop efficient algorithms to exploit labels.

View Article and Find Full Text PDF

A cooperative system of two species with bidirectional interactions.

Bull Math Biol

June 2014

School of Mathematics and Computational Science, Sun Yat-sen University, Guangzhou , 510275, People's Republic of China.

Cooperation between species is often regarded to mean that the increase of each species promotes the growth of the other. The well-known cooperative model is the Lotka-Volterra equations (LVEs). In the LVEs, population densities of species increase infinitely as the cooperation is strong, which is called the divergence problem.

View Article and Find Full Text PDF

Alternative-splicing-mediated gene expression.

Phys Rev E Stat Nonlin Soft Matter Phys

January 2014

School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China and Guangdong Province Key Laboratory of Computational Science and School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.

Alternative splicing (AS) is a fundamental process during gene expression and has been found to be ubiquitous in eukaryotes. However, how AS impacts gene expression levels both quantitatively and qualitatively remains to be fully explored. Here, we analyze two common models of gene expression, each incorporating a simple splice mechanism that a pre-mRNA is spliced into two mature mRNA isoforms in a probabilistic manner.

View Article and Find Full Text PDF