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Search Results: 1 - 10 of 18835 matches for " Xiaoxia Han "
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Genome-Wide Likelihood Ratio Tests under Heterogeneity  [PDF]
Xiaoxia Han, Yongzhao Shao
Open Journal of Statistics (OJS) , 2018, DOI: 10.4236/ojs.2018.83030
Abstract: The commonly used statistical methods in medical research generally assume patients arise from one homogeneous population. However, the existence and importance of significant heterogeneity have been widely documented. It is well known that common and complex human diseases usually have heterogeneous disease etiology, which often involves interplay of multiple genetic and environmental factors, leading to latent population substructure. Genome-wide association studies (GWAS) is a useful tool to uncover genetic association with disease of interest, while linkage analysis is a commonly used method to identify statistical association between the inheritance of a human disease and inheritance of marker loci that are in linkage with disease causing loci. We propose a likelihood ratio test for genome-wide linkage analysis under genetic heterogeneity using family data. We derive a closed-form formula for the LRT test statistic and provide explicit asymptotic null distribution. The closed form asymptotic distribution allows easy determination of the asymptotic p-values. Our extensive simulation studies indicate that the proposed test has proper type I error and good power under genetic heterogeneity. In order to simplify application of the proposed method for non-statisticians, we develop an R package gLRTH to implement the proposed LRT for genome-wide linkage analysis as well as Qian and Shao’s LRT for GWAS under heterogeneity. The newly developed open source R package gLRTH is available at CRAN.
Relationship between cardiovascular risk factors and traditional Chinese constitution in subjects with high-normal blood pressure  [PDF]
Hongju Jiang, Youwei Han, Runzhi Li, Suning Zhou, Xiaoxia Liu, Cong Cui, Shouqiang Chen, Wei Zhang
World Journal of Cardiovascular Diseases (WJCD) , 2013, DOI: 10.4236/wjcd.2013.32036
Abstract:

Objective: We explored the relationship between traditional Chinese constitution and risk factors for cardiovascular disease in subjects with high-normal blood pressure (BP). Methods: The traditional Chinese constitution of 80 subjects with high-normal BP was judged by questionnaires and interviews. Measurements of cardiovascular and metabolic health in- cluded BP, body weight, body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), 2-hour oral glucose tolerance test (OGTT2h), and waist cir- cumference. Statistical relationships between cardiovascular disease risk factors and specific Chinese constitution were evaluated by univariate and multivariate analyses. Results: Ping He, Tan Shi, and Yin Xu were the dominant constitutions in subjects with high-normal blood pressure. There were significant differences in weight, LDL-C, BMI, OGTT2h, and waist circumference between Tan Shi and Ping He (P < 0.01), in SBP and OGTT2h between Yin Xu and Ping He (P < 0.05), and weight, BMI, waist circumference, SBP, and LDL-C between Tan Shi and Yin Xu constitutions (P < 0.01). Logistic regression found a strong association between the Tan Shi constitution and LDL-C in subjects with high-normal blood pressure. Conclusion: Ping He, Tan Shi, and Yin Xu are the principle traditional Chinese constitutions in subject with high-normal blood pressure. The Tan Shi constitution is associated with multiple risk factors for cardiovascular disease (LDL-C, BMI, body weight, and waist circumference), while OGTT2h is closely related to the Yin Xu constitution.

A Research on the Evolution of Politic-Business Network, Relational Embedded and Family Enterprise Value: Regarding SAMSUNG Group as Example  [PDF]
Xiaoxia Huang
Open Journal of Business and Management (OJBM) , 2016, DOI: 10.4236/ojbm.2016.44069
Abstract: Globally, it is very common that many companies are keen to embed in the center of political-business (abbreviations with P-B) network [1]. The influence of government on enterprise is greatly important for it controls a large numbers of scarce and key resources and holds the power of approval on market access’s qualification and making regulations [2]. Then can close political-business network always bring positive benefits for enterprises value? Based on this, the paper takes the typicality and representative of cases as the standard and selects the case of SUMSANG to analyze the evolution relationship between P-B network, relational embedded and family business value. This paper puts forward that it is unreasonable to illustrate the positive correlation or negative correlation between them. The relationship between politics and business network is not simple or static, but is dynamic and nonlinear. The value of the enterprise is constantly changing with the degree of embedding in P-B network. There is a reasonable embedded threshold. Before reaching the “embedding threshold”, the value is increasing with the deepening of embedding degree; after the “embedding threshold”, the value is decreasing with the deepening of embedding degree. This is “inverted U” model of Uzzi [3].
Dust storm in Asia continent and its bio-environmental effects in the North Pacific: A case study of the strongest dust event in April, 2001 in central Asia
Yongxiang Han,Xiaomin Fang,Xiaoxia Xi,Lianchun Song,Shengli Yang
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-0723-2
Abstract: Testing the effects of iron fertilization in booming metabolism of microbes in North Pacific Ocean has become an important hot topic in current global climate change study. The first supportive evidence with natural iron inputs to ocean was obtained by Bishop and his colleagues at the PAPA region in North Pacific Ocean. They found a rapid increase of marine phytoplankton over North Pacific Ocean after a strong dust storm in April 2001. We demonstrate that the dust deposition flux during this dust storm period decreases exponentially with increasing distance from the dust source regions along the dust transport pathway, through integration of synoptic dynamics, changes of TOMS-Al (aerosol index) and surface PM10 values along the dust pathway and changes of particulate organic carbon and chlorophyll in surface oceans. This strong dust storm may result in deposition of about 3.1–5.8 μg/m3 eolian iron into the PAPA region in North Pacific Ocean, thus causing a rapid increase of marine phytoplankton productivity observed by Bishop and his colleagues. This work supplies more direct and detailed evidence, from continental dust process, to support the iron hypothesis with natural iron inputs to the surface oceans through dust storms.
Genome wide exploration of the origin and evolution of amino acids
Xiaoxia Liu, Jingxian Zhang, Feng Ni, Xu Dong, Bucong Han, Daxiong Han, Zhiliang Ji, Yufen Zhao
BMC Evolutionary Biology , 2010, DOI: 10.1186/1471-2148-10-77
Abstract: In this study, we statistically monitored the frequencies of 20 alpha-amino acids in 549 taxa from three kingdoms of life: archaebacteria, eubacteria, and eukaryotes. We found that the amino acids evolved independently in these three kingdoms; but, conserved linkages were observed in two groups of amino acids, (A, G, H, L, P, Q, R, and W) and (F, I, K, N, S, and Y). Moreover, the amino acids encoded by GC-poor codons (F, Y, N, K, I, and M) were found to "lose" their usage in the development from single cell eukaryotic organisms like S. cerevisiae to H. sapiens, while the amino acids encoded by GC-rich codons (P, A, G, and W) were found to gain usage. These findings further support the co-evolution hypothesis of amino acids and genetic codes.We proposed a new chronological order of the appearance of amino acids (L, A, V/E/G, S, I, K, T, R/D, P, N, F, Q, Y, M, H, W, C). Two conserved evolutionary paths of amino acids were also suggested: A→G→R→P and K→Y.The origin of life arising from either proteins or nucleic acids has been argued for nearly half century. Putting the "Chicken or Egg" question aside, there exist some unsolved problems. Which amino acid(s) appeared first in the prebiotic environment? What cause the different usage of amino acids in modern organisms? To address these questions, a number of hypotheses and theories, e.g. mutation drifts and natural selection, have been proposed. Multiple factors, such as genetic codes, physicochemical properties, mutation-selection equilibrium, amino acid biosynthesis, etc, are likely related to the variation of amino acid usage in organisms [1,2]. Since there is no way to trace geological evidence in the way scientists normally use in chronicling the evolution of organisms, an alternative path is needed to seek a clue from current living organisms.Observation of amino acid composition in proteins was recently applied as a statistical approach in facilitating various investigations of the evolution of genetic codes [3],
A Min-Conflict Heuristic-Based Web Service Chain Reconfiguration Approach  [PDF]
Haifeng Li, Xiaoxia Yang
Intelligent Information Management (IIM) , 2010, DOI: 10.4236/iim.2010.210068
Abstract: The state-of-art Web services composition approaches are facing more and more serious bottlenecks of effectiveness and stability with the increasing diversity and real-time requirements of applications, since new web service chain must be generated from “scratch” for each application. To break these bottlenecks, this paper presents a Min-Conflict Heuristic-Based Web Service Chain Reconfiguration Approach(MCHRC) to maximal reuse relative web services chain: a min-conflict heuristic based regression search algorithms is proposed to implement the web services chain reconfiguration based on the formal definition of process constraint and integrity constraint to guarantee the correctness and integrality of the reconfiguration. This benefits the service reuse and then can relieve the time complexity of web service composition and improve web services chain executing stability by reduce service provider load. Experimental results show that this approach makes significant improvement on the effectiveness of web services composition.
Application of Sub-Critical Water Extraction in Pharmaceutical Industry  [PDF]
Xiaoxia Liang, Qiaojia Fan
Journal of Materials Science and Chemical Engineering (MSCE) , 2013, DOI: 10.4236/msce.2013.15001
Abstract:

Sub-critical water extraction is a brand-new separation technology. This paper mainly discussed the principle, advantages of sub-critical water extraction, and its applications ranging from the medicinal plants traditionally used in Europe and Asia to produce pharmaceutical extracts (such as volatile oil, tannins, flavonoids, anthraquinone, lactone, etc.). Meanwhile, the prospect of sub-critical water extraction in plant extractives is also explored. It will be widely used in the field of medical plants, bringing huge economic benefits, environmental benefits and social benefits.

Environmental Sound Recognition Using Double-Level Energy Detection  [PDF]
Xiaoxia Zhang, Ying Li
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.43B004
Abstract:

The performance of classic Mel-frequency cepstral coefficients (MFCC) is unsatisfactory in noisy environment with different sound sources from nature. In this paper, a classification approach of the ecological environmental sounds using the double-level energy detection (DED) was presented. The DED was used to detect the existence of the sound signals under noise conditions. In addition, MFCC features from the frames which were detected the presence of the sound signals by DED were extracted. Experimental results show that the proposed technology has better noise immunity than classic MFCC, and also outperforms time-domain energy detection (TED) and frequency-domain energy detection (FED) respectively.

Progress on Fabric Electrodes Used in Biological Signal Acquisition  [PDF]
Zhen Liu, Xiaoxia Liu
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2015, DOI: 10.4236/jmmce.2015.33023
Abstract: Due to its convenience, wear ability, affinity, continuously monitoring biological signal, etc., fabric electrodes used in biological signal acquisition attracted more and more interest from researchers around the world. Fabric electrode is a kind of intelligent textiles, and its application is very prominent in biological signal acquisition, supercapacitors and ECG (electric signal) monitoring. There are many methods that can be used to prepare fabric electrodes. They are mainly metal plating, conductive polymer coating, magnetron sputtering, and gas phase deposition and impregnation. Besides, they select the appropriate substrate, conductive medium and composite way to get light fabric electrodes which have high conductivity and good conformability. Since the conductive properties of conductive polymers are weaker than those of metal, conductive polymer must undergo protonic acid doping. They can be polythiophene, polypyrrole, polyaniline, etc. However, at present, researchers commit more studies to metal or carbon-based electrodes. For example, a layer of silver film is platted on the fabric by magnetron sputtering to increase its conductivity. In this paper, the development of fabric electrodes was studied from several aspects, namely, the generation of biological signals, the overall design of the wearable monitoring systems, its classification, conductive principles, preparation of fabric electrode and application.
Progress on Fabric Electrodes Used in ECG Signals Monitoring  [PDF]
Zhen Liu, Xiaoxia Liu
Journal of Textile Science and Technology (JTST) , 2015, DOI: 10.4236/jtst.2015.13012
Abstract: Wearable monitoring system is designed for skin stimulation of conductive adhesive, prolonged physiological monitoring and biocompatibility, whose core is fabric electrodes and it can feedback physiological status by analysis of abnormal electrocardiogram (ECG). Fabric electrode is a sensor to collect biological signals based on textile materials including signals acquisition, processing systems and information feedback platform and so on. In this paper, the design methods and classification of medical electrodes would be introduced. It also sorted out the principle of biological electrical signals, the design methods and characteristics of different material and different structure electrodes from the point of dry electrodes and wet electrodes. There are many methods that can be used to prepare fabric electrodes. They are mainly metal plating, conductive polymer coating, magnetron sputtering, gas phase deposition and impregnation. Besides, they select the appropriate substrate, conductive medium and composite way to get light fabric electrodes which have high conductivity, good conformability. From the perspective of biological signal acquisition by fabric electrodes, this paper also sorted out the influence and approaches of biological signals and the way to feedback the physiological condition of human. As a new generation of bio-signal acquisition material, fabric electrode has met the requirements of the development of modern medicine. Fabric electrode is different from traditional conductive materials in the characteristics of comfort, intelligence, convenience, accuracy and so on.
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