62 research outputs found

    Analysis and Practical Guideline of Constraint-Based Boolean Method in Genetic Network Inference

    Get PDF
    Boolean-based method, despite of its simplicity, would be a more attractive approach for inferring a network from high-throughput expression data if its effectiveness has not been limited by high false positive prediction. In this study, we explored factors that could simply be adjusted to improve the accuracy of inferring networks. Our work focused on the analysis of the effects of discretisation methods, biological constraints, and stringency of Boolean function assignment on the performance of Boolean network, including accuracy, precision, specificity and sensitivity, using three sets of microarray time-series data. The study showed that biological constraints have pivotal influence on the network performance over the other factors. It can reduce the variation in network performance resulting from the arbitrary selection of discretisation methods and stringency settings. We also presented the master Boolean network as an approach to establish the unique solution for Boolean analysis. The information acquired from the analysis was summarised and deployed as a general guideline for an efficient use of Boolean-based method in the network inference. In the end, we provided an example of the use of such a guideline in the study of Arabidopsis circadian clock genetic network from which much interesting biological information can be inferred

    Global Profiling of Rice and Poplar Transcriptomes Highlights Key Conserved Circadian-Controlled Pathways and cis-Regulatory Modules

    Get PDF
    Circadian clocks provide an adaptive advantage through anticipation of daily and seasonal environmental changes. In plants, the central clock oscillator is regulated by several interlocking feedback loops. It was shown that a substantial proportion of the Arabidopsis genome cycles with phases of peak expression covering the entire day. Synchronized transcriptome cycling is driven through an extensive network of diurnal and clock-regulated transcription factors and their target cis-regulatory elements. Study of the cycling transcriptome in other plant species could thus help elucidate the similarities and differences and identify hubs of regulation common to monocot and dicot plants.Using a combination of oligonucleotide microarrays and data mining pipelines, we examined daily rhythms in gene expression in one monocotyledonous and one dicotyledonous plant, rice and poplar, respectively. Cycling transcriptomes were interrogated under different diurnal (driven) and circadian (free running) light and temperature conditions. Collectively, photocycles and thermocycles regulated about 60% of the expressed nuclear genes in rice and poplar. Depending on the condition tested, up to one third of oscillating Arabidopsis-poplar-rice orthologs were phased within three hours of each other suggesting a high degree of conservation in terms of rhythmic gene expression. We identified clusters of rhythmically co-expressed genes and searched their promoter sequences to identify phase-specific cis-elements, including elements that were conserved in the promoters of Arabidopsis, poplar, and rice.Our results show that the cycling patterns of many circadian clock genes are highly conserved across poplar, rice, and Arabidopsis. The expression of many orthologous genes in key metabolic and regulatory pathways is diurnal and/or circadian regulated and phased to similar times of day. Our results confirm previous findings in Arabidopsis of three major classes of cis-regulatory modules within the plant circadian network: the morning (ME, GBOX), evening (EE, GATA), and midnight (PBX/TBX/SBX) modules. Identification of identical overrepresented motifs in the promoters of cycling genes from different species suggests that the core diurnal/circadian cis-regulatory network is deeply conserved between mono- and dicotyledonous species

    Neuroendocrine–immune disequilibrium and endometriosis: an interdisciplinary approach

    Get PDF
    Endometriosis, a chronic disease characterized by endometrial tissue located outside the uterine cavity, affects one fourth of young women and is associated with chronic pelvic pain and infertility. However, an in-depth understanding of the pathophysiology and effective treatment strategies of endometriosis is still largely elusive. Inadequate immune and neuroendocrine responses are significantly involved in the pathophysiology of endometriosis, and key findings are summarized in the present review. We discuss here the role of different immune mechanisms particularly adhesion molecules, protein–glycan interactions, and pro-angiogenic mediators in the development and progression of the disease. Finally, we introduce the concept of endometrial dissemination as result of a neuroendocrine-immune disequilibrium in response to high levels of perceived stress caused by cardinal clinical symptoms of endometriosis

    Correlation between Structural and Optical Properties of Amorphous Selenium Films BY

    No full text
    Structural and optical properties of amorphous selenium films prepared by thermal evaporation are investigated. The structure of the films is varied by deposition at various substrate temperatures. Parameters describing the structure of the films are obtained by X-ray diffraction and small-angle X-ray scattering measurements. Optical parameters are determined in the visible and near infrared spectral region. The static refractive index and the temperature dependences of the Tauc gap and the Tauc slope are measured. Drastic changes in the structural and optical properties in the films are found depending on the substrate temperature. There is a good correlation between structural and optical parameters of the films. Es wurden strukturelle und optische Untersuchungen an amorphen Selenschichten, hergestellt durch thermisches Verdampfen, durchgefiihrt. Die Struktur der Schichten wird durch Abscheidung bei verschiedenen Substrattemperaturen variiert. Die Struktur der Schichten beschreibende Parameter werden durch Rontgenstreustrahlen und Kleinwinkelstreumessungen erhalten. Die optischen Parameter werden irn sichtbaren und nahen Infrarotbereich bestimmt. Es werden der statische Brechungsindew und die Temperaturabhangigkeiten des Tauc-Gaps und des Tauc-Anstieges gemessen. Es wird eine drastische Anderung der strukturellen und optischen Eigenschaften in Abhiingigkeit von der Substrat-temperatur gefunden. Die Korrelation zwischen den strukturellen und optischen Parametern der Schichten ist gut. 1

    A5

    No full text
    • …
    corecore