210 research outputs found

    The Gelfand Problem for the Infinity Laplacian

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    We study the asymptotic behavior as p ā†’ āˆž of the Gelfand problem āˆ’Ī”pu = Ī»eu in Ī© āŠ‚ Rn, u = 0 on āˆ‚Ī©. Under an appropriate rescaling on u and Ī», we prove uniform convergence of solutions of the Gelfand problem to solutions of min{|āˆ‡u|āˆ’Ī›eu, āˆ’Ī”āˆžu} = 0 in Ī©, u = 0 on āˆ‚Ī©. We discuss existence, non-existence, and multiplicity of solutions of the limit problem in terms of Ī›

    Investigation of stretch and curvature effects on flames

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    A Pilot Study on Real-time Monitoring of Heart Rate and Movement Speed in Middle-distance Race of Physical Education Classes

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    In Chinese universities, students need to participate in the middle-distance-race. Normally, female students are required to participate in the race of 800 meters, while male students are required to participate in the race of 1000 meters. However, it is difficult for teachers to grasp the real time information of students during the race. And there is a lack of timely communications between the teachers and students. Focusing on this issue, this study, with the use of POLAR heart rate sensor and other modern information technologies, expands the original function of the sensor to achieve a concurrent operation of detecting heart rates and automatically measuring the movement speed. The researchers have successfully designed a micro system to monitor the process of middle-distance race. Moreover, the study also engages in a preliminary experiment verification so as to provide object and effective reference and basis for the middle-distance race physical education teaching in universities

    Development of a Platform to Monitor User's Comfort Degree for Intelligent Environments

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    With the development of intelligent environments, people have increasing demands for comfortable living environments. The three major factors affecting users' comfort are thermal comfort, visual comfort and air quality. This paper presents a monitoring platform of comfort degree for intelligent environments based on ZigBee wireless sensor network that measures living environment's parameters and actively controls corresponding equipments according to the information collected and users' preferences. Wireless sensor network system is divided into three layers, the main node layer, function nodes layer and leaf nodes layer, respectively. The approach to routing is through a tree topology method. A Mini2440 development board is selected as the host computer, which communicates with the main node via serial interface. The monitoring platform presented in this paper is flexible, powerful, and scalable, which can be applied to the other monitoring fields with minor modifications

    A Novel YY1-miR-1 Regulatory Circuit in Skeletal Myogenesis Revealed by Genome-Wide Prediction of YY1-miRNA Network

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    microRNAs (miRNAs) are non-coding RNAs that regulate gene expression post-transcriptionally, and mounting evidence supports the prevalence and functional significance of their interplay with transcription factors (TFs). Here we describe the identification of a regulatory circuit between muscle miRNAs (miR-1, miR-133 and miR-206) and Yin Yang 1 (YY1), an epigenetic repressor of skeletal myogenesis in mouse. Genome-wide identification of potential down-stream targets of YY1 by combining computational prediction with expression profiling data reveals a large number of putative miRNA targets of YY1 during skeletal myoblasts differentiation into myotubes with muscle miRs ranking on top of the list. The subsequent experimental results demonstrate that YY1 indeed represses muscle miRs expression in myoblasts and the repression is mediated through multiple enhancers and recruitment of Polycomb complex to several YY1 binding sites. YY1 regulating miR-1 is functionally important for both C2C12 myogenic differentiation and injury-induced muscle regeneration. Furthermore, we demonstrate that miR-1 in turn targets YY1, thus forming a negative feedback loop. Together, these results identify a novel regulatory circuit required for skeletal myogenesis and reinforce the idea that regulatory circuitries involving miRNAs and TFs are prevalent mechanisms

    CYP72A enzymes catalyse 13-hydrolyzation of gibberellins

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    Bioactive gibberellins (GAs, diterpenes) are essential hormones in land plants, controlling many aspects of plant growth and developments. In flowering plants, 13-OH (low bioactivity; such as GA1) and 13-H GAs (high bioactivity; such as GA4) frequently coexist. However, the bona fide GA 13-hydroxylase and its physiological functions in Arabidopsis remain unknown. Here, we report that novel cytochrome P450 genes (CYP72A9 and its homologs) encode active GA 13- hydroxylases in Brassicaceae plants. CYP72A9-overexpressing plants exhibited semi-dwarfism, which was caused by significant reduction in GA4 levels. Biochemical assays revealed that recombinant CYP72A9 protein catalyzed the conversion from 13-H GAs to the corresponding 13-OH GAs. CYP72A9 was expressed predominantly in developing seeds in Arabidopsis. Freshly harvested seeds of cyp72a9 mutants germinated more quickly than wild-type, while long-term storage and stratification-treated seeds did not. The evolutionary origin of GA 13- oxidases from the CYP72A subfamily also was investigated and discussed here

    Cardiomyocyte-Restricted Deletion of PPARĪ²/Ī“ in PPARĪ±-Null Mice Causes Impaired Mitochondrial Biogenesis and Defense, but No Further Depression of Myocardial Fatty Acid Oxidation

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    It is well documented that PPARĪ± and PPARĪ²/Ī“ share overlapping functions in regulating myocardial lipid metabolism. However, previous studies demonstrated that cardiomyocyte-restricted PPARĪ²/Ī“ deficiency in mice leads to severe cardiac pathological development, whereas global PPARĪ± knockout shows a benign cardiac phenotype. It is unknown whether a PPARĪ±-null background would alter the pathological development in mice with cardiomyocyte-restricted PPARĪ²/Ī“ deficiency. In the present study, a mouse model with long-term PPARĪ²/Ī“ deficiency in PPARĪ±-null background showed a comparably reduced cardiac expression of lipid metabolism to those of single PPAR-deficient mouse models. The PPARĪ±-null background did not rescue or aggravate the cardiac pathological development linked to cardiomyocyte-restricted PPARĪ²/Ī“ deficiency. Moreover, PPARĪ±-null did not alter the phenotypic development in adult mice with the short-term deletion of PPARĪ²/Ī“ in their hearts, which showed mitochondrial abnormalities, depressed cardiac performance, and cardiac hypertrophy with attenuated expression of key factors in mitochondrial biogenesis and defense. The present study demonstrates that cardiomyocyte-restricted deletion of PPARĪ²/Ī“ in PPARĪ±-null mice causes impaired mitochondrial biogenesis and defense, but no further depression of fatty acid oxidation. Therefore, PPARĪ²/Ī“ is essential for maintaining mitochondrial biogenesis and defense in cardiomyocytes independent of PPARĪ±

    Comprehensive transcriptomic analysis revealing the regulatory dynamics and networks of the pituitary-testis axis in sheep across developmental stages

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    Spermatogenesis is a complex process intricately regulated by the hypothalamic-pituitary-testis (HPT) axis. However, research on the regulatory factors governing the HPT axis remains limited. This study addresses this gap by conducting a comprehensive analysis of transcriptomes from the pituitary and testis tissues across various developmental stages, encompassing embryonic day (E120), neonatal period (P0), pre-puberty (P90), and post-puberty day (P270). Utilizing edgeR and WGCNA, we identified stage-specific genes in both the pituitary and testis throughout the four developmental stages. Notably, 380, 242, 34, and 479 stage-specific genes were identified in the pituitary, while 886, 297, 201, and 3,678 genes were identified in the testis. Subsequent analyses unveiled associations between these stage-specific genes and crucial pathways such as the cAMP signaling pathway, GnRH secretion, and male gamete generation. Furthermore, leveraging single-cell data from the pituitary and testis, we identified some signaling pathways involving BMP, HGF, IGF, and TGF-Ī², highlighting mutual regulation between the pituitary and testis at different developmental stages. This study sheds light on the pivotal role of the pituitary-testis axis in the reproductive process of sheep across four distinct developmental stages. Additionally, it delves into the intricate regulatory networks governing reproduction, offering novel insights into the dynamics of the pituitary-testis axis within the reproductive system
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