75 research outputs found
FHF-independent conduction of action potentials along the leak-resistant cerebellar granule cell axon
Neurons in vertebrate central nervous systems initiate and conduct sodium action potentials in distinct subcellular compartments that differ architecturally and electrically. Here, we report several unanticipated passive and active properties of the cerebellar granule cellâs unmyelinated axon. Whereas spike initiation at the axon initial segment relies on sodium channel (Nav)-associated fibroblast growth factor homologous factor (FHF) proteins to delay Nav inactivation, distal axonal Navs show little FHF association or FHF requirement for high-frequency transmission, velocity and waveforms of conducting action potentials. In addition, leak conductance density along the distal axon is estimated as o1% that of somatodendritic membrane. The faster inactivation rate of FHF-free Navs together with very low axonal leak conductance serves to minimize ionic fluxes and energetic demand during repetitive spike conduction and at rest. The absence of FHFs from Navs at nodes of Ranvier in the central nervous system suggests a similar mechanism of current flux minimization along myelinated axons
Unified functional network and nonlinear time series analysis for complex systems science: The pyunicorn package
We introduce the \texttt{pyunicorn} (Pythonic unified complex network and
recurrence analysis toolbox) open source software package for applying and
combining modern methods of data analysis and modeling from complex network
theory and nonlinear time series analysis. \texttt{pyunicorn} is a fully
object-oriented and easily parallelizable package written in the language
Python. It allows for the construction of functional networks such as climate
networks in climatology or functional brain networks in neuroscience
representing the structure of statistical interrelationships in large data sets
of time series and, subsequently, investigating this structure using advanced
methods of complex network theory such as measures and models for spatial
networks, networks of interacting networks, node-weighted statistics or network
surrogates. Additionally, \texttt{pyunicorn} provides insights into the
nonlinear dynamics of complex systems as recorded in uni- and multivariate time
series from a non-traditional perspective by means of recurrence quantification
analysis (RQA), recurrence networks, visibility graphs and construction of
surrogate time series. The range of possible applications of the library is
outlined, drawing on several examples mainly from the field of climatology.Comment: 28 pages, 17 figure
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Identification of Copy Number Gain and Overexpressed Genes on Chromosome Arm 20q by an Integrative Genomic Approach in Cervical Cancer: Potential Role in Progression
Recurrent karyotypic abnormalities are a characteristic feature of cervical cancer (CC) cells, which may result in deregulated expression of important genes that contribute to tumor initiation and progression. To examine the role of gain of the long arm of chromosome 20 (20q), one of the common chromosomal gains in CC, we evaluated CC at various stages of progression using single nucleotide polymorphism (SNP) array, gene expression profiling, and fluorescence in situ hybridization (FISH) anal- yses. This analysis revealed copy number increase (CNI) of 20q in >50% of invasive CC and identified two focal amplicons at 20q11.2 and 20q13.13 in a subset of tumors. We further demonstrate that the acquisition of 20q gain occurs at an early stage in CC development and the high-grade squamous intraepithelial lesions (HSIL) that exhibit 20q CNI are associated (P 5 0.05) with persistence or progression to invasive cancer. We identified a total of 26 overexpressed genes as consequence of 20q gain (N 5 14), as targets of amplicon 1 (N 5 9; two genes also commonly expressed with 20q gain) and amplicon 2 (N 5 6; one gene also commonly expressed with 20q gain). These include a number of functionally important genes in cell cycle regulation (E2F1, TPX2, KIF3B, PIGT, and B4GALT5), nuclear function (CSEL1), viral replication (PSMA7 and LAMA5), methylation and chromatin remodeling (ASXL1, AHCY, and C20orf20), and transcription regulation (TCEA2). Our findings implicate a role for these genes in CC tumorigenesis, represent an important step toward the development of clinically significant biomarkers, and form a framework for testing as molecular therapeutic targets
Integrative genomics analysis of chromosome 5p gain in cervical cancer reveals target over-expressed genes, including Drosha
Background: Copy number gains and amplifications are characteristic feature of cervical cancer (CC) genomes for which the underlying mechanisms are unclear. These changes may possess oncogenic properties by deregulating tumor-related genes. Gain of short arm of chromosome 5 (5p) is the most frequent karyotypic change in CC. Methods: To examine the role of 5p gain, we performed a combination of single nucleotide polymorphism (SNP) array, fluorescence in situ hybridization (FISH), and gene expression analyses on invasive cancer and in various stages of CC progression. Results: The SNP and FISH analyses revealed copy number increase (CNI) of 5p in 63% of invasive CC, which arises at later stages of precancerous lesions in CC development. We integrated chromosome 5 genomic copy number and gene expression data to identify key target over expressed genes as a consequence of 5p gain. One of the candidates identified was Drosha (RNASEN), a gene that is required in the first step of microRNA (miRNA) processing in the nucleus. Other 5p genes identified as targets of CNI play a role in DNA repair and cell cycle regulation (BASP1, TARS, PAIP1, BRD9, RAD1, SKP2, and POLS), signal transduction (OSMR), and mitochondrial oxidative phosphorylation (NNT, SDHA, and NDUFS6), suggesting that disruption of pathways involving these genes may contribute to CC progression. Conclusion: Taken together, we demonstrate the power of integrating genomics data with expression data in deciphering tumor-related targets of CNI. Identification of 5p gene targets in CC denotes an important step towards biomarker development and forms a framework for testing as molecular therapeutic targets
Moisture Management Properties of Single Jersey Knitted Fabrics Made from Regenerated Bamboo: Polyester Core-Spun Yarns
Today, the capacity to regulate moisture is one of the most crucial qualities of knitted fabrics. This study focuses on the interaction between core ratio, twist, and loop length on the moisture management capabilities of single jersey knitted textiles manufactured from 100% regenerated bamboo, 80:20 regenerated bamboo: polyester yarns, and 60:40 regenerated bamboo: polyester yarns. The Box-Behnken experimental design was used to optimize the design parameters in this study. It was discovered that the moisture management qualities were improved by the increased polyester core content, high twist, and short loop length. Single jersey knitted fabrics made from 100% regenerated bamboo yarns swiftly wick away sweat and maintain moisture in their structure, resulting in a very fast wetting rate, spreading speed, and extremely large maximum wetted radius, as well as a very excellent AOTI value and very good OMMC ratings. Additionally, it can be suggested that single jersey knitted textiles consisting of core-spun yarns provide quick absorption and quick drying rates, meeting the needs of sportswear applications
Plasma levels of TIMP-1 are higher in 34-year-old individuals with severe  1-antitrypsin deficiency
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