Nuclear antisense effects in cyclophilin A pre‐mRNA splicing by oligonucleotides: a comparison of tricyclo‐DNA with LNA

The nuclear antisense properties of a series of tricyclo (tc)‐DNA oligonucleotide 9-15mers, targeted against the 3′ and 5′ splice sites of exon 4 of cyclophilin A (CyPA) pre‐mRNA, were evaluated in HeLa cells and compared with those of corresponding LNA‐oligonucleotides. While the 9mers showed no significant antisense effect, the 11-15mers induced exon 4 skipping and exon 3+4 double skipping to about an equal extent upon lipofectamine mediated transfection in a sequence‐ and dose‐dependent manner, as revealed by a RT-PCR assay. The antisense efficacy of the tc‐oligonucleotides was found to be superior to that of the LNA‐oligonucleotides in all cases by a factor of at least 4-5. A tc‐oligonucleotide 15mer completely abolished CyPA mRNA production at 0.2 µM concentration. The antisense effect was confirmed by western blot analysis which revealed a reduction in CyPA protein to 13% of its normal level. Fluorescence microscopic investigations with a fluorescein labeled tc‐15mer revealed a strong propensity for homogeneous nuclear localization of this backbone type after lipofectamine mediated transfection, while the corresponding lna 15mer showed a less clear cellular distribution pattern. Transfection without lipid carrier showed no significant internalization of both tc‐ and LNA‐ oligonucleotides. The obtained results confirm the power of tc‐DNA for nuclear antisense applications. Moreover, CyPA may become an interesting therapeutic target due to its important role in the early steps of the viral replication of HIV‐

Inhibition of HIV-1 multiplication by antisense U7 snRNAs and siRNAs targeting cyclophilin A

Human immunodeficiency virus 1 (HIV-1) multiplication depends on a cellular protein, cyclophilin A (CyPA), that gets integrated into viral particles. Because CyPA is not required for cell viability, we attempted to block its synthesis in order to inhibit HIV-1 replication. For this purpose, we used antisense U7 small nuclear RNAs (snRNAs) that disturb CyPA pre-mRNA splicing and short interfering RNAs (siRNAs) that target CyPA mRNA for degradation. With dual-specificity U7 snRNAs targeting the 3′ and 5′ splice sites of CyPA exons 3 or 4, we obtained an efficient skipping of these exons and a strong reduction of CyPA protein. Furthermore, short interfering RNAs targeting two segments of the CyPA coding region strongly reduced CyPA mRNA and protein levels. Upon lentiviral vector-mediated transduction, prolonged antisense effects were obtained for both types of antisense RNAs in the human T-cell line CEM-SS. These transduced CEM-SS cells showed a delayed, and for the siRNAs also reduced, HIV-1 multiplication. Since the two types of antisense RNAs function by different mechanisms, combining the two approaches may result in a synergistic effec

Effects of Valley Topography on Acoustic Communication in Birds: Why Do Birds Avoid Deep Valleys in Daqinggou Nature Reserve?

To investigate the effects of valley topography on the acoustic transmission of avian vocalisations, we carried out playback experiments in Daqinggou valley, Inner Mongolia, China. During the experiments, we recorded the vocalisations of five avian species, the large-billed crow (Corvus macrorhynchos Wagler, 1827), common cuckoo (Cuculus canorus Linnaeus, 1758), Eurasian magpie (Pica pica Linnaeus, 1758), Eurasian tree sparrow (Passer montanus Linnaeus, 1758), and meadow bunting (Emberiza cioides Brand, 1843), at transmission distances of 30 m and 50 m in the upper and lower parts of the valley and analysed the intensity, the fundamental frequency (F0), and the first three formant frequencies (F1/F2/F3) of the sounds. We also investigated bird species diversity in the upper and lower valley. We found that: (1) at the distance of 30 m, there were significant differences in F0/F1/F2/F3 in Eurasian magpies, significant differences in F1/F2/F3 in the meadow bunting and Eurasian tree sparrow, and partially significant differences in sound frequency between the upper and lower valley in the other two species; (2) at the distance of 50 m, there were significant differences in F0/F1/F2/F3 in two avian species (large-billed crow and common cuckoo) between the upper and lower valley and partially significant differences in sound frequency between the upper and lower valley in the other three species; (2) there were significant differences in the acoustic intensities of crow, cuckoo, magpie, and bunting calls between the upper and lower valley. (3) Species number and richness were significantly higher in the upper valley than in the lower valley. We suggested that the structure of valley habitats may lead to the breakdown of acoustic signals and communication in birds to varying degrees. The effect of valley topography on acoustic communication could be one reason for animal species avoiding deep valleys

Nuclear antisense effects in cyclophilin A pre-mRNA splicing by oligonucleotides: a comparison of tricyclo-DNA with LNA

The nuclear antisense properties of a series of tricyclo (tc)-DNA oligonucleotide 9–15mers, targeted against the 3′ and 5′ splice sites of exon 4 of cyclophilin A (CyPA) pre-mRNA, were evaluated in HeLa cells and compared with those of corresponding LNA-oligonucleotides. While the 9mers showed no significant antisense effect, the 11–15mers induced exon 4 skipping and exon 3+4 double skipping to about an equal extent upon lipofectamine mediated transfection in a sequence- and dose-dependent manner, as revealed by a RT–PCR assay. The antisense efficacy of the tc-oligonucleotides was found to be superior to that of the LNA-oligonucleotides in all cases by a factor of at least 4–5. A tc-oligonucleotide 15mer completely abolished CyPA mRNA production at 0.2 µM concentration. The antisense effect was confirmed by western blot analysis which revealed a reduction in CyPA protein to 13% of its normal level. Fluorescence microscopic investigations with a fluorescein labeled tc-15mer revealed a strong propensity for homogeneous nuclear localization of this backbone type after lipofectamine mediated transfection, while the corresponding lna 15mer showed a less clear cellular distribution pattern. Transfection without lipid carrier showed no significant internalization of both tc- and LNA- oligonucleotides. The obtained results confirm the power of tc-DNA for nuclear antisense applications. Moreover, CyPA may become an interesting therapeutic target due to its important role in the early steps of the viral replication of HIV-1

Inhibition of HIV-1 multiplication by antisense U7 snRNAs and siRNAs targeting cyclophilin A

Human immunodeficiency virus 1 (HIV-1) multiplication depends on a cellular protein, cyclophilin A (CyPA), that gets integrated into viral particles. Because CyPA is not required for cell viability, we attempted to block its synthesis in order to inhibit HIV-1 replication. For this purpose, we used antisense U7 small nuclear RNAs (snRNAs) that disturb CyPA pre-mRNA splicing and short interfering RNAs (siRNAs) that target CyPA mRNA for degradation. With dual-specificity U7 snRNAs targeting the 3′ and 5′ splice sites of CyPA exons 3 or 4, we obtained an efficient skipping of these exons and a strong reduction of CyPA protein. Furthermore, short interfering RNAs targeting two segments of the CyPA coding region strongly reduced CyPA mRNA and protein levels. Upon lentiviral vector-mediated transduction, prolonged antisense effects were obtained for both types of antisense RNAs in the human T-cell line CEM-SS. These transduced CEM-SS cells showed a delayed, and for the siRNAs also reduced, HIV-1 multiplication. Since the two types of antisense RNAs function by different mechanisms, combining the two approaches may result in a synergistic effect

Research on a Composite Voltage and Current Measurement Device for HVDC Networks

With the global trend to develop digital substation automation systems, measurement devices are required to be reliable, of small size and light weight and of acceptable accuracy in a wide frequency band. This article presents a combined high voltage direct current measurement method which comprises the above-mentioned features that makes it suitable for smart grids protection and control applications. The proposed measurement method utilizes Hall sensor array for dc current measurement. DC voltage is measured using a voltage divider circuit while the harmonic currents are measured using a square Rogowski coil made of four straight bars along with a high precision digital integration algorithm. A four-spectral line interpolation fast Fourier transform algorithm based on trapezoidal convolution window is proposed to improve the extraction accuracy of the dc and harmonic components from the measured signal. Experimental results show that the error variation of the proposed method is less than 0.098% for voltage measurement while it is less than 0.104% for current measurement. The harmonic measurement ratio error is less than 0.2% and the angle error is less than 8'

An Improved Constrained Order Optimization Algorithm for Uncertain SCUC Problem Solving

Studying the faster and more efficient method of solving the uncertain security-constrained unit commitment (SCUC) problem is an urgent need for the development of power systems under the background of large-scale wind power access and power dispatching. This study proposes an improved constrained order optimization (COO) algorithm to solve the uncertain SCUC problem. First, the data-driven discrete variable identification strategy is incorporated into the COO rough model, and then, the invalid security constraints identification strategy is incorporated into the COO accurate model. Finally, the improved COO algorithm combines the discrete variable identification with the invalid security constraint identification to make the uncertain SCUC decision. The results of the IEEE 118-bus test system showed that, compared with the traditional COO algorithm, the improved COO algorithm proposed has higher accuracy and better efficiency

A Data-Driven Approach for Online Inter-Area Oscillatory Stability Assessment of Power Systems Based on Random Bits Forest Considering Feature Redundancy

To utilize the rapidly refreshed operating data of power systems fully and effectively, an integrated scheme for inter-area oscillatory stability assessment (OSA) is proposed in this paper using a compositive feature selection unit and random bits forest (RBF) algorithm. This scheme consists of offline, update, and online stages, and it can provide fast and accurate estimation of the oscillatory stability margin (OSM) by using the real-time system operating data. In this scheme, a compositive feature selection unit is specially designed to realize efficient feature selection, which can significantly reduce the data dimensionality, effectively alleviate feature redundancy, and provide accurate correlation information to system operators. Then, the feature set consisting of the selected pivotal features is used for the RBF training to build the mapping relationships between the OSM and the system operating variables. Moreover, to enhance the robustness of the scheme in the face of variable operating conditions, an update stage is developed. The effectiveness of the integrated scheme is verified on the IEEE 39-bus system and a larger 1648-bus system. Tests of estimation accuracy, data processing speed, and the impact of missing data and noise data on this scheme are implemented. Comparisons with other methods reveal the superiority of the integrated scheme. In addition, the robustness of the scheme to variations in system topology, distribution among generators and loads, and peak and minimum load is studied