Reversible oligonucleotide chain blocking enables bead capture and amplification of T-Cell receptor alpha and beta chain mRNAs

Next-generation sequencing (NGS) has proven to be an exceptionally powerful tool for studying genetic variation and differences in gene expression profiles between cell populations. However, these population-wide studies are limited by their inability to detect variation between individual cells within a population, inspiring the development of single-cell techniques such as Drop-seq, which add a unique barcode to the mRNA from each cell prior to sequencing. Current Drop-seq technology enables capture, amplification, and barcoding of the entire mRNA transcriptome of individual cells. NGS can then be used to sequence the 3′-end of each message to build a cell-specific transcriptional landscape. However, current technology does not allow high-throughput capture of information distant from the mRNA poly-A tail. Thus, gene profiling would have much greater utility if beads could be generated having multiple transcript-specific capture sequences. Here we report the use of a reversible chain blocking group to enable synthesis of DNA barcoded beads having capture sequences for the constant domains of the T-cell receptor α and β chain mRNAs. We demonstrate that these beads can be used to capture and pair TCRα and TCRβ sequences from total T-cell RNA, enabling reverse transcription and PCR amplification of these sequences. This is the first example of capture beads having more than one capture sequence, and we envision that this technology will be of high utility for applications such as pairing the antigen receptor chains that give rise to autoimmune diseases or measuring the ratios of mRNA splice variants in cancer stem cells

Reliability assessment of automotive components under fatigue using numerical simulation and accelerated testing

In this paper, a Stochastic Response Surface (SRS) approach based on Polynomial Chaos Expansion (PCE) is used to conduct reliability analysis of automotive components subjected to fatigue loading. The PCE coefficients have been computed by regression analysis based on a quasi-random experimental design. In addition, an efficient truncation technique, namely low-rank index sets, has been used to reduce the number of unknown coefficients to be estimated, and consequently to reduce the number of finite element model calls required for the construction of the PCE. Once the PCE is obtained, the probability of failure for a target fatigue life is estimated by applying Monte-Carlo simulations. At the same time, fatigue accelerated testing are conducted on full scale automotive component to obtain experimental predictions of the structural reliability. The estimates of the probability of failure are in good agreement with those obtained by numerical computations based on PCE and Monte-Carlo simulations

Force de répulsion entre un courant sinusoïdal linéique et une bande conductrice mince : application aux problèmes de lévitation

In a previous work, the authors presented a semianalytical treatment of the electromagnetic field distribution in the case of a straight conductor carrying a sinusoidal current parallel to a thin conducting plate. The result of this investigation is extended here to the evaluation of the repulsive forces accompanying this type of electromagnetic interaction. The variation of such forces with geometric parameters is studied in the presence of a single conductor, and in the case of several conductors laying in a plane parallel to the surface of the material submitted to the induction phenomenon. The problem of lévitation in steady-state conditions is examined, in the light of this arrangement, for various conducting materials. Graphs illustrate the results obtained and make evident their practical interest particularly in the stationary case of magnetically levitated vehicles. </jats:p

Traitement semi-analytique du champ d'une source linéique de courant à proximité d'une bande conductrice mince

The authors study the electromagnetic interaction, in steady state conditions, between a straight conductor carrying sinusoidal current, and a finite thickness metallic plate. First, they develop a solution in terms of magnetic vector potential. Then, they give a special attention to the numerical évaluation of the field components in their integral form. A high stability appropriate quadrature method is proposed. The effect of some parameters on field diffusion within the metallic plate is also examined. </jats:p

MAPPING OF BURNED AREA USING PRESENCE AND BACKGROUND LEARNING FRAMEWORK ON THE GOOGLE EARTH ENGINE PLATFORM

Abstract. Mapping of burned areas caused by forest fires was always a main concern to researchers in the field of remote sensing. Thus, various spectral indices and classification techniques have been proposed in the literature. In such a problem, only one specific class is of real interest and could be referred to as a one-class classification problem. One-class classification methods are highly desirable for quick mapping of classes of interest. A common used solution to deal with One-Class classification problem is based on oneclass support vector machine (OC-SVM). This method has proved useful in classification of remote sensing images. However, overfitting problem and difficulty in tuning parameters have become the major obstacles for this method. The new Presence and Background Learning (PBL) framework does not require complicated model selection and can generate very high accuracy results. On the other hand the Google Earth Engine (GEE) portal provides access to satellite and other ancillary data, cloud computing, and algorithms for processing large amounts of data with relative ease. Therefore, this study mainly aims to investigate the possibility of using the PBL framework within the GEE platform to extract burned areas from freely available Landsat archive in the year 2015. The quality of the results obtained using PBL framework was assessed using ground truth digitized by qualified technicians and compared to other classification techniques: Thresholding burned area spectral Index (BAI) and OC-SVM classifiers. Experimental results demonstrate that PBL framework for mapping the burned areas shows the higher classification accuracy than the other classifiers, and it highlights the suitability for the cases with few positive labelled samples available, which facilitates the tedious work of manual digitizing. </jats:p