Comparative analysis of morphological and morphometrical characters in six isolates of Pratylenchus vulnus Allen & Jensen, 1951 (Nemata : Tylenchida)

Six populations de #Pratylenchus vulnus$ Allen & Jensen, 1951 provenant d'Europe et d'Amérique ont été analysées du point de vue morphologique et morphométrique. Certaines différences ont été observées pour quelques caractères morphologiques (structure du sac post-vulvaire, forme de la spermathèque, largeur des champs latéraux). Par contre, des différences significatives concernant tous les caractères morphométriques (excepté le rapport "m") ont été constatées entre les populations. Une analyse de corrélation canonique montre que les relations entre populations pourraient être fonction de leur origine géographique et/ou de leur plante hôte. (Résumé d'auteur

An Integral Formulation for Rectangular Wires in a 3D Magneto-Quasi-Static Field

This paper proposes an integral formulation for calculating the magnetic and ohmic losses in rectangular wires immersed in an external 3D magneto-quasi-static field. The formulation is based on some simplifying assumptions that allow to employ a collocation method with constant elements for the discretization, reducing the computational burden. Even if the assumptions introduce an approximation, for the application at hand the numerical tests have shown that the accuracy is still acceptable. Moreover, the computational time is drastically reduced with respect to other approaches based on the finite element method

Molecular dynamics simulations reveal canonical conformations in different pMHC/TCR interactions

The major defense system against microbial pathogens in vertebrates is the adaptive immune response and represents an effective mechanism in cancer surveillance. T cells represent an essential component of this complex system. They can recognize myriads of antigens as short peptides (p) originated from the intracellular degradation of foreign proteins presented by major histocompatibility complex (MHC) proteins. The clonotypic T-cell antigen receptor (TCR) is specialized in recognizing pMHC and triggering T cells immune response. It is still unclear how TCR engagement to pMHC is translated into the intracellular signal that initiates T-cell immune response. Some work has suggested the possibility that pMHC binding induces in the TCR conformational changes transmitted to its companion CD3 subunits that govern signaling. The conformational changes would promote phosphorylation of the CD3 complex ζ chain that initiates signal propagation intracellularly. Here, we used all-atom molecular dynamics simulations (MDs) of 500 ns to analyze the conformational behavior of three TCRs (1G4, ILA1 and ILA1α1β1) interacting with the same MHC class I (HLA-A*02:01) bound to different peptides, and modelled in the presence of a lipid bilayer. Our data suggest a correlation between the conformations explored by the β-chain constant regions and the T-cell response experimentally determined. In particular, independently by the TCR type involved in the interaction, the TCR activation seems to be linked to a specific zone of the conformational space explored by the β-chain constant region. Moreover, TCR ligation restricts the conformational space the MHC class I groove

2D Zernike polynomial expansion: finding the protein-protein binding regions

We present a method for efficiently and effectively assessing whether and where two proteins can interact with each other to form a complex. This is still largely an open problem, even for those relatively few cases where the 3D structure of both proteins is known. In fact, even if much of the information about the interaction is encoded in the chemical and geometric features of the structures, the set of possible contact patches and of their relative orientations are too large to be computationally affordable in a reasonable time, thus preventing the compilation of reliable interactome. Our method is able to rapidly and quantitatively measure the geometrical shape complementarity between interacting proteins, comparing their molecular iso-electron density surfaces expanding the surface patches in term of 2D Zernike polynomials. We first test the method against the real binding region of a large dataset of known protein complexes, reaching a success rate of 0.72. We then apply the method for the blind recognition of binding sites, identifying the real region of interaction in about 60% of the analyzed cases. Finally, we investigate how the efficiency in finding the right binding region depends on the surface roughness as a function of the expansion order

A Computationally Efficient Algorithm for Online Spectral Analysis of Beat-to-Beat Signals

Abstract Introduction Beat-by-beat time series of heart-rate or systolic and diastolic blood pressure data are made of unevenly sampled elements. In fact, these parameters can be estimated at a sampling frequency that corresponds to the instantaneous heart rate, which fluctuates over time. Since traditional spectral estimators are based on the Fourier Transform of the data, they need the input series to be evenly sampled to avoid distortions in the spectra. For this reason, the beat-to-beat series are interpolated and resampled evenly at a sampling frequency higher than the mean heart rate. Then, a batch of data is analysed by means of an FFT algorithm. These procedures are not particularly efficient when real time spectral analysis are needed. Here we propose a computationally efficient algorithm for the on-line Fourier analysis of beat-by-beat data. The method is based on the evaluation of the analytic expression of the Fourier Transform of the interpolated time-series, and does not require actual interpolation and resampling. The method is applied on simulated and real heart-rate data to show its capability to analyse unevenly sampled series, and the feasibility of running spectral analysis of cardiovascular data beat after beat. 2. The algorithm Fourier transform of linearly interpolated time series Let's consider a series of N unequally spaced events: X(t n ), n=1,…N. This series could be a beat-by-beat sequence of RR interval, or a series of blood pressure values. Let's call x(t) the continuous function of time t derived from X(t n ) by linear interpolation of the data

Baroreflex contribution to blood pressure and heart rate oscillations: time scales, time-variant characteristics and nonlinearities

The aim of this paper is to highlight the aspects of the baroreflex control of the cardiovascular system that could be relevant to the analysis and modelling of cardiovascular oscillations and regulation. In particular, complex and/or controversial issues of the baroreflex control are addressed on the basis of results obtained in previous studies by others as well as by our group. Attention has been focused on time-variant and nonlinear characteristics of the baroreflex function and on the influence of this physiological mechanism on different frequency regions of blood pressure and heart rate spectra

Corn Geospatial strategy: a more deeply understanding of hybrid competitiveness and performance by combining digital tools and data modeling

The comparative performance trials (CPT) of experimental and commercial cultivars in multi-environment trials, allow the determination of genotype (G) response to the different environment (E) and interaction (GxE). The final goal is to provide selection guidelines to identify the best genotypes to advance in the pipeline of the breeding program. Nowadays, the use of the digital information technologies to monitoring yield can be used in the CPTs to accurate measuring and recording of grain yield as well as the local environmental context. This research was carried out at 138 locations corresponding to commercial fields located in Argentina. The harvested was made with yield monitor and weighing machine wagon. To compare the grain yield of hybrids within each E and GXE interaction, the MLM of ANAVA with spatial correlation was adjusted for each location. Whereas, for CPT-without spatial data the ANAVA simple was applicate. The new analytic strategy showed greater power to: (a) find significant differences (p<0.05) in the GxE interaction, (b) increase 2.5 times the amount of information generated, i.e. than 1 CPT (1 location) analyzed with the new strategy. The new approach improves the data-driven decision making to support advancement processes from precommercial to commercial.Sociedad Argentina de Informática e Investigación Operativ