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We consider the genealogical tree of a stationary continuous state branching process with immigration. For a sub-critical stable branching mechanism, we consider the genealogical tree of the extant population at some fixed time and prove that, up to a deterministic time-change, it is distributed as a continuous-time Galton–Watson process with immigration. We obtain similar results for a critical stable branching mechanism when only looking at immigrants arriving in some fixed time-interval. For a general sub-critical branching mechanism, we consider the number of individuals that give descendants in the extant population. The associated processes (forward or backward in time) are pure-death or pure-birth Markov processes, for which we compute the transition rates. [ABSTRACT FROM AUTHOR]

• The asymptotic distribution of the projector associated with the SCM is given for arbitrary distributions of the useful signal and noise with finite fourth-order moments. • The asymptotic distribution of the DOA estimate given by the MUSIC algorithm is proved for both nonparametric non-Gaussian noise and parametric CES noise models. Theoretical evaluation of the loss of performance is given for heavy-tailed distributions of the noise which is significant for weak SNR and closely spaced sources. • For CES distributed observations, the asymptotic distribution of the projector associated with any M -estimate of the covariance matrix is given. This allows us to prove that this loss of performance can be alleviated. • These theoretical results are confirmed by some simulations performed with either a complex circular Student t -distribution or a complex generalized Gaussian distribution of the noise or the observations model. This paper addresses the theoretical analysis of the robustness of subspace-based algorithms with respect to non-Gaussian noise distributions using perturbation expansions. Its purpose is twofold. It aims, first, to derive the asymptotic distribution of the estimated projector matrix obtained from the sample covariance matrix (SCM) for arbitrary distributions of the useful signal and the noise. It proves that this distribution depends only of the second-order statistics of the useful signal, but also on the second and fourth-order statistics of the noise. Second, it derives the asymptotic distribution of the estimated projector matrix obtained from any M -estimate of the covariance matrix for both real (RES) and complex elliptical symmetric (CES) distributed observations. Applied to the MUSIC algorithm for direction-of-arrival (DOA) estimation, these theoretical results allow us to theoretically evaluate the performance loss of this algorithm for heavy-tailed noise distributions when it is based on the SCM, which is significant for weak signal-to-noise ratio (SNR) or closely spaced sources. These results also make it possible to prove that this performance loss can be alleviated by replacing the SCM by an M -estimate of the covariance for CES distributed observations, which has been observed until now only by numerical experiments. [ABSTRACT FROM AUTHOR]

• An extension of the matrix Slepian-Bangs formula to elliptical symmetric distributions under the assumption that the arbitrary density generator depends on unknown parameters is given. • This new matrix Slepian-Bangs formula involves a common structure to the existing one with a simple corrective coefficient. • Closed-form expressions of this coefficient are given for Student's t and generalized Gaussian distributions and are each compared according to different knowledge of the density generator. • This allows us to conclude that for an arbitrary parameterization, the Cramér-Rao bound may be very sensitive to the knowledge of the density generator for super-Gaussian distributions contrary to sub-Gaussian distributions. This paper mainly deals with an extension of the matrix Slepian-Bangs (SB) formula to elliptical symmetric (ES) distributions under the assumption that the arbitrary density generator depends on unknown parameters, aiming to rigorously quantify and understand the impact of this assumption on ES distributed parametric estimation models. This matrix SB formula is derived in a unified way within the framework of real (RES) and circular (C-CES) or noncircular (NC-CES) complex elliptically symmetric distributions, and then compared to the matrix SB formula obtained with fully known or completely unknown density generators. This new matrix SB formula involves a common structure to the existing one with a simple corrective coefficient. Closed-form expressions of this coefficient are given for Student's t and generalized Gaussian distributions and are each compared according to different knowledge of the density generator. This allows us to conclude that for an arbitrary parameterization, the Cramér-Rao bound (CRB) may be very sensitive to the knowledge of the density generator for super-Gaussian distributions contrary to sub-Gaussian distributions. Finally, we prove that for the parametrization with an unknown scale factor, the CRB for the estimation of the other parameters of the scatter matrix does not depend on the type of knowledge of the density generator. This latter result remains true for the specific noisy linear mixture data model where the parameter of interest is characterized by the range space of the mixing matrix. [ABSTRACT FROM AUTHOR]

This paper focuses on the Cramér Rao bound (CRB) of the azimuth, elevation and range with planar arrays for narrowband near-field source localization, using the exact expression of the time delay. Specifically, the aim of this paper is twofold. First, we derive explicit non-matrix closed-form expressions of approximations of these three CRBs. Second, we use these expressions to optimize near-field source localization. For deriving these expressions, we introduce conditions on the array geometry that allow us to decouple the azimuth, elevation and range parameters to a certain order in λ / r (in which λ and r denote the wavelength and the range, respectively). A particular attention is given to the popular array configurations which are the concentric uniform circular-based arrays, cross and square-based centro-symmetric arrays which satisfy these conditions. In order to control directions of arrivals (DOA) ambiguity, we propose a new criterion, which allows us to design non-uniform square [resp., cross]-based centro-symmetric array configurations with improved near-field range estimation capabilities without deteriorating the DOA precisions w.r.t. uniform square [resp., cross]-based arrays. Finally, we specify the accuracy of our proposed approximated CRBs׳expressions and isotropy׳s conditions w.r.t. the range and the number of sensors. [ABSTRACT FROM AUTHOR]

• General closed-form expressions of the deterministic Cramér Rao bound (DCRB), semiparametric DCRB, stochastic Cramér Rao bound (SCRB) and semiparametric SCRB for direction of arrival (DOA) estimation are given in complex elliptically symmetric (CES) data models. • Simple exact and asymptotic (for small DOA separation) interpretable closed-form expressions are presented for the DCRB and SCRB of the DOA for two equi-powered correlated known, arbitrary, circular or rectilinear sources in CES data models. • The dependence of these bounds on the magnitude and phase of the correlation is examined. • Using asymptotic expressions of DCRBs and SCRBs, interpretable closed-form expressions of Statistical Resolution Limit (SRL) based on Smith's criterion are derived in different scenarios. • Comments to explain how different parameters impact the derived SRLs and how also the SRLs derived from the SCRBs are much less optimistic than those that have so far been deduced only from the DCRB under the assumption of known sources are discussed. This paper analyzes the deterministic (DCRB) and the stochastic (SCRB) Cramér-Rao bound on direction-of-arrival (DOA) estimation for two equi-powered correlated complex circular or rectilinear sources affected by complex circular white noise in different complex elliptically symmetric (CES) data models. Beginning by decomposing these CRBs, into factors depending on signal and noise parameters, and on geometric parameters of the array, some new interpretable closed-form expressions are derived in particular scenarios. These expressions provide useful insight into the behavior of these CRB's dependence on the correlation factor. Approximate closed-form expressions of these CRBs for small DOA separation are also derived. These results lead to new formulas for statistical resolution limit (SRL) based on the Smith criterion at which an unbiased DOA estimation algorithm can resolve two closely-spaced circular or rectilinear sources. These SCRB-derived formulas are much less optimistic than those which have so far been deduced only from the DCRB under the assumption of known sources. [ABSTRACT FROM AUTHOR]

Recently, there has been an increased awareness that simplistic adaptation of performance analysis developed for random real-valued signals and parameters to the complex case may be inadequate or may lead to intractable calculations. Unfortunately, many fundamental statistical tools for handling complex-valued parameter estimators are missing or scattered in the open literature. In this paper, we survey some known results and provide a rigorous and unified framework to study the statistical performance of complex-valued parameter estimators with a particular attention paid to properness (i.e., second order circularity), specifically referring to the second-order statistical properties. In particular, some new properties relative to the properness of the estimates, asymptotically minimum variance bound and Whittle formulas are presented. A new look at the role of nuisance parameters is given, proving and illustrating that the noncircular Gaussian distributions do not necessarily improve the Cramer–Rao bound (CRB) with respect to the circular case. Efficiency of subspace-based complex-valued parameter estimators that are presented with a special emphasis is put on noisy linear mixture. [ABSTRACT FROM AUTHOR]

We study the pruning process developed by Abraham and Delmas (2012) on the discrete Galton–Watson sub-trees of the Lévy tree which are obtained by considering the minimal sub-tree connecting the root and leaves chosen uniformly at rate λ , see Duquesne and Le Gall (2002). The tree-valued process, as λ increases, has been studied by Duquesne and Winkel (2007). Notice that we have a tree-valued process indexed by two parameters: the pruning parameter θ and the intensity λ . Our main results are: construction and marginals of the pruning process, representation of the pruning process (forward in time that is as θ increases) and description of the growing process (backward in time that is as θ decreases) and distribution of the ascension time (or explosion time of the backward process) as well as the tree at the ascension time. A by-product of our result is that the super-critical Lévy trees independently introduced by Abraham and Delmas (2012) and Duquesne and Winkel (2007) coincide. This work is also related to the pruning of discrete Galton–Watson trees studied by Abraham, Delmas and He (2012). [ABSTRACT FROM AUTHOR]

Abstract: Widely Linear (WL) Minimum Mean Square Error (MMSE) estimation has received a great interest these last 20 years for second order (SO) noncircular signals. In the context of radio communications networks, it has been shown in particular that WL MMSE receivers allow to implement Single Antenna Interference Cancellation (SAIC) of one rectilinear interference, such as Binary Phase Shift Keying (BPSK) or Amplitude Shift Keying (ASK) interference, or of quasi-rectilinear interference, such as Minimum Shift keying (MSK), Gaussian MSK (GMSK) or Offset Quadrature Amplitude Modulation (OQAM) interference, hence their great interest for Global System for Mobile Communications (GSM) cellular networks in particular. However, one may wonder whether WL MMSE receivers remain attractive for SO noncircular nonrectilinear interferences, not so scarce in practice. The purpose of this paper is mainly to answer to this important question by giving, in a self-contained and unified way, some new insights into the behavior, properties and performance of the WL MMSE beamformer in the presence of arbitrary noncircular signals and interference which are not necessarily rectilinear. It is shown in particular that, surprisingly, WL MMSE receivers lose their practical interest for strong interferences which are not rectilinear. This breakthrough thus generates a new open problem for the choice between linear and WL MMSE receiver corresponding to the detection of rectilinearity (and/or quasi-rectilinearity), instead of noncircularity, in a given noisy observation. Although this question is out of the scope of this paper, we finally propose preliminary tools based on blind source separation methods to solve this problem. [Copyright &y& Elsevier]

We perform a pruning procedure on a Lévy tree and instead of throwing away the removed sub-tree, we regraft it on a given branch (not related to the Lévy tree). We prove that the tree constructed by regrafting is distributed as the original Lévy tree, generalizing a result of Addario-Berry, Broutin and Holmgren where only Aldous’s tree is considered. As a consequence, we obtain that the “average pruning time” of a leaf is distributed as the height of a leaf picked at random in the Lévy tree. [ABSTRACT FROM AUTHOR]

• This paper derives interpretable unified closed-form expressions for the threshold ASNR along the Cox and the Sharman and Durrani criteria associated with the conventional MUSIC and NC MUSIC algorithms in the context of arbitrary circular or rectilinear distributed correlated sources and circular CES distributed noise. • Using these expressions, we investigate the impact of the non-Gaussianity of the noise, as well as of the phase and magnitude of the correlation of the sources. • In particular, we prove for the first time that the phase of the correlation, which is the non-circularity phase separation for rectilinear sources, may have a strong impact on the resolution and a zero phase may lead to overly optimistic resolution. • We quantify the resolution benefit provided when the SCM is replaced by M - estimates of the covariance matrix for CES observations. The concept of threshold array signal-to-noise ratio (ASNR) which is defined as the minimal SNR at which specific high-resolution algorithms are able to resolve two closely spaced far-field sources, allows to quantify and to compare sensors array performance in localizing remote targets. This paper generalizes and extends the expressions of the threshold ASNR given in the literature for the conventional and non-circular (NC) MUSIC direction-of-arrival (DOA) estimation algorithms in the context of uncorrelated stochastic circular or rectilinear Gaussian sources and circular complex Gaussian (C-CG) noise, in a more general stochastic framework. We assume that the sources are correlated with an arbitrary distribution, which is inherent in a context of multipath or smart jammers, and that the noise is circular complex elliptically symmetric (C-CES) distributed, which can model impulsive noise with heavy-tailed distributions. The C-CES and NC-CES distributed observations are also considered to quantify the gain in resolution provided when the sample covariance matrix (SCM) of the observations is replaced by M -estimates of this matrix. Asymptotic approaches and perturbation analysis have been performed to derive closed-form expressions of the mean null spectra of the two considered MUSIC algorithms for both observation models, which allow us to derive, for the first time, general unified explicit analytical expressions of the threshold ASNR along the Cox and the Sharman and Durrani criteria. These expressions allow us to quantify the impact of the non-Gaussianity of noise and observations, as well as of the phase and magnitude of the correlation on the resolution threshold, and to quantify the benefit provided when the SCM is replaced by M -estimates of this covariance matrix for CES observations. Finally, numerical illustrations are included to support our theoretical analysis. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the problem of testing impropriety (i.e., second-order noncircularity) of a sequence of complex-valued random variables (RVs) based on the generalized likelihood ratio test (GLRT) for Gaussian distributions is considered. Asymptotic (w.r.t. the data length) distributions of the GLR are given under the hypothesis that RVs are proper or improper, and under the true, not necessarily Gaussian distribution of the RVs. The considered RVs are independent but not necessarily identically distributed: assumption which has never been considered until now. This enables us to deal with the practical important situations of noncircular RVs disturbed by residual frequency offsets and additive circular noise. The receiver operating characteristic (ROC) of this test is derived as byproduct, an issue previously overlooked. Finally illustrative examples are presented in order to strengthen the obtained theoretical results. [Copyright &y& Elsevier]

Abstract: A performance analysis of likelihood ratio test (LRT)-based and generalized likelihood ratio test (GLRT)-based array receivers for the detection of a known real-valued signal corrupted by a potentially noncircular interference is considered in this paper. The distribution of the decision statistics associated with the LRT and GLRT is studied. This allows us to give exact closed-form expressions of the probability of detection (P D) and false alarm (P FA) for two LRT-based receivers. Then, asymptotic (with respect to the data length) closed-form expressions are given for P D and P FA for four GLRT-based receivers. Finally, in order to strengthen the obtained results, some illustrative examples are presented. [Copyright &y& Elsevier]

Abstract: We consider the bifurcating Markov chain model introduced by Guyon to detect cellular aging from cell lineage. To take into account the possibility for a cell to die, we use an underlying super-critical binary Galton–Watson process to describe the evolution of the cell lineage. We give in this more general framework a weak law of large number, an invariance principle and thus fluctuation results for the average over all individuals in a given generation, or up to a given generation. We also prove that the fluctuations over each generation are independent. Then we present the natural modifications of the tests given by Guyon in cellular aging detection within the particular case of the auto-regressive model. [ABSTRACT FROM AUTHOR]

Abstract: In this correspondence we mainly consider the asymptotic distribution of the estimator of circularity coefficients of scalar and multidimensional complex random variables. A particular attention is paid to rectilinear RV. After deriving new properties of the circularity coefficients, the maximum likelihood estimate of the circularity coefficients in the Gaussian case and asymptotic distribution of this estimate for arbitrary distributions are given. Finally, an illustrative example is presented in order to strengthen the obtained theoretical results. [Copyright &y& Elsevier]

Abstract: In many detection applications, the main performance criterion is the signal to interference plus noise ratio (SINR). After linear filtering, the optimal SINR corresponds to the maximum value of a Rayleigh quotient, which can be interpreted as the largest generalized eigenvalue of two covariance matrices. Using an extension of Szegö''s theorem for the generalized eigenvalues of Hermitian block Toeplitz matrices, an expression of the theoretical asymptotic optimal SINR w.r.t. the number of taps is derived for arbitrary arrays with a limited but arbitrary number of sensors and arbitrary spectra. This bound is interpreted as an optimal zero-bandwidth spatial SINR in some sense. Finally, the speed of convergence of the optimal wideband SINR for a limited number of taps is analyzed for several interference scenarios. [Copyright &y& Elsevier]

Abstract: We consider an initial Eve-population and a population of neutral mutants, such that the total population dies out in finite time. We describe the evolution of the Eve-population and the total population with continuous state branching processes, and the neutral mutation procedure can be seen as an immigration process with intensity proportional to the size of the population. First we establish a Williams’ decomposition of the genealogy of the total population given by a continuum random tree, according to the ancestral lineage of the last individual alive. This allows us to give a closed formula for the probability of simultaneous extinction of the Eve-population and the total population. [Copyright &y& Elsevier]

Abstract: This paper addresses subspace-based direction of arrival (DOA) estimation and its purpose is to complement previously available theoretical results generally obtained for specific algorithms. We focus on asymptotically (in the number of measurements) minimum variance (AMV) estimators based on estimates of orthogonal projectors obtained from singular value decompositions of sample covariance matrices in the general context of noncircular complex signals. After extending the standard AMV bound to statistics whose first covariance matrix of its asymptotic distribution is singular and deriving explicit expressions of this first covariance matrix associated with several projection-based statistics, we give closed-form expressions of AMV bounds based on estimates of different orthogonal projectors. This enable us to prove that these AMV bounds attain the stochastic Cramer–Rao bound (CRB) in the case of circular or noncircular Gaussian signals. [Copyright &y& Elsevier]

Abstract: We consider the height process of a Lévy process with no negative jumps, and its associated continuous tree representation. Using tools developed by Duquesne and Le Gall, we construct a fragmentation process at height, which generalizes the fragmentation at height of stable trees given by Miermont. In this more general framework, we recover that the dislocation measures are the same as the dislocation measures of the fragmentation at nodes introduced by Abraham and Delmas, up to a factor equal to the fragment size. We also compute the asymptotics for the number of small fragments. [Copyright &y& Elsevier]

Abstract: This paper addresses asymptotically minimum variance (AMV) of parameter estimators within the class of algorithms based on second-order statistics for estimating parameter of strict-sense stationary complex circular processes. As an application, the estimation of the frequencies of cisoids for mixed spectra time series containing a sum of cisoids and an MA process is considered. [Copyright &y& Elsevier]

Using an approximating scheme with the Brownian snake, we prove the existence of solution to a martingale problem for super Brownian motion with interactions. [Copyright &y& Elsevier]

The purpose of this paper is to determine the domain of validity of spatial covariance-based narrowband DOA algorithms when processing non-narrowband data. By focusing on the case of one source and two equipowered uncorrelated sources of the same bandwidth, we examine order detection and asymptotic bias and covariance w.r.t. the bandwidth and the number of snapshots given by any narrowband algorithm. An order detector scheme, based on numerical analysis arguments introduced in channel order detection, is proposed. Closed-form expressions are given for the asymptotic bias and covariance of the DOA''s estimated by the MUSIC algorithm, for which we show the key role that bandwidth plays w.r.t. the demodulation frequency. Furthermore, a common closed-form expression of the Cramer–Rao bound is given for the DOA parameter of a narrowband or wideband source, whose spectrum is symmetric w.r.t. the demodulation frequency, in the case of an arbitrary array. This allows us to prove that the MUSIC algorithm retains its efficiency over a large bandwidth range under these conditions. [Copyright &y& Elsevier]

• This paper has shown that all the NC subspace-based algorithms built from the SCM designed for uncorrelated rectilinear sources embedded in spatially white CCG noise can be also applied for correlated rectilinear sources in the contexts of SCM estimate with C-CES noise and M-estimate with NC-CES observations. • A perturbation analysis has been performed to derive closed-form expressions for the asymptotic covariance matrices of DOA estimates for three NC MUSIC-like algorithms in two CES data models. • Interpretable closed-form expressions of the asymptotic variance of the estimated DOA of two equi-power correlated sources has been derived for the first time. • A number of properties that highlight how the asymptotic variances of NC MUSIClike DOA estimation algorithms depend on key parameters such as SNR, DOA and phase separations, correlation factor and C-CES noise parameters were derived. • Analytical robustness results were illustrated proving that the use of robust Mestimators enhances the robustness of the subspace-based DOA estimation algorithms against heavy-tailed C-CES observations model deviations, with negligibleloss in performance for C-CG distributed observations. This paper focuses on a theoretical performance analysis of subspace-based algorithms for the localization of spatially correlated rectilinear sources embedded in circular complex elliptically symmetric (C-CES) distributed noise model and also when the observations are non-circular CES (NC-CES) distributed with dependent scatter matrices on the direction of arrival (DOA) parameters. A perturbation analysis has been performed to derive closed-form expressions for the asymptotic covariance matrices of DOA estimates for non-circular subspace-based algorithms in two CES data models. Robustness of subspace-based algorithms is theoretical evaluated using robust covariance matrix estimators (instead of the sample covariance matrix (SCM)). We prove, for the first time, interpretable closed-form expressions of the asymptotic variance of the estimated DOA of two equi-power correlated sources, which allows us to derive a number of properties describing the DOA variance's dependence on signals parameters and non-Gaussian distribution of the noise. Different robustness properties are theoretically analyzed. In particular, we prove in the framework of NC-CES distributed observations, that Tyler's M -estimator enhances the performance for heavy-tailed distributions w.r.t. the SCM, with negligible loss in performance for circular Gaussian distributed observations. Finally, some Monte Carlo illustrations are given for quantifying this robustness and specifying the domain of validity of our theoretical asymptotic results. [ABSTRACT FROM AUTHOR]

• Asymptotic (in the number of measurements) distributions of estimates of the orthogonal projector associated with different M -estimates of the covariance matrix in the context of RES, C-CES, and NC-CES distributed observations whose covariance is low rank structured are given in the same framework. • The asymptotically minimum variance (AMV) subspace-based estimator of the parameter of interest characterized by the column subspace of the mixing matrix for general linear mixtures models, associated with the M -estimates of the covariance matrix is derived. • A common closed-form expression of the AMV bound which can be used as a benchmark against which any subspace-based algorithms are tested is derived. • It is proved that the AMV bound attains the stochastic CRB in the case of ML M -estimate of the covariance matrix for RES, C-CES, and NC-CES distributed observations • We specify the conditions for which the AMV bound based on Tyler's M -estimate attains this stochastic CRB for complex Student t and complex generalized Gaussian distributions. • It is proved that the stochastic CRB is equal to the semiparametric CRB recently introduced for this model. Subspace-based algorithms that exploit the orthogonality between a sample subspace and a parameter-dependent subspace have proved very useful in many applications in signal processing. The purpose of this paper is to complement theoretical results already available on the asymptotic (in the number of measurements) performance of subspace-based estimators derived in the Gaussian context to real elliptical symmetric (RES), circular complex elliptical symmetric (C-CES) and non-circular CES (NC-CES) distributed observations in the same framework. First, the asymptotic distribution of M -estimates of the orthogonal projection matrix is derived from those of the M -estimates of the covariance matrix. This allows us to characterize the asymptotically minimum variance (AMV) estimator based on estimates of orthogonal projectors associated with different M -estimates of the covariance matrix. A closed-form expression is then given for the AMV bound on the parameter of interest characterized by the column subspace of the mixing matrix of general linear mixture models. We also specify the conditions under which the AMV bound based on Tyler's M -estimate attains the stochastic Cramér-Rao bound (CRB) for the complex Student t and complex generalized Gaussian distributions. Finally, we prove that the AMV bound attains the stochastic CRB in the case of maximum likelihood (ML) M -estimate of the covariance matrix for RES, C-CES and NC-CES distributed observations, which is equal to the semiparametric CRB (SCRB) recently introduced. [ABSTRACT FROM AUTHOR]

• First method for the simultaneous detection of NFs, NIIMs, dyes and CAP. • The acid hydrolysis and derivatization steps for NFs was simplified. • Not only conventional NFs but other four NFs (NPIR, DNSH, PSH, AMG) were analyzed. • The QuEChERS was used to extract NFs, NIIMs, dyes and CAP in aquatic products. LC-MS/MS method was developed for the efficient identification and quantification of 21 banned substances including various nitroimidazoles, nitrofurans, pharmacologically-active dyes and chloramphenicol, respectively in aquaculture products. The sample preparation was started by acid-treatment with 2-nitrobenzaldehyde (NBA) to liberate matrix-bound residues of nitrofurans. A modified QuEChERS method was optimized for the extraction and clean-up of the target analytes. The metabolites of the four conventional nitrofurans (nitrofurantoin, furazolidone, nitrofurazone and furaltadone) and of three other nitrofurans (nifursol, nifuroxazide, and nitrovin), and an underivatizable nitrofuran (nifurpirinol) were simultaneously detected. Furthermore, 21 banned substances were quantified by LC-MS/MS with ESI using one single injection. To evaluate and validate the performance of the method, the criteria of the Decision (EC) no 2002/657 were applied. Decision limit (CCα) of target analytes ranged 0.067–1.655 μg/kg in aquaculture products. The recovery ranged 77.2%–125.6%, and the relative standard deviations of inter-day analyses (RSD) were less than 25%. [ABSTRACT FROM AUTHOR]

• A closed-form expression of the SINR at the output of a family of third-order Volterra MVDR beamformers is given. • Interpretable closed-form expressions of this SINR are derived in the particular case of 2 sensors in the presence of single digitally linearly modulated interference. • These closed-form expression allow us to quantify the impact of the pulse-shape filtering (pulse shape filter, oversampling factor and initial sampling time). • This sensitivity study proves that the high performance gain of these third-order Volterra MVDR beamformers with respect to the Capon algorithm for a square pulse shape filter are lost in the presence of intersymbol interference. Linear beamformers are optimal, in a mean square (MS) sense, when the signal of interest (SOI) and observations are jointly Gaussian and circular. Otherwise, optimal beamformers become non-linear with a structure depending on the unknown joint probability distribution of the SOI and observations. In this context, third-order Volterra minimum variance distortionless response (MVDR) beamformers have been proposed recently to improve the performance of linear beamformers in the presence of non-Gaussian and potentially non-circular interference, omnipresent in practical situations. High performance gains have been obtained for binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) interference having a square pulse shaping filter in particular. However in practice, for spectral efficiency reasons, most of signals use non-square pulse shaping filters, such as square root raised cosine filter. It is then important to analyze the sensitivity of third-order MVDR beamformers to interference pulse shaping filter, which is the purpose of this paper. [ABSTRACT FROM AUTHOR]

The French poet Apollinaire enrolled in the French army during World War I. In 1916, he sustained a penetrating brain injury when a fragment of shrapnel pierced his helmet in the right temporal region. Neurosurgical techniques were at that time standardized to manage the significant number of war-related neurosurgical casualties. Apollinaire, who experienced transient fainting followed by left-sided hemiparesis 2 months after his trauma, underwent trepanation. The poet's personality and behavior changed dramatically after his trauma. These neurobehavioral changes, associated with preserved cognition and no other neurologic dysfunction, were later described as Apollinaire syndrome. These personality changes were accompanied by flourishing writing changes. Hence, 15 months after his penetrating brain injury, the poet introduced the term "surrealism" to the world in his play The Breasts of Tiresias , giving birth to a major movement that paved the way for the 20th century. Linguistic shifts such as phonologic and semantic word games were at the forefront of the narrative process of the play. Traumatic brain injury often leads to cognitive impairment. In the case of Apollinaire, if the ballistic trauma were also responsible for diffuse axonal injury, it could have also led to semantic and social cognition impairment, in addition to the neuropsychological disorders that had already been widely documented by his friends and family. The world will always remember Apollinaire's writing genius as deeply associated with the birth of surrealism. But what if the poet's new writing style was caused, at least in part, by the unexpected help of a lost shrapnel fragment? [ABSTRACT FROM AUTHOR]

Microcystins (MCs) are toxins produced by several cyanobacteria species found worldwide. MC-LR is the most frequent. Here, we used the human Caco-2 cell line grown on semi-permeable filter supports as an in vitro model for determining MC-LR intestinal bidirectional transport. In this study, there was very low and time-dependent apparent permeability of MC-LR. To identify the limiting factors involved in the low permeability of MC-LR, a mathematical model was constructed to get physiologically relevant and informative parameters. The apical-to-basolateral transport was characterised by a rapid and substantial decrease in apical MC-LR concentrations (24–40% of the initial amount). In the basolateral compartment, the concentrations increased slowly after a lag time, but represented only a small fraction of the loaded concentrations (0.3–1.3%) after 24 h. This weak permeability was mainly due to a low clearance of efflux (from the cellular to the basolateral compartment) and effective secretion (from the cellular to the apical compartment). During the basolateral-to-apical transport, we observed a slow decrease in basolateral concentrations and a rapid increase in apical concentrations. In conclusion, modelling has the potential to highlight the key mechanisms involved in the complex kinetics of toxin transport. [ABSTRACT FROM AUTHOR]

• We extend, for R and QR data-like MUI and arbitrary propagation channels, the standard two-input SAIC/MAIC WL receivers to data-like MUI with an arbitrary non-zero residual FO, showing that SAIC/MAIC remains possible in this case. • We prove that for a data-like MUI having a non-zero residual frequency offset and spectrally overlapping with the SOI, the extended two-input SAIC/MAIC WL receiver is less efficient for QR signals than for R ones. • We extend, for QR data-like MUI and arbitrary propagation channels, the enhanced three-input SAIC/MAIC WL receiver aleady introduced to data-like MUI with a non-zero residual residual frequency offset, allowing a SAIC/MAIC improvement with respect to the extended two-input SAIC/MAIC WL receivers. • We analyze, both analytically and by simulations, for both R and QR data-like MUI, the impact of the non-zero MUI residual frequency offset on the performance of the proposed extended two and three-input WL FRESH receivers. Widely linear (WL) receivers have been developed in the past for single antenna interference cancellation (SAIC) of one rectilinear (R) or quasi-rectilinear (QR) data-like multi-user interference (MUI) or co-channel interference (CCI) in particular. The SAIC technology has been implemented in global system for mobile communications (GSM) handsets in particular and has been further analyzed for voice services over adaptive multi-user channels on one slot (VAMOS) standard. It remains of great interest for several current and future applications using R or QR signals, such as anti-collisions processing in radio frequency identification (RFID) or in satellite-AIS systems and to densify 5G and Beyond 5G (B5G) networks through one dimensional signaling or over-loaded large MU-MIMO systems. It may be required to cancel the inter-symbol interference (ISI) of control and non-payload communications (CNPC) links of unmanned aerial vehicles (UAV) and the inter-carrier interference (ICI) of filter bank multi-carrier offset quadrature amplitude modulation (FBMC-OQAM), which are now candidate for B5G mobile networks. For these challenging applications, the development of enhanced WL filtering based SAIC or Multiple Antenna Interference Cancellation (MAIC) receivers for R and QR signals may be of great interest. Such a receiver, corresponding to a three-input WL frequency shift (FRESH) receiver, has been introduced recently for QR signals. However this WL receiver is not robust to a data-like MUI having a residual frequency offset (FO), which occurs for most of the previous applications. In this context, the paper first extends, for arbitrary propagation channels, the standards (for R and QR MUI) and the enhanced (for QR MUI) SAIC/MAIC WL receivers to MUI with a non-zero FO. Then, it shows the less efficiency of the two-input WL receiver for QR MUI with a non-zero FO and the performance improvement obtained with the three-input WL receiver. Finally, it analyzes, both analytically and by simulations, for R and QR MUI, the impact of the MUI FO on the performance of the proposed receivers. The results of the paper should allow the development of new powerful WL receivers for UAV CNPC links, anti-collisions AIS systems and for FBMC-OQAM networks in particular. [ABSTRACT FROM AUTHOR]

Victoria Pure Blue BO is a dye that bears some therapeutic activity and that can be retrieved in effluent or may be used in aquaculture as a prohibited drug. In this study, the metabolism and tissue distribution during uptake and depuration of VPBO were investigated in order to propose a residue marker of illegal treatment in fish. The dye was administered to rainbow trout (oncorhynchus mykiss) for one day by water bath at a dose of 0.1 mg.L−1. The concentrations of VPBO in all tissues increased rapidly during the treatment period, reaching a C max of 567 ± 301 μg.L−1 in plasma and 1846 μg kg−1 ±517 for liver after 2 h. After placing the rainbow trout in a clean water bath for a 64 day-period of depuration, the concentrations in the tissues and plasma decreased to reach comparable levels for muscle and for skin after 33 days. The concentrations measured were still above the LOQ at 2.26 ± 0.48 μg kg−1 for muscle and 2.85 ± 1.99 μg kg−1 for skin at the end of the depuration period. The results indicated the existence of 14 phase I metabolites and one glucuronide conjugated metabolite. Non-compartmental analysis was applied to assess the pharmacokinetic parameters. The half-life in edible muscle of the main metabolite detected, deethyl-leuco-VPBO, was found to be 22.5 days compared to a half-life of 19.7 days for the parent VPBO. This study provides new information to predict a VPBO drug treatment of aquacultured species via a proposed new residue marker. Image 1 • The metabolism of Victoria Pure Blue BO (VPBO) was investigated in rainbow trout. • Residues were detected by LC-HRMS in muscle, plasma, skin, and liver. • The half-lives of VPBO and the main metabolite were assessed. • Deethyl-leuco-VPBO is proposed as a marker of exposure to VPBO in rainbow trout. [ABSTRACT FROM AUTHOR]

Introduction: The military operations carried out by the French armed forces, occasionally require the use of the Surgical Life-saving Module (SLM), to ensure the surgical support of its soldiers. Due to its extreme mobility and capacity of fast deployment, SLM is particularly useful in small-scale military operations, such as Special Forces missions. In 2017, the French SLM was for the first time used to ensure surgical support of allied forces, which were lacking forward surgical capabilities.Materials and Methods: the SLM is a mobile, heliborne, airborne, surgical structure with parachuting capability onto land or sea, therefore essentially focused on life-saving procedures, also known as "damage control" surgery. Due to the need for mobility and rapid implementation, the SLM is limited to a maximum of 5 interventions or, in terms of injuries, to 1 or 2 seriously injured patients.Results: Over a period of 2 months, 5 medical teams were successively deployed with the SLM. A total of 157 casualties were treated. The most common injuries were caused by shrapnel 561%), followed by firearms (36%), and blunt trauma (2.5%). Injuries included the limbs (56%), thorax (18%), abdomen (13%), head (11%), and neck (2%). The average ISS was 8.5 (1-25) with 26 patients presenting with an ISS greater than or equal to 15. The average NISS was 10.8 (1-75) with 34 casualties having an NISS equal to or greater than 15. The surgical procedures were broken down as follows: 126 dressings, 16 laparotomies, 7 thoracotomies, 12 isolated thoracic drains (without thoracotomy), 1 cervicotomy, 12 amputations, 7 limb splints, 2 limb fasciotomies, 2 external fixators and 1 femoral fracture traction.Conclusions: The numerous SLM deployments in larger operations highlighted its ability to adapt both in terms of equipment and personnel. Continuous management of equipment logistics, robust personnel training, and appropriate organization of the evacuation procedures, were the key elements for optimizing combat casualty care. As a consequence, the SLM appears to be an operational surgical unit of choice during deployments. [ABSTRACT FROM AUTHOR]

Introduction France deployed to Afghanistan from 2001 to 2014 within the International Security and Assistance Force. A French role 3 hospital was built in 2009 in the vicinity of Kabul International Airport (KaIA). The objectives of this study were to describe the epidemiology, management, and outcome of war-related craniocerebral injuries during the Afghan campaign in a French role 3 hospital. Methods From March 1, 2010 to September 30, 2012, we conducted a retrospective descriptive study in Kabul, Afghanistan. All patients presenting with a ballistic craniocerebral injury to the KaIA role 3 hospital were included. Results We analyzed 48 records. Mean age was 21.9 years (1–46 years) with a 37:11 (male:female) sex ratio and a majority Afghan population ( n = 41). Civilians represented 64.6% ( n = 31) of casualties. On the battlefield, mean Glasgow Coma Scale score was 9.4 [3–15]. On arrival at the KaIA field hospital, 20 of the 48 patients were hemodynamically unstable. All patients underwent a full-body computed tomography scan. The majority of our casualties had associated injuries. Neurosurgery was indicated for 42 (87.5%) patients. The surgery consisted of wound debridement plane by plane associated with decompressive craniectomy ( n = 11), debridement craniectomy ( n = 19), and craniotomy ( n = 12). A total of 32.4% wounded died at the point of injury, 8.4% at the emergency department, and 16.9% after surgery. Conclusions War casualties with ballistic head injuries were predominantly multitraumatized patients with hemodynamic compromise requiring neurosurgical damage control management and multidisciplinary care. The neurosurgeon has thus an essential role to play. [ABSTRACT FROM AUTHOR]

To describe clinical presentations of intracranial sinusitis complications in childhood, their pitfalls and imaging findings. This retrospective IRB-approved single-center study included infants diagnosed with sinusitis and empyema and/or other intracranial complications who underwent imaging between September 2008 and September 2019. Three radiologists individually reviewed clinical charts and imaging findings, including sinusitis complications and at-risk anatomical variations. 21 children (76% males and 24% females, mean age 13±3.1 years) with imaging pansinusitis were included. Headache (95%) and fever (90%) were the main clinical nonspecific signs. Ten (48%) children presented an extradural empyema, nine (43%) children had a subdural empyema and two (10%) children had both. Frontal location sinusitis was the most common (76%). In MRI, all empyema presented as a hypo intensity on pre-contrast T1-WI, a hyperintensity on T2-WI, a reduced apparent diffusion coefficient (ADC) on diffusion weighted imaging (DWI) and a peripheral contrast enhancement on post-contrast T1-WI. CT or MRI revealed intracranial complications such as a collection size increase (52%), a midline shift (62%), intraparenchymal abscesses (24%), a cerebral venous thrombosis (29%), an intracranial pressure increase (29%), cerebral ischemia (43%) and Pott's Puffy Tumor (10%). Imaging highlighted sinus anatomical abnormalities in 52% of cases. All children were treated with sinus drainage and/or neurosurgery. Long-term follow-up was favorable in 14 cases (67%). Complications of sinusitis are life threatening in the studied population. Empyema and cerebral complications may be misleading. Brain contrast-enhanced CT covering sinuses and orbits, is mainly the first examination done but MRI is mandatory. [ABSTRACT FROM AUTHOR]

Purpose: To compare early brain MRI using a composite imaging score and outcome at one year in asphyxiated newborns treated by hypothermia.Methods: This retrospective study included for two years consecutive asphyxiated term newborns treated by hypothermia for hypoxic-ischemic encephalopathy, and who had brain MRI before day 8. Therapeutic hypothermia was initiated within the first 6 h of life and continued for 72 h. Imaging protocol included T1 and T2 sequences, diffusion-weighted imaging (DWI), evaluated with a specific composite score, and spectroscopy. Clinical evaluation was performed at one year of age, outcome was classified as favorable/unfavorable. The primary endpoint was the correlation between our MRI score and outcome with the definition of a threshold. The secondary endpoints were to find the most relevant criteria within the score and to evaluate objective signal measurements to support subjective criteria.Results: Among the 33 included patients, 9 died during the first days of life, 20 had a favorable outcome, 4 an unfavorable one. MRI score was correlated to a poor clinical outcome (p < 0.001). Most of the criteria within the score and spectroscopy results were relevant (p < 0.05). Cerebral edema was objectively assessed by the signal intensity ratio of white matter compared to cerebrospinal fluid (CSF) on T2-weighted images (p < 0.001).Conclusion: MRI score was predictive of neurodevelopmental outcome at one year. The most relevant criteria within the score were DWI abnormalities in basal ganglia and thalami and loss of white-cortical grey matter differentiation. Signal intensity ratio between white matter and CSF higher than 0.75 supports the presence of edema. [ABSTRACT FROM AUTHOR]