Probing eigenfunction nonorthogonality by parametric shifts of resonance widths

Recently, it has been shown that the change of resonance widths in an open system under a perturbation of its interior is a sensitive indicator of the nonorthogonality of resonance states. We apply this measure to quantify parametric motion of the resonances. In particular, a strong redistribution of the widths is linked with the maximal degree of nonorthogonality. Then for weakly open chaotic systems we discuss the effect of spectral rigidity on the statistical properties of the parametric width shifts, and derive the distribution of the latter in a picket-fence model with equidistant spectrum

Similar glassy features in the NMR response of pure and disordered La1.88Sr0.12CuO4

High Tc superconductivity in La2-xSrxCuO4 coexists with (striped and glassy) magnetic order. Here, we report NMR measurements of the 139La spin-lattice relaxation, which displays a stretched-exponential time dependence, in both pure and disordered x=0.12 single crystals. An analysis in terms of a distribution of relaxation rates T1^-1 indicates that i) the spin-freezing temperature is spatially inhomogeneous with an onset at Tg(onset)=20 K for the pristine samples, and ii) the width of the T1^-1 distribution in the vicinity of Tg(onset) is insensitive to an ~1% level of atomic disorder in CuO2 planes. This suggests that the stretched-exponential 139La relaxation, considered as a manifestation of the systems glassiness, may not arise from quenched disorder.Comment: 7 pages, to be published in Phys. Rev.

Preempted phonon-mediated superconductivity in the infinite-layer nickelates

Nickelate superconductors are outstanding materials with intriguing analogies with the cuprates. These analogies suggest that their superconducting mechanism is similarly unconventional, although this fundamental question is currently under debate. Here, we scrutinize the role played by electronic correlations in enhancing the electron-phonon coupling in the infinite-layer nickelates and the extent to which this may promote superconductivity. Specifically, we use $ab$ $initio$ many-body perturbation theory to perform state-of-the-art $GW$ and Eliashberg-theory calculations. We find that the electron-phonon coupling is in effect enhanced compared to density-functional-theory calculations. This enhancement may lead to low-$T_c$ superconductivity in the parent compounds already. However, it remains marginal in the sense that it cannot explain the record $T_c$s obtained with doping. Conventional superconductivity then appears to be preempted by another mechanism in the infinite-layer nickelates.Comment: 6 pages, 4 figures, 1 table + Supplementary Informatio

Large enhancement of the thermopower in Nax_xCoO2_2 at high Na doping

Research on the oxide perovskites has uncovered electronic properties that are strikingly enhanced compared with those in conventional metals. Examples are the high critical temperatures of the cuprate superconductors and the colossal magnetoresistance in the manganites. The conducting layered cobaltate $\rm Na_xCoO_2$ displays several interesting electronic phases as $x$ is varied including water-induced superconductivity and an insulating state that is destroyed by field. Initial measurements showed that, in the as-grown composition, $\rm Na_xCoO_2$ displays moderately large thermopower $S$ and conductivity $\sigma$. However, the prospects for thermoelectric cooling applications faded when the figure of merit $Z$ was found to be small at this composition (0.6$<x<$0.7). Here we report that, in the poorly-explored high-doping region $x>$0.75, $S$ undergoes an even steeper enhancement. At the critical doping $x_p\sim$ 0.85, $Z$ (at 80 K) reaches values $\sim$40 times larger than in the as-grown crystals. We discuss prospects for low-temperature thermoelectric applications.Comment: 6 pages, 7 figure

Realtime Cardiac Arrhythmias Monitoring for Pervasive Healthcare

International audienc

A Real-Time Continuous Cardiac Arrhythmias Detection System: RECAD

International audienc

Haplodiploidization of maize (Zea mays L) through induced gynogenesis assisted by glossy markers and its use in breeding

Reliable detection of haploids at the seedling stage is a prerequisite for the use of haplodiploidization through in situ gynogenesis in maize breeding. The use of recessive alleles of glossy genes as markers makes this detection possible in various materials. Two synthetics with a wide genetic basis: flint glossy1 CGT and dent glossy6 DGT were studied. After pollination with the FIGH 1 inducer, they produced haploid seedlings at a rate of 0.64 and 0.93%, respectively. The rate is increased (0.94% on average) for the CGT (C 0) synthetic after selfing, in S1 progenies. The distribution of 203 S1 families showed a significant deviation in comparison with a Poisson distribution. The DGT synthetic showed an increase in induction rate when a new synthetic was formed with doubled haploid (DH) lines, suggesting that 'inductibility' may have some genetic effects. No spontaneous doubling was shown by the haploid seedlings of either synthetic. Colchicine treatment allowed a recovery of male fertility in 30 to 60% of detected haploids according to the experiments. The progeny recovery rate was influenced by the genetic basis, as the DGT synthetic gave better results than the CGT synthetic. The growing period also had an influence upon the recovery of fertile ears. Hybrids produced from heterotic DH lines showed an agronomic potential similar to standard hybrids. It is concluded that in situ gynogenesis assisted by the use of glossy markers can now be used in maize breeding.Haplodiploïdisation du maïs (Zea mays L) par gynogenèse induite assistée par marqueurs glossy et son application en sélection. L'utilisation effective de l'haplodiploïdisation par gynogenèse in situ en sélection du maïs nécessite une détection fiable des haploïdes au stade plantule. Le marquage génotypique par des allèles récessifs des gènes glossy permet cette détection. Deux «synthétiques» à base large: CGT (cornée glossyl tardive), DGT (dentée glossy6 tardive), ont été étudiées. Pollinisées par l'inducteur FIGH 1, elles ont produit des plantes haploïdes à des taux respectifs de : 0,64 et 0,93 %. Pour la synthétique CGT (C0), ce taux est augmenté (0,94 % en moyenne) lorsque l'on passe de la première génération aux descendances S1. L'analyse de la distribution de l'induction de 203 S1 de CGT montre une déviation significative par rapport à une distribution de Poisson. Dans la population DGT, le taux d'induction de plantes haploïdes s'est accru par la constitution d'une «synthétique» à partir de lignées haploïdes doublées (HD). Cela suggère des effets génétiques pour «l'inductibilité». Les plantules haploïdes provenant de CGT et DGT n'ont pas présenté de diploïdisation spontanée. Le traitement à la colchicine permet la restauration de la fertilité mâle dans 30 à 60 % des cas selon les essais. Le taux de descendances diploïdes fertiles obtenues par rapport au nombre d'haploïdes traités varie en fonction du matériel génétique (DGT est supérieure à CGT) et des périodes de culture des plantes traitées colchicine. Des hybrides réalisés à partir de lignées HD complémentaires possèdent un potentiel agronomique intéressant, parfois proche des témoins. La gynogenèse in situ assistée par marqueurs glossy est envisageable en sélection

Haplodiploidization of maize (Zea mays L) through induced gynogenesis assisted by glossy markers and its use in breeding

Reliable detection of haploids at the seedling stage is a prerequisite for the use of haplodiploidization through in situ gynogenesis in maize breeding. The use of recessive alleles of glossy genes as markers makes this detection possible in various materials. Two synthetics with a wide genetic basis: flint glossy1 CGT and dent glossy6 DGT were studied. After pollination with the FIGH 1 inducer, they produced haploid seedlings at a rate of 0.64 and 0.93%, respectively. The rate is increased (0.94% on average) for the CGT (C 0) synthetic after selfing, in S1 progenies. The distribution of 203 S1 families showed a significant deviation in comparison with a Poisson distribution. The DGT synthetic showed an increase in induction rate when a new synthetic was formed with doubled haploid (DH) lines, suggesting that 'inductibility' may have some genetic effects. No spontaneous doubling was shown by the haploid seedlings of either synthetic. Colchicine treatment allowed a recovery of male fertility in 30 to 60% of detected haploids according to the experiments. The progeny recovery rate was influenced by the genetic basis, as the DGT synthetic gave better results than the CGT synthetic. The growing period also had an influence upon the recovery of fertile ears. Hybrids produced from heterotic DH lines showed an agronomic potential similar to standard hybrids. It is concluded that in situ gynogenesis assisted by the use of glossy markers can now be used in maize breeding.Haplodiploïdisation du maïs (Zea mays L) par gynogenèse induite assistée par marqueurs glossy et son application en sélection. L'utilisation effective de l'haplodiploïdisation par gynogenèse in situ en sélection du maïs nécessite une détection fiable des haploïdes au stade plantule. Le marquage génotypique par des allèles récessifs des gènes glossy permet cette détection. Deux «synthétiques» à base large: CGT (cornée glossyl tardive), DGT (dentée glossy6 tardive), ont été étudiées. Pollinisées par l'inducteur FIGH 1, elles ont produit des plantes haploïdes à des taux respectifs de : 0,64 et 0,93 %. Pour la synthétique CGT (C0), ce taux est augmenté (0,94 % en moyenne) lorsque l'on passe de la première génération aux descendances S1. L'analyse de la distribution de l'induction de 203 S1 de CGT montre une déviation significative par rapport à une distribution de Poisson. Dans la population DGT, le taux d'induction de plantes haploïdes s'est accru par la constitution d'une «synthétique» à partir de lignées haploïdes doublées (HD). Cela suggère des effets génétiques pour «l'inductibilité». Les plantules haploïdes provenant de CGT et DGT n'ont pas présenté de diploïdisation spontanée. Le traitement à la colchicine permet la restauration de la fertilité mâle dans 30 à 60 % des cas selon les essais. Le taux de descendances diploïdes fertiles obtenues par rapport au nombre d'haploïdes traités varie en fonction du matériel génétique (DGT est supérieure à CGT) et des périodes de culture des plantes traitées colchicine. Des hybrides réalisés à partir de lignées HD complémentaires possèdent un potentiel agronomique intéressant, parfois proche des témoins. La gynogenèse in situ assistée par marqueurs glossy est envisageable en sélection

Wireless sensor networks dedicated to remote continuous real-time cardiac arrhythmias detection and diagnosis

International audienc