Characterization of barley (Hordeum vulgare L.) NAC transcription factors suggests conserved functions compared to both monocots and dicots

<p>Abstract</p> <p>Background</p> <p>The NAC transcription factor family is involved in the regulation of traits in both monocots and dicots of high agronomic importance. Understanding the precise functions of the NAC genes can be of utmost importance for the improvement of cereal crop plants through plant breeding. For the cereal crop plant barley (<it>Hordeum vulgare </it>L.) only a few <it>NAC </it>genes have so far been investigated.</p> <p>Results</p> <p>Through searches in publicly available barley sequence databases we have obtained a list of 48 barley <it>NAC </it>genes (<it>HvNACs</it>) with 43 of them representing full-length coding sequences. Phylogenetic comparisons to Brachypodium, rice, and Arabidopsis NAC proteins indicate that the barley NAC family includes members from all of the eight NAC subfamilies, although by comparison to these species a number of <it>HvNACs </it>still remains to be identified. Using qRT-PCR we investigated the expression profiles of 46 <it>HvNACs </it>across eight barley tissues (young flag leaf, senescing flag leaf, young ear, old ear, milk grain, late dough grain, roots, and developing stem) and two hormone treatments (abscisic acid and methyl jasmonate).</p> <p>Conclusions</p> <p>Comparisons of expression profiles of selected barley <it>NAC </it>genes with the published functions of closely related <it>NAC </it>genes from other plant species, including both monocots and dicots, suggest conserved functions in the areas of secondary cell wall biosynthesis, leaf senescence, root development, seed development, and hormone regulated stress responses.</p

Évaluation des volumes et de la fonction du ventricule gauche par IRM 5D entièrement autonome des mouvements cardiaque et repiratoire, aquis en respiration libre en comparaison aux acquisitions standard par IRM 2D lors d’apnées

Introduction : De nombreuses évolutions des acquisitions d’imagerie à résonance magnétique cardiaque se sont développées au cours des dernières années. Le but de cette étude est de tester l’hypothèse que l’acquisition de donnée 5D entièrement autonome des mouvements cardiaque et respiratoire, acquis en respiration libre permet une évaluation fiable des volumes et de la fraction d’éjection du ventricule gauche. Méthodologie : Trois versions d’une nouvelle technique d’acquisition de données d’IRM cardiaque 5D a été appliquée sur 9 volontaires et 5 patients à 1.5T. A partir des données obtenues les paramètres physiologiques ont été extraits et les images ont été reconstruites. Le protocole standard a aussi été appliqué sur le groupe de participants. La fonction du ventricule gauche a été évaluée et a permis de faire des comparaisons entre les techniques d'acquisition. Résultats : Les analyses ont démontré une bonne concordance des moyennes des volumes télédiastoliques du ventricule gauche avec 159.3 ± 64.7ml pour la technique 5D et 161.6 ± 51.6ml pour la technique standard. En revanche, les résultats des paramètres systoliques ne concordent pas entre les deux techniques. Nous observons une surestimation du volume télésystolique de manière significative 84.3 ± 35.4ml pour la technique standard contre 65.3 ± 24.5ml avec la technique 5D (p=0.0021). Ce qui découle à une sous estimation du volume d’éjection 75.5 ± 32.0ml contre 96.3 ± 28.4ml (p= 0.0006), ainsi qu’une sous estimation de la fraction d’éjection avec 47.3 ± 6.6% contre 60.0 ± 4.5% (p=0.0031). Conclusion : L'acquisition de données 5D entièrement autonome des mouvements cardiaque et respiratoire, acquis en respiration libre permet une quantification du volume télédiastolique mais pas du volume télésystolique, ni du volume d’éjection, ni de la fraction d’éjection

Pulse Wave Amplitude Drops during Sleep are Reliable Surrogate Markers of Changes in Cortical Activity.

BACKGROUND: During sleep, sudden drops in pulse wave amplitude (PWA) measured by pulse oximetry are commonly associated with simultaneous arousals and are thought to result from autonomic vasoconstriction. In the present study, we determine whether PWA drops were associated with changes in cortical activity as determined by EEG spectral analysis. METHODS: A 20% decrease in PWA was chosen as a minimum for a drop. A total of 1085 PWA drops from 10 consecutive sleep recordings were analyzed. EEG spectral analysis was performed over 5 consecutive epochs of 5 seconds: 2 before, 1 during, and 2 after the PWA drop. EEG spectral analysis was performed over delta, theta, alpha, sigma, and beta frequency bands. Within each frequency band, power density was compared across the five 5-sec epochs. Presence or absence of visually scored EEG arousals were adjudicated by an investigator blinded to the PWA signal and considered associated with PWA drop if concomitant. RESULTS: A significant increase in EEG power density in all EEG frequency bands was found during PWA drops (P < 0.001) compared to before and after drop. Even in the absence of visually scored arousals, PWA drops were associated with a significant increase in EEG power density (P < 0.001) in most frequency bands. CONCLUSIONS: Drops in PWA are associated with a significant increase in EEG power density, suggesting that these events can be used as a surrogate for changes in cortical activity during sleep. This approach may prove of value in scoring respiratory events on limited-channel (type III) portable monitors. CITATION: Delessert A; Espa F; Rossetti A; Lavigne G; Tafti M; Heinzer R. Pulse wave amplitude drops during sleep are reliable surrogate markers of changes in cortical activity. SLEEP 2010;33(12):1687-1692