Two-dimensional plasmons in the random impedance network model of disordered thin-film nanocomposites

Random impedance networks are widely used as a model to describe plasmon resonances in disordered metal-dielectric nanocomposites. In order to study thin films, two-dimensional networks are often used despite the fact that such networks correspond to a two-dimensional electrodynamics [J.P. Clerc et al, J. Phys. A 29, 4781 (1996)]. In the present work, we propose a model of two-dimensional systems with three-dimensional Coulomb interaction and show that this model is equivalent to a planar network with long-range capacitive connections between sites. In a case of a metal film, we get a known dispersion $\omega \propto \sqrt{k}$ of plane-wave two-dimensional plasmons. In the framework of the proposed model, we study the evolution of resonances with decreasing of metal filling factor. In the subcritical region with metal filling $p$ lower than the percolation threshold $p_c$, we observe a gap with Lifshitz tails in the spectral density of states (DOS). In the supercritical region $p>p_c$, the DOS demonstrates a crossover between plane-wave two-dimensional plasmons and resonances associated with small clusters.Comment: 8 pages, 3 figures, revtex; references adde

Chestnut and poplar RAV genes in tree seasonal dormancy

Plants from temperate regions adapt to changing environmental conditions along the year. Trees have evolved mechanisms that allow them to monitor and anticipate the seasons, and cycle between growth and winter dormancy states. Dormancy is initiated by shortening of photoperiod, and afterwards, as a result of a drop in temperature, trees reach a state of endodormancy, the inability of resume growth in response to inductive conditions. Chilling requirement needs to be fulfilled in order to release from endodormancy and gain the ability to resume growth in response to good conditions. The signalling networks that regulate dormancy in perennials are poorly understood. We had previously shown that CsRAV1, a chestnut homolog of Arabidopsis TEM1 and TEM2, induced sylleptic branching in poplar [1]. In this work we characterize the role of chestnut and poplar RAV genes in dormancy. The expression profile of CsRAV1, PtaRAV1 and PtaRAV2 along the year showed that all three genes were induced during winter and maintained high expression levels until early spring. These data suggested that CsRAV1, PatRAV1 and PtaRAV2 were involved in the regulation of winter dormancy in trees. To test this hypothesis we have used over-expressing CsRAV1, and knock-down PtaRAV1 and PtaRAV2 transgenic poplars. The phenology of the transgenic lines will be discussed. It has been reported that Arabidopsis TEM1 binds to the FT promoter. An in silico screening of TEM1 DNA recognition sites in the promoter region of the Populus trichocarpa homologous FT genes revealed that the RAV1 motif was not conserved. Moreover, the over-expression of CsRAV1 in Arabidopsis did not phenocopy the over-expression of AtTEM1 and AtTEM2, suggesting a functional divergence of RAV family members. To gain insight on the molecular function of tree RAV genes, we performed a transcriptomic analysis with RNA from the poplar transgenic lines, and protein-binding microarrays to identify the cis-acting elements for CsRAV1, PtaRAV1 and PtaRAV2. The identification of the binding elements and their occurrence in the genes differentially expressed will be presented. In conclusion, our study reveals a possible function of RAV transcriptional regulators in the control of winter dormancy in trees

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Temperature-depnedent disruption of circadian oscillations in woody plants-A mathematical approach

Poste

Molecular Evolution of Slow and Quick Anion Channels (SLACs and QUACs/ALMTs)

Electrophysiological analyses conducted about 25 years ago detected two types of anion channels in the plasma membrane of guard cells. One type of channel responds slowly to changes in membrane voltage while the other responds quickly. Consequently, they were named SLAC, for SLow Anion Channel, and QUAC, for QUick Anion Channel. Recently, genes SLAC1 and QUAC1/ALMT12, underlying the two different anion current components, could be identified in the model plant Arabidopsis thaliana. Expression of the gene products in Xenopus oocytes confirmed the quick and slow current kinetics. In this study we provide an overview on our current knowledge on slow and quick anion channels in plants and analyze the molecular evolution of ALMT/QUAC-like and SLAC-like channels. We discovered fingerprints that allow screening databases for these channel types and were able to identify 192 (177 non-redundant) SLAC-like and 422 (402 non-redundant) ALMT/QUAC-like proteins in the fully sequenced genomes of 32 plant species. Phylogenetic analyses provided new insights into the molecular evolution of these channel types. We also combined sequence alignment and clustering with predictions of protein features, leading to the identification of known conserved phosphorylation sites in SLAC1-like channels along with potential sites that have not been yet experimentally confirmed. Using a similar strategy to analyze the hydropathicity of ALMT/QUAC-like channels, we propose a modified topology with additional transmembrane regions that integrates structure and function of these membrane proteins. Our results suggest that cross-referencing phylogenetic analyses with position-specific protein properties and functional data could be a very powerful tool for genome research approaches in general

Signalling games and the role of precommitment

SIGLETIB Hannover: RO 2708(190) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Temporal evolution of GFP in 500 cells.

<p><b>(A)</b> Oscillations after 2 days. <b>(B)</b> Oscillations after 30 days.</p

Model prediction for typical temporal oscillations of GFP in different cells.

<p>Various colours denote various cells. Black solid line represents arithmetic mean of the modelled 200 cells. Black dashed line represents weighted arithmetic mean.</p

Examples of clusters of <i>E</i>. <i>coli</i> cells showing oscillatory behaviour.

<p>The <i>gfp</i> expression in clusters of cells transformed with both the repressilator and the communication plasmid was followed in a time-lapse microscope for 1080 min (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0180155#pone.0180155.s003" target="_blank">S3 Video</a>). Snapshots of five growing clusters of cells were taken periodically both in fluorescence (A) and bright-field (B). Each coloured line represents a different cluster of cells (C). Pictures in (A) and (B) correspond to the representative cluster of cells plotted as a green line in (C). Images were acquired every 20 min and the fluorescence intensity of each cluster of cells was determined using the ImageJ software.</p

Cellular synchronization.

<p>Standard deviation of GFP proteins per cell indicates how the system evolves to a synchronized state. SD is calculated for all cells in a 5 h interval basis.</p