Between-clone, between-leaf and within-leaf variation in leaf epidermis traits in Iris pumila clones

The goal of this study was to analyze variation and covariation in epidermal characteristics (epidermal cell density -ECD, stomata density - SD, and stomata index - SI) on Iris pumila clones on between-clone, between-leaf and within-leaf levels. ECD (similar to the pattern previously observed for SD) increased from the base to the top of leaf, while SI remained constant. Results of profile analyses indicated that clones, individual plants whitin clones (ramets), and three successive leaves on the same plant were not significantly different for examined characteristics, but genetic variation for position effect was detected (significant Zone x clone interaction). Results of the contrast analysis confirmed differences between the base and middle leaf positions for ECD (similar to those for SD) as well as between clone variation for those differences. Observed differences between leaf zones and correlations between analyzed traits were mostly consistent with the expansion hypothesis of stomata differentiation. [Projekat Ministarstva nauke Republike Srbije, br. OI 173025

Variable-range hopping in quasi-one-dimensional electron crystals

We study the effect of impurities on the ground state and the low-temperature dc transport in a 1D chain and quasi-1D systems of many parallel chains. We assume that strong interactions impose a short-range periodicicity of the electron positions. The long-range order of such an electron crystal (or equivalently, a $4 k_F$ charge-density wave) is destroyed by impurities. The 3D array of chains behaves differently at large and at small impurity concentrations $N$. At large $N$, impurities divide the chains into metallic rods. The low-temperature conductivity is due to the variable-range hopping of electrons between the rods. It obeys the Efros-Shklovskii (ES) law and increases exponentially as $N$ decreases. When $N$ is small, the metallic-rod picture of the ground state survives only in the form of rare clusters of atypically short rods. They are the source of low-energy charge excitations. In the bulk the charge excitations are gapped and the electron crystal is pinned collectively. A strongly anisotropic screening of the Coulomb potential produces an unconventional linear in energy Coulomb gap and a new law of the variable-range hopping $-\ln\sigma \sim (T_1 / T)^{2/5}$. $T_1$ remains constant over a finite range of impurity concentrations. At smaller $N$ the 2/5-law is replaced by the Mott law, where the conductivity gets suppressed as $N$ goes down. Thus, the overall dependence of $\sigma$ on $N$ is nonmonotonic. In 1D, the granular-rod picture and the ES apply at all $N$. The conductivity decreases exponentially with $N$. Our theory provides a qualitative explanation for the transport in organic charge-density wave compounds.Comment: 20 pages, 7 figures. (v1) The abstract is abridged to 24 lines. For the full abstract, see the manuscript (v2) several changes in presentation per referee's comments. No change in result

Comparison of Blue Light-Filtering IOLs and UV Light-Filtering IOLs for Cataract Surgery: A Meta-Analysis

Background: A number of published randomized controlled trials have been conducted to evaluate visual performance of blue light-filtering intraocular lenses (IOL) and UV light-filtering intraocular lenses (IOL) after cataract phacoemulsification surgery. However, results have not always been consistent. Therefore, we carried out a meta-analysis to compare the effectiveness of blue light-filtering IOLs versus UV light-filtering IOLs in cataract surgery. Methods and Findings: Comprehensive searches of PubMed, Embase, Cochrane Library and the Chinese BioMedical literature databases were performed using web-based search engines. Fifteen trials (1690 eyes) were included for systematic review, and 11 of 15 studies were included in this meta-analysis. The results showed that there were no significant differences in postoperative mean best corrected visual acuity, contrast sensitivity, overall color vision, or in the blue light spectrum under photopic light conditions between blue light-filtering IOLs and UV light-filtering IOLs [WMD = 20.01, 95%CI (20.03, 0.01), P = 0.46; WMD = 0.07, 95%CI (20.04, 0.19), P = 0.20; SMD = 0.14, 95%CI (20.33, 0.60), P = 0.566; SMD = 0.20, 95%CI (20.04, 0.43), P = 0.099]. However, color vision with blue light-filtering IOLs was significantly reduced in the blue light spectrum under mesopic light conditions [SMD = 0.74, 95%CI (0.29, 1.18), P = 0.001]. Conclusion: This meta-analysis demonstrates that postoperative visual performance with blue light-filtering IOLs is approximately equal to that of UV light-filtering IOLs after cataract surgery, but color vision with blue light-filtering IOL

Stellar Dynamics and Star Formation Histories of z ~ 1 Radio-loud Galaxies

Galaxie

Electron mechanism for the tilting transition in La2-x SrxCuO4

It is shown that the tilting deformation is couplet to the electrons through the tilting induced variation of the Umklapp matrix elements. The latter are important only for small concentrations of Sr if the electron-electron interaction, (which are assumed to be repulsive), are reasonably small. The leading term in the resulting deformation energy is quadratic in the tilting deformation and leads to the critical devease of the tilting mode frequency when the temperature is lowered. The resistivity, although enhanced by Umklapps, is continuous through the tilting transition. The model bears some ressemblence to that developed previously for 4k F deformations in organic superconductors. Some consequences of the model for the high Tc superconductivity are briefly discussed.Nous montrons que la déformation qui fait onduler les plans CuO2 est couplée aux électrons par l'intermédiaire de la variation des éléments de matrice Umklapp dans l'interaction électron-électron. Ces derniers ne sont importants que pour de faibles concentrations de Sr, si les interactions, supposées alors répulsives, sont suffisamments petites. Le premier terme dans la contribution à l'énergie de déformation est quadratique en déformation et diminue de façon critique la fréquence des modes d'ondulation lorque la température décroît. La résistivité, bien qu'augmentée par Umklapp, est continue à travers la transition à la phase ondulée. Notre modèle ressemble quelque peu à celui développé précédemment pour les supraconducteurs organiques. Nous discutons aussi brièvement les propriétés du modèle qui concernent la supraconductivité à Tc élevée

Antibacterial activity of modified natural clinoptilolite against clinical isolates of Acinetobacter baumannii

The antibacterial activity of natural zeolite (NZ) containing 2.03 wt.% of Cu2+ (CuNZ), 5.07 of Ag+ (AgNZ) or 8.50 of benzalkonium ion (BCNZ) were tested against clinical isolates of Acinetobacter baumannii belonging to European clone I and II. Isolate from clone II was more sensitive to CuNZ and AgNZ with minimum bactericidal concentration (MBC) 125 and 31.2 mg L-1, respectively than isolate from clone I with MBC of 250 mg L-1 for both CuNZ and AgNZ. Isolate from clone I was more sensitive to BCNZ with MBC 250 mg L-1 than isolate from clone II with MBC 500 mg L-1. The minimum inhibitory concentration (MIC) values were the same or slightly lower than the MBC values. The antibacterial activity of CuNZ, AgNZ and BCNZ against the A. baumannii European clone I and II was due to the activity of cations loaded onto NZ while not to the NZ used as support material. The antibacterial activity of CuNZ, AgNZ and BCNZ opens a possibility of future clinical investigations and its application

Antibacterial activity of copper-containing clinoptilolite/PVC composites toward clinical isolate of Acinetobacter baumannii

The multidrug-resistant bacteria Acinetobacter baumannii cause serious hospital infections. Commercial poly(vinyl chloride) (PVC) used for endotracheal tubes was modified in order to obtain a composite with an antibacterial effect towards a clinical isolate of A. baumannii ST145. The composites were prepared by addition of different amounts of copper-containing zeolite tuff (CuZ) and by successive impregnation with D-tyrosine (D-Tyr) solution. The composites that were obtained by addition of CuZ (CuZ PVC) only did not exhibit an antibacterial effect. The impregnation of the CuZ PVC by D-Tyr resulted in an antibacterial effect which was explained by a synergistic effect of CuZ and D-Tyr. Rheological tests confirmed that the modification of PVC by CuZ does not affect its processability and reformability