Antiferromagnetic Alignment and Relaxation Rate of Gd Spins in the High Temperature Superconductor GdBa_2Cu_3O_(7-delta)

The complex surface impedance of a number of GdBa$_2$Cu$_3$O$_{7-\delta}$ single crystals has been measured at 10, 15 and 21 GHz using a cavity perturbation technique. At low temperatures a marked increase in the effective penetration depth and surface resistance is observed associated with the paramagnetic and antiferromagnetic alignment of the Gd spins. The effective penetration depth has a sharp change in slope at the N\'eel temperature, $T_N$, and the surface resistance peaks at a frequency dependent temperature below 3K. The observed temperature and frequency dependence can be described by a model which assumes a negligibly small interaction between the Gd spins and the electrons in the superconducting state, with a frequency dependent magnetic susceptibility and a Gd spin relaxation time $\tau_s$ being a strong function of temperature. Above $T_N$, $\tau_s$ has a component varying as $1 / (T - T_N)$, while below $T_N$ it increases $\sim T^{-5}$.Comment: 4 Pages, 4 Figures. Submitted to Phys. Rev.

Corrigendum to “Seasonal variations of Quercus pubescens isoprene emissions from an in natura forest under drought stress and sensitivity to futureclimate change in the Mediterranean area”

International audienc

Non-Locality and Strong Coupling in the Heavy Fermion Superconductor CeCoIn5_{5}: A Penetration Depth Study

We report measurements of the magnetic penetration depth $\lambda$ in single crystals of CeCoIn$_{5}$ down to $\sim$0.14 K using a tunnel-diode based, self-inductive technique at 28 MHz. While the in-plane penetration depth tends to follow a power law, $\lambda_{//} \sim {\it T}^{3/2}$, the data are better described as a crossover between linear ({\it T} $\gg$ ${\it T}^\ast$) and quadratic ({\it T} $\ll {\it T}^\ast$) behavior, with ${\it T}^\ast$ the crossover temperature in the strong-coupling limit. The {\it c}-axis penetration depth $\lambda_{\perp}$ is linear in {\it T}, providing evidence that CeCoIn$_{5}$ is a {\it d}-wave superconductor with line nodes along the {\it c}-axis. The different temperature dependences of $\lambda_{//}$ and $\lambda_{\perp}$ rule out impurity effects as the source of ${\it T}^{\ast}$.Comment: 4 pages, 3 figure

Global non-covalent SUMO interaction networks reveal SUMO-dependent stabilization of the non-homologous end joining complex

In contrast to our extensive knowledge on covalent small ubiquitin-like modifier (SUMO) target proteins, we are limited in our understanding of non-covalent SUMO-binding proteins. We identify interactors of different SUMO isoforms-monomeric SUMO1, monomeric SUMO2, or linear trimeric SUMO2 chains-using a mass spectrometry-based proteomics approach. We identify 379 proteins that bind to different SUMO isoforms, mainly in a preferential manner. Interestingly, XRCC4 is the only DNA repair protein in our screen with a preference for SUMO2 trimers over mono-SUMO2, as well as the only protein in our screen that belongs to the non-homologous end joining (NHEJ) DNA double-strand break repair pathway. A SUMO interaction motif (SIM) in XRCC4 regulates its recruitment to sites of DNA damage and phosphorylation of S320 by DNA-PKcs. Our data highlight the importance of non-covalent and covalent sumoylation for DNA double-strand break repair via the NHEJ pathway and provide a resource of SUMO isoform interactors.Cancer Signaling networks and Molecular Therapeutic

Transcriptome pathways unique to dehydration tolerant relatives of modern wheat

Among abiotic stressors, drought is a major factor responsible for dramatic yield loss in agriculture. In order to reveal differences in global expression profiles of drought tolerant and sensitive wild emmer wheat genotypes, a previously deployed shock-like dehydration process was utilized to compare transcriptomes at two time points in root and leaf tissues using the Affymetrix GeneChip(R) Wheat Genome Array hybridization. The comparison of transcriptomes reveal several unique genes or expression patterns such as differential usage of IP(3)-dependent signal transduction pathways, ethylene- and abscisic acid (ABA)-dependent signaling, and preferential or faster induction of ABA-dependent transcription factors by the tolerant genotype that distinguish contrasting genotypes indicative of distinctive stress response pathways. The data also show that wild emmer wheat is capable of engaging known drought stress responsive mechanisms. The global comparison of transcriptomes in the absence of and after dehydration underlined the gene networks especially in root tissues that may have been lost in the selection processes generating modern bread wheats

Volatile diterpene emission by two Mediterranean Cistaceae shrubs

Mediterranean vegetation emits a wide range of biogenic volatile organic compounds (BVOCs) among which isoprenoids present quantitatively the most important compound class. Here, we investigated the isoprenoid emission from two Mediterranean Cistaceae shrubs, Halimium halimifolium and Cistus ladanifer, under controlled and natural conditions, respectively. For the first time, diurnal emission patterns of the diterpene kaurene were detected in real-time by Proton-Transfer-Reaction-Timeof- Flight-Mass-Spectrometer. Kaurene emissions were strongly variable among H. halimifolium plants, ranging from 0.01 ± 0.003 to 0.06 ± 0.01 nmol m−2 s−1 in low and high emitting individuals, respectively. They were in the same order of magnitude as monoterpene (0.01 ± 0.01 to 0.11 ± 0.04 nmol m−2 s−1) and sesquiterpene (0.01 ± 0.01 to 0.52 nmol m−2 s−1) emission rates. Comparable range and variability was found for C. ladanifer under natural conditions. Labelling with 13C-pyruvate suggested that emitted kaurene was not derived from de novo biosynthesis. The high kaurene content in leaves, the weak relationship with ecophysiological parameters and the tendency of higher emissions with increasing temperatures in the field indicate an emission from storage pools. This study highlights significant emissions of kaurene from two Mediterranean shrub species, indicating that the release of diterpenes into the atmosphere should probably deserve more attention in the futureinfo:eu-repo/semantics/publishedVersio

Stabilization of a Subgrade Composed by Low Plasticity Clay with Rice Husk Ash

The construction of road works in the world has always been a challenge for engineering, especially in areas where the conditions and types of soil are not adequate for the execution of this type of projects. The present investigation has as main objective to determine the influence that has the rice husk ash (RHA) to stabilize the subgrade layer of a pavement, composed of a low resistance clayey soil. RHA is a waste and pollutant material for the environment; therefore that its use can be considered as an economic and ecological alternative. Thus, several tests were carried out where it proved the value of CBR increased from 4.30% to 20.70%, by adding a 20% RHA dosage, achieving its optimum value to be considered a very good subgrade. In this way, it is possible to affirm that the addition of RHA improves the geotechnical properties of the soil

Characterization of bacillus isolates of potato rhizosphere from Andean soils of Peru and their potential PGPR characteristics

A. Lopez-Lopez, M. A. Rogel-Hernandez, Monica Rosenblueth, and L. Raymundo are thanked for technical assistance. This research was supported by Consejo Nacional de Ciencia y Tecnologia (Concytec), Integrated Crop Management Division of International Potato Center (CIP), FDA biol-111/UNALM, DGAPA-PAPIIT IN200709 project, and Red Biofag-Cyted. We are grateful to Dr. Andreas Oswald (CIP) for his support in the collection of samples.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte