Identifying the genetic control of salinity tolerance in the bread wheat landrace Mocho de Espiga Branca.

Salinity tolerance in bread wheat is frequently reported to be associated with low leaf sodium (Na+) concentrations. However, the Portuguese landrace, Mocho de Espiga Branca, accumulates significantly higher leaf Na+ but has comparable salinity tolerance to commercial bread wheat cultivars. To determine the genetic loci associated with the salinity tolerance of this landrace, an F2 mapping population was developed by crossing Mocho de Espiga Branca with the Australian cultivar Gladius. The population was phenotyped for 19 salinity tolerance subtraits using both non-destructive and destructive techniques. Genotyping was performed using genotyping-by-sequencing (GBS). Genomic regions associated with salinity tolerance were detected on chromosomes 1A, 1D, 4B and 5A for the subtraits of relative and absolute growth rate (RGR, AGR respectively), and on chromosome 2A, 2B, 4D and 5D for Na+, potassium (K+) and chloride (Cl-) accumulation. Candidate genes that encode proteins associated with salinity tolerance were identified within the loci including Na+/H+ antiporters, K+ channels, H+-ATPase, calcineurin B-like proteins (CBLs), CBL-interacting protein kinases (CIPKs), calcium dependent protein kinases (CDPKs) and calcium-transporting ATPase. This study provides a new insight into the genetic control of salinity tolerance in a Na+ accumulating bread wheat to assist with the future development of salt tolerant cultivars.

Social mobilization and political change in countries governed by the left: The cases of Argentina and Brazil.

This paper analyses the socio-political dynamics after the financial crash in two countries governed by the left, Argentina and Brazil. Whilst the economic crisis had an effect on the general distributive capacity of leftwing coalitions, it remains unclear why the political resolution of such a crisis adopted anti-regime features in Brazil and the form of an institutional alternation of power in Argentina. Our aim is to understand the new socio-political dynamics and their implications in the crisis of the left turn, especially the relationship between social mobilization and political change in the context of Argentina and Brazil. In doing so, the paper contributes to the growing body of literature interested in the intersections between social movements and the state. Based on the analysis of original qualitative and quantitative data on social protests events in both countries 2011-2015, the paper suggests that the complexity of changes in the socio-political dynamics can be captured by looking at three dimensions of the problem: grammar of mobilization, social imaginaries, and political representation. The main argument is that the different types of left turn strategy developed in both countries affected in turn the responses to the economic crisis and the new cycle of mobilization. The kirchnerist's movimentista strategy in Argentina contrasted with the demobilizing strategy of the PT in Brazil. Whilst the former contributed to channel the high and polarized levels of activism within the polity, the latter resulted in the crisis of the long cycle of political representation opened with the transition to democracy.

Safety of two different doses of simvastatin plus rifaximin in decompensated cirrhosis (LIVERHOPE-SAFETY): a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Statins have beneficial effects on intrahepatic circulation and decrease portal hypertension and rifaximin modulates the gut microbiome and might prevent bacterial translocation in patients with cirrhosis. Therefore, this drug combination might be of therapeutic benefit in patients with decompensated cirrhosis. However, there is concern regarding the safety of statins in patients with decompensated cirrhosis. We assessed the safety of two different doses of simvastatin, in combination with rifaximin, in patients with decompensated cirrhosis. METHODS: We did a double-blind, randomised, placebo-controlled, phase 2 trial in patients with decompensated cirrhosis and moderate-to-severe liver failure from nine university hospitals in six European countries (Italy, France, Holland, Germany, the UK, and Spain). Patients older than 18 years with Child-Pugh class B or C disease were eligible. We randomly assigned patients (1:1:1) to receive either simvastatin 40 mg/day plus rifaximin 1200 mg/day, simvastatin 20 mg/day plus rifaximin 1200 mg/day, or placebo of both medications for 12 weeks. Randomisation was stratified according to Child-Pugh class (B vs C) and restricted using blocks of multiples of three. The primary endpoint was development of liver or muscle toxicity, as defined by changes in liver aminotransferases (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), alkaline phosphastase, and creatine kinase. The study is registered with the European Union Clinical Trials Register, 2016-004499-23, and with ClinicalTrials.gov, NCT03150459. FINDINGS: The study recruitment period was between July 28, 2017, and Jan 2, 2018. Follow-up finished on March 12, 2018. 50 patients were randomly assigned to simvastatin 40 mg/day plus rifaximin 1200 mg/day (n=18), simvastatin 20 mg/day plus rifaximin 1200 mg/day (n=16), or placebo of both medications (n=16). Six patients (two from each group) were excluded. Therefore, the full analysis set included 44 patients (16 in the simvastatin 40 mg/day plus rifaximin 1200 mg/day group, 14 in the simvastatin 20 mg/day plus rifaximin mg/day group, and 14 in the placebo group). After a safety analyses when the first ten patients completed treatment, treatment was stopped prematurely in the simvastatin 40 mg/day plus rifaximin group due to recommendations by the data safety monitoring board. Patients in the simvastatin 40 mg/day plus rifaximin group showed a significant increase in AST and ALT compared with the placebo group (mean differences between the groups at the end of treatment for AST 130 IU/L [95% CI 54 to 205; p=0·0009] and for ALT 61 IU/L [22 to 100; p=0·0025]. We observed no significant differences at 12 weeks in AST and ALT between the simvastatin 20 mg/day plus rifaximin and placebo group (for AST -14 IU/L [-91 to 64; p=0·728] and for ALT -8 IU/L [-49 to 33; p=0·698]). We observed no significant differences in alkaline phosphatase between the the simvastatin 40 mg/day plus rifaximin or the simvastatin 20 mg/day plus rifaximin groups compared with placebo. Patients in the simvastatin 40 mg/day plus rifaximin group showed an increase in creatine kinase at the end of treatment compared with patients in the placebo group (1009 IU/L [208 to 1809]; p=0·014). We observed no significant changes in creatine kinase in the simvastatin 20 mg/day plus rifaximin group (4·2 IU/L [-804 to 813]; p=0·992). Three (19%) patients in the simvastatin 40 mg/day group developed liver and muscle toxicity consistent with rhabdomyolysis. The number of patients who stopped treatment because of adverse events was significantly higher in the simvastatin 40 mg/day plus rifaximin group (nine [56%] of 16 patients) compared with the other two groups (two [14%] of 14 for both groups; p=0·017). There were no serious unexpected adverse reactions reported during the study. INTERPRETATION: Treatment with simvastatin 40 mg/day plus rifaximin in patients with decompensated cirrhosis was associated with a significant increase in adverse events requiring treatment withdrawal, particularly rhabdomyolysis, compared with simvastatin 20 mg/day plus rifaximin. We recommend simvastatin 20 mg/day as the dose to be used in studies investigating the role of statins in patients with decompensated cirrhosis. FUNDING: Horizon 20/20 European programme.

Differential expression of microRNAs and potential targets under drought stress in barley.

Drought is a crucial environmental constraint limiting crop production in many parts of the world. microRNA (miRNA) based gene regulation has been shown to act in several pathways, including crop response to drought stress. Sequence based profiling and computational analysis have revealed hundreds of miRNAs and their potential targets in different plant species under various stress conditions, but few have been biologically verified. In this study, 11 candidate miRNAs were tested for their expression profiles in barley. Differences in accumulation of only four miRNAs (Ath-miR169b, Osa-miR1432, Hv-miRx5 and Hv-miR166b/c) were observed between drought-treated and well-watered barley in four genotypes. miRNA targets were predicted using degradome analysis of two, different genotypes, and genotype-specific target cleavage was observed. Inverse correlation of mature miRNA accumulation with miRNA target transcripts was also genotype dependent under drought treatment. Drought-responsive miRNAs accumulated predominantly in mesophyll tissues. Our results demonstrate genotype-specific miRNA regulation under drought stress and evidence for their role in mediating expression of target genes for abiotic stress response in barley.

Strigolactone promotes degradation of DWARF14, an α/ß hydrolase essential for strigolactone signaling in Arabidopsis.

Strigolactones (SLs) are phytohormones that play a central role in regulating shoot branching. SL perception and signaling involves the F-box protein MAX2 and the hydrolase DWARF14 (D14), proposed to act as an SL receptor. We used strong loss-of-function alleles of the Arabidopsis thaliana D14 gene to characterize D14 function from early axillary bud development through to lateral shoot outgrowth and demonstrated a role of this gene in the control of flowering time. Our data show that D14 distribution in vivo overlaps with that reported for MAX2 at both the tissue and subcellular levels, allowing physical interactions between these proteins. Our grafting studies indicate that neither D14 mRNA nor the protein move over a long range upwards in the plant. Like MAX2, D14 is required locally in the aerial part of the plant to suppress shoot branching. We also identified a mechanism of SL-induced, MAX2-dependent proteasome-mediated degradation of D14. This negative feedback loop would cause a substantial drop in SL perception, which would effectively limit SL signaling duration and intensity.

Large terminase conformational change induced by connector binding in bacteriophage T7.

During bacteriophage morphogenesis DNA is translocated into a preformed prohead by the complex formed by the portal protein, or connector, plus the terminase, which are located at an especial prohead vertex. The terminase is a powerful motor that converts ATP hydrolysis into mechanical movement of the DNA. Here, we have determined the structure of the T7 large terminase by electron microscopy. The five terminase subunits assemble in a toroid that encloses a channel wide enough to accommodate dsDNA. The structure of the complete connector-terminase complex is also reported, revealing the coupling between the terminase and the connector forming a continuous channel. The structure of the terminase assembled into the complex showed a different conformation when compared with the isolated terminase pentamer. To understand in molecular terms the terminase morphological change, we generated the terminase atomic model based on the crystallographic structure of its phage T4 counterpart. The docking of the threaded model in both terminase conformations showed that the transition between the two states can be achieved by rigid body subunit rotation in the pentameric assembly. The existence of two terminase conformations and its possible relation to the sequential DNA translocation may shed light into the molecular bases of the packaging mechanism of bacteriophage T7.

Hydration of barium monohydroxide in (H2O)(1-3) clusters: theory and experiment.

The ionization energies (IEe's) of small BaOH(H2O)m clusters (m = 1-3), as generated in a laser vaporization-supersonic expansion source have been determined by laser photoionization experiments over the 3.65-4.55 eV energy range. Complementary ab initio studies show that the IEe's are in good agreement with computed adiabatic ionization energies and that BaOH(H2O)m structures with a direct coordination of the Ba atom to water molecules are favored over those that are characterized by H-bonded networks involving H2O molecules and the OH group of BaOH. Additional calculations have been performed on the hydration energies for the most stable isomers of the relevant BaOH(H2O)1-3 clusters. A comparison is made between the closed-shell title system and the results of related theoretical studies on the open-shell alkali monohydroxides, which allows for an interpretation of the opposite trends that are found in the cluster size dependence of the vertical ionization energies for both series of systems, and highlights the role of the BaOH unpaired electron in its ionization process. Altogether, the present evidence suggests for the initial steps of the BaOH hydration process to be dominated by electrostatic and polarization interactions between the Ba(+) and OH(-) ion cores, which become both increasingly solvated upon sequential addition of water molecules.

The role of orbiting resonances in the vibrational relaxation of I(2)(B,v' = 21) by collisions with He at very low energies: a theoretical and experimental study.

The low-energy collisions of I(2)(B,v' = 21) with He involving collision-induced vibrational relaxation of I(2) are investigated both experimentally and by means of wave packet simulations. The theoretical cross sections exhibit a structure of peaks originated by orbiting resonances of the I(2)(B,v' = 21) - He van der Waals complex formed in the I(2) + He collisions. Such a structure has similar characteristics as the structure of peaks found in the experimental cross sections. In fact, four of the five peaks of the measured cross sections appear at positions nearly coincident with those of four of the peaks found in the theoretical cross sections. Thus this result confirms the experimental finding that enhancement of I(2) vibrational relaxation is caused by the population of I(2)(B,v' = 21) - He orbiting resonances populated upon the low-energy collisions. The possibility of using this mechanism in the vibrational cooling of diatomic molecules is discussed.

New determination of the adiabatic ionization potential of the BaOH radical from laser photoionization-molecular beam experiments and ab initio calculations.

The adiabatic ionization potential of the BaOH radical, as generated in a laser vaporization-supersonic expansion source has been determined by laser photoionization experiments to be (4.55 ± 0.03) eV. This value supports the three lowest out of seven previous experimental estimates, the former ranging from 4.35 to 4.62 eV. The present result is compared to ab initio calculations, as performed using both quantum chemistry at different levels of theory and density functional theory, and trying several effective core potentials and their accompanying basis sets for Ba. The most satisfactory agreement is obtained for either the adiabatic or vertical ionization potentials that derive from post-Hartree-Fock [MP2 and CCSD(T)] treatments of electron correlation, along with consideration of relativistic effects and extensive basis sets for Ba, in both BaOH and BaOH(+). Such conclusions extend to the results of related calculations on the Ba-OH dissociation energies of BaOH and BaOH(+), which were performed to help in calibrating the present computational study. Bonding in BaOH/BaOH(+), as well as possible sources of discrepancy with previous experimental determinations of the BaOH adiabatic ionization potential are discussed.

Photoionization and ab initio study of Ba(H2O)n (n = 1-4) clusters.

An experimental and theoretical study of the photoionization energies (IE's) of Ba(H(2)O)(n) clusters containing up to n = 4 water molecules has been performed. The clusters were generated by a pick-up source combining laser vaporization with pulsed supersonic expansion, and then photoionized by radiation of 272.5-340 nm. The experimentally determined IE(e)'s for n = 1 to 4 are 4.56 ± 0.05, 4.26 ± 0.05, 3.90 ± 0.05 and 3.71 ± 0.05 eV. This cluster size dependence of IE is reproduced within ±0.06 eV employing the mPW1PW91 density-functional and CCSD(T, Full) quantum-chemical methods combined with the 6-311++G(d,p) basis set for the H and O atoms and three different relativistic effective core potentials for Ba atoms. The calculations indicate that the lowest energy hydration structures represent the most relevant contributions to both the vertical and adiabatic ionization energies. Experimental and theoretical evidence correlates with the progressive surface-delocalization of the electron from the hydration cavity around the Ba atom and suggests that the intra-cluster electron transfer is possible even for small aggregates.

H-bonded network rearrangements in the S0, S1 and D0 states of neutral and cationic p-cresol(H2O)(NH3) complexes.

The H-bonded network rearrangements in the S(0), S(1) and D(0) states of the neutral and cationic p-CreOH(H(2)O)(NH(3)) complexes were studied experimentally by means of (1 + 1)/(1 + 1') REMPI (Resonantly Enhanced MultiPhoton Ionization) and time resolved LIF (Laser Induced Fluorescence) spectroscopies combined with DFT (Density Functional Theory) calculations at the B3LYP/6-311G++(d,p) level. A comparison of the rearrangement process of the H-bonded network in the three states is given. Two cyclic H-bonded isomers were found on the S(0) potential energy surface and the results indicate that the rearrangement in this state is unlikely at the temperature of the supersonic expansion due to the presence of a high-energy barrier (7503 cm(-1)). On the other hand, the re-determination of the S(1) excited state lifetimes confirms that neither the H-bonded rearrangement nor the excited state hydrogen transfer (ESHT) reaction takes place in the S(1) state at the excitation energies of this work. Thus, it is concluded that the absorption of the second photon to reach the D(0) state takes place from the S(1) state of the cyclic-(OH-OH(2)-NH(3)) isomer. A preferential evaporation of H(2)O upon vertical ionization of the cyclic-(OH-OH(2)-NH(3)) isomer is observed which is consistent with a statistical redistribution of the internal energy. Nevertheless, our theoretical calculations suggest that initial excitation of the H-bonded network rearrangement modes may also play a role to leave the H(2)O molecule as a terminal moiety in a chain-(OH-NH(3)-OH(2))(+) isomer. The reaction pathway for the solvent rearrangement involves a double proton transfer process with a very low energy barrier (575 cm(-1)) that is overcome at the vertical ionization energy of the complex.

Unexpected size distribution of Ba(H2O)n clusters: why is the intensity of the Ba(H2O)1 cluster anomalously low?

An experimental and theoretical study on the reactivity of neutral Ba atoms with water clusters has been conducted to unravel the origin of the irregular intensity pattern observed in one-photon ionization mass spectra of a Ba(H(2)O)(n)/BaOH(H(2)O)(n-1) (n = 1-4) cluster distribution, which was generated in a laser vaporization-supersonic expansion source. The most remarkable irregular feature is the finding for n = 1 of a lower intensity for the Ba(+)(H(2)O)(n) peak with respect to that of BaOH(+)(H(2)O)(n-1), which is opposite to the trend for n = 2-4. Rationalization of the data required consideration of a distinct behavior of ground-state and electronically excited state Ba atoms in inelastic and reactive Ba + (H(2)O)(n) encounters that can occur in the cluster source. Within this picture, the generation of Ba(H(2)O)(n) (n > 1) association products results from stabilizing collisions with atoms of the carrier gas, which are favored by intramolecular vibrational redistribution that operates on the corresponding collision intermediates prior to stabilization; the latter is unlikely to occur for Ba + (H(2)O) encounters. Overall, this interpretation is consistent with additional in-source laser excitation and quenching experiments, which aimed to explore qualitatively the effect of perturbing the Ba atom electronic state population distribution on the observed intensity pattern, as well as with the energetics of various possible reactions for the Ba + H(2)O system that derive from high level ab initio calculations.

Chemiluminescence from the Ba((3)P)+N(2)O-->BaO(A (1)Sigma(+))+N(2) reaction: Collision energy effects on the product rotational alignment and energy release.

Both fully dispersed unpolarized and polarized chemiluminescence spectra from the Ba((3)P)+N(2)O reaction have been recorded under hyperthermal laser-ablated atomic beam-Maxwellian gas conditions at three specific average collision energies E(c) in the range of 4.82-7.47 eV. A comprehensive analysis of the whole data series suggests that the A (1)Sigma(+)-->X (1)Sigma(+) band system dominates the chemiluminescence. The polarization results revealed that the BaO(A (1)Sigma(+)) product rotational alignment is insensitive to its vibrational state upsilon(') at E(c)=4.82 eV but develops into an strong negative correlation between product rotational alignment and upsilon(') at 7.47 eV. The results are interpreted in terms of a direct mechanism involving a short-range, partial electron transfer from Ba((3)P) to N(2)O which is constrained by the duration of the collision, so that the reaction has a larger probability to occur when the collision time is larger than the time needed for N(2)O bending. The latter in turn determines that, at any given E(c), collinear reactive intermediates are preferentially involved when the highest velocity components of the corresponding collision energy distributions are sampled. Moreover, the data at 4.82 eV suggest that a potential barrier to reaction which favors charge transfer to bent N(2)O at chiefly coplanar geometries is operative for most of the reactive trajectories that sample the lowest velocity components. Such a barrier would arise from the relevant ionic-covalent curve crossings occurring in the repulsive region of the covalent potential Ba((3)P)cdots, three dots, centeredN(2)O((1)Sigma(+)); from this crossing the BaO(A (1)Sigma(+)) product may be reached through mixings in the exit channel with potential energy surfaces leading most likely to the spin-allowed b (3)Pi and a (3)Sigma(+) products. The variation with increasing E(c) of both the magnitude of the average BaO(A (1)Sigma(+)) rotational alignment and the BaO(A (1)Sigma(+)) rovibrational excitation, as obtained from spectral simulations of the unpolarized chemiluminescence spectra, consistently points to additional dynamic factors, most likely the development of induced repulsive energy release as the major responsible for the angular momentum and energy disposal at the two higher E(c) studied. The results of a simplified version of the direct interaction with product repulsion-distributed as in photodissociation model do not agree with the observed average product rotational alignments, showing that a more realistic potential energy surface model will be necessary to explain the present results.

Effect of the intermolecular hydrogen bond conformation on the structure and reactivity of the p-cresol(H2O)(NH3) van der Waals complex.

The structure and reactivity of p-CrOH(NH(3))(2) and p-CrOH(H(2)O)(NH(3)) complexes were studied using mass-resolved one-colour resonance-enhanced multi-photon ionization and laser-induced fluorescence (LIF) spectroscopy together with DFT calculations. At the excitation energy of this work, the S(1) state of p-CrOH(NH(3))(2) shows a sub-nanosecond lifetime, as determined by time-resolved LIF spectra, as a consequence of a hydrogen transfer process that results in NH(4)(NH(3)) as a reaction product. Substitution of NH(3) by H(2)O closes the reaction channel as evidenced by the absence of excited-state hydrogen transfer (ESHT) reaction products, (H(3)O(NH(3)) or NH(4)(H(2)O)) and results in a dramatic effect on the S(1) lifetime of the p-CrOH(H(2)O)(NH(3)) complex which rises to (12 +/- 2) ns. According to density functional theory calculations, the most stable isomer of the p-CrOH(H(2)O)(NH(3)) complex is a cyclic structure, in which H(2)O acts as the H acceptor of the phenolic OH group (c-OH-H(2)O-NH(3)). However, the ESHT process is energetically disallowed upon electronic excitation.

Vibrational energy transfer between I2(B (3)Pi(0u)+, nu' = 21) and He at very low temperatures: impulsive versus complex formation mechanisms assisted by tunneling through the centrifugal barrier.

The temperature dependence of the state-to-state vibrational relaxation rate constant (k(nu)(21-Delta nu)) for collisions between I(2)(B,nu(')=21) and He at very low kinetic energies was studied. The fluorescence from I(2)(B,nu(')=21-Delta nu(')) with Delta nu(')=1-5 indicates that in the temperature range of 0.6-8.2 K these states are populated by only one collision with He. The behavior of k(nu)(21-Delta nu) with temperature can be divided into two groups. The group with quantum changes Delta nu(')=1-3 shows scattering resonances in the low temperature region, with a general monotonical decrease of the rate constant with temperature, suggesting the importance of van der Waals interactions. This behavior is supported by the calculation of the probability of tunneling through the centrifugal barriers. For collisions in which 4-5 quanta are lost in a single event, there are no evidences of scattering resonances and the values of the relaxation rate constants could be determined only at the highest temperatures of this study. This suggests that relaxation occurs via impulsive collisions. The branching ratios for each channel are also temperature dependent and this behavior also suggests that the energy transfer mechanism changes with Delta nu(').

Accounting for the dependence of P(E',E) on the maximum impact parameter in classical trajectory calculations: application to the H2O-H2O collisional relaxation.

In this work we report a novel methodology that is able to predict how energy transfer transition probability density functions [P(E',E)] change with the maximum impact parameter (bmax) used in trajectory calculations (TC's). The method assumes that P(E',E) can be described by a sum of exponential functions and that all the trajectories with an initial impact parameter beyond a certain critical value will contribute only to the elastic peak [P(E',E) for E'=E]. This approach is applied to H2O-H2O collisions at different initial vibrational energies of the excited molecules and temperatures of bath gas. The results show that it is possible to reproduce with high accuracy the whole P(E',E) obtained from a given bmax, using the results of TC's performed at another bmax. The new methodology also leads us to propose a new criterion to choose the value of bmax.