Measurement of chi_c1 and chi_c2 production with sqrts = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χc1 and χc2 charmonium states are measured in pp collisions at √s = 7TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χc states are reconstructed through the radiative decay χc → J/ψγ (with J/ψ → μ+μ−) where photons are reconstructed from γ → e+e− conversions. The production rate of the χc2 state relative to the χc1 state is measured for prompt and non-prompt χc as a function of J/ψ transverse momentum. The prompt χc cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χc decays. The fractions of χc1 and χc2 produced in b-hadron decays are also measured.

Measurement of the production of a W boson in association with a charm quark in pp collisions at sqrts = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at ps = 7TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio ơ(W++c)/ơ(W−+c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s–s quark asymmetry.

The differential production cross section of the phi (1020) meson in sqrts = 7 TeV pp collisions measured with the ATLAS detector

Ameasurement is presented of the φ×BR(φ → K+K−) production cross section at √s = 7 TeV using pp collision data corresponding to an integrated luminosity of 383 μb−1, collected with theATLAS experiment at the LHC. Selection of φ(1020) mesons is based on the identification of charged kaons by their energy loss in the pixel detector. The differential cross section ismeasured as a function of the transverse momentum, pT,φ , and rapidity, yφ, of the φ(1020) meson in the fiducial region 500< pT,φ <1200MeV, |yφ| < 0.8, kaon pT,K > 230 MeV and kaon momentum pK < 800 MeV. The integrated φ(1020)-meson production cross section in this fiducial range is measured to be σφ×BR(φ → K+K−) = 570 ± 8 (stat) ± 66 (syst) ± 20 (lumi) μb.

Species richness, but not phylogenetic diversity, influences community biomass production and temporal stability in a re-examination of 16 grassland biodiversity studies

* Hundreds of experiments have now manipulated species richness (SR) of various groups of organisms and examined how this aspect of biological diversity influences ecosystem functioning. Ecologists have recently expanded this field to look at whether phylogenetic diversity (PD) among species, often quantified as the sum of branch lengths on a molecular phylogeny leading to all species in a community, also predicts ecological function. Some have hypothesized that phylogenetic divergence should be a superior predictor of ecological function than SR because evolutionary relatedness represents the degree of ecological and functional differentiation among species. But studies to date have provided mixed support for this hypothesis. * Here, we reanalyse data from 16 experiments that have manipulated plant SR in grassland ecosystems and examined the impact on above-ground biomass production over multiple time points. Using a new molecular phylogeny of the plant species used in these experiments, we quantified how the PD of plants impacts average community biomass production as well as the stability of community biomass production through time. * Using four complementary analyses, we show that, after statistically controlling for variation in SR, PD (the sum of branches in a molecular phylogenetic tree connecting all species in a community) is neither related to mean community biomass nor to the temporal stability of biomass. These results run counter to past claims. However, after controlling for SR, PD was positively related to variation in community biomass over time due to an increase in the variances of individual species, but this relationship was not strong enough to influence community stability. * In contrast to the non-significant relationships between PD, biomass and stability, our analyses show that SR per se tends to increase the mean biomass production of plant communities, after controlling for PD. The relationship between SR and temporal variation in community biomass was either positive, non-significant or negative depending on which analysis was used. However, the increases in community biomass with SR, independently of PD, always led to increased stability. These results suggest that PD is no better as a predictor of ecosystem functioning than SR. * Synthesis. Our study on grasslands offers a cautionary tale when trying to relate PD to ecosystem functioning suggesting that there may be ecologically important trait and functional variation among species that is not explained by phylogenetic relatedness. Our results fail to support the hypothesis that the conservation of evolutionarily distinct species would be more effective than the conservation of SR as a way to maintain productive and stable communities under changing environmental conditions.

Direct and indirect effects of invasion by the alien tree Ailanthus altissima on riparian plant communities and ecosystem multifunctionality

Most existing studies addressing the effects of invasive species on biodiversity focus on species richness ignoring better indicators of biodiversity and better predictors of ecosystem functioning such as the diversity of evolutionary histories (phylodiversity). Moreover, no previous study has separated the direct effect of alien plants on multiple ecosystem functions simultaneously (multifunctionality) from those indirect ones mediated by the decrease on biodiversity caused by alien plants. We aimed to analyze direct and indirect effects, mediated or not by its effect on biodiversity, of the invasive tree Ailanthus altissima on ecosystem multifunctionality of riparian habitats under Mediterranean climate. We measured vegetation attributes (species richness and phylodiversity) and several surrogates of ecosystem functioning (understory plant biomass, soil enzyme activities, available phosphorous and organic matter) in plots infested by A. altissima and in control (non-invaded) ones. We used structural equation modelling to tease apart the direct and indirect effects of A. altissima on ecosystem multifunctionality. Our results suggest that lower plant species richness, phylodiversity and multifunctionality were associated to the presence of A. altissima. When analyzing each function separately, we found that biodiversity has the opposite effect of the alien plant on all the different functions measured, therefore reducing the strength of the effect (either positive or negative) of A. altissima on them. This is one of the few existing studies addressing the effect of invasive species on phylodiversity and also studying the effect of invasive species on multiple ecosystem functions simultaneously.

The maize lipoxygenase, ZmLOX10 , mediates green leaf volatile, jasmonate and herbivore-induced plant volatile production for defense against insect attack

Fatty acid derivatives are of central importance for plant immunity against insect herbivores; however, majorregulatory genes and the signals that modulate these defense metabolites are vastly understudied, especiallyin important agro-economic monocot species. Here we show that products and signals derived from a singleZea mays (maize) lipoxygenase (LOX), ZmLOX10, are critical for both direct and indirect defenses to herbiv-ory. We provide genetic evidence that two 13-LOXs, ZmLOX10 and ZmLOX8, specialize in providing substratefor the green leaf volatile (GLV) and jasmonate (JA) biosynthesis pathways, respectively. Supporting the spe-cialization of these LOX isoforms, LOX8 and LOX10 are localized to two distinct cellular compartments, indi-cating that the JA and GLV biosynthesis pathways are physically separated in maize. Reduced expression ofJA biosynthesis genes and diminished levels of JA in lox10 mutants indicate that LOX10-derived signaling isrequired for LOX8-mediated JA. The possible role of GLVs in JA signaling is supported by their ability to par-tially restore wound-induced JA levels in lox10 mutants. The impaired ability of lox10 mutants to produceGLVs and JA led to dramatic reductions in herbivore-induced plant volatiles (HIPVs) and attractiveness toparasitoid wasps. Because LOX10 is under circadian rhythm regulation, this study provides a mechanistic linkto the diurnal regulation of GLVs and HIPVs. GLV-, JA- and HIPV-deficient lox10 mutants display compro-mised resistance to insect feeding, both under laboratory and field conditions, which is strong evidence thatLOX10-dependent metabolites confer immunity against insect attack. Hence, this comprehensive gene toagro-ecosystem study reveals the broad implications of a single LOX isoform in herbivore defense.

Plant elicitor peptides are conserved signals regulating direct and indirect antiherbivore defense

Insect-induced defenses occur in nearly all plants and are regulated by conserved signaling pathways. As the first described plant peptide signal, systemin regulates antiherbivore defenses in the Solanaceae, but in other plant families, peptides with analogous activity have remained elusive. In the current study, we demonstrate that a member of the maize (Zea mays) plant elicitor peptide (Pep) family, ZmPep3, regulates responses against herbivores. Consistent with being a signal, expression of the ZmPROPEP3 precursor gene is rapidly induced by Spodoptera exigua oral secretions. At concentrations starting at 5 pmol per leaf, ZmPep3 stimulates production of jasmonic acid, ethylene, and increased expression of genes encoding proteins associated with herbivory defense. These include proteinase inhibitors and biosynthetic enzymes for production of volatile terpenes and benzoxazinoids. In accordance with gene expression data, plants treated with ZmPep3 emit volatiles similar to those from plants subjected to herbivory. ZmPep3-treated plants also exhibit induced accumulation of the benzoxazinoid phytoalexin 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside. Direct and indirect defenses induced by ZmPep3 contribute to resistance against S. exigua through significant reduction of larval growth and attraction of Cotesia marginiventris parasitoids. ZmPep3 activity is specific to Poaceous species; however, peptides derived from PROPEP orthologs identified in Solanaceous and Fabaceous plants also induce herbivory-associated volatiles in their respective species. These studies demonstrate that Peps are conserved signals across diverse plant families regulating antiherbivore defenses and are likely to be the missing functional homologs of systemin outside of the Solanaceae.

Addendum to “Electroweak Sudakov effects in W, Z and γ production at large transverse momentum”

In this addendum to T. Becher and X. Garcia i Tormo, Phys. Rev. D 88, 013009 (2013), we give results for the electroweak Sudakov corrections in gauge-boson production at large transverse momentum pT at proton colliders. For the results to be easily usable, we provide a simple and accurate parametrization of the corrections as a function of pT and the center-of-mass energy s√. Additionally, we also discuss the dependence of the electroweak corrections on the rapidity of the produced boson and comment on the complications that arise in the photon-production case due to isolation requirements.

Masticatory function and nutrition in old age

Nowadays, many people retain their natural teeth until late in life as a result of the large success of preventive strategies. However, there is still a very high prevalence of edentulism especially in elderly patients and many of these patients are provided with inadequate dental prostheses. In addition, many elderly citizens suffer from systemic diseases leading to increased drug prescription with age. This may have direct or indirect negative effects on the health and integrity of oral tissues like teeth, mucosa or muscles. There is growing evidence that a close interaction between the general medical condition and oral health exists. From a dental point of view, the chewing ability and capacity and its interaction with the nutritional status seem to be especially important. For example, complete denture wearers present a significant oral disability, which often leads to a gradual deterioration of their individual dietary habits. The improvement of maximum bite force and chewing efficiency may be an important prerequisite for an adequate nutrition. Those functional parameters can often be improved by providing functional dental prostheses or by stabilizing complete dentures with endosseous implants. Nevertheless, an improvement of the nutritional status can only be achieved through a close collaboration with dieticians or clinical nutritionists.

Production and characterisation of monoclonal antibodies specific for bovine interleukin-4

Genetic immunisation is a simple method for producing polyclonal antibodies in mice. By this method, we produced antibodies against bovine interleukin-4 (BoIL-4). After a final injection with a recombinant BoIL-4 protein, nine stable hybridoma cell lines were established which secreted monoclonal antibodies (MAbs) against this cytokine. Specific binding of each of the MAbs to recombinant BoIL-4 produced by Escherichia coli, baculovirus, and Trypanosoma brucei was demonstrated in an indirect ELISA and/or in Western blotting. These MAbs recognise the same antigenic region localised in the first 47 amino acids of the mature protein. None of them was able to neutralise the biological activity of the BoIL-4 under the conditions tested but one allowed the detection of BoIL-4 by flow cytometry.