Plant-associated microbiota as a source of antagonistic bacteria against the phytopathogen Erwinia amylovora

Control of bacterial plant diseases is a major concern, as they affect economically important species and spread easily, such as the case of fire blight of rosaceous caused by Erwinia amylovora. In the search for alternatives to the use of agrochemicals and antibiotics, this work presents a screening of natural bacterial antagonists of this relevant and devastating phytopathogen. We recovered bacterial isolates from different plant tissues and geographical origins and then selected those with the strongest ability to reduce fire blight symptoms ex vivo and remarkable in vitro antagonistic activity against E. amylovora. None of them elicited a hypersensitivity reaction in tobacco leaves, most produced several hydrolytic enzymes and presented other biocontrol and/or plant growth-promoting activities, such as siderophore production and phosphate solubilization. These isolates, considered as biocontrol candidates, were identified by 16S rRNA sequencing as Pseudomonas rhizosphaerae, Curtobacterium flaccumfaciens, Enterobacter cancerogenus, Pseudomonas azotoformans, Rosenbergiella epipactidis and Serratia plymuthica. This is the first time that the last five bacterial species are reported to have biocontrol potential against E. amylovora

Bulk Axions, Brane Back-reaction and Fluxes

Extra-dimensional models can involve bulk pseudo-Goldstone bosons (pGBs) whose shift symmetry is explicitly broken only by physics localized on branes. Reliable calculation of their low-energy potential is often difficult because it requires details of the stabilization of the extra dimensions. In rugby ball solutions, for which two compact extra dimensions are stabilized in the presence of only positive-tension brane sources, the effects of brane back-reaction can be computed explicitly. This allows the calculation of the shape of the low-energy pGB potential and response of the extra dimensional geometry as a function of the perturbing brane properties. If the pGB-dependence is a small part of the total brane tension a very general analysis is possible, permitting an exploration of how the system responds to frustration when the two branes disagree on what the proper scalar vacuum should be. We show how the low-energy potential is given by the sum of brane tensions (in agreement with common lore) when only the brane tensions couple to the pGB. We also show how a direct brane coupling to the flux stabilizing the extra dimensions corrects this result in a way that does not simply amount to the contribution of the flux to the brane tensions. We calculate the mass of the would-be zero mode, and briefly describe several potential applications, including a brane realization of `natural inflation,' and a dynamical mechanism for suppressing the couplings of the pGB to matter localized on the branes. Since the scalar can be light enough to be relevant to precision tests of gravity (in a technically natural way) this mechanism can be relevant to evading phenomenological bounds.Comment: 36 pages, JHEP styl

Scalar-field Pressure in Induced Gravity with Higgs Potential and Dark Matter

A model of induced gravity with a Higgs potential is investigated in detail in view of the pressure components related to the scalar-field excitations. The physical consequences emerging as an artifact due to the presence of these pressure terms are analysed in terms of the constraints parting from energy density, solar-relativistic effects and galactic dynamics along with the dark matter halos.Comment: 26 pages, 3 figures, Minor revision, Published in JHE

Seeking legitimacy through CSR: Institutional Pressures and Corporate Responses of Multinationals in Sri Lanka

Arguably, the corporate social responsibility (CSR) practices of multinational enterprises (MNEs) are influenced by a wide range of both internal and external factors. Perhaps most critical among the exogenous forces operating on MNEs are those exerted by state and other key institutional actors in host countries. Crucially, academic research conducted to date offers little data about how MNEs use their CSR activities to strategically manage their relationship with those actors in order to gain legitimisation advantages in host countries. This paper addresses that gap by exploring interactions between external institutional pressures and firm-level CSR activities, which take the form of community initiatives, to examine how MNEs develop their legitimacy-seeking policies and practices. In focusing on a developing country, Sri Lanka, this paper provides valuable insights into how MNEs instrumentally utilise community initiatives in a country where relationship-building with governmental and other powerful non-governmental actors can be vitally important for the long-term viability of the business. Drawing on neo-institutional theory and CSR literature, this paper examines and contributes to the embryonic but emerging debate about the instrumental and political implications of CSR. The evidence presented and discussed here reveals the extent to which, and the reasons why, MNEs engage in complex legitimacy-seeking relationships with Sri Lankan institutions

An algorithm to reduce the occupational space in gender segregation studies

This paper presents an algorithm based on the bootstrap to select an admissible aggregation level, that is, the minimum number of occupational categories that yield a gender segregation value not significantly smaller than that obtained from the large number of occupational categories usually available in any data set. The approach is illustrated using labour force survey data for Spain for the comparison of gender segregation in 1977 and 1992, as well as 1994 and 2000. To measure gender segregation, an additively decomposable segregation index based on the entropy concept is used. Despite a substantial simplification in the size of the occupation space, the decrease in the segregation index is very small and not significant, regardless of the year. Consequently, intertemporal changes in gender segregation can be studied using a greatly reduced classification of occupations that permits an easier interpretation of results.Publicad

White matter injury restoration after stem cell administration in subcortical ischemic stroke

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Introduction]: An animal model of subcortical ischemic stroke with white matter affectation was induced in rats by injection of endothelin-1. At 24 hours, 2 × 10 6 ADMSC were administered intravenously to the treatment group. Functional evaluation, lesion size, fiber tract integrity, cell death, proliferation, white matter repair markers (Olig-2, NF, and MBP) and NogoA were all studied after sacrifice (7 days and 28 days). ADMSC migration and implantation in the brain as well as proteomics analysis and functions of the secretome were also analyzed. [Results]: Neither ADMSC migration nor implantation to the brain was observed after ADMSC administration. In contrast, ADMSC implantation was detected in peripheral organs. The treatment group showed a smaller functional deficit, smaller lesion area, less cell death, more oligodendrocyte proliferation, more white matter connectivity and higher amounts of myelin formation. The treated animals also showed higher levels of white matter-associated markers in the injured area than the control group. Proteomics analysis of the ADMSC secretome identified 2,416 proteins, not all of them previously described to be involved in brain plasticity. [Conclusions]: White matter integrity in subcortical stroke is in part restored by ADMSC treatment; this is mediated by repair molecular factors implicated in axonal sprouting, remyelination and oligodendrogenesis. These findings are associated with improved functional recovery after stroke.This study was supported by research grants PS12/01754, PI11/00909 and INVICTUS (RD12/0014) (Spanish Neurovascular Network), SAF2010-37926, ProteoRed-PT13/0001/0017 and a Sara Borrell postdoctoral fellowship (CD12/00706, to LOO) from Research Institute Carlos III, Ministry of Science and Innovation of Spain. Furthermore, TS (CP12/03121) and FC (CP14/00154) are recipients of a research contract from Miguel Servet Program of Instituto de Salud Carlos III-Peer Reviewe

A Rapid Subtractive Immunization Method to Prepare Discriminatory Monoclonal Antibodies for Food E. coli O157:H7 Contamination

To detect food E. coli O157:H7 contamination rapidly and accurately, it is essential to prepare high specific monoclonal antibodies (mAbs) against the pathogen. Cyclophosphamide (Cy)-mediated subtractive immunization strategy was performed in mice to generate mAbs that react with E. coli O157:H7, but not with other affiliated bacteria. Specificity of 19 mAbs was evaluated by ELISA and/or dot-immunogold filtration assay (DIGFA). Immunogloubin typing, affinity and binding antigens of 5 selected mAbs were also analysed. MAbs 1D8, 4A7, 5A2 were found to have high reactivity with E. coli O157:H7 and no cross-reactivity with 80 other strains of bacteria including Salmonella sp., Shigella sp., Proteus sp., Yersinia enterocolitica, Staphylococcus aureus, Klebsiella pneumoniae, Citrobacter freundii and other non-E. coli O157:H7 enteric bacteria. Their ascetic titers reached 1∶106 with E. coli O157:H7 and affinity constants ranged from 1.57×1010 to 2.79×1010 L/mol. The antigens recognized by them were different localized proteins. Furthermore, immune-colloidal gold probe coated with mAb 5A2 could specifically distinguish minced beef contaminated by E. coli O157:H7 from 84 other bacterial contaminations. The Cy-mediated subtractive immunization procedure coupled with hybridoma technology is a rapid and efficient approach to prepare discriminatory mAbs for detection of E. coli O157:H7 contamination in food

Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age