Role of BacA in Lipopolysaccharide Synthesis, Peptide Transport, and Nodulation by \u3cem\u3eRhizobium\u3c/em\u3e sp. Strain NGR234

BacA of Sinorhizobium meliloti plays an essential role in the establishment of nitrogen-fixing symbioses with Medicago plants, where it is involved in peptide import and in the addition of very-long-chain fatty acids (VLCFA) to lipid A of lipopolysaccharide (LPS). We investigated the role of BacA in Rhizobium species strain NGR234 by mutating the bacA gene. In the NGR234 bacA mutant, peptide import was impaired, but no effect on VLCFA addition was observed. More importantly, the symbiotic ability of the mutant was comparable to that of the wild type for a variety of legume species. Concurrently, an acpXL mutant of NGR234 was created and assayed. In rhizobia, AcpXL is a dedicated acyl carrier protein necessary for the addition of VLCFA to lipid A. LPS extracted from the NGR234 mutant lacked VLCFA, and this mutant was severely impaired in the ability to form functional nodules with the majority of legumes tested. Our work demonstrates the importance of VLCFA in the NGR234-legume symbiosis and also shows that the necessity of BacA for bacteroid differentiation is restricted to specific legume-Rhizobium interactions

Auditory experience modulates frontoparietal theta activity serving fluid intelligence

Children who are hard of hearing are at risk for developmental language and academic delays compared with children with normal hearing. Some work suggests that high-order cognitive function, including fluid intelligence, may relate to language and academic outcomes in children with hearing loss, but findings in these studies have been mixed and to date, there have been no studies of the wholebrain neural dynamics serving fluid intelligence in the context of hearing loss. To this end, this study sought to identify the impact of hearing loss and subsequent hearing aid use on the neural dynamics serving abstract reasoning in children who are hard of hearing relative to children with normal hearing using magnetoencephalography. We found significant elevations in occipital and parietal theta activity during early stimulus evaluation in children who are hard of hearing relative to normal-hearing peers. In addition, we found that greater hearing aid use was significantly related to reduced activity throughout the fronto-parietal network. Notably, there were no differences in alpha dynamics between groups during later-stage processing nor did alpha activity correlate with hearing aid use. These cross-sectional data suggest that differences in auditory experience lead to widespread alterations in the neural dynamics serving initial stimulus processing in fluid intelligence in children

Auto-driven Photo Elicitation Interviews in Research with Children: Ethical and Practical Considerations

Children can sometimes find it difficult to articulate their experiences if they have to rely solely on words. Giving children the opportunity to use arts-based research approaches can support their participation in research and create a bridge that enables them to express their perspectives and feelings. This paper focuses on the ethical and practical considerations when using photo elicitation interviews (PEI) in research with children. The discussion and examples provided are drawn from an international study that used auto-driven PEI, where photographs are taken by children themselves, to explore children’s experiences of living with a chronic condition and the impact condition management may have on their everyday lives. In this paper we critically explore the issues arising from our use of PEI including children’s participation and engagement, balancing power and control, and keeping children safe. The main areas of focus for the paper are how PEI provided a means of shifting control; how setting photographic boundaries influenced our PEI study with children; and how we addressed risks associated with the method. Our experience shows that PEI is an engaging and valuable research method, providing a powerful medium for obtaining rich data with children. However, PEI is challenging and it requires researchers to conscientiously address ethical and practical aspects that extend beyond those inherent to standard (words-alone) interviews

Measuring maternal mortality : an overview of opportunities and options for developing countries

Background:There is currently an unprecedented expressed need and demand for estimates of maternal mortality in developing countries. This has been stimulated in part by the creation of a Millennium Development Goal that will be judged partly on the basis of reductions in maternal mortality by 2015. Methods: Since the launch of the Safe Motherhood Initiative in 1987, new opportunities for data capture have arisen and new methods have been developed, tested and used. This paper provides a pragmatic overview of these methods and the optimal measurement strategies for different developing country contexts. Results: There are significant recent advances in the measurement of maternal mortality, yet also room for further improvement, particularly in assessing the magnitude and direction of biases and their implications for different data uses. Some of the innovations in measurement provide efficient mechanisms for gathering the requisite primary data at a reasonably low cost. No method, however, has zero costs. Investment is needed in measurement strategies for maternal mortality suited to the needs and resources of a country, and which also strengthen the technical capacity to generate and use credible estimates. Conclusion: Ownership of information is necessary for it to be acted upon: what you count is what you do. Difficulties with measurement must not be allowed to discourage efforts to reduce maternal mortality. Countries must be encouraged and enabled to count maternal deaths and act.WJG is funded partially by the University of Aberdeen. OMRC is partially funded by the London School of Hygiene and Tropical Medicine. CS and SA are partially funded by Johns Hopkins University. CAZ is funded by the Health Metrics Network at the World Health Organization. WJG, OMRC, CS and SA are also partially supported through an international research program, Immpact, funded by the Bill & Melinda Gates Foundation, the Department for International Development, the European Commission and USAID

A remembrance of things (best) forgotten: The 'allegorical past' and the feminist imagination

This is the author's PDF version of an article published in Feminist theology© 2012. The definitive version is available at http://fth.sagepub.com/This article discusses the US TV series Mad Men, which is set in an advertising agency in 1960s New York, in relation to two key elements which seem significant for a consideration of the current state of feminism in church and academy, both of which centre around what it means to remember or (not) to forget

In vitro polishing effectiveness of interdental aids on root surfaces

. The purpose of this study was: (1) to determine whether polishing standardized proximal root surfaces with dental floss, Superfloss, wood and plastic interdental cleaners, using a polishing paste, produces any significant change on root surface roughness; and (2) to determine the effectiveness of different number of strokes in polishing. 80 tooth specimens were prepared, 10 in each of 8 sample groups. Each proximal root surface was standardized with 600A grit silicone carbide paper and polished with either waxed dental floss, Superfloss, wood or plastic interdental cleaners, using alkali aluminum silicate polishing paste. All specimens were mounted on a flossing machine and polished with 10 or 20 strokes. Before and after polishing, measurements were recorded with the Surfanalyzer 150 System to produce profile and average roughness tracings. Average maximum peak heights, mean number of peaks, and mean average roughness values were calculated from the tracings. The data were analyzed statistically by paired t-test and Student t-test. No significant mean differences were found between the number of strokes used. No significant differences were found for waxed dental floss in relation to the values analyzed. Significant differences were found for maximum peak heights for Superfloss following 20 strokes of polishing. However, no significant differences were found for Superfloss for mean number of peaks and average roughness. Significant differences were found for average roughness values, maximum peak heights, and mean number of peaks for the wood and plastic interdental cleaners. It was concluded that root surface roughness increased significantly with the use of wood and plastic interdental cleaners but not with waxed dental floss or Superfloss.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75532/1/j.1600-051X.1986.tb00853.x.pd

A pilot study comparing the metabolic profiles of elite-level athletes from different sporting disciplines

Background: The outstanding performance of an elite athlete might be associated with changes in their blood metabolic profile. The aims of this study were to compare the blood metabolic profiles between moderate- and high-power and endurance elite athletes and to identify the potential metabolic pathways underlying these differences. Methods: Metabolic profiling of serum samples from 191 elite athletes from different sports disciplines (121 high- and 70 moderate-endurance athletes, including 44 high- and 144 moderate-power athletes), who participated in national or international sports events and tested negative for doping abuse at anti-doping laboratories, was performed using non-targeted metabolomics-based mass spectroscopy combined with ultrahigh-performance liquid chromatography. Multivariate analysis was conducted using orthogonal partial least squares discriminant analysis. Differences in metabolic levels between high- and moderate-power and endurance sports were assessed by univariate linear models. Results: Out of 743 analyzed metabolites, gamma-glutamyl amino acids were significantly reduced in both high-power and high-endurance athletes compared to moderate counterparts, indicating active glutathione cycle. High-endurance athletes exhibited significant increases in the levels of several sex hormone steroids involved in testosterone and progesterone synthesis, but decreases in diacylglycerols and ecosanoids. High-power athletes had increased levels of phospholipids and xanthine metabolites compared to moderate-power counterparts. Conclusions: This pilot data provides evidence that high-power and high-endurance athletes exhibit a distinct metabolic profile that reflects steroid biosynthesis, fatty acid metabolism, oxidative stress, and energy-related metabolites. Replication studies are warranted to confirm differences in the metabolic profiles associated with athletes’ elite performance in independent data sets, aiming ultimately for deeper understanding of the underlying biochemical processes that could be utilized as biomarkers with potential therapeutic implications

The Type Ia Supernova Rate in Radio and Infrared Galaxies from the CFHT Supernova Legacy Survey

We have combined the large SN Ia database of the Canada-France-Hawaii Telescope Supernova Legacy Survey and catalogs of galaxies with photometric redshifts, VLA 1.4 GHz radio sources, and Spitzer infrared sources. We present eight SNe Ia in early-type host galaxies which have counterparts in the radio and infrared source catalogs. We find the SN Ia rate in subsets of radio and infrared early-type galaxies is ~1-5 times the rate in all early-type galaxies, and that any enhancement is always <~ 2 sigma. Rates in these subsets are consistent with predictions of the two component "A+B" SN Ia rate model. Since infrared properties of radio SN Ia hosts indicate dust obscured star formation, we incorporate infrared star formation rates into the "A+B" model. We also show the properties of SNe Ia in radio and infrared galaxies suggest the hosts contain dust and support a continuum of delay time distributions for SNe Ia, although other delay time distributions cannot be ruled out based on our data.Comment: 14 pages, 6 figures, 7 tables, accepted for publication in A

The Supernova Legacy Survey 3-year sample: Type Ia Supernovae photometric distances and cosmological constraints

We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15 < z < 1.1) discovered during the first three years of the Supernova Legacy Survey (SNLS). These events were detected and their multi-colour light curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshifts. Systematic uncertainties arising from light curve modeling are studied, making use of two techniques to derive the peak magnitude, shape and colour of the supernovae, and taking advantage of a precise calibration of the SNLS fields. A flat LambdaCDM cosmological fit to 231 SNLS high redshift Type Ia supernovae alone gives Omega_M = 0.211 +/- 0.034(stat) +/- 0.069(sys). The dominant systematic uncertainty comes from uncertainties in the photometric calibration. Systematic uncertainties from light curve fitters come next with a total contribution of +/- 0.026 on Omega_M. No clear evidence is found for a possible evolution of the slope (beta) of the colour-luminosity relation with redshift.Comment: (The SNLS Collaboration) 40 pages, 32 figures, Accepted in A&