The iron abundance of the Magellanic Bridge

High-resolution Hubble Space Telescope ultraviolet spectra for five B-type stars in the Magellanic Bridge and in the Large (LMC) and Small (SMC) Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates obtained from late-type stars or the optical lines in B-type stars by approximately 0.5 dex. This may be due to systematic errors possibly arising from non-local thermodynamic equilibrium (non-LTE) effects or from errors in the atomic data, as similar low Fe abundances have previously been reported from the analysis of the ultraviolet spectra of Galactic early-type stars. The iron abundance estimates for all three Bridge targets appear to be significantly lower than those found for the SMC and LMC by approximately -0.5 and -0.8 dex, respectively, and these differential results should not be affected by any systematic errors present in the absolute abundance estimates. These differential iron abundance estimates are consistent with the underabundances for C, N, O, Mg and Si of approximately -1.1 dex relative to our Galaxy previously found in our Bridge targets. The implications of these very low metal abundances for the Magellanic Bridge are discussed in terms of metal deficient material being stripped from the SMC.

New ways to break an old bond: the bacterial carbon-phosphorus hydrolases and their role in biogeochemical phosphorus cycling

Phosphonates are organophosphorus molecules that contain the highly stable C-P bond, rather than the more common, and more labile, C-O-P phosphate ester bond. They have ancient origins but their biosynthesis is widespread among more primitive organisms and their importance in the contemporary biosphere is increasingly recognized; for example phosphonate-P is believed to play a particularly significant role in the productivity of the oceans. The microbial degradation of phosphonates was originally thought to occur only under conditions of phosphate limitation, mediated exclusively by the poorly characterized C-P lyase multienzyme system, under Pho regulon control. However, more recent studies have demonstrated the Pho-independent mineralization by environmental bacteria of three of the most widely distributed biogenic phosphonates: 2-aminoethylphosphonic acid (ciliatine), phosphonoacetic acid, and 2-amino-3-phosphonopropionic acid (phosphonoalanine). The three phosphonohydrolases responsible have unique specificities and are members of separate enzyme superfamilies; their expression is regulated by distinct members of the LysR family of bacterial transcriptional regulators, for each of which the phosphonate substrate of the respective degradative operon serves as coinducer. Previously no organophosphorus compound was known to induce the enzymes required for its own degradation. Whole-genome and metagenome sequence analysis indicates that the genes encoding these newly described C-P hydrolases are distributed widely among prokaryotes. As they are able to function under conditions in which C-P lyases are inactive, the three enzymes may play a hitherto-unrecognized role in phosphonate breakdown in the environment and hence make a significant contribution to global biogeochemical P-cycling.

Objective assessment of cardiopulmonary resuscitation skills of 10-11 year-old schoolchildren using two different external chest compression to ventilation ratios

Study which shows that 10-11 yr olds are capable of effective CPR after a single 2 hour training session using the ABC for Life programme. However they perfrom more effective CPR when using a ratio of 15:2 rather than 30:2 chest compressions : ventilations

Frequency of participation of 8-12 year old children with cerebral palsy: a multi-centre cross sectional European study

Participation in home, school and community is important for all children; and little is known about the frequency of participation of disabled children. Frequency of participation is a valuable outcome measure for evaluating habilitation programmes for disabled children and for planning social and health services.

We investigated how frequency of participation varied between children with cerebral palsy and the general population; and examined variation across countries to understand better how the environmental factors such as legislation, public attitudes and regulation in different countries might influence participation.

We undertook a multi-centre, population-based study in children with and without cerebral palsy. Working from the Life-H instrument, we developed a questionnaire to capture frequency of participation in 8–12-year-old children. In nine regions of seven European countries, parents of 813 children with cerebral palsy and 2939 children from the general populations completed the questionnaire.

Frequency of participation for each question was dichotomised about the median; multivariable logistic regressions were carried out.

In the general population, frequency of participation varied between countries. Children with cerebral palsy participated less frequently in many but not all areas of everyday life, compared with children from the general population. There was regional variation in the domains with reduced participation and in the magnitude of the differences. We discuss how this regional variation might be explained by the different environments in which children live. Attending a special school or class was not associated with further reduction in participation in most areas of everyday life.

Antioxidants and periodontitis in 60-70 year- old men

Objective: The aim was to investigate the association between periodontal health and the serum levels of various antioxidants including carotenoids, retinol and vitamin E in a homogenous group of Western European men.
Materials and Methods: A representative sample of 1258 men aged 60-70 years, drawn from the population of Northern Ireland, was examined between 2001 and 2003. Each participant had six or more teeth, completed a questionnaire and underwent a clinical periodontal examination. Serum lipid-soluble antioxidant levels were measured by high-performance liquid chromatography with diode array detection. Multivariable analysis was carried out using logistic regression with adjustment for possible confounders. Models were constructed using two measures of periodontal status (low- and high-threshold periodontitis) as dependent variables and the fifths of each antioxidant as a predictor variable.
Results: The levels of a- and ß-carotene, ß-cryptoxanthin and zeaxanthin were highly significantly lower in the men with low-threshold periodontitis (p<0.001). These carotenoids were also significantly lower in high-threshold periodontitis. There were no significant differences in the levels of lutein, lycopene, a- and ?-tocopherol or retinol in relation to periodontitis. In fully adjusted models, there was an inverse relationship between a number of carotenoids (a- and ß-carotene and ß-cryptoxanthin) and low-threshold periodontitis. ß-Carotene and ß-cryptoxanthin were the only antioxidants that were associated with an increased risk of high-threshold severe periodontitis. The adjusted odds ratio for high-threshold periodontitis in the lowest fifth relative to the highest fifth of ß-cryptoxanthin was 4.02 (p=0.003).
Conclusion: It is concluded that low serum levels of a number of carotenoids, in particular beta-cryptoxanthin and beta-carotene, were associated with an increased prevalence of periodontitis in this homogenous group of 60-70-year-old Western European men.

Salt-bridge dynamics control substrate-induced conformational change in the membrane transporter GlpT.

Active transport of substrates across cytoplasmic membranes is of great physiological, medical and pharmaceutical importance. The glycerol-3-phosphate (G3P) transporter (GlpT) of the E. coli inner membrane is a secondary active antiporter from the ubiquitous major facilitator superfamily that couples the import of G3P to the efflux of inorganic phosphate (Pi) down its concentration gradient. Integrating information from a novel combination of structural, molecular dynamics simulations and biochemical studies, we identify the residues involved directly in binding of substrate to the inward-facing conformation of GlpT, thus defining the structural basis for the substrate-specificity of this transporter. The substrate binding mechanism involves protonation of a histidine residue at the binding site. Furthermore, our data suggest that the formation and breaking of inter- and intradomain salt bridges control the conformational change of the transporter that accompanies substrate translocation across the membrane. The mechanism we propose may be a paradigm for organophosphate:phosphate antiporters.