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Objective:Investigating a large and ethnically diverse cohort from the Pacific region, we aimed to replicate and extend the recently reported findings that a CREBRF genetic variant is strongly associated with body mass index in Samoans.Methods:A birth cohort of more than six thousand children was utilised. In this study, genotyping of two markers (rs12513649 and rs373863828) was undertaken in Māori, Pacific, European and Asian individuals in the cohort.Results:We report that these CREBRF genetic variants are not confined to Samoans but are prevalent in all other Pacific populations sampled, including Māori. We found that the rs373863828 variant was significantly associated with growth at 4 years of age. On average, we observed allele-specific increases in weight (P=0·004, +455 g, s.e. 0.158), height (P=0·007, +0·70 cm, s.e. 0.26) and waist circumference (P=0·004, +0·70 cm, s.e. 0.24) at 4 years of age. The rs373863828 variant was not associated with birth weight (P=0·129).Conclusions:We replicated the finding that a CREBRF variant is associated with increased body mass. We then built on the original findings by demonstrating the prevalence of the rs12513649 and rs373863828 variants in multiple Pacific population groups and by demonstrating that the rs373863828 variant is associated with growth in early childhood. Pacific population groups experience a disproportionately high burden of obesity, starting in early childhood. This new knowledge offers potential for evidence-based interventions aimed at establishing healthy growth trajectories from the earliest possible age.

BRITE-Constellation (where BRITE stands for BRIght Target Explorer) is an international nanosatellite mission to monitor photometrically, in two colours, the brightness and temperature variations of stars generally brighter than mag(V) ? 4 with precision and time coverage not possible from the ground. The current mission design consists of six nanosats (hence Constellation): two from Austria, two from Canada, and two from Poland. Each 7 kg nanosat carries an optical telescope of aperture 3 cm feeding an uncooled CCD. One instrument in each pair is equipped with a blue filter; the other with a red filter. Each BRITE instrument has a wide field of view (?24°), so up to about 15 bright stars can be observed simultaneously, sampled in 32 × 32 pixels sub-rasters. Photometry of additional fainter targets, with reduced precision but thorough time sampling, will be possible through onboard data processing. The BRITE sample is dominated by the most intrinsically luminous stars: massive stars seen at all evolutionary stages, and evolved medium-mass stars at the very end of their nuclear burning phases. The goals of BRITE-Constellation are to (1) measure p- and g-mode pulsations to probe the interiors and ages of stars through asteroseismology; (2) look for varying spots on the stars surfaces carried across the stellar disks by rotation, which are the sources of co-rotating interaction regions in the winds of the most luminous stars, probably arising from magnetic subsurface convection; and (3) search for planetary transits.

Vegetation monitoring, currently complemented by climatic data in particular rainfall areas, does not always supply sufficient information to provide reliable guidelines for appropriate stocking densities on ranch or reserve scale. This paper considers how the nutrient status of animals may be used to improve the setting of management guidelines by reflecting how wild herbivores perform under differing environmental and management conditions. Faecal nitrogen concentrations of between 13 and 16 g kg-1 are above a threshold level that indicates a dietary deficiency which may precipitate nutritional stress in animals (such as happened during the 1991/1992 drought). Faecal phosphorous concentrations of between 1.9 and 2.0 g kg-1 over a long period of time would indicate a deficiency that may lead to low reproductive rates. Faecal analysis could therefore be used to assess whether applied stocking densities will allow grazers, and probably mixed feeders such as impala too, to select for a diet of sufficient quality for maintenance.

Previous studies of Campylobacter jejuni have suggested that flagellin is an adhesin for epithelial cells and that motility is a virulence factor of this bacterium. The role of flagella in the interactions of C. jejuni with nonpolarized and polarized epithelial cells was examined with flagellar mutants. Flagellated, nonmotile (flaA flaB+ Mot-) and nonflagellated, nonmotile (flaA flaB Mot-) mutants of C. jejuni were constructed by in vivo homologous recombination and gene replacement techniques. Both classes of mutants were found to adhere to cells of human epithelial origin (INT 407) equally well; however, on the basis of the percentage of the inoculum internalized, internalization of the flaA flaB Mot- mutants was decreased by factors ranging from approximately 30 to 40 compared with the parent. The flaA flaB+ Mot- mutant was internalized by the INT 407 cells at levels six- to sevenfold higher than the flaA flaB Mot- mutants. Both classes of mutants, unlike the parent, were unable to translocate across polarized Caco-2 monolayers. These results indicate that flagella are not involved in C. jejuni adherence to epithelial cells but that they do play a role in internalization. Furthermore, the results suggest that either the motility of C. jejuni or the product of flaA is essential for the bacterium to cross polarized epithelial cell monolayers.

A 2.7-kilobase DNA fragment carrying the entire exotoxin A (ETA) structural gene was divided into three nonoverlapping probes. Two probes covering the ETA structural gene were used in colony hybridization experiments to determine whether sequences homologous to the ETA gene could be detected in genera other than Pseudomonas or in Pseudomonas species other than Pseudomonas aeruginosa. The majority of strains examined other than the P. aeruginosa strains failed to react in the colony hybridization assays. Some Pseudomonas spp. other than P. aeruginosa and some Bordetella spp. did react in colony hybridization assays with the probes. However, additional studies in which we used Southern hybridization methods indicated that these reactions were apparently nonspecific and that the ETA gene is limited to P. aeruginosa. Studies in which we used all three ETA-related probes in Southern hybridization experiments to analyze the ETA gene and surrounding sequences in P. aeruginosa strains isolated from diverse sources revealed the following: (i) the incidence of the ETA gene in P. aeruginosa is approximately equal to 95%; (ii) there are strains which have been isolated from human infections that do not carry the ETA structural gene; (iii) there is a maximum of one copy of the ETA gene per genome in any given strain; (iv) sequences within and 4 to 5 kilobases downstream of the ETA structural gene appear to be well conserved in different strains of P. aeruginosa; and (v) in contrast, sequences immediately upstream of the ETA structural gene are considerably rearranged from strain to strain. A multicopy plasmid carrying the entire cloned ETA gene was transferred to a tox- P. aeruginosa strain. This strain synthesized and secreted mature, full-length ETA, but the amount produced was small considering the multicopy nature of the plasmid. Synthesis of toxin in this strain was only minimally affected by iron. Our data suggest that the synthesis of ETA is positively regulated. Finally, we found that the presence of the ETA gene is independent of the ability of P. aeruginosa to produce several other recognized virulence factors, supporting the concept of the multifactorial nature of P. aeruginosa virulence.

Analysis of RNA isolated from Pseudomonas aeruginosa PA103 and PAKS grown under Fe2+-limiting (0.08 microgram/ml) and Fe2+-sufficient (10 micrograms/ml) conditions demonstrated that exotoxin A (ETA) expression is regulated by Fe2+ at the level of transcription. S1 nuclease mapping revealed two 5' termini of the tox transcript, 89 base pairs (bp) (S1A) and 62 bp (S1B) 5' to the ETA initiation codon. There appeared to be no consensus promoter sequence for either tox transcript. An 8-bp direct repeat was found 5' to the start of transcript S1A. Transcript S1B mapped 8 bp upstream of a dodecamer sequence conserved between the ETA and phospholipase C genes of P. aeruginosa. Multicopy plasmids in which the expression of ETA is directed from the Escherichia coli trp promoter (ptrpETA-RSF1010) or the tox promoter (pCMtox) were constructed and mobilized into a Tox-P. aeruginosa strain, WR5. WR5 synthesized and secreted high levels of ETA when it was expressed from the E. coli trp promoter; however, the synthesis of ETA from its own promoter in this strain was very low. These and other data suggest that the expression of ETA is under a positive control mechanism. A fusion of the ETA promoter fragment to lacZ was constructed. Use of this fusion plasmid revealed that this DNA fragment directed the synthesis of beta-galactosidase in E. coli at very low levels and that the synthesis of beta-galactosidase from this fusion in E. coli was not regulated by Fe2+.

Previous studies of cholera toxin and Escherichia coli heat-labile enterotoxin have suggested that proteolytic cleavage plays an important role in the expression of ADP-ribosyltransferase activity and toxicity. Specifically, several studies have implicated a trypsin-like cleavage at arginine 192, which lies within an exposed region subtended by a disulfide bond in the intact A subunit, in toxicity. To investigate the role of this modification in the enzymatic and cytotonic properties of heat-labile enterotoxin, the response of purified, recombinant A subunit to tryptic activation and the effect of substituting arginine 192 with glycine on the activities of the holotoxin were examined. The recombinant A subunit of heat-labile enterotoxin exhibited significant levels of ADP-ribosyltransferase activity that were only nominally increased (approximately twofold) by prior limited trypsinolysis. The enzymatic activity also did not appear to be affected by auto-ADP-ribosylation that occurs during the high-level synthesis of the recombinant A subunit in E. coli. A mutant form of the holotoxin containing the arginine 192-to-glycine substitution exhibited levels of cytotonic activity for CHO cells that were similar to that of the untreated, wild-type holotoxin but exhibited a marked delay in the ability to increase intracellular levels of cyclic AMP in Caco-2 cells. The results indicate that trypsin-like cleavage of the A subunit of E. coli heat-labile enterotoxin at arginine 192 is not requisite to the expression of enzymatic activity by the A subunit and further reveal that this modification, although it enhances the biological and enzymatic activities of the toxin, is not absolutely required for the enterotoxin to elicit cytotonic effects.

BRIght Target Explorer(BRITE) Constellation, the first nanosatellite mission applied to astrophysical research, is a collaboration among Austria, Canada and Poland. The fleet of satellites (6 launched; 5 functioning) performs precise optical photometry of the brightest stars in the night sky. A pioneering mission like BRITE-with optics and instruments restricted to small volume, mass and power in several nanosatellites, whose measurements must be coordinated in orbit-poses many unique challenges. We discuss the technical issues, including problems encountered during on-orbit commissioning (especially higher-than-expected sensitivity of the CCDs to particle radiation). We describe in detail how the BRITEteam has mitigated these problems, and provide a complete overview of mission operations. This paper serves as a template for how to effectively plan, build and operate future low-cost niche-driven space astronomy missions.

Although bovids have been studied for decades, debate still exists about their diets. To address this problem, we examined bovid dietary ecology through analysis of stable carbon isotopes. We analyzed tooth enamel, bone collagen, and hair from 312 individual bovids, representing 27 species from southern Africa. Although dietary information from the literature is usually supported by this technique, our results and the literature are sometimes highly divergent. For instance, our results indicate that Taurotragus oryx and Raphicerus campestris eat less grass than is widely believed. Furthermore, contrary to most theoretical expectations, our data indicate no relationship between body size and percentage of monocots consumed by southern African Bovidae. Although many researchers have abandoned the idea that bovid soft-tissue anatomy is strongly indicative of diet, we demonstrate a strong relationship between the percentage of grass in a bovid's diet and several hard-tissue craniodental indices.