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QC 20181212

A Ni-based pyrochlore catalyst was synthesized using the modified Pechini method. In this method, 1 wt% Ni was doped into the La2Zr2O7 pyrochlore structure. The catalyst was characterized by H2-TPR, TPO, XRD, and EXAFS, and tested for its methane reforming activity under bi-reforming reaction conditions; i.e.; in the presence of CO2 and steam: 3CH4+CO2+2H2O⇌4CO+8H2 Repeated TPR/TPO cycles showed that the two consecutive TPR spectra do not change, showing that the catalyst is stable at high temperatures, and that the nickel oxidation/reduction process is reversible. The catalyst showed constant activity with time at all temperatures in the range of 700-950 °C over a cumulative period of 170 h. After this series of bi-reforming tests, TPO of the spent catalyst was carried out, which showed detectable but unquantifiable carbon deposition. The presence of steam in bi-reforming greatly limits carbon deposition compared to directly related dry-reforming tests on this same catalyst., QC 20160520

OBJECTIVES: To investigate the suggested role of Porphyromonas gingivalis peptidylarginine deiminase (PAD) in the relationship between the aetiology of periodontal disease and experimentally induced arthritis and the possible association between these two conditions. METHODS: A genetically modified PAD-deficient strain of P. gingivalis W50 was produced. The effect of this strain, compared to the wild type, in an established murine model for experimental periodontitis and experimental arthritis was assessed. Experimental periodontitis was induced following oral inoculation with the PAD-deficient and wild type strains of P. gingivalis. Experimental arthritis was induced via the collagen antibody induction process and was monitored by assessment of paw swelling and micro-CT analysis of the radio-carpal joints. Experimental periodontitis was monitored by micro CT scans of the mandible and histological assessment of the periodontal tissues around the mandibular molars. Serum levels of anti-citrullinated protein antibodies (ACPA) and P. gingivalis were assessed by ELISA. RESULTS: The development of experimental periodontitis was significantly reduced in the presence of the PAD-deficient P. gingivalis strain. When experimental arthritis was induced in the presence of the PAD-deficient strain there was less paw swelling, less erosive bone damage to the joints and reduced serum ACPA levels when compared to the wild type P. gingivalis inoculated group. CONCLUSION: This study has demonstrated that a PAD-deficient strain of P. gingivalis was associated with significantly reduced periodontal inflammation. In addition the extent of experimental arthritis was significantly reduced in animals exposed to prior induction of periodontal disease through oral inoculation of the PAD-deficient strain versus the wild type. This adds further evidence to the potential role for P. gingivalis and its PAD in the pathogenesis of periodontitis and exacerbation of arthritis. Further studies are no

The 4MOST consortium is currently halfway through a Conceptual Design study for ESO with the aim to develop a wide-field (>3 square degree, goal >5 square degree), high-multiplex (>1500 fibres, goal 3000 fibres) spectroscopic survey facility for an ESO 4m-class telescope (VISTA). 4MOST will run permanently on the telescope to perform a 5 year public survey yielding more than 20 million spectra at resolution R∼5000 (λ=390-1000 nm) and more than 2 million spectra at R∼20,000 (395-456.5 nm & 587-673 nm). The 4MOST design is especially intended to complement three key all-sky, space-based observatories of prime European interest: Gaia, eROSITA and Euclid. Initial design and performance estimates for the wide-field corrector concepts are presented. Two fibre positioner concepts are being considered for 4MOST. The first one is a Phi-Theta system similar to ones used on existing and planned facilities. The second one is a new R-Theta concept with large patrol area. Both positioner concepts effectively address the issues of fibre focus and pupil pointing. The 4MOST spectrographs are fixed configuration two-arm spectrographs, with dedicated spectrographs for the high- and low-resolution fibres. A full facility simulator is being developed to guide trade-off decisions regarding the optimal field-of-view, number of fibres needed, and the relative fraction of high-to-low resolution fibres. The simulator takes mock catalogues with template spectra from Design Reference Surveys as starting point, calculates the output spectra based on a throughput simulator, assigns targets to fibres based on the capabilities of the fibre positioner designs, and calculates the required survey time by tiling the fields on the sky. The 4MOST consortium aims to deliver the full 4MOST facility by the end of 2018 and start delivering high-level data products for both consortium and ESO community targets a year later with yearly increments., Sponsors: The Society of Photo-Optical Instrumentation Engineers (SPIE)

Since the mid-1990s the Coorong, a 130-km-long coastal wetland of international importance in southeastern South Australia, has undergone serious decline due largely to prolonged drought and reduced inflows of surface and ground water from its hinterland. Tenuously connected to the ocean at its northern extremity, it is effectively separated into two lagoons by a narrow channel at its mid-point. The southern part is now permanently hypersaline. Here we report the results of an attempt to track the biogeochemical status of the estuary over the last 5000 years employing a consortium of elemental, isotopic and biomarker parameters. The sediment samples analysed came from two cores, each 6-7 m in length, retrieved from sites located halfway along the present-day northern and southern lagoons. The sediments at the southern locality are richer in total organic carbon and total nitrogen than those in the northern core reflecting higher net deposition of organic matter (OM) and nutrients in the southern lagoon. Comparison of the delta C-13(org) and delta N-15 profiles of the two cores reveals that the lower reaches of the Coorong have always been a restricted, O-2 depleted water body that is both more saline and prone to more intensive denitrification of NO3- (aq) than the northern lagoon. Prominent among the aliphatic hydrocarbons preserved in the sediments of the southern lagoon are the C-20 highly branched isoprenoid (HBI), 2,6,10-trimethyl-7-(3-methylbutyl)-dodecane, a putative marker of epiphytic diatoms, and C-15-C-35 n-alkanes with a marked odd/even predominance in the C-21, range. These and other biomarkers are consistent with OM derived from a mixed population of algae, cyanobacteria and other eubacteria.The C isotopic signature of the HBI alkane is consistently heavier than those of the C-23, C-25, C-27 and C-29 n-alkanes (presumably from planktonic chlorophytes +/- aquatic metaphytes), which in turn are heavier than the coexisting even-carbon-numbered homologues

We determine the metallicity distribution function (MDF) of the Galactic halo by means of a sample of 1638 metal-poor stars selected from the Hamburg/ESO objective-prism survey (HES). The sample was corrected for minor biases introduced by the strategy for spectroscopic follow-up observations of the metal-poor candidates, namely "best and brightest stars first". Comparison of the metallicities [Fe/H] of the stars determined from moderate-resolution (i.e., R similar to 2000) follow-up spectra with results derived from abundance analyses based on high-resolution spectra (i.e., R > 20 000) shows that the [Fe/H] estimates used for the determination of the halo MDF are accurate to within 0.3 dex, once highly C-rich stars are eliminated. We determined the selection function of the HES, which must be taken into account for a proper comparison between the HES MDF with MDFs of other stellar populations or those predicted by models of Galactic chemical evolution. The latter show a reasonable agreement with the overall shape of the HES MDF for [Fe/H] > -3.6, but only a model of Salvadori et al. (2007) with a critical metallicity for low-mass star formation of Z(cr) = 10(-3.4) Z(circle dot) reproduces the sharp drop at [Fe/H] similar to -3.6 present in the HES MDF. Although currently about ten stars at [Fe/H] < -3.6 are known, the evidence for the existence of a tail of the halo MDF extending to [Fe/H] similar to -5.5 is weak from the sample considered in this paper, because it only includes two stars [Fe/H] < -3.6. Therefore, a comparison with theoretical models has to await larger statistically complete and unbiased samples. A comparison of the MDF of Galactic globular clusters and of dSph satellites to the Galaxy shows qualitative agreement with the halo MDF, derived from the HES, once the selection function of the latter is included. However, statistical tests show that the differences between these are still highly significant.

Titanium alloy has been used as a material for orthopaedic implants, however drawbacks still exist. Considerable efforts have been taken to modify the surface structure of the implant material and improve the biological performance. Previously we have demonstrated that biomaterials surface modification has a significant effect on the regulation of osteogenesis. We have investigated the behaviour of human osteoclasts on sol-gel coated carbonated hydroxyapatite on anodized titanium alloy. Osteoclasts cultured on the modified surface were able to attach and spread, exhibiting the characteristic peripheral brush border. Successful differentiation of the monocytes into osteoclasts and their attachment to the coated surface and the formation of resorption-like imprints indicated that carbonate hydroxyapatite (CHAP) coated titanium alloy play a significant role in regulating the functional activity of osteoclasts.