We present the first application of a 'multiple-tracer' redshift-space distortion (RSD) analysis to an observational galaxy sample, using data from the Galaxy and Mass Assembly (GAMA) survey. Our ...data set is an r < 19.8 magnitude-limited sample of 178 579 galaxies covering the redshift interval z < 0.5 and area 180 deg2. We obtain improvements of 10-20 per cent in measurements of the gravitational growth rate compared to a single-tracer analysis, deriving from the correlated sample variance imprinted in the distributions of the overlapping galaxy populations. We present new expressions for the covariances between the auto-power and cross-power spectra of galaxy samples that are valid for a general survey selection function and weighting scheme. We find no evidence for a systematic dependence of the measured growth rate on the galaxy tracer used, justifying the RSD modelling assumptions, and validate our results using mock catalogues from N-body simulations. For multiple tracers selected by galaxy colour, we measure normalized growth rates in two independent redshift bins f...8(z = 0.18) = 0.36 ± 0.09 and f...8(z = 0.38) = 0.44 ± 0.06, in agreement with standard GR gravity and other galaxy surveys at similar redshifts. (ProQuest: ... denotes formulae/symbols omitted.)
Abstract
The galaxy pairwise velocity dispersion (PVD) can provide important tests of non-standard gravity and galaxy formation models. We describe measurements of the PVD of galaxies in the Galaxy ...and Mass Assembly (GAMA) survey as a function of projected separation and galaxy luminosity. Due to the faint magnitude limit (r < 19.8) and highly complete spectroscopic sampling of the GAMA survey, we are able to reliably measure the PVD to smaller scales (r⊥ = 0.01 h − 1 Mpc) than previous work. The measured PVD at projected separations r⊥ ≲ 1 h − 1 Mpc increases near monotonically with increasing luminosity from σ12 ≈ 200 km s − 1 at Mr = −17 mag to σ12 ≈ 600 km s − 1 at Mr ≈ −22 mag. Analysis of the Gonzalez-Perez et al. (2014) galform semi-analytic model yields no such trend of PVD with luminosity: the model overpredicts the PVD for faint galaxies. This is most likely a result of the model placing too many low-luminosity galaxies in massive haloes.
•A high-kinetic flotation machine has been developed for fine particle flotation.•Pilot- and full-scale tests show an order of magnitude improvement in flotation rate.•Results from multiple ...pilot-scale investigations for sulfide recovery are presented.•StackCell reduces power, foundation loads, space requirements and capital investment.
For decades, the conventional flotation machine has been the accepted tool for processing sulfide ores. As plant capacity increases, machine size has evolved to as much as 600 cubic meters to keep pace with the required retention times. However, the excessively large size of these machines requires extreme floor space, foundations and power to operate. Recent work conducted by Eriez has shown that high-efficiency flotation machines which are based on focused energy input can achieve similar results with significantly less retention time, floor space and power. Comparable performance is achieved through intense contacting in a separate chamber which provides concentrated energy input focused specifically on bubble/particle interaction. When compared to conventional technology, data show that this novel approach can achieve the same recovery as a mechanical cell in a fraction of the residence time. This paper will discuss the theory of operation of the StackCell™ and present data from various lab- and pilot-scale test programs.
The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters ...and trace the evolution of X-ray scaling relations. In this paper we present the first data release from the XMM Cluster Survey (XCS-DR1). This consists of 503 optically confirmed, serendipitously detected, X-ray clusters. Of these clusters, 256 are new to the literature and 357 are new X-ray discoveries. We present 463 clusters with a redshift estimate (0.06 < z < 1.46), including 261 clusters with spectroscopic redshifts. The remainder have photometric redshifts. In addition, we have measured X-ray temperatures (T
X) for 401 clusters (0.4 < T
X < 14.7 keV). We highlight seven interesting subsamples of XCS-DR1 clusters: (i) 10 clusters at high redshift (z > 1.0, including a new spectroscopically confirmed cluster at z= 1.01); (ii) 66 clusters with high T
X (>5 keV); (iii) 130 clusters/groups with low T
X (<2 keV); (iv) 27 clusters with measured T
X values in the Sloan Digital Sky Survey (SDSS) 'Stripe 82' co-add region; (v) 77 clusters with measured T
X values in the Dark Energy Survey region; (vi) 40 clusters detected with sufficient counts to permit mass measurements (under the assumption of hydrostatic equilibrium); (vii) 104 clusters that can be used for applications such as the derivation of cosmological parameters and the measurement of cluster scaling relations. The X-ray analysis methodology used to construct and analyse the XCS-DR1 cluster sample has been presented in a companion paper, Lloyd-Davies et al.
Engagement of Fcγ-receptors triggers a range of downstream signalling events resulting in a diverse array of immune functions. As a result, blockade of Fc-mediated function is an important strategy ...for the control of several autoimmune and inflammatory conditions. We have generated a hexameric-Fc fusion protein (hexameric-Fc) and tested the consequences of multi-valent Fcγ-receptor engagement in in vitro and in vivo systems. In vitro engagement of hexameric-Fc with FcγRs showed complex binding interactions that altered with receptor density and triggered the internalisation and degradation of Fcγ-receptors. This caused a disruption of Fc-binding and phagocytosis. In vivo, in a mouse ITP model we observed a short half-life of hexameric-Fc but were nevertheless able to observe inhibition of platelet phagocytosis several days after hexameric-Fc dosing. In cynomolgus monkeys, we again observed a short half-life, but were able to demonstrate effective FcγR blockade. These findings demonstrate the ability of multi-valent Fc-based therapeutics to interfere with FcγR function and a potential mechanism through which they could have a sustained effect; the internalisation and degradation of FcγRs.
In this work, we investigate in detail the effects the local environment (groups and pairs) has on galaxies with stellar mass similar to the Milky Way (L* galaxies). A volume limited sample of 6150 ...galaxies are visually classified to determine the emission features, morphological type and presence of a disc. This large sample allows for the significant characteristics of galaxies to be isolated (e.g. stellar mass and group halo mass), and their codependencies determined.
We observe that galaxy-galaxy interactions play the most important role in shaping the evolution within a group halo; the main role of halo mass is in gathering the galaxies together to encourage such interactions. Dominant pair galaxies find their overall star formation enhanced when the pair's mass ratio is close to 1; otherwise, we observe the same galaxies as we would in an unpaired system. The minor galaxy in a pair is greatly affected by its companion galaxy, and while the star-forming fraction is always suppressed relative to equivalent stellar mass unpaired galaxies, it becomes lower still when the mass ratio of a pair system increases.
We find that, in general, the close galaxy-galaxy interaction rate drops as a function of halo mass for a given amount of stellar mass. We find evidence of a local peak of interactions for Milky Way stellar mass galaxies in Milky Way halo mass groups. Low-mass haloes, and in particular Local Group mass haloes, are an important environment for understanding the typical evolutionary path of a unit of stellar mass.
We find compelling evidence for galaxy conformity in both groups and pairs, where morphological type conformity is dominant in groups, and emission class conformity is dominant in pairs. This suggests that group scale conformity is the result of many galaxy encounters over an extended period of time, while pair conformity is a fairly instantaneous response to a transitory interaction.
We present a direct measurement of the mean halo occupation distribution (HOD) of galaxies taken from the eleventh data release (DR11) of the Sloan Digital Sky Survey-III Baryon Oscillation ...Spectroscopic Survey (BOSS). The HOD of BOSS low-redshift (LOWZ: 0.2 < z < 0.4) and Constant-Mass (CMASS: 0.43 < z < 0.7) galaxies is inferred via their association with the dark matter haloes of 174 X-ray-selected galaxy clusters drawn from the XMM Cluster Survey (XCS). Halo masses are determined for each galaxy cluster based on X-ray temperature measurements, and range between log sub( 10)(M sub( 180)/M...) = 13 and 15. Our directly measured HODs are consistent with the HOD-model fits inferred via the galaxy-clustering analyses of Parejko et al. for the BOSS LOWZ sample and White et al. for the BOSS CMASS sample. Under the simplifying assumption that the other parameters that describe the HOD hold the values measured by these authors, we have determined a best-fitting alpha-index of 0.91 plus or minus 0.08 and 1.27... for the CMASS and LOWZ HOD, respectively. These alpha-index values are consistent with those measured by White et al. and Parejko et al. In summary, our study provides independent support for the HOD models assumed during the development of the BOSS mock-galaxy catalogues that have subsequently been used to derive BOSS cosmological constraints. (ProQuest: ... denotes formulae/symbols omitted.)
In this study we compared the results of three methods of fixation for scaphoid non-union. The implants used were the AO 2 mm mini-fragment screw, the Herbert screw and the Kirschner (K) wires. ...Between 1990 and 1999, 132 patients underwent surgery for scaphoid fractures. We used the modified Filan and Herbert classification. Patients with acute fractures and patients requiring vascularised bone grafts were excluded. Twenty-six non-unions were fixed with an AO mini-fragment screw, 58 with a Herbert screw, and nine with K-wires. Radiological union was achieved in 85% of cases using the AO screw, 77% using the Herbert screw and 55% using the K-wire fixation. Statistically there was no significant difference between the AO and Herbert screw groups in terms of rate and speed of radiological union. The mechanical strength of the implant and the compression achieved did not seem to influence the union rate and speed. The type of bone graft (iliac crest or distal radius) did not significantly affect the union rates. Finally, K-wire fixation, either as a primary method or as a salvage procedure, produced inferior results and required prolonged immobilisation in plaster.
Background:
Anti-drug antibodies (ADA) against natalizumab develop early during treatment. ADA persistency is defined by two consecutive positive results as performed by the current qualitative ELISA ...assay (positive/negative). Very little is known about the magnitude of the natalizumab ADA response and persistency.
Design/methods:
We developed a highly sensitive natalizumab ADA titration assay on the Meso Scale Discovery (MSD) platform and a pharmacokinetic (PK) assay. We included 43 patients with a positive ELISA-ADA result within 6 months of treatment initiation (baseline) of whom a follow-up serum sample was available 12–30 months after treatment start. MSD-ADA titres and drug levels were measured.
Results:
Median MSD-ADA titre at baseline was 4881 and 303 at follow-up. A titre of >400 at baseline had a 94% sensitivity and 89% specificity to predict ADA persistency. Reversion to ADA negativity occurred in 10 patients with mean drug levels of 10.8 μg/mL. The median trough drug level in ADA-positive samples was 0 µg/mL. PK levels and ADA titres correlated strongly negatively (r = −0.67).
Conclusion:
High baseline natalizumab ADA titres accurately predict persistency. Despite continuous treatment, the majority of patients with persistent ADA had no detectable drug levels indicating loss of efficacy in line with phase 3 study results.
The microstructural evolution of titanium alloys during subtransus isothermal forging (IF) has been effectively demonstrated using a testing methodology developed at Imperial College London. Double ...truncated cone specimen geometries were isothermally deformed at near beta transus temperatures to obtain microstructural information for a range of strains within a single specimen. The methodology was applied to the near beta alloy, Ti-10V-2Fe-3Al, to determine the effect of strain, strain rate, and IF subtransus temperature on microstructural evolution.
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