Metabolic profiling predicts response to anti-tumor necrosis factor α therapy in patients with rheumatoid arthritis

<p>Objective: Anti–tumor necrosis factor (anti-TNF) therapies are highly effective in rheumatoid arthritis (RA) and psoriatic arthritis (PsA), but a significant number of patients exhibit only a partial or no therapeutic response. Inflammation alters local and systemic metabolism, and TNF plays a role in this. We undertook this study to determine if the patient's metabolic fingerprint prior to therapy could predict responses to anti-TNF agents.</p> <p>Methods: Urine was collected from 16 RA patients and 20 PsA patients before and during therapy with infliximab or etanercept. Urine metabolic profiles were assessed using nuclear magnetic resonance spectroscopy. Discriminating metabolites were identified, and the relationship between metabolic profiles and clinical outcomes was assessed.</p> <p>Results: Baseline urine metabolic profiles discriminated between RA patients who did or did not have a good response to anti-TNF therapy according to European League Against Rheumatism criteria, with a sensitivity of 88.9% and a specificity of 85.7%, with several metabolites contributing (in particular histamine, glutamine, xanthurenic acid, and ethanolamine). There was a correlation between baseline metabolic profiles and the magnitude of change in the Disease Activity Score in 28 joints from baseline to 12 months in RA patients (P = 0.04). In both RA and PsA, urinary metabolic profiles changed between baseline and 12 weeks of anti-TNF therapy. Within the responders, urinary metabolite changes distinguished between etanercept and infliximab treatment.</p> <p>Conclusion: The clear relationship between urine metabolic profiles of RA patients at baseline and their response to anti-TNF therapy may allow development of novel approaches to the optimization of therapy. Differences in metabolic profiles during treatment with infliximab and etanercept in RA and PsA may reflect distinct mechanisms of action.</p&gt

A Universal Vertical Stellar Density Distribution Law for the Galaxy

We reduced the observational logarithmic space densities in the vertical direction up to 8 kpc from the galactic plane, for stars with absolute magnitudes (5,6], (6,7] and [5,10] in the fields #0952+5245 and SA114, to a single exponential density law. One of three parameters in the quadratic expression of the density law corresponds to the local space density for stars with absolute magnitudes in question. There is no need of any definition for scaleheights or population types. We confirm with the arguments of non-discrete thin and thick discs for our Galaxy and propose a single structure up to several kiloparsecs from the galactic plane. The logarithmic space densities evaluated by this law for the ELAIS field fit to the observational ones. Whereas, there are considerable offsets for the logarithmic space densities produced by two sets of classical galactic model parameters from the observational ones, for the same field.Comment: 9 pages, 1 figure and 10 tables, accepted for publication in Astrophysics & Space Scienc

An improved instrumental variable method for industrial robot model identification

Abstract Industrial robots are electro-mechanical systems with double integrator behaviour, necessitating operation and model identification under closed-loop control conditions. The Inverse Dynamic Identification Model (IDIM) is a mechanical model based on Newton’s laws that has the advantage of being linear with respect to the parameters. Existing Instrumental Variable (IDIM-IV) estimation provides a robust solution to this estimation problem and the paper introduces an improved IDIM-PIV method that takes account of the additive noise characteristics by adding prefilters that provide lower variance estimates of the IDIM parameters. Inspired by the prefiltering approach used in optimal Refined Instrumental Variable (RIV) estimation, the IDIM-PIV method identifies the nonlinear physical model of the robot, as well as the noise model resulting from the feedback control system. It also has the advantage of providing a systematic prefiltering process, in contrast to that required for the previous IDIM-IV method. The issue of an unknown controller is also considered and resolved using existing parametric identification. The evaluation of the new estimation algorithms on a six degrees-of-freedom rigid robot shows that they improve statistical efficiency, with the controller either known or identified as an intrinsic part of the IDIM-PIV algorithm

Electronics Letters

The optimal refined instrumental variable method for the estimation of the Box-Jenkins (BJ) model is modified so that it functions as an optimal filter and state-estimation algorithm. In contrast to the previously developed minimal and non-minimal state-space (NMSS) forms for an Auto-Regressive Moving Average with eXogenous variables (ARMAX) model, the new algorithm requires the introduction of a novel extended NMSS form. This facilitates representation of the more general noise component of the BJ model. The approach can be used for adaptive filtering and state variable feedback control

EUV Spectra of the Full Solar Disk: Analysis and Results of the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS)

We analyze EUV spectra of the full solar disk from the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS) spanning a period of two years. The observations were obtained via a fortuitous off-axis light path in the 140 -- 270 Angstrom passband. The general appearance of the spectra remained relatively stable over the two-year time period, but did show significant variations of up to 25% between two sets of Fe lines that show peak emission at 1 MK and 2 MK. The variations occur at a measured period of 27.2 days and are caused by regions of hotter and cooler plasma rotating into, and out of, the field of view. The CHIANTI spectral code is employed to determine plasma temperatures, densities, and emission measures. A set of five isothermal plasmas fit the full disk spectra well. A 1 -- 2 MK plasma of Fe contributes 85% of the total emission in the CHIPS passband. The standard Differential Emission Measures (DEMs) supplied with the CHIANTI package do not fit the CHIPS spectra well as they over-predict emission at temperatures below log(T) = 6.0 and above log(T) = 6.3. The results are important for cross-calibrating TIMED, SORCE, SOHO/EIT, and CDS/GIS, as well as the recently launched Solar Dynamics Observatory.Comment: 27 Pages, 13 Figure

The Influences of Diesel Particulate Filter Installation on Air Pollutant Emissions for Used Vehicles

Three kinds of diesel particulate filters (DPFs) were installed on used diesel-powered vehicles to investigate their influences on air pollutant emissions. The air pollutant emissions were measured before, after and running for specific distances to assess the deterioration effect. The emission measurement was performed on a chassis dynamometer. The results show that emissions of smoke, CO and HC are all reduced after DPF installation. After 20000 km driving, the emission concentrations of the above 3 criteria air pollutants do not increase in comparison with that right after installation. When DPFs are installed, the emissions of PAHs (polycyclic aromatic hydrocarbons) are reduced by 85.6-89.4% and 69.0-89.2% for heavy-duty diesel vehicles (HDVs) and light-duty diesel vehicles (LDVs), respectively. After driving 20000 km for HDVs and 2500 km for LDVs, PAH emissions do not increase in comparison with that right after installation, indicating that the DPFs do not deteriorate after driving for the test mileages. The lower molecular weight PAHs predominates in the exhaust both before and after DPF installation. The results also show the reduction rate is higher for higher molecular weight PAHs due to their tendency to adsorb on particulate

Hexatic-Herringbone Coupling at the Hexatic Transition in Smectic Liquid Crystals: 4-ϵ\epsilon Renormalization Group Calculations Revisited

Simple symmetry considerations would suggest that the transition from the smectic-A phase to the long-range bond orientationally ordered hexatic smectic-B phase should belong to the XY universality class. However, a number of experimental studies have constantly reported over the past twenty years "novel" critical behavior with non-XY critical exponents for this transition. Bruinsma and Aeppli argued in Physical Review Letters {\bf 48}, 1625 (1982), using a $4-\epsilon$ renormalization-group calculation, that short-range molecular herringbone correlations coupled to the hexatic ordering drive this transition first order via thermal fluctuations, and that the critical behavior observed in real systems is controlled by a `nearby' tricritical point. We have revisited the model of Bruinsma and Aeppli and present here the results of our study. We have found two nontrivial strongly-coupled herringbone-hexatic fixed points apparently missed by those authors. Yet, those two new nontrivial fixed-points are unstable, and we obtain the same final conclusion as the one reached by Bruinsma and Aeppli, namely that of a fluctuation-driven first order transition. We also discuss the effect of local two-fold distortion of the bond order as a possible missing order parameter in the Hamiltonian.Comment: 1 B/W eps figure included. Submitted to Physical Review E. Contact: [email protected]

Nucleon mass and sigma term from lattice QCD with two light fermion flavors

We analyze Nf=2 nucleon mass data with respect to their dependence on the pion mass down to mpi = 157 MeV and compare it with predictions from covariant baryon chiral perturbation theory (BChPT). A novel feature of our approach is that we fit the nucleon mass data simultaneously with the directly obtained pion-nucleon sigma-term. Our lattice data below mpi = 435 MeV is well described by O(p^4) BChPT and we find sigma=37(8)(6) MeV for the sigma-term at the physical point. Using the nucleon mass to set the scale we obtain a Sommer parameter of r_0=0.501(10)(11) fm.Comment: 26 pages, 11 figures, 5 tables. Version to appear in NPB with a few more details on the fit parameter

Agronomic biofortification of leafy vegetables grown in an Oxisol, Alfisol and Vertisol with isotopically labelled selenium (77Se)

Selenium biofortification of crops is a proven technology for improving dietary nutrition. This study used isotopically labelled selenate (>99% enriched 77Se) to assess uptake and Se availability to two green vegetables, Brassica napus L (B. napus) and Amaranthus retroflexus L (A. retroflexus) grown in three contrasting Malawi soils: a Vertisol (calcareous), Alfisol (moderately acidic) and Oxisol (acidic). Plants were grown under glasshouse conditions (4 replicates; 6 kg soil per pot) following application of 77Se-enriched selenate at rates equivalent to 0, 10 and 20 g ha−1. Leaves were harvested at fortnightly intervals and the plants were then allowed to re-grow, to simulate cultivation practice. Leaf samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) for selenium isotopes (77Se and 78Se). The isotopic data were processed to quantify the contribution to plant Se concentration from the fertilizer and the soil. Both concentration and uptake of the fertilizer 77Se declined sharply with sequential harvests due to progressive fixation of 77Se in the soil rather than exhaustion (by uptake) of the Se applied. Initially the bioavailability of fertilizer Se was three orders of magnitude greater than the soil Se but this declined to the same order of magnitude by the end of the trial. Application of 77Se had no effect on uptake of soil-derived Se. There were marked differences between the three soils studied. The relative bio-availability of the fertilizer Se followed the sequence (Vertisol > Alfisol > Oxisol) but the two crops showed the same trend in decline of fertilizer Se uptake. Thus, fixation of selenium in the soils studied was sufficiently rapid that Se biofortification of green vegetables subject to several harvests would require multiple applications during the growing season

Spin density wave dislocation in chromium probed by coherent x-ray diffraction

We report on the study of a magnetic dislocation in pure chromium. Coherent x-ray diffraction profiles obtained on the incommensurate Spin Density Wave (SDW) reflection are consistent with the presence of a dislocation of the magnetic order, embedded at a few micrometers from the surface of the sample. Beyond the specific case of magnetic dislocations in chromium, this work may open up a new method for the study of magnetic defects embedded in the bulk.Comment: 8 pages, 7 figure