Targeting inflammatory pathways in axial spondyloarthritis.

The triggers and pathogenesis of axial spondyloarthritis (axSpA) are not yet completely understood. However, therapeutic agents targeting tumor necrosis factor-α and interleukin-17 inflammatory pathways have proven successful in suppressing many of the clinical symptoms and signs of axSpA, giving us an indication of which pathways are responsible for initiating and maintaining the inflammation. The mechanisms that eventuate in syndesmophytes and ankyloses are less clear. This review addresses these two critical pathways of inflammation, discussing their nature and these factors that may activate or enhance the pathways in patients with axSpA. In addition, genetic and other markers important to the inflammatory pathways implicated in axSpA are explored, and prognostic biomarkers are discussed. Treatment options available for the management of axSpA and their associated targets are highlighted

Measurement of the lunar neutron density profile

An in situ measurement of the lunar neutron density from 20 to 400 g/sq cm depth between the lunar surface was made by the Apollo 17 Lunar Neutron Probe Experiment using particle tracks produced by the B10(n, alpha)Li7 reaction. Both the absolute magnitude and depth profile of the neutron density are in good agreement with past theoretical calculations. The effect of cadmium absorption on the neutron density and in the relative Sm149 to Gd157 capture rates obtained experimentally implies that the true lunar Gd157 capture rate is about one half of that calculated theoretically

Observation of non-lithophile behavior for U

In the Hvittis enstatite chondrite fission track radiography shows that U is highly concentrated in CaS (oldhamite), with a concentration of 400±50 ppb. The oldhamite U concentrations are equilibrated, although intergrain concentration variations of less than 15% would not be detected. Various approaches to a U material balance do not agree, but at least 50% and, more likely, nearly 100% of the U is concentrated in CaS. It is likely that CaS is the major reservoir for other actinide and lanthanide elements as well. Consequently, enstatite chondrites may provide reliable Pu/U abundance ratios. The highly reducing formation conditions for enstatite chondrites have caused U to deviate from lithophile behaviour, but K is observed to remain lithophile. Although this observation may not be generalizable, we propose that discussions of radioactive heating of planetary cores should include U and Th and not focus exclusively on K

An upper limit on anomalous dust emission at 31 GHz in the diffuse cloud [LPH96]201.663+1.643

[LPH96]201.663+1.643, a diffuse H{\sc ii} region, has been reported to be a candidate for emission from rapidly spinning dust grains. Here we present Cosmic Background Imager (CBI) observations at 26-36 GHz that show no evidence for significant anomalous emission. The spectral index within the CBI band, and between CBI and Effelsberg data at 1.4/2.7 GHz, is consistent with optically thin free-free emission. The best-fitting temperature spectral index from 2.7 to 31 GHz, $\beta=-2.06 \pm 0.03$, is close to the theoretical value, $\beta=-2.12$ for $T_{e}=9100$ K. We place an upper limit of 24% ~ (2\sigma) for excess emission at 31 GHz as seen in a 6\arcmin FWHM beam. Current spinning dust models are not a good fit to the spectrum of LPH96. No polarized emission is detected in the CBI data with an upper limit of 2% on the polarization fraction.Comment: 5 pages, 3 figures, submitted to ApJ

The solar system boron abundance

The concentrations of B in seven carbonaceous chondritic meteorites have been determined by the use of two different analytical techniques. The data correspond to a B/H ratio of about 10^(-9) compared to the value of 10^(-8) previously proposed by Cameron, Colgate, and Grossman. However, the meteoritic abundance remains at least a factor of 2-10 higher than various estimates of the solar photosphere abundance. We conclude that both meteoritic and photospheric B and Be abundances must be considered in comparisons with nucleosynthesis calculations. Using our revised B abundances and assuming ^7Li was synthesized in the big bang, we find that the residual ^6Li/1°B, ^9Be/^(10)B, and ^(11)B/^(10)B abundance ratios are well matched by the production rates for bombardment of a CNO mixture of solar proportions by protons and a-particles with a kinetic energy per nucleon spectrum of the form E^(-1.8)

Fundamental Cycles and Graph Embeddings

In this paper we present a new Good Characterization of maximum genus of a graph which makes a common generalization of the works of Xuong, Liu, and Fu et al. Based on this, we find a new polynomially bounded algorithm to find the maximum genus of a graph

Magnetospheric particle acceleration and X-ray emission of pulsars

The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the surface of neutron star and trigger the acceleration of particles. The charged particles are accelerated mainly in the field of magneto-dipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magneto-dipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.Comment: minor correction on table format, 20 pages (4 figures, 1 table), submitted to International Journal of Modern Physics

Infrared Excess and Molecular Gas in the Galactic Worm GW46.4+5.5

We have carried out high-resolution (~3') HI and CO line observations along one-dimensional cuts through the Galactic worm GW46.4+5.5. By comparing the HI data with IRAS data, we have derived the distributions of I_100 excess and tau_100 excess, which are respectively the 100 mum intensity and 100 mum optical depth in excess of what would be expected from HI emission. In two observed regions, we were able to make a detailed comparison of the infrared excess and the CO emission. We have found that tau_100 excess has a very good correlation with the integrated intensity of CO emission, W_CO, but I_100 excess does not. There are two reasons for the poor correlation between I_100 excess and W_CO: firstly, there are regions with enhanced infrared emissivity without CO, and secondly, dust grains associated with molecular gas have a low infrared emissivity. In one region, these two factors completely hide the presence of molecular gas in the infrared. In the second region, we could identify the area with molecular gas, but I_100 excess significantly underestimates the column density of molecular hydrogen because of the second factor mentioned above. We therefore conclude that tau_100 excess, rather than I_100 excess, is an accurate indicator of molecular content along the line of sight. We derive tau_100/N(H)=(1.00+-0.02)*10^-5~(10^20 cm^-2)^-1, and X=N(H_2)/W_CO=~0.7*10^20 cm^-2 (K km s^-1)^-1. Our results suggest that I_100 excess could still be used to estimate the molecular content if the result is multiplied by a correction factor xi_c=_HI/_H_2 (~2 in the second region), which accounts for the different infrared emissivities of atomic and molecular gas. We also discuss some limitations of this work.Comment: 10 pages, 9 postscript figures, uses aas2pp4.sty to be published in Astrophyslcal Journa