Context. The Gaia mission has released the second data set (Gaia DR2), which contains parallaxes and proper motions for a large number of massive, young stars. Aims. We investigate the spiral ...structure in the solar neighborhood revealed by Gaia DR2 and compare it with that depicted by VLBI maser parallaxes. Methods. We examined three samples with different constraints on parallax uncertainty and distance errors and stellar spectral types: (1) all OB stars with parallax errors of less than 10%; (2) only O-type stars with 0.1 mas errors imposed and with parallax distance errors of less than 0.2 kpc; and (3) only O-type stars with 0.05 mas errors imposed and with parallax distance errors of less than 0.3 kpc. Results. In spite of the significant distance uncertainties for stars in DR2 beyond 1.4 kpc, the spiral structure in the solar neighborhood demonstrated by Gaia agrees well with that illustrated by VLBI maser results. The O-type stars available from DR2 extend the spiral arm models determined from VLBI maser parallaxes into the fourth Galactic quadrant, and suggest the existence of a new spur between the Local and Sagittarius arms.
The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a ...full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5
σ
, for all
δ
CP
values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3
σ
(5
σ
) after an exposure of 5 (10) years, for 50% of all
δ
CP
values. It will also make precise measurements of other parameters governing long-baseline neutrino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to
sin
2
2
θ
13
to current reactor experiments.
Background & Aims
Increases in mucosal immune cells have frequently been observed in irritable bowel syndrome (IBS) patients. However, this finding is not completely consistent between studies, ...possibly due to a combination of methodological variability, population differences and small sample sizes. We performed a meta‐analysis of case–control studies that compared immune cell counts in colonic biopsies of IBS patients and controls.
Methods
PubMed and Embase were searched in February 2017. Results were pooled using standardized mean difference (SMD) and were considered significant when zero was not within the 95% confidence interval (CI). Heterogeneity was assessed based on I2 statistics where I2 ≤ 50% and I2 > 50% indicated fixed and random effect models, respectively.
Key Results
Twenty‐two studies on 706 IBS patients and 401 controls were included. Mast cells were increased in the rectosigmoid (SMD: 0.38 95% CI: 0.06‐0.71; P = .02) and descending colon (SMD: 1.69 95% CI: 0.65‐2.73; P = .001) of IBS patients. Increased mast cells were observed in both constipation (IBS‐C) and diarrhea predominant IBS (IBS‐D). CD3+ T cells were increased in the rectosigmoid (SMD: 0.53 95% CI: 0.21‐0.85; P = .001) and the descending colon of the IBS patients (SMD: 0.79, 95% CI 0.28‐1.30; P = .002). This was possibly in relation to higher CD4+ T cells in IBS (SMD: 0.33 95% CI: 0.01‐0.65; P = .04) as there were no differences in CD8+ T cells.
Conclusions & Inferences
Mast cells and CD3+ T cells are increased in colonic biopsies of patients with IBS vs non‐inflamed controls. These changes are segmental and sometimes IBS‐subtype dependent. The diagnostic value of the quantification of colonic mucosal cells in IBS requires further investigation.
Studies have indicated changes in the intestinal immune cell counts of IBS patients; however, these findings are not consistent. The current study shows that the number of colonic mast cells, CD3+ T cells and CD4+ T cells are increased in IBS. These changes are colonic segmental and sometimes IBS‐subtype dependent. Figure shows density/number of mast cells in colorectal biopsies of patients with IBS vs healthy controls. (A) Ascending colon, (B) Descending colon, (C) Rectosigmoid.
In components built by selective laser melting (SLM), possible anisotropy in microstructure significantly affects mechanical properties (i.e. service performance) and there is a constant effort to ...solve this problem. This work carried out a comparative study using fully dense AlSi10Mg alloy and in-situ nano-TiB2 decorated AlSi10Mg composite samples processed by SLM. The aim was at clarifying the effect of integrated nanoparticles on the anisotropy of the as-built component. Microstructure and texture evolution were investigated by scanning and transmission electron microscopy, electron backscatter diffraction, X-ray and neutron diffraction. The SLMed AlSi10Mg sample shows a coarse columnar grain structure with and fiber orientation texture and obvious anisotropy in mechanical properties. However, the nano-TiB2 modified AlSi10Mg sample exhibits fine equiaxed grains, no preferred crystallographic texture and remarkably reduced anisotropy. Besides, both tensile strength and ductility have been improved in the SLMed TiB2 decorated AlSi10Mg sample. The preliminary mechanism upon grain refinement effect due to nano-TiB2 particles on columnar-to-equiaxed transition and reduction of anisotropy was discussed.
Display omitted
•A competition growth of and fiber texture is found in SLMed Al alloy.•The introduction of TiB2 eliminates texture and anisotropic mechanical behavior.•Random orientation of TiB2 nucleation agents determines random orientation of Al.•Both strength and ductility have been improved in SLMed TiB2/AlSi10Mg alloy.
Abstract We report measurements of trigonometric parallax and proper motion for two 6.7 GHz methanol and two 22 GHz water masers located in the far portion of the Sagittarius spiral arm as part of ...the BeSSeL Survey. Distances for these sources are estimated from parallax measurements combined with three-dimensional kinematic distances. The distances of G033.64−00.22, G035.57−00.03, G041.15−00.20, and G043.89−00.78 are 9.9 ± 0.5, 10.2 ± 0.6, 7.6 ± 0.5, and 7.5 ± 0.3 kpc, respectively. Based on these measurements, we suggest that the Sagittarius arm segment beyond about 8 kpc from the Sun in the first Galactic quadrant should be adjusted radially outward relative to previous models. This supports the suggestion of Xu et al. that the Sagittarius and Perseus spiral arms might merge in the first quadrant before spiraling inward to the far end of the Galactic bar.
The Deep Underground Neutrino Experiment (DUNE), a 40-kton underground liquid argon time projection chamber experiment, will be sensitive to the electron-neutrino flavor component of the burst of ...neutrinos expected from the next Galactic core-collapse supernova. Such an observation will bring unique insight into the astrophysics of core collapse as well as into the properties of neutrinos. The general capabilities of DUNE for neutrino detection in the relevant few- to few-tens-of-MeV neutrino energy range will be described. As an example, DUNE’s ability to constrain the
ν
e
spectral parameters of the neutrino burst will be considered.
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