We present a three-dimensional (3D) extinction map of the southern sky. The map covers the SkyMapper Southern Survey (SMSS) area of ∼14,000 deg2 and has spatial resolutions between 6 9 and 27′. Based ...on the multi-band photometry of SMSS, the Two Micron All Sky Survey, the Wide-Field Infrared Survey Explorer Survey, and the Gaia mission, we have estimated values of the r-band extinction for ∼19 million stars with the spectral energy distribution analysis. Together with the distances calculated from the Gaia data release 2 (DR2) parallaxes, we have constructed a 3D extinction map of the southern sky. By combining our 3D extinction map with those from the literature, we present an all-sky 3D extinction map, and use it to explore the 3D distribution of the Galactic dust grains. We use two different models, one consisting of a single disk and another of two disks, to fit the 3D distribution of the Galactic dust grains. The data is better fitted by a two-disk model, yielding smaller values of the Bayesian Information Criterion. The best-fit model has scale heights of 73 and 225 pc for the "thin" and "thick" dust disks, respectively.
Using a sample of nearly 140,000 primary red-clump stars selected from the LAMOST and Gaia surveys, we have identified a large sample of "young" /Fe-enhanced stars with stellar ages younger than 6.0 ...Gyr and /Fe ratios greater than 0.15 dex. The stellar ages and /Fe ratios are measured from LAMOST spectra, using a machine-learning method trained with common stars in the LAMOST-APOGEE fields (for /Fe) and in the LAMOST-Kepler fields (for stellar age). The existence of these "young" /Fe-enhanced stars is not expected from the classical Galactic chemical evolution models. To explore their possible origins, we have analyzed the spatial distribution, and the chemical and kinematic properties of those stars and compared the results with those of the chemically thin and thick disk populations. We find that those "young" /Fe-enhanced stars have distributions in number density, metallicity, C/N abundance ratio, velocity dispersion, and orbital eccentricity that are essentially the same as those of the chemically thick disk population. Our results clearly show those so-called "young" /Fe-enhanced stars are not really young but genuinely old. Although other alternative explanations can not be fully ruled out, our results suggest that the most possible origin of these old stars is the result of stellar mergers or mass transfer.
The rotation curve (RC) of the Milky Way out to ~100 kpc has been constructed using ~16,000 primary red clump giants (PRCGs) in the outer disc selected from the LAMOST Spectroscopic Survey of the ...Galactic Anti-centre (LSS-GAC) and the Sloan Digital Sky Survey (SDSS)-III/APOGEE survey, combined with ~5700 halo K giants (HKGs) selected from the SDSS/SEGUE survey. To derive the RC, the PRCG sample of the warm disc population and the HKG sample of halo stellar population are, respectively, analysed using a kinematical model allowing for the asymmetric drift corrections and re-analysed using the spherical Jeans equation along with measurements of the anisotropic parameter beta currently available. The typical uncertainties of RC derived from the PRCG and HKG samples are, respectively, 5-7 km s super( -1) and several tens km s super( -1). We determine a circular velocity at the solar position, ... and an azimuthal peculiar speed of the Sun, ..., both in good agreement with the previous determinations. The newly constructed RC has a generally flat value of 240 km s super( -1) within a Galactocentric distance rof 25 kpc and then decreases steadily to 150 km s super( -1) at r ~ 100 kpc. On top of this overall trend, the RC exhibits two prominent localized dips, one at r ~ 11 kpc and another at r ~ 19 kpc. From the newly constructed RC, combined with other constraints, we have built a parametrized mass model for the Galaxy, yielding a virial mass of the Milky Way's dark matter halo of ... and a local dark matter density, ... (ProQuest: ... denotes formulae/symbols omitted.)
Soil acidification is a major problem in soils of intensive Chinese agricultural systems. We used two nationwide surveys, paired comparisons in numerous individual sites, and several long-term ...monitoring-field data sets to evaluate changes in soil acidity. Soil pH declined significantly (P < 0.001) from the 1980s to the 2000s in the major Chinese crop-production areas. Processes related to nitrogen cycling released 20 to 221 kilomoles of hydrogen ion (H⁺) per hectare per year, and base cations uptake contributed a further 15 to 20 kilomoles of H⁺ per hectare per year to soil acidification in four widespread cropping systems. In comparison, acid deposition (0.4 to 2.0 kilomoles of H⁺ per hectare per year) made a small contribution to the acidification of agricultural soils across China.
Whiteflies (Bemisia tabaci) are phloem feeders, and some invasive species are composed of cryptic species complexes that cause extensive crop damage, particularly via the direct transmission of plant ...viruses. Apoptosis is a type of programmed cell death essential for organismal development and tissue homeostasis. The caspases belong to a family of cysteine proteases that play a central role in the initiation of apoptosis in many organisms. Here, we employed a comprehensive genomics approach to identity caspases in B. tabaci Middle East Asia Minor 1 (MEAM1), an invasive whitefly that carries a cryptic species complex that is devastating to crops. Four caspase genes were identified, and their motif compositions were predicted. Structures were relatively conserved in both putative effector and initiator caspases. Expression patterns of caspase genes differed across insect developmental stages. Three caspase genes were induced immediately after ultraviolet (UV) treatment. Expression levels of Bt‐caspase‐1 and Bt‐caspase‐3b increased in the midgut and salivary glands during apoptosis induced by UV treatments, whereas silencing of both genes reduced UV‐triggered apoptosis. Our study demonstrates that Bt‐caspase‐1 and Bt‐caspase‐3b, respectively, act as putative initiator and effector apoptotic caspases in the MEAM1 whitefly.
Using a sample of nearly 140,000 red clump stars selected from the LAMOST and Gaia Galactic surveys, we have mapped mean vertical velocity in the X-Y plane for a large volume of the Galactic disk (6 ...< R < 16 kpc; −20 < φ < 50°; kpc). A clear signature where increases with R is detected for the chemically thin disk. The signature for the thick disk, however, is not significant, in line with the hot nature of this disk component. For the thin disk, the warp signature shows significant variations in both the radial and azimuthal directions, in excellent agreement with the previous results of star counts. Fitting the two-dimensional distribution of with a simple long-lived static warp model yields a line-of-node angle for this kinematic warp of about 12 5, again consistent with the previous results.
Protein serine/threonine phosphatase-1 (PP-1) is one of the key enzymes responsible for dephosphorylation in vertebrates. Protein dephosphorylation via PP-1 is implicated in many different biological ...processes including gene expression, cell cycle control, transformation, neuronal transmission, apoptosis, autophage and senescence. However, whether PP-1 directly controls animal development remains to be investigated. Here, we present direct evidence to show that PP-1 plays an essential role in regulating eye development of vertebrates. Using goldfish as a model system, we have shown the following novel results. First, inhibition of PP-1 activity leads to death of a majority of the treated embryos, and the survived embryos displayed severe phenotype in the eye. Second, knockdown of each catalytic subunit of PP-1 with morpholino oligomers leads to partial (PP-lα knockdown) or complete (PP-lβ or PP-lγ knockdown) death of the injected embryos. The survived embryos from PP-1α knockdown displayed clear retardation in lens differentiation. Finally, overexpression of each subunit of PP-1 also causes death of majority of the injected embryos and leads to abnormal development of goldfish eye. Mechanistically, Pax-6 is one of the major downstream targets mediating the effects of PP-1 function since the eye phenotype in Pax-6 knockdown fish is similar to that derived from overexpression of PP-1. Together, our results for the first time provide direct evidence that protein phosphatase-1 plays a key role in governing normal eye formation during goldfish development.
Tire-road friction coefficient is an important parameter for vehicle stability and active safety systems. However, precise measurement of tire-road friction coefficient is hard to achieve without ...expensive equipment. Considering easy availability and good economy, this paper proposes a method which first combines auxiliary particle filter and the iterated extended kalman filter (APF-IEKF), and then processes the results of the first step using iteration algorithm. APF-IEKF is used to estimate the slip angle of the front tires with strong nonlinearity and non-Gaussian noise, in which APF filters non-Gaussian noise and reach a preliminary estimation of sideslip angle, then IEKF is used to optimize the result, making the estimation of the sideslip angle more accurate. The iteration algorithm is used to estimate the tire-road friction coefficient based on self-aligning torque, which is more sensitive to tire slip angle and provides faster estimation. In this way, this method can estimate tire road friction coefficient more accurately and in real time. Both numerical simulation in Carsim/Simulink and actual off-vehicle tests in winter are provided to demonstrate the efficiency of the proposed algorithm.
•A method that combines APF-IEKF and iteration algorithm is proposed for tire-road friction coefficient.•Tire slip angle estimated by APF-IEKF is much more accurate than common UKF because it is fit for non-Gaussian noise.•Tire-road friction coefficient estimate by proposed method is also much more accurate.
By using the 'standard pair' technique of pairing stars of almost nil and high extinction but otherwise with almost identical stellar parameters from the Sloan Digital Sky Survey (SDSS), and ...combining this information with photometry from the SDSS, Galaxy Evolution Explorer (GALEX), Two Micron All Sky Survey (2MASS) and Wide-field Infrared Survey Explorer (WISE) photometry ranging from the far ultraviolet (UV) to the mid-infrared (mid-IR), we measure dust reddening in the FUV − NUV, NUV − u, u − g, g − r, r − i, i − z, z − J, J − H, H − Ks, Ks − W1 and W1 − W2 colours for thousands of Galactic stars. The measurements, together with the E(B − V) values given by Schlegel et al., allow us to derive the observed, model-free reddening coefficients for these colours. The results are compared with previous measurements and with the predictions of various Galactic reddening laws. We find that (i) the dust reddening map of Schlegel et al. overestimates E(B − V) by about 14 per cent, consistent with the recent work of Schlafly et al. and Schlafly & Finkbeiner; (ii) after accounting for the differences in reddening normalization, the newly deduced reddening coefficients for colours FUV − NUV, NUV − u, u − g, g − r, r − i, i − z, z − J, J − H and H − Ks differ by respectively −1640, 15.5, 12.6, −0.8, 3.4, −0.7, 3.5, 2.5 and 1.4 per cent from the predictions of the Fitzpatrick reddening law for an assumed total-to-selective extinction ratio R(V) = 3.1, and by respectively −1730, 13.0 , 8.1, 10.0, 8.0, −13.5, −1.7, −6.7 and −17.1 per cent from the predictions of the CCM reddening law; and (iii) all the new reddening coefficients, except those for NUV − u and u − g, favour the R(V) = 3.1 Fitzpatrick reddening law over the R(V) = 3.1 CCM and O'Donnell reddening laws. Using the Ks-band extinction coefficient predicted by the R(V) = 3.1 Fitzpatrick law and the observed reddening coefficients, we deduce new extinction coefficients for the FUV, NUV, u, g, r, i, z, J, H, W1 and W2 passbands. We recommend that the new reddening and extinction coefficients should be used in the future and that the Fitzpatrick reddening law in the UV should probably be updated. We stress, however, that the FUV- and NUV-band coefficients should be used with caution, given their relatively large measurement uncertainties. Finally, potential applications of the 'standard pair' technique with the upcoming LAMOST Galactic surveys are discussed.
A regulator of the protein phosphatase 2A (PP2A), α4, has been implicated in a variety of functions that regulate many cellular processes. To explore the role of α4 in human cell transformation and ...tumorigenesis, we show that α4 is highly expressed in human cells transformed by chemical carcinogens including benzo(a)pyrene, aflatoxin B(1), N-methyl-N'-nitro-N-nitrosoguanidine, nickel sulfate and in several hepatic and lung cancer cell lines. In addition, overexpression of α4 was detected in 87.5% (74/80) of primary hepatocellular carcinomas, 84.0% (21/25) of primary lung cancers and 81.8% (9/11) of primary breast cancers, indicating that α4 is ubiquitously highly expressed in human cancer. Functional studies revealed that elevated α4 expression results in an increase in cell proliferation, promotion of cell survival and decreased PP2A-attributable activity. Importantly, ectopic expression of α4 permits non-transformed human embryonic kidney cells (HEKTER) and L02R cells to form tumors in immunodeficient mice. Furthermore, we show that the highly expressed α4 in transformed cells or human tumors is not regulated by DNA hypomethylation. A microRNA, miR-34b, that suppresses the expression of α4 through specific binding to the 3'-untranslated region of α4 is downregulated in transformed or human lung tumors. Taken together, these observations identify that α4 possesses an oncogenic function. Reduction of PP2A activity due to an enhanced α4-PP2A interaction contributes directly to chemical carcinogen-induced tumorigenesis.
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