Needle δ13C and mobile carbohydrates in Pinus koraiensis in relation to decreased temperature and increased moisture along an elevational gradient in NE China

A tree's crown interacts with atmospheric variables such as CO2, temperature, and humidity. Physioecology of leaves/needles (e.g. δ13C, mobile carbohydrates, and nitrogen) is, therefore, strongly affected by microclimate in and surrounding a tree crown. To understand the physiological responses of leaves to changes in air temperature and moisture, we measured δ13C, soluble sugars, starch, and total nitrogen (N) concentrations in current year and 1-yr-old needles of Pinus koraiensis trees, and compared the growing season air temperature and relative humidity within and outside P. koraiensis crowns along an elevational gradient from 760 to 1,420ma.s.l. on Changbai Mountain, NE China. Our results indicated that needle N and mobile carbohydrates concentrations, as well as needle δ13C values changed continuously with increasing elevation, corresponding to a continuous decrease in air temperature and an increase in relative humidity. Needle carbon and nitrogen status is highly significantly negatively correlated with temperature, but positively correlated with relative humidity. These results indicate that increases in air temperature in combination with decreases in relative humidity may result in lower levels of N and mobile carbohydrates in P. koraiensis trees, suggesting that future climate changes such as global warming and changes in precipitation patterns will directly influence the N and carbon physiology at P. koraiensis individual level, and indirectly affect the competitive ability, species composition, productivity and functioning at the stand and ecosystem level in NE China. Due to the relatively limited range of the transect (760-1,420m) studied, further research is needed to explain whether the present results are applicable to scales across large elevational gradient

The impact of urban trees on concentrations of PAHs and other gaseous air pollutants in Yanji, northeast China

It is generally conceived that trees can clean polluted air in urban areas sufficiently enough to be considered providers of a vital ecosystem service, although there have not been many field studies showing this in practice in the neighbourhood scale. Using passive sampling methods, we investigated the effect of urban park trees on the concentrations of gaseous polycyclic aromatic hydrocarbons (PAHs), nitrogen dioxide (NO2), ground-level ozone (O3) and sulfur dioxide (SO2) in early summer in the temperate zone city of Yanji, northeast China. Concentrations of total gaseous PAHs and certain PAH constituents were higher and concentrations of O3 lower in tree-covered areas compared to nearby open areas, while tree cover did not affect the concentrations of NO2 and SO2. The higher PAH concentrations under tree canopies may associate with air-soil gas exchange and the trapping of polluted air under canopies. Lower O3 concentrations in tree-covered areas may result from a combination of absorption of O3 by tree canopies, and lower temperatures and solar radiation under tree canopies compared to open areas.Peer reviewe

SDSS-IV MaNGA: the inner density slopes of nearby galaxies

We derive the mass-weighted total density slopes within the effective (half-light) radius, γ′, for more than 2000 nearby galaxies from the SDSS-IV (Sloan Digital Sky Survey IV) MaNGA survey using Jeans-anisotropic-models applied to integral field unit observations. Our galaxies span a wide range of the stellar mass (109 M⊙ 100 km s−1, the density slope has a mean value 〈γ′〉 = 2.24 and a dispersion σγ = 0.22, almost independent of velocity dispersion, consistent with previous lensing and stellar dynamical analysis. We also quantitatively confirm with high accuracy a turnover in the γ′–σv relation is present at σ ∼ 100 km s−1, below which the density slope decreases rapidly with σv, consistent with the results reported by previous analysis of ATLAS3D survey. Our analysis shows that a large fraction of dwarf galaxies (below M* = 1010 M⊙) have total density slopes shallower than 1, which implies that they may reside in cold dark matter haloes with shallow density slopes. We compare our results with that of galaxies in hydrodynamical simulations of EAGLE, Illustris, and IllustrisTNG projects, and find all simulations predict shallower density slopes for massive galaxies with high σv. Finally, we explore the dependence of γ′ on the positions of galaxies in haloes, namely centrals versus satellites, and find that for the same velocity dispersion, the amplitude of γ′ is higher for satellite galaxies by about 0.1

SDSS-IV MaNGA:global stellar population and gradients for about 2000 early-type and spiral galaxies on the mass-size plane

We perform full spectrum fitting stellar population analysis and Jeans Anisotropic modelling (JAM) of the stellar kinematics for about 2000 early-type galaxies (ETGs) and spiral galaxies from the MaNGA DR14 sample. Galaxies with different morphologies are found to be located on a remarkably tight mass plane which is close to the prediction of the virial theorem, extending previous results for ETGs. By examining an inclined projection (‘the mass-size’ plane), we find that spiral and early-type galaxies occupy different regions on the plane, and their stellar population properties (i.e. age, metallicity and stellar mass-to-light ratio) vary systematically along roughly the direction of velocity dispersion, which is a proxy for the bulge fraction. Galaxies with higher velocity dispersions have typically older ages, larger stellar mass-to-light ratios and are more metal rich, which indicates that galaxies increase their bulge fractions as their stellar populations age and become enriched chemically. The age and stellar mass-to-light ratio gradients for low-mass galaxies in our sample tend to be positive ( centre<outer ), while the gradients for most massive galaxies are negative. The metallicity gradients show a clear peak around velocity dispersion log10σe ≈ 2.0, which corresponds to the critical mass ∼3 × 1010M⊙ of the break in the mass-size relation. Spiral galaxies with large mass and size have the steepest gradients, while the most massive ETGs, especially above the critical mass Mcrit≳2×1011M⊙ , where slow rotator ETGs start dominating, have much flatter gradients. This may be due to differences in their evolution histories, e.g. mergers

Construction, validation and, visualization of a web-based nomogram to identify the best candidates for primary tumor resection in advanced cutaneous melanoma patients

BackgroundExisting studies have shown whether primary site resection (PSR) in cutaneous melanoma (CM) patients with stage IV is controversial. Our study aimed to identify the clinical characteristics of CM patients with stage IV who benefited from PSR on a population-based study.MethodsWe retrospectively reviewed stage IV CM patients in the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. Patients were divided into surgical and non-surgical groups according to whether PSR was performed or not. According to the median cancer-specific survival (CSS) time of the non-surgery group, the surgical group was divided into the surgery-benefit group and the non-surgery-benefit group. Multivariate cox regression analysis was used to explore independent CSS prognostic factors in the surgical group. Then, based on the independent prognostic factors of the surgical group, we established a web-based nomogram based on logistics regression.ResultsA total of 574 stage IV CM patients were included in our study, and 491 (85.60%) patients were included in the surgical group. The clinical characteristics (benefit group and non-benefit group) included age, M stage, lesion location, and ulceration status. These independent prognostic factors were includeed to construct a web-based nomogram.ConclusionsWe constructed a web-based nomogram. This model was suitable for identifying the best candidates suitable for PSR in stage IV CM patients

Efficient COI barcoding using high throughput single-end 400 bp sequencing

Background Over the last decade, the rapid development of high-throughput sequencing platforms has accelerated species description and assisted morphological classification through DNA barcoding. However, the current high-throughput DNA barcoding methods cannot obtain full-length barcode sequences due to read length limitations (e.g. a maximum read length of 300 bp for the Illumina’s MiSeq system), or are hindered by a relatively high cost or low sequencing output (e.g. a maximum number of eight million reads per cell for the PacBio’s SEQUEL II system). Results Pooled cytochrome c oxidase subunit I (COI) barcodes from individual specimens were sequenced on the MGISEQ-2000 platform using the single-end 400 bp (SE400) module. We present a bioinformatic pipeline, HIFI-SE, that takes reads generated from the 5′ and 3′ ends of the COI barcode region and assembles them into full-length barcodes. HIFI-SE is written in Python and includes four function modules of filter, assign, assembly and taxonomy. We applied the HIFI-SE to a set of 845 samples (30 marine invertebrates, 815 insects) and delivered a total of 747 fully assembled COI barcodes as well as 70 Wolbachia and fungi symbionts. Compared to their corresponding Sanger sequences (72 sequences available), nearly all samples (71/72) were correctly and accurately assembled, including 46 samples that had a similarity score of 100% and 25 of ca. 99%. Conclusions The HIFI-SE pipeline represents an efficient way to produce standard full-length barcodes, while the reasonable cost and high sensitivity of our method can contribute considerably more DNA barcodes under the same budget. Our method thereby advances DNA-based species identification from diverse ecosystems and increases the number of relevant applications

Efficient \u3ci\u3eCOI\u3c/i\u3e Barcoding Using High Throughput Single-End 400 bp Sequencing

Background Over the last decade, the rapid development of high-throughput sequencing platforms has accelerated species description and assisted morphological classification through DNA barcoding. However, the current highthroughput DNA barcoding methods cannot obtain full-length barcode sequences due to read length limitations (for example, a maximum read length of 300 bp for the Illumina’s MiSeq system), or are hindered by a relatively high cost or low sequencing output (e.g. a maximum number of eight million reads per cell for the PacBio’s SEQUEL II system). Results Pooled cytochrome c oxidase subunit I (COI) barcodes from individual specimens were sequenced on the MGISEQ-2000 platform using the single-end 400 bp (SE400) module. We present a bioinformatic pipeline, HIFI-SE, that takes reads generated from the 5′ and 3′ ends of the COI barcode region and assembles them into full-length barcodes. HIFI-SE is written in Python and includes four function modules of filter, assign, assembly, and taxonomy. We applied the HIFI-SE to a set of 845 samples (30 marine invertebrates, 815 insects) and delivered a total of 747 fully assembled COI barcodes as well as 70 Wolbachia and fungi symbionts. Compared to their corresponding Sanger sequences (72 sequences available), nearly all samples (71/72) were correctly and accurately assembled, including 46 samples that had a similarity score of 100% and 25 of ca. 99%. Conclusions The HIFI-SE pipeline represents an efficient way to produce standard full-length barcodes, while the reasonable cost and high sensitivity of our method can contribute considerably more DNA barcodes under the same budget. Our method thereby advances DNA-based species identification from diverse ecosystems and increases the number of relevant applications

SDSS-IV MaNGA:environmental dependence of stellar age and metallicity gradients in nearby galaxies

We present a study on the stellar age and metallicity distributions for 1105 galaxies using the STARLIGHT software on MaNGA integral field spectra. We derive age and metallicity gradients by fitting straight lines to the radial profiles, and explore their correlations with total stellar mass M*, NUV-r colour and environments, as identified by both the large scale structure (LSS) type and the local density. We find that the mean age and metallicity gradients are close to zero but slightly negative, which is consistent with the inside-out formation scenario. Within our sample, we find that both the age and metallicity gradients show weak or no correlation with either the LSS type or local density environment. In addition, we also study the environmental dependence of age and metallicity values at the effective radii. The age and metallicity values are highly correlated with M* and NUV-r and are also dependent on LSS type as well as local density. Low-mass galaxies tend to be younger and have lower metallicity in low-density environments while high-mass galaxies are less affected by environment.Comment: 18 pages, 24 figures, accepted for publication in MNRA