Multilevel Nitrogen Additions Alter Chemical Composition and Turnover of the Labile Fraction Soil Organic Matter via Effects on Vegetation and Microorganisms

Global nitrogen (N) deposition greatly impacts soil carbon sequestration. A 2- yr multiple N addition (0, 10, 20, 40, 80, and 160 kg N·ha- 1·yr- 1) experiment was conducted in alpine grassland to illustrate the mechanisms underlying the observed soil organic matter (SOM) dynamics on the Qinghai- Tibet Plateau (QTP). Labile fraction SOM (LF- SOM) fingerprints were characterized by pyrolysis- gas chromatography/tandem- mass spectrometry, and microbial functional genes (GeoChip 4.6) were analyzed in conjunction with LF- SOM fingerprints to decipher the responses of LF- SOM transformation to N additions. The significant correlations between LF- SOM and microbial biomass, between organic compounds in LF- SOM and compound degradation- related genes, and between LF- SOM and net ecosystem exchange implied LF- SOM were the main fraction utilized by microorganisms and the most sensitive fraction to N additions. The LF- SOM increased at the lowest N addition levels (10 and 20 kg N·ha- 1·yr- 1) and decreased at higher N addition levels (40 to 160 kg N·ha- 1·yr- 1), but the decrease of LF- SOM was weakened at 160 kg N·ha- 1·yr- 1 addition. The nonlinear response of LF- SOM to N additions was due to the mass balance between plant inputs and microbial degradation. Plant- derived compounds in LF- SOM were more sensitive to N addition than microbial- derived and aromatic compounds. It is predicted that when the N deposition rate increased by 10 kg N·ha- 1·yr- 1 on the QTP, carbon sequestration in the labile fraction may increase by nearly 170% compared with that under the current N deposition rate. These findings provide insight into future N deposition impacts on LF- SOM preservation on the QTP.Key PointsThe LF- SOM quantity increased at the lowest N additions (N10 and N20) and decreased from N40 to N160, but the decrease was weakened at the highest N addition (N160)Plant- derived compounds in LF- SOM were more sensitive to N addition than microbial- derived and aromatic compoundsThe organic compounds in LF- SOM were significantly correlated with compound degradation- related genesPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154963/1/jgrg21637_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154963/2/jgrg21637.pd

Methological quality of systematic reviews and meta-analyses on acupuncture for stroke: a review of review

Objective: To assess the methodological quality of systematic reviews and meta-analyses regarding acupuncture intervention for stroke and the primary studies within them. Methods: Two researchers searched PubMed, Cumulative index to Nursing and Allied Health Literature, Embase, ISI Web of Knowledge, Cochrane, Allied and Complementary Medicine, Ovid Medline, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang and Traditional Chinese Medical Database to identify systematic reviews and meta-analyses about acupuncture for stroke published from the inception to December 2016. Review characteristics and the criteria for assessing the primary studies within reviews were extracted. The methodological quality of the reviews was assessed using adapted Oxman and Guyatt Scale. The methodological quality of primary studies was also assessed. Results: Thirty-two eligible reviews were identified, 15 in English and 17 in Chinese. The English reviews were scored higher than the Chinese reviews (P=0.025), especially in criteria for avoiding bias and the scope of search. All reviews used the quality criteria to evaluate the methodological quality of primary studies, but some criteria were not comprehensive. The primary studies, in particular the Chinese reviews, had problems with randomization, allocation concealment, blinding, dropouts and withdrawals, intent-to-treat analysis and adverse events. Conclusions: Important methodological flaws were found in Chinese systematic reviews and primary studies. It was necessary to improve the methodological quality and reporting quality of both the systematic reviews published in China and primary studies on acupuncture for stroke

Wideband saturable absorption in few-layer molybdenum diselenide (MoSe₂) for Q-switching Yb-, Er- and Tm-doped fiber lasers.

We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap saturable absorption in MoSe2, which is explained in the context of edge-states, building upon studies of other semiconducting transition metal dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2 to the growing catalog of TMDs with remarkable optical properties, which offer new opportunities for photonic devices.EJRK and TH acknowledge support from the Royal Academy of Engineering (RAEng), through RAEng Fellowships.This is the author accepted manuscript. The final version is available from the Optical Society of Amercia via http://dx.doi.org/ via http://dx.doi.org/10.1364/OE.23.02005

Few-layer MoS<inf>2</inf> saturable absorbers for short-pulse laser technology: Current status and future perspectives [Invited]

Few-layer molybdenum disul de (MoS2) is emerging as a promising quasi-two-dimensional material, further extending the library of suitable layered nanomaterials with exceptional optical properties for use in saturable absorber devices that enable short-pulse generation in laser systems. In this article, we catalog and review the nonlinear optical properties of few-layer MoS2, summarize recent progress in processing and integration into saturable absorber devices and comment on the current status and future perspectives of MoS2-based pulsed lasers.The authors would like to thank J. R. Taylor for fruitful discussions. EJRK and TH acknowledge support from the Royal Academy of Engineering (RAEng).This is the author accepted manuscript. The final version is available from OSA via https://www.osapublishing.org/prj/abstract.cfm?URI=prj-3-2-A30

Pigment mixing effect realized with pre-dyed opaque yarns for Jacquard textile design development

In modern Jacquard weaving, the application of yarn color variety is limited to electronic Jacquard machinery and realizing a wide scope of weave colors can be challenging. Therefore, when reproducing a pictorial image with a small yarn variety, artwork colors are defined by a CMYK (cyan, magenta, yellow, and black) system and its primary color data are used to associate with weave structures. In alignment with a CMYK pattern layout, shaded weave structures are incorporated to expand the accessible gamut of weave colors and natural shading is realized by different cover factors in the warp and weft. The mixing effect of CMYK yarns is intended for resolving the technical limitations of current digital Jacquard weaving. In this study, quantitative research is designed to examine four yarn mixing effects for which pairs of CMYK yarns are superimposed (e.g., [C]+[M], [C]+[Y], [M]+[Y], [C]+[K], [M]+[K], [Y]+[K]) and 90 different weave colors are produced in six groups. Once they are formatted in a standardized size, weave samples are measured by a spectrophotometer and analyzed by three coordinates (L*, a*, and b*) of a CIELAB color system. As shown by the analysis results, the weave colors bear not only varied brightness, hue, and chroma alternations, but also a great similarity to the pigment mixing effect. In application of the color mixing effect, a new way of woven color presentation is achieved and introduced as a new development of Jacquard design

Tunable Q-switched fiber laser based on saturable edge-state absorption in few-layer molybdenum disulfide (MoS₂).

We fabricate a few-layer molybdenum disulfide (MoS₂) polymer composite saturable absorber by liquid-phase exfoliation, and use this to passively Q-switch an ytterbium-doped fiber laser, tunable from 1030 to 1070 nm. Self-starting Q-switching generates 2.88 μs pulses at 74 kHz repetition rate, with over 100 nJ pulse energy. We propose a mechanism, based on edge states within the bandgap, responsible for the wideband nonlinear optical absorption exhibited by our few-layer MoS₂ sample, despite operating at photon energies lower than the material bandgap.EJRK acknowledges support from the Royal Academy of Engineering (RAEng), through a RAEng Fellowship, RCTH from EPSRC (EP/G037221/1), GH from a CSC Cambridge International Scholarship, and TH from the RAEng (Graphlex). The authors also acknowledge ThorLabs for access to their technical drawings.This is the accepted manuscript. The final version is available at http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-22-25-31113. © 2014 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited

Gradient colour deviation in woven textiles to correspond to pictorial images in diversity

This study aims to propose optimal weaving conditions for creation of a natural shading effect in woven textiles. By applying the weave structure and pattern theories, the two core parts of weaving are explored and examined towards improving realisation of gradient weave colours. When planning experiments, weave repeat sizes from 12- to 30-thread are created into a shaded weave series and compounded in a multi-weft figuring method. In terms of weave pattern, a colour spectrum image is designed and its split primary colour layers (e.g. cyan, magenta, yellow and black) are employed as a weave pattern. In conjunction with varied weaving conditions, a colour spectrum image is reproduced in 19 different woven forms. In this study, comparative analysis is approached based on the samples resulted from trials and the practical research is explained in detail of weave structure and weave pattern specifications to propose the core principle of establishing gradient colour deviation

Solution processed MoS2-PVA composite for sub-bandgap mode-locking of a wideband tunable ultrafast Er:fiber laser

Abstract We fabricate a free-standing few-layer molybdenum disulfide (MoS2)-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1,535 nm to 1,565 nm, are generated, corresponding to photon energies below the MoS2 material bandgap. These results contribute to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications.MZ wishes to acknowledge funding from the EPSRC (EP/K03705), RCTH from the EPSRC (EP/G037221/1), GH from a CSC Cambridge International Scholarship, EJRK from the Royal Academy of Engineering (RAEng), through a RAEng Fellowship and TH from the RAEng (Graphlex).This is the final version. It was first published by Springer at http://link.springer.com/article/10.1007%2Fs12274-014-0637-