68 research outputs found
Unpacking the impact of OFDI speed and rhythm on innovation performance: Evidence from Chinese firms
In this study, we focus on the temporal behaviors – speed and rhythm – of outward foreign direct investment (OFDI) by emerging multinational enterprises (EMNEs) and examine the effect of such behaviors on innovation performance. Using a learning perspective, we argue that OFDI speed has an inverted U-shaped effect on EMNEs’ innovation performance, whereas the relationship between the uneven rhythm of OFDI and innovation performance is negative. The results, based on OFDI panel data of 1,092 Chinese firms, support our predictions that a moderate OFDI speed and a more regular pattern of OFDI expansion provide sources of competitiveness and contribute to firms’ innovation performance
A Solar Eruption Driven by Rapid Sunspot Rotation
We present the observation of a major solar eruption that is associated with
fast sunspot rotation. The event includes a sigmoidal filament eruption, a
coronal mass ejection, and a GOES X2.1 flare from NOAA active region 11283. The
filament and some overlying arcades were partially rooted in a sunspot. The
sunspot rotated at 10 per hour rate during a period of 6 hours
prior to the eruption. In this period, the filament was found to rise gradually
along with the sunspot rotation. Based on the HMI observation, for an area
along the polarity inversion line underneath the filament, we found gradual
pre-eruption decreases of both the mean strength of the photospheric horizontal
field () and the mean inclination angle between the vector magnetic field
and the local radial (or vertical) direction. These observations are consistent
with the pre-eruption gradual rising of the filament-associated magnetic
structure. In addition, according to the Non-Linear Force-Free-Field
reconstruction of the coronal magnetic field, a pre-eruption magnetic flux rope
structure is found to be in alignment with the filament, and a considerable
amount of magnetic energy was transported to the corona during the period of
sunspot rotation. Our study provides evidences that in this event sunspot
rotation plays an important role in twisting, energizing, and destabilizing the
coronal filament-flux rope system, and led to the eruption. We also propose
that the pre-event evolution of may be used to discern the driving
mechanism of eruptions
Metal-free graphene-carbon nitride hybrids for photodegradation of organic pollutants in water
Hybrid photocatalysts of graphitic carbon nitride (g-C3N4) and reduced graphene oxide (rGO) composites were prepared in one-pot via a thermal condensation of melamine with different amounts of graphene oxide (GO). As metal-free hybrids, the prepared photocatalysts presented enhanced performances in photooxidation of both methylene blue and phenol in water solutions under various light irradiations. The level of rGO significantly affected MB photodegradation efficiencies. The introduced graphene can improve the MB adsorption and optical absorption in visible light region, therefore enables the hybrids to efficiently degrade MB under visible light with wavelengths longer than 430 nm. The metal-free photocatalysts were also able to degrade phenol effectively and the effects of catalyst loading and initial phenol concentration were investigated. This study provided an efficient and environmentally benign photocatalyst for degradation of organic pollutants in water, with complete prevention of secondary contamination from metal-leaching
Clinical outcomes and spinal growth after posterior hemivertebra resection and short segment fusion in children
Abstract To evaluate the corrective effect of posterior hemivertebra resection and short-segment fusion surgery on pediatric patients and to assess the impact of short-segment fixation surgery on vertebral development during follow-up, a retrospective analysis was performed on 28 pediatric patients who underwent posterior hemivertebra resection surgery. The corrective effect was evaluated by comparing indicators such as segmental scoliosis Cobb angle, upper and lower compensatory curves and trunk balance at different time points. Meanwhile, the vertebral and spinal canal diameters of instrumented vertebrae and adjacent noninstrumented vertebrae were measured and compared to assess vertebral and spinal canal development. The correction rate of segmental scoliosis was 72.2%. The estimated mean vertebral volume of the instrumented vertebra was slightly lower than that of the unfused segment at the final follow-up, but the difference was not statistically significant. The growth rate of the spinal canal during follow-up was much smaller than that of the vertebral body. In summary, internal fixation at a young age shows no significant inhibitory effects on spinal development within the fusion segment. Posterior hemivertebra resection and short-segment fusion surgery are safe and effective
Digital gene-expression of alfalfa saponin extract on laying hens
Cardiovascular disease is a major cause of death worldwide, so people are advised to limit their intake of dietary cholesterol [1]. Egg consumption has been seriously reduced because of the high levels of cholesterol [2]. The objective of this study was to evaluate the cholesterol metabolism effects of alfalfa saponin extract (ASE) in liver and ovary tissues using digital gene-expression (DGE) profiling analysis. The liver and ovary tissues were isolated from laying hens fed with ASE for RNA sequencing. Here, we provide detailed experimental methods and analysis pipeline in our study to identify digital gene expression of alfalfa saponin extract on laying hens and analysis pipeline published by Singh and colleagues in the PLOS ONE [3]. The data generated in our work provide meaningful information for understanding the molecular mechanisms underlying the cholesterol-lowering effects of ASE
Photoelectrical response of hybrid graphene-PbS quantum dot devices
Hybrid graphene-PbS quantum dot devices are fabricated on an n-type silicon substrate capped with a thin SiO2 layer and are characterized by photoelectrical measurements. It is shown that the resistance of the graphene channel in the devices exhibits detectable changes when a laser beam is switched on and off on the quantum dots. The model that explains the observed photoresponse phenomenon is illustrated. We also show that the photoresponse signal, i.e., the photoinduced change in the resistance of the graphene channel can be tuned in both magnitude and sign with a voltage applied to the back gate of the devices and is related to the derivative of the transfer characteristics of the graphene channel. Our work shows that the simple hybrid graphene-PbS quantum dot devices can be employed for photodetection applications. (C) 2013 AIP Publishing LLC
Correlation between mRNA abundance in the leaves of Maverick and CUF101 varieties and illumination time under artificial growth conditions.
<p>Correlation between mRNA abundance in the leaves of Maverick and CUF101 varieties and illumination time under artificial growth conditions.</p
Screening and identification of key genes regulating fall dormancy in alfalfa leaves
<div><p>Fall dormancy (FD) determines the adaptation of an alfalfa variety and affects alfalfa production and quality. However, the molecular mechanism underlying FD remains poorly understood. Here, 44 genes regulating FD were identified by comparison of the transcriptomes from leaves of Maverick (fall-dormant alfalfa) and CUF101(non-fall-dormant), during FD and non-FD and were classified them depending on their function. The transcription of IAA-amino acid hydrolase ILR1-like 1, abscisic acid receptor PYL8, and monogalactosyldiacylglycerol synthase-3 in Maverick leaves was regulated by daylength and temperature, and the transcription of the abscisic acid receptor PYL8 was mainly affected by daylength. The changes in the expression of these genes and the abundance of their messenger RNA (mRNA) in Maverick leaves differed from those in CUF101 leaves, as evidenced by the correlation analysis of their mRNA abundance profiles obtained from April to October. The present findings suggested that these genes are involved in regulating FD in alfalfa.</p></div
Genome-Wide Identification of Different Dormant <i>Medicago sativa</i> L. MicroRNAs in Response to Fall Dormancy
<div><p>Background</p><p>MicroRNAs (miRNAs) are a class of regulatory small RNAs (sRNAs) that regulate gene post-transcriptional expression in plants and animals. High-throughput sequencing technology is capable of identifying small RNAs in plant species. Alfalfa (<i>Medicago sativa</i> L.) is one of the most widely cultivated perennial forage legumes worldwide, and fall dormancy is an adaptive characteristic related to the biomass production and winter survival in alfalfa. Here, we applied high-throughput sRNA sequencing to identify some miRNAs that were responsive to fall dormancy in standard variety (Maverick and CUF101) of alfalfa.</p><p>Results</p><p>Four sRNA libraries were generated and sequenced from alfalfa leaves in two typical varieties at distinct seasons. Through integrative analysis, we identified 51 novel miRNA candidates of 206 families. Additionally, we identified 28 miRNAs associated with fall dormancy in standard variety (Maverick and CUF101), including 20 known miRNAs and eight novel miRNAs. Both high-throughput sequencing and RT-qPCR confirmed that eight known miRNA members were up-regulated and six known miRNA members were down-regulated in response to fall dormancy in standard variety (Maverick and CUF101). Among the 51 novel miRNA candidates, five miRNAs were up-regulated and three miRNAs were down-regulated in response to fall dormancy in standard variety (Maverick and CUF101), and five of them were confirmed by Northern blot analysis.</p><p>Conclusion</p><p>We identified 20 known miRNAs and eight new miRNA candidates that were responsive to fall dormancy in standard variety (Maverick and CUF101) by high-throughput sequencing of small RNAs from <i>Medicago sativa</i>. Our data provide a useful resource for investigating miRNA-mediated regulatory mechanisms of fall dormancy in alfalfa, and these findings are important for our understanding of the roles played by miRNAs in the response of plants to abiotic stress in general and fall dormancy in alfalfa.</p></div
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