571 research outputs found
How do firms in strategic emerging industries influence their peers’ innovation strategies?
Drawing on signaling theory, peer effect, and the awarenessmotivation-capability (AMC) framework, we examine the role of
strategic emerging industries (SEI) firms in raising the awareness
and motivation of non-SEI firms’ R&D activities, including gaining
government R&D subsidies and adopting internal R&D investment, while considering the moderate effect of non-SEI firms’ capability factor. Based on the data of Chinese listed firms from SEI
and non-SEI, the empirical results reveal that (a) the number of
SEI firms funded by government R&D has an inverted U-shape
relationship with the amount that non-SEI firms gain from government R&D subsidies, and has a positive relationship with the
investment of non-SEI firms on internal R&D. (b) The financial performance of SEI firms funded by government R&D motivates nonSEI firms to gain government R&D subsidies and invest in internal
R&D. (c) These relationships are strengthened by the relative scale
of the non-SEI firms
Growth of Outward Propagating Fast-magnetosonic/Whistler Waves in the Inner Heliosphere Observed by Parker Solar Probe
The solar wind in the inner heliosphere has been observed by Parker Solar Probe (PSP) to exhibit abundant wave activities. The cyclotron wave modes responding to ions or electrons are among the most crucial wave components. However, their origin and evolution in the inner heliosphere close to the Sun remains a mystery. Specifically, it remains unknown whether it is an emitted signal from the solar atmosphere or an eigenmode growing locally in the heliosphere due to plasma instability. To address and resolve this controversy, we must investigate the key quantity of the energy change rate of the wave mode. We develop a new technique to measure the energy change rate of plasma waves, and apply this technique to the wave electromagnetic fields measured by PSP. We provide the wave Poynting flux in the solar wind frame, identify the wave nature to be the outward propagating fast-magnetosonic/whistler wave mode instead of the sunward propagating waves. We provide the first evidence for growth of the fast-magnetosonic/whistler wave mode in the inner heliosphere based on the derived spectra of the real and imaginary parts of the wave frequencies. The energy change rate rises and stays at a positive level in the same wavenumber range as the bumps of the electromagnetic field power spectral densities, clearly manifesting that the observed fast-magnetosonic/whistler waves are locally growing to a large amplitude
WKGM: Weight-K-space Generative Model for Parallel Imaging Reconstruction
Deep learning based parallel imaging (PI) has made great progresses in recent
years to accelerate magnetic resonance imaging (MRI). Nevertheless, it still
has some limitations, such as the robustness and flexibility of existing
methods have great deficiency. In this work, we propose a method to explore the
k-space domain learning via robust generative modeling for flexible
calibration-less PI reconstruction, coined weight-k-space generative model
(WKGM). Specifically, WKGM is a generalized k-space domain model, where the
k-space weighting technology and high-dimensional space augmentation design are
efficiently incorporated for score-based generative model training, resulting
in good and robust reconstructions. In addition, WKGM is flexible and thus can
be synergistically combined with various traditional k-space PI models, which
can make full use of the correlation between multi-coil data and
realizecalibration-less PI. Even though our model was trained on only 500
images, experimental results with varying sampling patterns and acceleration
factors demonstrate that WKGM can attain state-of-the-art reconstruction
results with the well-learned k-space generative prior.Comment: 11pages, 12 figure
Possible Generation Mechanism for Compressional Alfv\'enic Spikes as Observed by Parker Solar Probe
The solar wind is found by Parker Solar Probe (PSP) to be abundant with
Alfv\'enic velocity spikes and magnetic field kinks. Temperature enhancement is
another remarkable feature associated with the Alfv\'enic spikes. How the
prototype of these coincident phenomena is generated intermittently in the
source region becomes a hot topic of wide concerns. Here we propose a new model
introducing guide-field discontinuity into the interchange magnetic
reconnection between open funnels and closed loops with different magnetic
helicities. The modified interchange reconnection model not only can accelerate
jet flows from the newly opening closed loop but also excite and launch
Alfv\'enic wave pulses along the newly-reconnected and post-reconnected open
flux tubes. We find that the modeling results can reproduce the following
observational features: (1) Alfv\'en disturbance is pulsive in time and
asymmetric in space; (2) Alfv\'enic pulse is compressible with temperature
enhancement and density variation inside the pulse. We point out that three
physical processes co-happening with Alfv\'en wave propagation can be
responsible for the temperature enhancement: (a) convection of heated jet flow
plasmas (decrease in density), (b) propagation of compressed slow-mode waves
(increase in density), and (c) conduction of heat flux (weak change in
density). We also suggest that the radial nonlinear evolution of the Alfv\'enic
pulses should be taken into account to explain the formation of magnetic
switchback geometry
Efficient Energy Conversion through Vortex Arrays in the Turbulent Magnetosheath
Turbulence is often enhanced when transmitted through a collisionless plasma shock. We investigate how the enhanced turbulent energy in the Earth's magnetosheath effectively dissipates via vortex arrays. This research topic is of great importance as it relates to particle energization at astrophysical shocks across the universe. Wave modes and intermittent coherent structures are the key candidate mechanisms for energy conversion in turbulent plasmas. Here, by comparing in-situ measurements in the Earth's magnetosheath with a theoretical model, we find the existence of vortex arrays at the transition between the downstream regions of the Earth's bow shock. Vortex arrays consist of quasi-orthogonal kinetic waves and exhibit both high volumetric filling factors and strong local energy conversion, thereby showing a greater dissipative energization than traditional waves and coherent structures. Therefore, we propose that vortex arrays are a promising mechanism for efficient energy conversion in the sheath regions downstream of astrophysical shocks
The role of Th17 cells in endocrine organs: Involvement of the gut, adipose tissue, liver and bone
T Helper 17 (Th17) cells are adaptive immune cells that play myriad roles in the body. Immune–endocrine interactions are vital in endocrine organs during pathological states. Th17 cells are known to take part in multiple autoimmune diseases over the years. Current evidence has moved from minimal to substantial that Th17 cells are closely related to endocrine organs. Diverse tissue Th17 cells have been discovered within endocrine organs, including gut, adipose tissue, liver and bone, and these cells are modulated by various secretions from endocrine organs. Th17 cells in these endocrine organs are key players in the process of an array of metabolic disorders and inflammatory conditions, including obesity, insulin resistance, nonalcoholic fatty liver disease (NAFLD), primary sclerosing cholangitis (PSC), osteoporosis and inflammatory bowel disease (IBD). We reviewed the pathogenetic or protective functions played by Th17 cells in various endocrine tissues and identified potential regulators for plasticity of it. Furthermore, we discussed the roles of Th17 cells in crosstalk of gut-organs axis
Editorial: Genetics and Molecular Mechanisms of Oral and Esophageal Squamous Cell Carcinoma
Oral squamous cell carcinoma (OSCC) is the most common histopathological type of oral cancer,
with typical characteristics of low 5-year survival rate and poor prognosis (1, 2). Importantly, there
are many factors affecting its occurrence and progression, in which genome alterations are critical
indicators of the proper diagnosis and treatment (3). Carcinogenesis is a multi-step process, which
involves the accumulation of genetic and epigenetic changes of oncogenes or tumor suppressor
genes (4).Therefore, better understanding of the genetic and molecular disorders of the disease is the
key to early diagnosis, appropriate treatment and improving the prognosis of patients
Global synthesis of the classifications, distributions, benefits and issues of terracing
For thousands of years, humans have created different types of terraces in different sloping conditions, meant to mitigate flood risks, reduce soil erosion and conserve water. These anthropogenic landscapes can be found in tropical and subtropical rainforests, deserts, and arid and semiarid mountains across the globe. Despite the long history, the roles of and the mechanisms by which terracing improves ecosystem services (ESs) remain poorly understood. Using literature synthesis and quantitative analysis, the worldwide types, distributions, major benefits and issues of terracing are presented in this review. A key terracing indicator, defined as the ratio of different ESs under terraced and non-terraced slopes (δ), was used to quantify the role of terracing in providing ESs. Our results indicated that ESs provided by terracingwas generally positive because themean values of δ were mostly greater than one. The most prominent role of terracing was found in erosion control (11.46 ± 2.34), followed by runoff reduction (2.60 ± 1.79), biomass accumulation (1.94 ± 0.59), soil water recharge (1.20±0.23), and nutrient enhancement (1.20±0.48). Terracing, to a lesser extent, could also enhance the survival rates of plant seedlings, promote ecosystem restoration, and increase crop yields.While slopes experiencing severe human disturbance (e.g., overgrazing and deforestation) can generally become more stable after terracing, negative effects of terracing may occur in poorly-designed or poorly-managed terraces. Among the reasons are the lack of environmental legislation, changes in traditional concepts and lifestyles of local people, as well as price decreases for agricultural products. All of these can accelerate terrace abandonment and degradation. In light of these findings, possible solutions regarding socio-economic changes and techniques to improve already degraded terraces are discussed
The development of rainfall retrievals from radar at Darwin
17 USC 105 interim-entered record; under review.The article of record as published may be found at https://doi.org/10.5194/amt-14-53-2021The U.S. Department of Energy Atmospheric Radiation Measurement program Tropical Western Pacific site hosted a C-band polarization (CPOL) radar in Darwin, Australia. It provides 2 decades of tropical rainfall characteristics useful for validating global circulation models. Rainfall retrievals from radar assume characteristics about the droplet size distribution (DSD) that vary significantly. To minimize the uncertainty associated with DSD variability, new radar rainfall techniques use dual polarization and specific attenuation estimates. This study challenges the applicability of several specific attenuation and dual-polarization-based rainfall estimators in tropical settings using a 4-year archive of Darwin disdrometer datasets in conjunction with CPOL observations. This assessment is based on three metrics: statistical uncertainty estimates, principal component analysis (PCA), and comparisons of various retrievals from CPOL data. The PCA shows that the variability in R can be consistently attributed to reflectivity, but dependence on dualpolarization quantities was wavelength dependent for 1 10 mm h−1 . Rainfall estimates during these conditions primarily originate from deep convective clouds with median drop diameters greater than 1.5 mm. An uncertainty analysis and intercomparison with CPOL show that a Colorado State University blended technique for tropical oceans, with modified estimators developed from video disdrometer observations, is most appropriate for use in all cases, such as when 1 10 mm h−1 (deeper convective rain).Argonne National Laboratory’s work was supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, under contract DE-AC02-06CH11357. This work has been supported by the Office of Biological and Environmental Research (OBER) of the U.S. Department of Energy (DOE) as part of the Climate Model Development and Validation activity. NOAA PSL contributes effort with funding from the Weather Program Office’s Precipitation Prediction Grand Challenge. The development of the Python ARM radar toolkit was funded by the ARM program part of the Office of Biological and Environmental Research (OBER) of the U.S. Department of Energy (DOE). The work from Monash University and the Bureau of Meteorology was partly supported by the U.S. Department of Energy Atmospheric Systems Research Program through the grant DE-SC0014063. BD contributions are supported by the U.S. Department of Energy Atmospheric Systems Research Program through the grant DE-SC0017977
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