126 research outputs found
Shrubland biomass and root-shoot allocation along a climate gradient in China
Background – Shrublands are receiving increasing attention because of climate change. However, knowledge about biomass allocation of shrublands at the community level and how this is regulated by climate is of limited availability but critical for accurately estimating carbon stocks and predicting global carbon cycles. Methods – We sampled 50 typical shrublands along a climate gradient in China and investigated the biomass allocation of shrubland at the community level and the effect of climate on biomass allocation. Shrub biomass was estimated using species-specific allometric relationships and the biomass of understory herbs was collected by excavating the whole plant. Regression analysis was used to examine the relationships between the biomass and the climate factors. RMA were conducted to establish the allometric relationships between the root and the shoot biomass at the community level.Key results – Shoot, root, and total biomass of shrub communities across different sites were estimated with median values of 206.5, 145.8, and 344.5 g/m2, respectively. Shoot, root, and total biomass of herb communities were estimated at 68.2, 58.9, and 117.2 g/m2, respectively. The median value of the R/S ratio of shrub communities was 0.58 and that of herb communities was 0.84. The R/S ratio of the shrub community showed a negative relationship with mean annual temperature and mean annual precipitation and a positive relationship with total annual sunshine and the aridity index. The R/S ratio of the herb community however showed a weak relationship with climate factors. Shoot biomass of the shrub community was nearly proportional to root biomass with a scaling exponent of 1.17, whereas shoot biomass of the herb community was disproportional to root biomass with a scaling exponent of 2.1.Conclusions – In shrublands, root biomass was more affected than shoot biomass by climate factors and this is related to water availability as a result of biomass allocation change of the shrub community. The understory herb community was less affected by climate due to the modification of the overstory–understory interaction to the climate-induced biomass allocation pattern. Shoot biomass of shrubs scales isometrically with root biomass at the community level, which supports the isometric theory of above-ground and below-ground biomass partitioning
Cloud-Magnetic Resonance Imaging System: In the Era of 6G and Artificial Intelligence
Magnetic Resonance Imaging (MRI) plays an important role in medical
diagnosis, generating petabytes of image data annually in large hospitals. This
voluminous data stream requires a significant amount of network bandwidth and
extensive storage infrastructure. Additionally, local data processing demands
substantial manpower and hardware investments. Data isolation across different
healthcare institutions hinders cross-institutional collaboration in clinics
and research. In this work, we anticipate an innovative MRI system and its four
generations that integrate emerging distributed cloud computing, 6G bandwidth,
edge computing, federated learning, and blockchain technology. This system is
called Cloud-MRI, aiming at solving the problems of MRI data storage security,
transmission speed, AI algorithm maintenance, hardware upgrading, and
collaborative work. The workflow commences with the transformation of k-space
raw data into the standardized Imaging Society for Magnetic Resonance in
Medicine Raw Data (ISMRMRD) format. Then, the data are uploaded to the cloud or
edge nodes for fast image reconstruction, neural network training, and
automatic analysis. Then, the outcomes are seamlessly transmitted to clinics or
research institutes for diagnosis and other services. The Cloud-MRI system will
save the raw imaging data, reduce the risk of data loss, facilitate
inter-institutional medical collaboration, and finally improve diagnostic
accuracy and work efficiency.Comment: 4pages, 5figures, letter
Integrating metabolomics, bionics, and culturomics to study probiotics-driven drug metabolism
Many drugs have been shown to be metabolized by the human gut microbiome, but probiotic-driven drug-metabolizing capacity is rarely explored. Here, we developed an integrated metabolomics, culturomics, and bionics framework for systematically studying probiotics-driven drug metabolism. We discovered that 75% (27/36 of the assayed drugs) were metabolized by five selected probiotics, and drugs containing nitro or azo groups were more readily metabolized. As proof-of-principle experiments, we showed that Lacticaseibacillus casei Zhang (LCZ) could metabolize racecadotril to its active products, S-acetylthiorphan and thiorphan, in monoculture, in a near-real simulated human digestion system, and in an ex vivo fecal co-culture system. However, a personalized effect was observed in the racecadotril-metabolizing activity of L. casei Zhang, depending on the individual’s host gut microbiome composition. Based on data generated by our workflow, we proposed a possible mechanism of interactions among L. casei Zhang, racecadotril, and host gut microbiome, providing practical guidance for probiotic-drug co-treatment and novel insights into precision probiotics
XCloud-VIP: Virtual Peak Enables Highly Accelerated NMR Spectroscopy and Faithful Quantitative Measures
Background: Nuclear Magnetic Resonance (NMR) spectroscopy is an important
bio-engineering tool to determine the metabolic concentrations, molecule
structures and so on. The data acquisition time, however, is very long in
multi-dimensional NMR. To accelerate data acquisition, non-uniformly sampling
is an effective way but may encounter severe spectral distortions and
unfaithful quantitative measures when the acceleration factor is high.
Objective: To reconstruct high fidelity spectra from highly accelerated NMR and
achieve much better quantitative measures. Methods: A virtual peak (VIP)
approach is proposed to self-learn the prior spectral information, such as the
central frequency and peak lineshape, and then feed these information into the
reconstruction. The proposed method is further implemented with cloud computing
to facilitate online, open, and easy access. Results: Results on synthetic and
experimental data demonstrate that, compared with the state-of-the-art method,
the new approach provides much better reconstruction of low-intensity peaks and
significantly improves the quantitative measures, including the regression of
peak intensity, the distances between nuclear pairs, and concentrations of
metabolics in mixtures. Conclusion: Self-learning prior peak information can
improve the reconstruction and quantitative measures of spectra. Significance:
This approach enables highly accelerated NMR and may promote time-consuming
applications such as quantitative and time-resolved NMR experiments
A review of point set registration: from pairwise registration to groupwise registration
Abstract: This paper presents a comprehensive literature review on point set registration. The state-of-the-art modeling methods and algorithms for point set registration are discussed and summarized. Special attention is paid to methods for pairwise registration and groupwise registration. Some of the most prominent representative methods are selected to conduct qualitative and quantitative experiments. From the experiments we have conducted on 2D and 3D data, CPD-GL pairwise registration algorithm [1] and JRMPC groupwise registration algorithm [2,3] seem to outperform their rivals both in accuracy and computational complexity. Furthermore, future research directions and avenues in the area are identified
Surfactant-Free Synthesis of Reduced Graphene Oxide Supported Well-Defined Polyhedral Pd-Pt Nanocrystals for Oxygen Reduction Reaction
Well-defined polyhedral Pd-Pt nanocrystals anchored on the reduced graphene oxide (rGO) are successfully synthesized via a facile and efficient surfactant-free solvothermal route. The formation mechanism is carefully illustrated via tuning the surface state of rGO substrate and the Pd/Pt ratio in Pd-Pt nanocrystals. rGO substrates with continuous smooth surface, which can offer continuous 2D larger π electrons, play important roles in the formation of the well-defined polyhedral Pd-Pt nanocrystals. Suitable Pd/Pt ratio, which determines the affinity between the rGO substrate and polyhedral Pd-Pt nanocrystals, is another important factor for the formation of polyhedral Pd-Pt nanocrystals. Due to the well-defined surface of Pd-Pt nanocrystals, rich corners and edges from polyhedral structure, as well as more exposed (111) facets, the low-Pt polyhedral Pd-Pt nanocrystals anchored on rGO, used as electrocatalysts, exhibit high electrocatalytic activity for oxygen reduction reaction with excellent methanol tolerance
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