Optimal Rate of Kernel Regression in Large Dimensions

We perform a study on kernel regression for large-dimensional data (where the sample size $n$ is polynomially depending on the dimension $d$ of the samples, i.e., $n\asymp d^{\gamma}$ for some $\gamma >0$ ). We first build a general tool to characterize the upper bound and the minimax lower bound of kernel regression for large dimensional data through the Mendelson complexity $\varepsilon_{n}^{2}$ and the metric entropy $\bar{\varepsilon}_{n}^{2}$ respectively. When the target function falls into the RKHS associated with a (general) inner product model defined on $\mathbb{S}^{d}$, we utilize the new tool to show that the minimax rate of the excess risk of kernel regression is $n^{-1/2}$ when $n\asymp d^{\gamma}$ for $\gamma =2, 4, 6, 8, \cdots$. We then further determine the optimal rate of the excess risk of kernel regression for all the $\gamma>0$ and find that the curve of optimal rate varying along $\gamma$ exhibits several new phenomena including the {\it multiple descent behavior} and the {\it periodic plateau behavior}. As an application, For the neural tangent kernel (NTK), we also provide a similar explicit description of the curve of optimal rate. As a direct corollary, we know these claims hold for wide neural networks as well

Association of the onset of self-feeding with subsequent Developmental Coordination Disorder: A prospective cohort study in China

Background: Successful self-feeding reflects the readiness of early motor development and environmental impacts, and the onset of self-feeding as a developmental milestone might be a predictor of subsequent motor development in children. In this study, we explored the association between the onset of self-feeding and childhood risk of Developmental Coordination Disorder in children from one-child and two-child families. Methods: We conducted a data-linkage prospective cohort study from 38 kindergartens in 6 cities in China. A total of 11,727 preschoolers were included in the final analysis and were assessed with the Movement Assessment Battery for Children-second edition (MABC-2) Test. The information on early self-feeding onset was obtained from parents. The mixed and multi-level logistic models utilizing a random intercept were used to investigate the associations between the onset time of self-feeding and subsequent motor performance. Results: The results showed that, compared with those beginning self-feeding at or younger than 12 months of age, children starting self-feeding at 13-24 months, 25-36 months, and later than 36 months, showed a decrease in their total MABC-2 scores of 2.181, 3.026 and 3.874, respectively; and had an increased risk of suspected DCD by 36.0%, 101.6%, 102.6% respectively; they also had 30.2%, 46.6%, 71.2% increased prevalence of at risk of suspected DCD, when adjusting for both child and family characteristics (each p<0.05). Significant associations were observed in fine motor, gross motor, and balance subtests (each p<0.05) in groups with a delayed onset of self-feeding. However, the strength of the associations was mitigated in the fine motor and balance subtests in children with a sibling. Conclusion: The delayed onset time of self-feeding acts as an early behavioural marker for later childhood motor impairment. Moreover, children with a sibling may benefit from additional interaction and their motor developmental pattern may be affected by the presence of a sibling.

Overview and prospect of the detection capability of China's first precipitation measurement satellite FY-3G

Based on introducing the technical characteristics of FY-3G, which is China's first precipitation measurement satellite and successfully launched at 09∶36 BT on April 16 in 2023, this paper focuses on the precipitation detection capabilities and application prospect in rainstorm monitoring of FY-3G. The results show that, with an orbit at 407 km and an inclination angle of 50°, and equipped with a dual-frequency Ka/Ku band precipitation measurement radar, microwave, and optical imaging instruments, the FY-3G satellite can detect the three-dimensional structure of disastrous weather systems such as typhoon, heavy rainfall, and other strong convection events in most of China. At the design level, FY-3G has precipitation detection capabilities comparable to the current US Second Generation Global Precipitation Measurement Program (GPM) Core Satellite (GPMCO), but better payload types, quantities, and channel settings compared with the GPMCO satellite. After the service operation, the FY-3G satellite, together with other polar-orbiting meteorological satellites such as FY-3 AM, PM, and EM, as well as high-orbit geostationary satellites, will form the Fengyun precipitation detection constellation system, which will improve the overall precipitation detection capability of the Fengyun Satellite constellation and provide stronger basic support for meteorological disaster prevention and mitigation

Heterologous Production of Microbial Ribosomally Synthesized and Post-translationally Modified Peptides

Ribosomally synthesized and post-translationally modified peptides, or RiPPs, which have mainly isolated from microbes as well as plants and animals, are an ever-expanding group of peptidic natural products with diverse chemical structures and biological activities. They have emerged as a major category of secondary metabolites partly due to a myriad of microbial genome sequencing endeavors and the availability of genome mining software in the past two decades. Heterologous expression of RiPP gene clusters mined from microbial genomes, which are often silent in native producers, in surrogate hosts such as Escherichia coli and Streptomyces strains can be an effective way to elucidate encoded peptides and produce novel derivatives. Emerging strategies have been developed to facilitate the success of the heterologous expression by targeting multiple synthetic biology levels, including individual proteins, pathways, metabolic flux and hosts. This review describes recent advances in heterologous production of RiPPs, mainly from microbes, with a focus on E. coli and Streptomyces strains as the surrogate hosts

Linking potential nitrification rates, nitrogen cycling genes and soil properties after remediating the agricultural soil contaminated with heavy metal and fungicide

Hosseini Bai, S ORCiD: 0000-0001-8646-6423Apart from the contaminant removal, the remediation of agricultural soil should also pay more attention to soil nutrient retention and biogeochemical cycling. This study aimed to evaluate changes of soil properties, potential nitrification rates (PNRs), and functional gene abundances and link their relationships after remediating co-contaminated agricultural soil with Medicago sativa L. (alfalfa) planting, alone or together with biochar application. Compared with the control (CK), alfalfa planting, alone or together with biochar application, could significantly increase soil organic matter (SOM) contents and discrepantly affect soil pH values. The PNRs of the amended treatments were significantly higher than that of the CK. Moreover, alfalfa plantings also enhanced the abundances of functional genes related to soil nitrification and denitrification, with the sole exception of nosZ gene. Stepwise regression analysis revealed that the PNRs were best described by the gene abundance ratios of AOB amoA/nifH and nirS gene abundances. Compared with the CK, alfalfa planting, alone or with biochar application, could restore nitrogen cycling in the co-contaminated agricultural soil and enhance the PNRs via decreasing contaminant bio-availabilities and increasing SOM contents and gene abundance ratios of AOB amoA/nifH. © 2017 Elsevier Lt

Assisted phytoremediation of a co-contaminated soil with biochar amendment: Contaminant removals and bacterial community properties

Hosseini Bai, S ORCiD: 0000-0001-8646-6423There are growing trends of combined contaminations in agricultural soils, and therefore it is urgently needed to remediate contaminated soils with eco-friendly approaches. This study aimed to evaluate the effects of Medicago sativa L. (alfalfa) planting, alone or together with biochar additions, on contaminant removals and bacterial properties in an agricultural soil contaminated by heavy metal and organic fungicide. The treatments in this study included: the control (CK), alfalfa planting (AP), alfalfa planting +1.5% biochar addition (w/w) (AP + 1.5B), alfalfa planting +3.0% biochar addition (AP + 3.0B), and alfalfa planting +6.0% biochar addition (AP + 6.0B). Relative to the alfalfa planting only, extra biochar additions increased alfalfa biomass and heavy metal cadmium (Cd) phytoextraction. The alfalfa planting, alone or together with biochar additions, significantly decreased soil iprodione concentrations. After 90 days of remediation, bacterial 16S rRNA gene abundances of the AP, AP + 1.5B, AP + 3.0B and AP + 6.0B treatments were 1.69, 3.84, 3.34 and 3.13 times as great as that obtained from the CK treatment, respectively. The AP + 1.5B treatment had the highest richness estimators and Shannon diversity index, but the AP + 6.0B treatment had the lowest invsimpson diversity index among the five treatments. The relative abundances of Bacteroidetes and Nitrospirae were enhanced by the alfalfa phytoremediation, alone or together with biochar additions. Our results suggest that the alfalfa has promising potentials in the remediation of co-contaminated soil and in the increases of soil bacterial biomass and community diversity. Simultaneously, biochar is beneficial to enhance Cd phytoextraction, however, biochar addition rate would need to be optimized. © 2019 Elsevier B.V

Aspirin Caused Intestinal Damage through FXR and ET-1 Signaling Pathways

Aspirin is a non-steroidal, anti-inflammatory drug often used long term. However, long-term or large doses will cause gastrointestinal adverse reactions. To explore the mechanism of intestinal damage, we used non-targeted metabolomics; farnesoid X receptor (FXR) knockout mice, which were compared with wild-type mice; FXR agonists obeticholic acid (OCA) and chenodeoxycholic acid (CDCA); and endothelin-producing inhibitor estradiol to explore the mechanisms of acute and chronic intestinal injuries induced by aspirin from the perspective of molecular biology. Changes were found in the bile acids taurocholate acid (TCA) and tauro-β-muricholic acid (T-β-MCA) in the duodenum, and we detected a significant inhibition of FXR target genes. After additional administration of the FXR agonists OCA and CDCA, duodenal villus damage and inflammation were effectively improved. The results in the FXR knockout mice and wild-type mice showed that the overexpression of endothelin 1 (ET-1) was independent of FXR regulation after aspirin exposure, whereas CDCA was able to restore the activation of ET-1, which was induced by aspirin in wild-type mice in an FXR-dependent manner. The inhibition of ET-1 production could also effectively protect against small bowel damage. Therefore, the study revealed the key roles of the FXR and ET-1 pathways in acute and chronic aspirin-induced intestinal injuries, as well as strategies on alleviating aspirin-induced gastrointestinal injury by activating FXR and inhibiting ET-1 overexpression

Linking Carbendazim Accumulation with Soil and Endophytic Microbial Community Diversities, Compositions, Functions, and Assemblies: Effects of Urea-hydrogen Peroxide and Nitrification Inhibitors

Fungicide carbendazim accumulation in soils and plants is a wide concern. Nitrogen (N) is a substantial nutrient limiting crop growth and affecting soil microbial activity and the community in degrading fungicides. We investigated the effects of urea-hydrogen peroxide (UHP) and nitrification inhibitors Dicyandiamide (DCD) and 3,4-dimethylpyrazole phosphate (DMPP) on carbendazim accumulation and soil and endophytic microbial communities. The UHP application had negligible influences on soil and plant carbendazim accumulation, but the combined UHP and DCD decreased soil carbendazim accumulation by 5.31% and the combined UHP and DMPP decreased plant carbendazim accumulation by 44.36%. The combined UHP and nitrification inhibitor significantly decreased the ratios of soil Firmicutes and endophytic Ascomycota. Soil microbial community assembly was governed by the stochastic process, while the stochastic and deterministic processes governed the endophyte. Our findings could provide considerable methods to reduce fungicide accumulation in soil–plant systems with agricultural N management strategies

Minor increases in Phyllostachys edulis (Moso bamboo) biomass despite evident alterations of soil bacterial community structure after phosphorus fertilization alone: Based on field studies at different altitudes

Hosseini Bai, S ORCiD: 0000-0001-8646-6423Understanding the relationships among bamboo growth, soil microbial community and phosphorus (P) fertilization may shed new light on the optimization of P application rate and ecological function of P nutrient in forest ecosystem. This study aimed to evaluate the impacts of P fertilizations (25 and 50 kg P ha−1) on Phyllostachys edulis (Moso bamboo) growths, soil nutrient contents and microbial properties at different altitudes (300 and 800 m) and to link Moso bamboo growths with abiotic and biotic factors. Compared with the blank control, P fertilizations alone generated negligible impacts on the increases of Moso bamboo biomass and soil available P contents. Bacterial and fungal community diversities kept relatively stable after P fertilizations. Contrastingly, relative to the control, 25 kg P ha−1 application significantly enhanced the relative abundance of Proteobacteria and changed bacterial community structure at low altitude. At low and high altitudes, 50 kg P ha−1 applications significantly increased the relative abundances of Ascomycota. The Moso bamboo growth might be stimulated by the increases of soil total nitrogen, available P, Proteobacteria and Ascomycota. Our results demonstrated that P fertilization alone significantly changed soil bacterial community structure but generated negligibly stimulating role in the increase of Moso bamboo biomass. © 2019 Elsevier B.V

Interactive effects of biochar addition and elevated carbon dioxide concentration on soil carbon and nitrogen pools in mine spoil

Hosseini Bai, S ORCiD: 0000-0001-8646-6423Purpose: This study aimed to assess the effects of biochar on improving nitrogen (N) pools in mine spoil and examine the effects of elevated CO2 on soil carbon (C) storage. Materials and methods: The experiment consisted of three plant species (Austrostipa ramossissima, Dichelachne micrantha, and Lomandra longifolia) planted in the N-poor mine spoil with application of biochar produced at three temperatures (650, 750, and 850 °C) under both ambient (400 μL L−1) and elevated (700 μL L−1) CO2. We assessed mine spoil total C and N concentrations and stable C and N isotope compositions (δ13C and δ15N), as well as hot water extractable organic C (HWEOC) and total N (HWETN) concentrations. Results and discussion: Soil total N significantly increased following biochar application across all species. Elevated CO2 induced soil C loss for A. ramossissima and D. micrantha without biochar application and D. micrantha with the application of biochar produced at 750 °C. In contrast, elevated CO2 exhibited no significant effect on soil total C for A. littoralis, D. micrantha, or L. longifolia under any other biochar treatments. Conclusions: Biochar application is a promising means to improve N retention and thus, reduce environmentally harmful N fluxes in mine spoil. However, elevated CO2 exhibited no significant effects on increasing soil total C, which indicated that mine spoil has limited potential to store rising atmospheric CO2. © 2017, Springer-Verlag GmbH Germany