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In the field of target tracking, probability multiple hypothesis tracking (PMHT) algorithm, as a batch processing algorithm, has much less computation than the traditional multiple hypothesis tracking algorithm. Currently, the application of PMHT algorithm is limited by centralized processing. On the basis of the traditional algorithm, this study firstly derives the algorithm likelihood under sensor network to obtain the post-correlation parameter under multi-sensor algorithm, followed by hybrid consensus based on the consensus processing strategy, and finally the posteriori estimation of the target parameters is accomplished by using Kalman filtering. This study enables the PMHT algorithm to be applied to the fully distributed sensor network without fusion centers. The experimental results show that under different clutter densities, the distributed PMHT has more than 90% improvement in tracking error compared to the single-sensor algorithm. Distributed PMHT has close tracking performance and faster computation compared to centralized algorithms. [ABSTRACT FROM AUTHOR]

A lack of empirical evidence for the microbial regulation of ecosystem processes, including carbon (C) degradation, hinders our ability to develop a framework to directly incorporate the genetic composition of microbial communities in the enzyme-driven Earth system models. Herein we evaluated the linkage between microbial functional genes and extracellular enzyme activity in soil samples collected across three geographical regions of Australia. We found a strong relationship between different functional genes and their corresponding enzyme activities. This relationship was maintained after considering microbial community structure, total C and soil pH using structural equation modelling. Results showed that the variations in the activity of enzymes involved in C degradation were predicted by the functional gene abundance of the soil microbial community (R2>0.90 in all cases). Our findings provide a strong framework for improved predictions on soil C dynamics that could be achieved by adopting a gene-centric approach incorporating the abundance of functional genes into process models.

To compare the volatile flavor characteristics of red jujube from different origins, volatile aroma components of jujube fruit from five origins (Xinzheng, Lingbao, Yulin, Hotan and Dezhou) were analyzed by headspace solid-phase microextraction combined with gas chromatography mass spectrometry. The results showed that a total of 51 compounds were identified, among which the most volatile compounds were contained in Xinjiang Hotan jujube. Combined with multivariate statistical analysis, the differences in the overall volatile flavor substances of red jujube from different origins could be well distinguished. Under the conditions of satisfying the variable importance in projection>1 and P<0.05, 13 differential characteristic aroma substances, including methyl caproate, methyl decanoate, hexanal, and benzaldehyde, were screened out from red jujube samples, which imparted unique almond, sweet, and fruity flavors to red jujube. The results of this study clarify the chemical substance basis of the aroma quality of red jujube from different origins, provide a new idea for the origin tracing study of red jujube, and further provide a scientific basis for the rational processing and utilization of jujube fruit resources. [ABSTRACT FROM AUTHOR]

Replacing synthetic fertilizer by organic manure has been shown to reduce emissions of nitrous oxide (N2O), but the specific roles of ammonia oxidizing microorganisms and gross nitrogen (N) transformation in regulating N2O remain unclear. Here, we examined the effect of completely replacing chemical fertilizer with organic manure on N2O emissions, ammonia oxidizers, gross N transformation rates using a 13‐year field manipulation experiment. Our results showed that organic manure reduced cumulative N2O emissions by 16.3%–210.3% compared to chemical fertilizer. The abundance of ammonia oxidizing bacteria (AOB) was significantly lower in organic manure compared with chemical fertilizer during three growth stages of maize. Organic manure also significantly decreased AOB alpha diversity and changed their community structure. However, organic manure substitution increased the abundance of ammonia oxidizing archaea and the alpha diversity of comammox Nitrospira compared to chemical fertilizer. Interestingly, organic manure decreased organic N mineralization by 23.2%–32.9%, and autotrophic nitrification rate by 10.5%–45.4%, when compared with chemical fertilizer. This study also found a positive correlation between AOB abundance, organic N mineralization and gross autotrophic nitrification rate with N2O emission, and their contribution to N2O emission was supported by random forest analysis. Our study highlights the key roles of ammonia oxidizers and N transformation rates in predicting cropland N2O. [ABSTRACT FROM AUTHOR]