10 research outputs found
A method for estimating particulate organic carbon at the sea surface based on geodetector and machine learning
Particulate organic carbon (POC) is an essential component of the carbon pump within marine organisms. Exploring estimation methods for POC holds substantial significance for understanding the marine carbon cycle. In this study, we investigated the spatial heterogeneity of 30 factors and POC concentrations using geodetector to account for nonlinearity, diversity, and complexity. Ultimately, 20 factors including sea surface temperature, sea surface salinity, and chlorophyll-a were selected as modeling variables. Six machine learning modelsâbackpropagation neural network, convolutional neural network, attention-based neural network, random forest (RF), adaptive boosting, and extreme gradient boosting were used to compare their performance. The results indicate that among the six machine learning algorithms, RF exhibits the strongest performance, with a root mean square error of 0.11 [log(mg/m3)] and an average percentage deviation of 2.73%. Global annual average sea surface POC concentrations were estimated for 2007 and compared to NASAâs POC product. The outcomes indicate that the RF model-based estimation method displays enhanced accuracy in estimating POC concentrations within intricate coastal environments, while the backpropagation neural network performed better in estimating POC concentrations in open ocean areas. Leveraging the RF model, global sea surface POC concentrations were estimated for the years 2007 through 2016, enabling a spatiotemporal analysis. The analysis unveils heightened POC concentrations in coastal regions and lower levels in open ocean areas. Furthermore, POC concentrations were greater in high-latitude regions compared to mid and low latitude counterparts. In conclusion, the global sea surface POC product in this study exhibits heightened spatial resolution and improved data completeness in contrast to other products. It enhances the accuracy of conventional POC estimation methods, particularly within coastal regions
A Study of the Regional Vocational Training Efficiency of Migrant Workers
Based on DEA-Tobit model, the efficiency of occupational training for rural migrant workers of 30 provinces and cities was studied in this paper. The results indicated that there are significant differences among these 30 provinces and cities. Technical efficiency of East areas is lower than average level. Moreover, there is a significant negative correlation between the efficiency and Average education attainment, and a significant positive correlation between the efficiency and proportion of rural population
Application of engineering- R&D integrated thinking mode for innovative talents cultivation of intelligent navigation experimental class
In view of the four prominent contradictions in the traditional engineering thinking teaching system of surveying and mapping engineering, which are difficult to meet the new requirements of innovative talents cultivation, a new talent training mode based on the integration of engineering and re-search thinking is proposed. Taking surveying and mapping engineering (intelligent navigation experimental class) as the research object, the multi-level training system of âthinking transformation - professional development - model transformationâ was designed, and the reform and practice were carried out from the multiple links of âcurriculum system - textbook construction - practical teaching - innovation creditsâ. The teaching practice in the past four years shows that the integrated thinking mode of engineering and research has been well applied in the cultivation of innovative talents in the intelligent navigation experimental class, and has achieved remarkable results in many aspects, such as the improvement of innovation ability, the promotion of teaching and practice system, the construction and application of teaching materials, and the development of disciplines and specialties, laying a solid foundation for the output of top innovative talents in the intelligent navigation experimental class
A path to humanâraccoon dog harmony: Identifying factors influencing the tolerance of urban residents in Shanghai towards a neglected species
Abstract Humanâwildlife interactions become increasingly common in urban areas across all continents and ecosystem types. Depending on the context, humanâwildlife interactions can be categorized as harmonious, neutrality, or in conflict and raises cultural, economic and ecological challenges in maintaining urban biodiversity. Understanding the mechanism behind the tolerance of residents to the presence of wildlife is vital to promoting a harmonious coexistence between humans and wildlife in urban environments. To advance our knowledge of this mechanism, we developed a questionnaire to survey residents in Shanghai, China about their knowledge of and attitude towards raccoon dogs (Nyctereutes procyonoides), a species whose population is increasing in urban areas. Using 281 questionnaires, we conducted structural equation modelling to examine how relational values, including familiarity with raccoon dogs, perceived benefits and risks, together with residents' trust in wildlife management authorities, interactively influence the tolerance for this species. We found that the residents' familiarity with raccoon dogs positively influenced their tolerance, both directly and indirectly through increased perceived benefits and reduced perceived risks. Furthermore, trust in wildlife management authorities contributed to higher tolerance through perceived benefits. Our results suggested that education about the relational values of raccoon dogs to the public can reduce the traditional negative connotation for this species and promote the coexistence of people and raccoon dogs in Shanghai urban environment. Based on our understanding about how raccoon dogs were culturally constructed and the willingness of residents to share landscapes with the species, we advocate that relational values play an important role in future urban biodiversity conservation planning. We also advocate for education programs that familiarize the public with raccoon dogs as well as other species, which can turn urban humanâwildlife conflicts into harmonious relationships in Shanghai and other urban areas. Read the free Plain Language Summary for this article on the Journal blog
Ultradeep Lysine Crotonylome Reveals the Crotonylation Enhancement on Both Histones and Nonhistone Proteins by SAHA Treatment
Lysine
crotonylation is a newly discovered protein post-translational
modification and was reported to share transferases and deacylases
with lysine acetylation. The acetyltransferase p300 was reported to
also contain crotonyltransferase activity, and class I histone deacetylases
were demonstrated to be the major histone decrotonylases. However,
the decrotonylases for nonhistone proteins are unclear. Moreover,
because of the lack of high-quality pan-antibodies, large-scale analysis
of crotonylome still remains a challenge. In this work, we comprehensively
studied lysine crotonylome on both histones and nonhistone proteins
upon SAHA treatment and dramatically identified 10âŻ163 lysine
crotonylation sites in A549 cells. This is the first identification
of tens of thousands of lysine crotonylation sites and also the largest
lysine crotonylome data set up to now. Moreover, a parallel-reaction-monitoring-based
experiment was performed for validation, which presented highly consistent
results with the SILAC experiments. By intensive bioinformatic analysis,
it was found that lysine crotonylation participates in a wide range
of biological functions and processes. More importantly, it was revealed
that both the crotonylation and acetylation levels of most core histones
sites and a number of nonhistone proteins as well as some known substrates
of class IIa and IIb HDACs were up-regulated after SAHA treatment.
These results suggest that SAHA may have decrotonylation inhibitory
activities on both histones and nonhistone proteins by inhibiting
HDACs
Ultradeep Lysine Crotonylome Reveals the Crotonylation Enhancement on Both Histones and Nonhistone Proteins by SAHA Treatment
Lysine
crotonylation is a newly discovered protein post-translational
modification and was reported to share transferases and deacylases
with lysine acetylation. The acetyltransferase p300 was reported to
also contain crotonyltransferase activity, and class I histone deacetylases
were demonstrated to be the major histone decrotonylases. However,
the decrotonylases for nonhistone proteins are unclear. Moreover,
because of the lack of high-quality pan-antibodies, large-scale analysis
of crotonylome still remains a challenge. In this work, we comprehensively
studied lysine crotonylome on both histones and nonhistone proteins
upon SAHA treatment and dramatically identified 10âŻ163 lysine
crotonylation sites in A549 cells. This is the first identification
of tens of thousands of lysine crotonylation sites and also the largest
lysine crotonylome data set up to now. Moreover, a parallel-reaction-monitoring-based
experiment was performed for validation, which presented highly consistent
results with the SILAC experiments. By intensive bioinformatic analysis,
it was found that lysine crotonylation participates in a wide range
of biological functions and processes. More importantly, it was revealed
that both the crotonylation and acetylation levels of most core histones
sites and a number of nonhistone proteins as well as some known substrates
of class IIa and IIb HDACs were up-regulated after SAHA treatment.
These results suggest that SAHA may have decrotonylation inhibitory
activities on both histones and nonhistone proteins by inhibiting
HDACs
Strong terahertz absorption of monolayer graphene embedded into a microcavity
Terahertz reflection behaviors of metallic-grating-dielectric-metal (MGDM) microcavity with a monolayer graphene embedded into the dielectric layer are theoretically investigated. A tunable wideband reflection dip at about the FabryâPĂ©rot resonant frequency of the structure is found. The reflectance at the dip frequency can be electrically tuned in the range of 96.5% and 8.8%. Because of the subwavelength distance between the metallic grating and the monolayer graphene, both of the evanescent grating slit waveguide modes and the evanescent Rayleigh modes play key roles in the strong absorption by the graphene layer. The dependence of reflection behaviors on the carrier scattering rate of graphene is analyzed. A prototype MGDM-graphene structure is fabricated to verify the theoretical analysis. Our investigations are helpful for the developments of electrically controlled terahertz modulators, switches, and reconfigurable antennas based on the MGDM-graphene structures