Retrieving rice (Oryza sativa L.) net photosynthetic rate from UAV multispectral images based on machine learning methods

Photosynthesis is the key physiological activity in the process of crop growth and plays an irreplaceable role in carbon assimilation and yield formation. This study extracted rice (Oryza sativa L.) canopy reflectance based on the UAV multispectral images and analyzed the correlation between 25 vegetation indices (VIs), three textural indices (TIs), and net photosynthetic rate (Pn) at different growth stages. Linear regression (LR), support vector regression (SVR), gradient boosting decision tree (GBDT), random forest (RF), and multilayer perceptron neural network (MLP) models were employed for Pn estimation, and the modeling accuracy was compared under the input condition of VIs, VIs combined with TIs, and fusion of VIs and TIs with plant height (PH) and SPAD. The results showed that VIs and TIs generally had the relatively best correlation with Pn at the jointing–booting stage and the number of VIs with significant correlation (p< 0.05) was the largest. Therefore, the employed models could achieve the highest overall accuracy [coefficient of determination (R2) of 0.383–0.938]. However, as the growth stage progressed, the correlation gradually weakened and resulted in accuracy decrease (R2 of 0.258–0.928 and 0.125–0.863 at the heading–flowering and ripening stages, respectively). Among the tested models, GBDT and RF models could attain the best performance based on only VIs input (with R2 ranging from 0.863 to 0.938 and from 0.815 to 0.872, respectively). Furthermore, the fusion input of VIs, TIs with PH, and SPAD could more effectively improve the model accuracy (R2 increased by 0.049–0.249, 0.063–0.470, and 0.113–0.471, respectively, for three growth stages) compared with the input combination of VIs and TIs (R2 increased by 0.015–0.090, 0.001–0.139, and 0.023–0.114). Therefore, the GBDT and RF model with fused input could be highly recommended for rice Pn estimation and the methods could also provide reference for Pn monitoring and further yield prediction at field scale

Deletion of Exon 20 of the Familial Dysautonomia Gene Ikbkap in Mice Causes Developmental Delay, Cardiovascular Defects, and Early Embryonic Lethality

Familial Dysautonomia (FD) is an autosomal recessive disorder that affects 1/3,600 live births in the Ashkenazi Jewish population, and leads to death before the age of 40. The disease is characterized by abnormal development and progressive degeneration of the sensory and autonomic nervous system. A single base pair substitution in intron 20 of the Ikbkap gene accounts for 98% of FD cases, and results in the expression of low levels of the full-length mRNA with simultaneous expression of an aberrantly spliced mRNA in which exon 20 is missing. To date, there is no animal model for the disease, and the essential cellular functions of IKAP - the protein encoded by Ikbkap - remain unknown. To better understand the normal function of IKAP and in an effort to generate a mouse model for FD, we have targeted the mouse Ikbkap gene by homologous recombination. We created two distinct alleles that result in either loss of Ikbkap expression, or expression of an mRNA lacking only exon 20. Homozygosity for either mutation leads to developmental delay, cardiovascular and brain malformations, accompanied with early embryonic lethality. Our analyses indicate that IKAP is essential for expression of specific genes involved in cardiac morphogenesis, and that cardiac failure is the likely cause of abnormal vascular development and embryonic lethality. Our results also indicate that deletion of exon 20 abolishes gene function. This implies that the truncated IKAP protein expressed in FD patients does not retain any significant biological function

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

The Influence of Financial Aid Systems on Student Academic Development in Higher Education in China

The main purpose of this paper is to analyze the relationship between the multiple mixed financial aid systems and the academic development of college students in Chinese higher education. Under the assistance of National Student Financial Aid Center of China, this study used sample data from the questionnaire survey conducted among students in 11 colleges and universities, and used logistic regression analysis based on human capital theory and student development theory to investigate the effects of different forms of financial aid on students’ academic development in higher education. The main results of the study showed that, firstly, receiving National Scholarships, National Encouragement Scholarships, and National Student Loans were significantly and positively correlated with receiving excellent grades, but receiving National Grants and work-study positions were significantly and negatively correlated with receiving excellent grades. Secondly, receiving higher National Scholarships and work-study funding significantly increased students’ probability of receiving excellent grades, but receiving higher National Student Loans funding significantly decreased students’ probability of receiving excellent grades. Further analysis of the influence of different forms of financial support on students’ academic development revealed that receiving National Scholarships and National Encouragement Scholarships can significantly increase the probability of study exchanges between sponsored students, teachers, and classmates and of attending seminars; receiving higher National Scholarships and work-study positions can help sponsored students clarify their study goals and increase study exchanges with teachers and classmates. The results of this study showed that the students’ academic development is influenced by the National Scholarships and work-study positions. Based on the results of the empirical study, countermeasures and suggestions were proposed in terms of precise financial aid systems, allocation of financial aid resources, and work-study positions, so as to improve the impact of higher education mixed financial aid systems on college students’ academic development in China

A Predictive Analysis on Emerging Technology Utilization in Industrialized Construction in the United States and China

Considering the increasing use of emerging technologies in industrialized construction in recent years, the primary objective of this article is to develop and validate predictive models to predict the emerging technology utilization level of industrialized construction industry practitioners. Our preliminary research results indicate that the company background and personal career profiles can significantly affect practitioners’ technology utilization level. Thus, our prediction model is based on four variables: company size, company type, working experience, and working position. The United States and China are selected as the case studies to validate the prediction model. First, a well-designed questionnaire survey is distributed to the industrialized construction industry practitioners from the two countries, which leads to 81 and 99 valid responses separately. Then, ordinal logistic regression is used to develop a set of models to predict the practitioners’ utilization level of the four main technology types. Finally, the external test dataset consisting of 16 cases indicates the prediction models have a high accuracy. The results also reflect some differences of the technology utilization status in the industrialized construction industry between the United States and China. The major contribution of this research is offering an efficient and accurate method to predict practitioners’ technology utilization level in industrialized construction. Significantly, the models are believed to have a wide application in promoting the emerging technologies in the actual industrialized construction

The Influence of Financial Aid Systems on Student Academic Development in Higher Education in China

The main purpose of this paper is to analyze the relationship between the multiple mixed financial aid systems and the academic development of college students in Chinese higher education. Under the assistance of National Student Financial Aid Center of China, this study used sample data from the questionnaire survey conducted among students in 11 colleges and universities, and used logistic regression analysis based on human capital theory and student development theory to investigate the effects of different forms of financial aid on students’ academic development in higher education. The main results of the study showed that, firstly, receiving National Scholarships, National Encouragement Scholarships, and National Student Loans were significantly and positively correlated with receiving excellent grades, but receiving National Grants and work-study positions were significantly and negatively correlated with receiving excellent grades. Secondly, receiving higher National Scholarships and work-study funding significantly increased students’ probability of receiving excellent grades, but receiving higher National Student Loans funding significantly decreased students’ probability of receiving excellent grades. Further analysis of the influence of different forms of financial support on students’ academic development revealed that receiving National Scholarships and National Encouragement Scholarships can significantly increase the probability of study exchanges between sponsored students, teachers, and classmates and of attending seminars; receiving higher National Scholarships and work-study positions can help sponsored students clarify their study goals and increase study exchanges with teachers and classmates. The results of this study showed that the students’ academic development is influenced by the National Scholarships and work-study positions. Based on the results of the empirical study, countermeasures and suggestions were proposed in terms of precise financial aid systems, allocation of financial aid resources, and work-study positions, so as to improve the impact of higher education mixed financial aid systems on college students’ academic development in China

Factors Influencing Sustainable Development Literacy among Engineering Undergraduates in China: Based on the College Impact Model

Achieving carbon neutrality is a major strategy to combat climate change and achieve sustainable development. Training engineering undergraduates with sustainable development literacy is an important way to achieve this goal in the field of higher education. Based on the college impact model, this research surveyed 1070 engineering undergraduates in Chinese universities to explore the influence of institutional support on undergraduates’ sustainable development literacy, and the empirical analysis was conducted using Structural Equation Modeling. The results showed that institutional support positively and significantly influenced the sustainability development literacy of engineering undergraduates, and student engagement had a mediating role in the relationship between institutional support and sustainability development literacy. Relevant recommendations for cultivating engineering undergraduates with high-level sustainability development literacy are proposed here

An analysis of the Singapore stock market, and its commercial banking and real estate industries

The objective of this report is to study and analyze the performance of securities listed on the Singapore stock exchange. Performance of the various industries was examined and two sectors were narrowed down for more in-depth investigation and discussion. This study focuses on the factors influencing stock performance and assesses how significant events in the history of time may have affected it. Our findings have showed that both banking and real estate industries are greatly affected by changes in government regulations and global happenings. This is because both industries are heavily regulated by Singapore government and our vast trading ties with other countries have made us vulnerable to global events. Hence, it is crucial for investors to be updated with the developments of government regulations in these 2 industries as changes would have significant impact on stock prices of the firms.BUSINES