This paper attempted a perspective of the imperial examination system in ancient China and human capital accumulation.A kind of new explanatory hypothesis of the Needham's Puzzle was proposed then：The different system of China and Europe resulted in the diverse path of human capital accumulation, which yielded the discrepancy of economic results as well.The purpose of the imperial examination system in ancient China was that the high talented group was selected to work in public management department and other groups with lower intelligence worked in general production department.On the contrary, Europe had been dominated under the feudal system so that groups worked in two departments randomly.The economic level was higher, by contrast, during the earlier times in China.However, the accumulation of human capital in the general production department was slow that caused slower economic growth.European had been surpassed Chinese finally.
The development of contemporary art has enabled traditional artistic expressions such as painting, photography, and sculpture to gradually break the rigid mode under the traditional ideology, develop different forms and contents, and gradually expand the artist's understanding of the essence of art. What art creates is not the ice-cold presentation of artworks, but rather, the powerful conveyance of the artist's personal value. The development of artificial intelligence(AI) in the field of art has attracted an increasing amount of attention. However, we should analyze new things like the AI art dialectically.
At least 16.5 million people died of hunger in the Great Famine of China from 1959 to 1961. One direct reason is huge grain yield reduction. Here we show that massive sparrow slaughter which resulted in pest outbreaks is an important cause of grain yield reduction. The data we extracted from historical records shows ~2.1 billion sparrows were killed in 1958 and severe pest outbreaks followed. Further mechanism test shows that the consumption of pesticide during 1958 to 1961 was several times that of other years. While due to capacity restrictions, the supply of pesticide was still in shortage. Furthermore, provinces with a greater shortage of pesticide supplies also had more sparrows slaughtered. The unrecovered grain yield by pesticide is ~10.4% of the total grain output. Regression result shows sparrow slaughter caused annual loss of ~7 million metric tons of grain which could have fed ~28 million people. Our theory can explain approximately 33% reduction in crop yields in those years. This paper reveals a negative ecological case, which again warns human kind about the importance of maintaining ecological balance.
Abstract Background The progression of Alzheimer’s Disease (AD) is heterogeneous with different brain regions manifesting pathology at different times during the disease. Differential sequences of grey matter (GM) volume changes, defining imaging‐based subtypes, may represent alternative disease origins, pathways or severity. Additionally, volumes of white matter hyperintensities (WMH), which increase with age, are associated with AD. In this study we used a machine learning method to estimate three types of AD trajectories and assessed their WMH load and longitudinal prognosis. Method Subtype and Stage Inference (SuStaIn; Young et al., https://doi.org/10.1038/s41467‐018‐05892‐0 ) was used to estimate data‐driven disease progresion subtypes from cross‐sectional GM volumes in 795 subjects (from ADNI1/GO/2 with baseline 3T MRI scans processed with FreeSurfer 5.1 passing data quality control). Following additional quality control WMH volumes for 575 of these ADNI subjects were calculated using a Bayesian Model Selection method BaMoS (Sudre et al., https://doi.org/10.1109/TMI.2015.2419072 ) from three diagnostic groups: Healthy Controls (HC; n=181), Mild Cognitive Impairment (MCI; n=310) and Alzheimer’s Disease (AD; n=85). The association between SuStaIn subtypes and WMH and diagnostic conversion rates were evaluated using multiple pairwise comparisons and survival analysis, respectively. Result SuStaIn identified three subtypes with distinct atrophy patterns: typical (atrophy begins in hippocampus and amygdala), cortical (atrophy starts in the temporal lobe, followed by cingulate and insula) and subcortical (atrophy begins in pallidum, putamen and caudate) (Figure 1). Participants with the subcortical subtype exhibited a significantly slower rate of clinical progression to MCI or AD (Figure 2, Table 1). Furthemore, subjects with the subcortical subtype showed lower median WMH (Figure 3a), a pattern observed across the diagnostic groups (Figure 3b). Conclusion Participants classified as the subcortical subtype were least likely to have white matter structural changes associated with neurodegeneration and displayed the slowest rate of clinical conversion. While late hippocampal involvement in the subcortical subtype may explain less severe clinical symptoms and slower disease progression, the reason for lower WMH associated with this subtype trajectory is unknown. Further studies are needed to investigate the link between WMH and AD atrophy subtypes.
Abstract Background To address change in the gender gap of life expectancy (GGLE) in Shanghai from 1973 to 2018, and to identify the major causes of death and age groups associated with the change over time. Methods The temporal trend in GGLE was evaluated using retrospective demographic analysis with Joinpoint regression. Causes of death were coded in accordance with the International Classification of Diseases and mapped with the Global Burden of Disease (GBD) cause list. The life table technique and decomposition method were used to express changes in GGLE. Results The trend of GGLE in Shanghai experienced two phases, i.e., a decrease from 8.4 to 4.2 years in the descent phase (1973–1999) and a fluctuation between 4.0 and 4.9 years in the plateau phase (1999–2018). The reduced age-specific mortality rates tended to concentrate to a narrower age range, from age 0–9 and above 30 years in the descent phase to age above 55 years in the plateau phase. Gastroesophageal and liver cancer, communicable, chronic respiratory, and digestive diseases were once the major contributors to narrow GGLE in the descent phase. While, importance should be attached to a widening effect on GGLE by lung cancer, cardiovascular diseases, other neoplasms like colorectal and pancreatic cancer, and diabetes in the recent plateau phase. Conclusions Non-communicable diseases (NCDs) have made GGLE enter a plateau phase from a descent phase in Shanghai, China. Public efforts to reduce excess mortalities for male NCDs, cancers, cardiovascular diseases, chronic respiratory diseases, and diabetes in particular and health policies focused on the middle-aged and elderly population might further narrow GGLE. This will also ensure improvements in health and health equity in Shanghai China.
Abstract It is known for decades that dental epithelium and mesenchyme can reconstitute and regenerate a functional tooth. However, the mechanism of tooth reconstitution remains largely unknown due to the lack of an efficient in vitro model. Here, a chemically defined culture system is established that supports tooth reconstitution, further development with normal anatomy, and prompt response to chemical interference in key developmental signaling pathways, termed as toothoids. By using such a system, it is discovered that, during reconstitution, instead of resetting the developmental clock, dental cells reorganized and restarted from the respective developmental stage where they are originally isolated. Moreover, co‐stimulation of Activin A and Hedgehog/Smoothened agonist (SAG) sustained the initial induction of tooth fate from the first branchial arch, which would be otherwise quickly lost in culture. Furthermore, activation of Bone Morphogenetic Protein (BMP) signaling triggered efficient enamel formation in the late‐stage toothoids, without affecting the normal development of ameloblasts. Together, these data highlight the toothoid culture as a powerful tool to dissect the molecular mechanisms of tooth reconstitution and regeneration.
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