TET2‐Mediated Spatiotemporal Changes of 5‐Hydroxymethylcytosine During Organogenesis in the Late Mouse Fetus

Objective: This study examined the factors related to the morphogenesis of the craniofacial complex of the CL/Fr mouse fetus affected with CLP based on the findings of a lateral cephalogram. Design: Embryo transfer experiments were performed to determine the effect of the fetus weight, dam strain, dam weight, and litter size on the intra-uterine craniofacial morphogenesis of CL/Fr mouse fetuses. On the 18th gestational day, each pregnant dam that had received CL/Fr mouse embryos was laparotomized to remove the transferred fetuses that had developed in the uteri of the cleft lip and palate (CLP)-susceptible CL/Fr strain dam and the CLP-resistant C57BL strain dam. A cephalometric observation of the craniofacial morphology of each fetus was subsequently performed. Results: Based on a multiple regression analysis, the standardized partial regression coefficients of the affected fetus weight, the dam weight, and the litter size on the maxillary size of the affected CL/Fr fetus were 0.71 (p < .01), 0.03, and −0.07. According to a least-squares analysis of variance, the dam strain effect in addition to the effect of the affected fetus weight on the maxillary size and the cranial size of the affected fetuses was significant (p < .01 for cranial size, p < .05 for maxillary size) and close to a significant level (p = .09) for the mandibular size of the affected fetuses. The adjusted maxillary size and cranial size after statistically eliminating the effects of the affected fetus weight, dam weight, and lifter size on each original craniofacial size of the affected fetuses that had developed in the CL/Er dam strain were also significantly smaller than those of the affected fetuses that had developed in the C57BL dam strain. Conclusions: The present results indicate that the craniofacial growth of the CL/Fr mouse fetus affected with CLP increased in proportion to the fetus weight. The dam strain effect, in addition to the effect of the affected fetus weight, could thus not be ignored when the etiology of the spontaneous CLP was examined, while the uterine environment, provided by the CL/Fr strain dam, retarded the intra-uterine craniofacial growth of the affected fetuses. It was therefore concluded that the dam strain effect, as well as the effect of the affected fetus weight, both play an important role on the craniofacial morphogenesis of the CL/Fr strain of the affected fetuses that developed in both strain dams.

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Spatiotemporal Changes of Riverbed and Surrounding Environment in Yongding River (Beijing section) in the Past 40 Years

Journal of Imaging Science and Technology ◽

10.2352/j.imagingsci.technol.2020.64.4.040407 ◽

2020 ◽

Vol 64 (4) ◽

pp. 40407-1-40407-13 ◽

Cited By ~ 1

Author(s):

Ran Pang ◽

He Huang ◽

Tri Dev Acharya

Keyword(s):

Economic Development ◽

Water Conservation ◽

Human Activities ◽

Urban Areas ◽

Water Volume ◽

Cropland Area ◽

The Past ◽

Surrounding Environment ◽

Spatiotemporal Changes ◽

Yongding River

Abstract Yongding River is one of the five major river systems in Beijing. It is located to the west of Beijing. It has influenced culture along its basin. The river supports both rural and urban areas. Furthermore, it influences economic development, water conservation, and the natural environment. However, during the past few decades, due to the combined effect of increasing population and economic activities, a series of changes have led to problems such as the reduction in water volume and the exposure of the riverbed. In this study, remote sensing images were used to derive land cover maps and compare spatiotemporal changes during the past 40 years. As a result, the following data were found: forest changed least; cropland area increased to a large extent; bareland area was reduced by a maximum of 63%; surface water area in the study area was lower from 1989 to 1999 because of the excessive use of water in human activities, but it increased by 92% from 2010 to 2018 as awareness about protecting the environment arose; there was a small increase in the built-up area, but this was more planned. These results reveal that water conservancy construction, agroforestry activities, and increasing urbanization have a great impact on the surrounding environment of the Yongding River (Beijing section). This study discusses in detail how the current situation can be attributed to of human activities, policies, economic development, and ecological conservation Furthermore, it suggests improvement by strengthening the governance of the riverbed and the riverside. These results and discussion can be a reference and provide decision support for the management of southwest Beijing or similar river basins in peri-urban areas.

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Spatiotemporal Changes in Vegetation Cover and Its Influencing Factors in the Loess Plateau of China Based on the Geographically Weighted Regression Model

Forests ◽

10.3390/f12060673 ◽

2021 ◽

Vol 12 (6) ◽

pp. 673

Author(s):

Chen Yang ◽

Meichen Fu ◽

Dingrao Feng ◽

Yiyu Sun ◽

Guohui Zhai

Keyword(s):

Regression Model ◽

Influencing Factors ◽

Loess Plateau ◽

Geographically Weighted Regression ◽

Vegetation Cover ◽

Weighted Regression ◽

Vegetation Coverage ◽

The Loess Plateau ◽

Geographically Weighted Regression Model ◽

Spatiotemporal Changes

Vegetation plays a key role in ecosystem regulation and influences our capacity for sustainable development. Global vegetation cover has changed dramatically over the past decades in response to both natural and anthropogenic factors; therefore, it is necessary to analyze the spatiotemporal changes in vegetation cover and its influencing factors. Moreover, ecological engineering projects, such as the “Grain for Green” project implemented in 1999, have been introduced to improve the ecological environment by enhancing forest coverage. In our study, we analyzed the changes in vegetation cover across the Loess Plateau of China and the impacts of influencing factors. First, we analyzed the latitudinal and longitudinal changes in vegetation coverage. Second, we displayed the spatiotemporal changes in vegetation cover based on Theil-Sen slope analysis and the Mann-Kendall test. Third, the Hurst exponent was used to predict future changes in vegetation coverage. Fourth, we assessed the relationship between vegetation cover and the influence of individual factors. Finally, ordinary least squares regression and the geographically weighted regression model were used to investigate the influence of various factors on vegetation cover. We found that the Loess Plateau showed large-scale greening from 2000 to 2015, though some regions showed decreasing vegetation cover. Latitudinal and longitudinal changes in vegetation coverage presented a net increase. Moreover, some areas of the Loess Plateau are at risk of degradation in the future, but most areas showed a sustainable increase in vegetation cover. Temperature, precipitation, gross domestic product (GDP), slope, cropland percentage, forest percentage, and built-up land percentage displayed different relationships with vegetation cover. Geographically weighted regression model revealed that GDP, temperature, precipitation, forest percentage, cropland percentage, built-up land percentage, and slope significantly influenced (p < 0.05) vegetation cover in 2000. In comparison, precipitation, forest percentage, cropland percentage, and built-up land percentage significantly affected (p < 0.05) vegetation cover in 2015. Our results enhance our understanding of the ecological and environmental changes in the Loess Plateau.

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