Forests are facing several challenges related to forest deforestation mostly due to the actions of man. The study used a CA-Markov model to examine land use/land cover dynamics from 1986 to 2022, as well as estimate future changes from 2022 to 2052 in the Mount Nlonako forest and peripheries. Three types of Landsat images (Landsat 4 - 5 Thematic Mapper (TM) images of 1986 and 2004, and Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI-TIRS) image of 2022) were used for diachronic analysis. The results revealed six major land use/land cover classes namely: Dense forest, Clear forest, Farmland, Savannah, Built-up Area and Bare floor. Accuracy rates for land use/land cover classification ranged from 89.85% to 93.11%. The prediction model was accepted with an overall satisfaction rate of 84.08%. The Dense Forest class has been steadily decreasing from 138320.94 ha (75.42%) in 1986 to 84161.34 ha (45.89%) in 2022, corresponding to a total loss of 54159.6 ha (29.53%) over the 36-year period and is projected to reach 39028.34 ha (21.28%) in 2052 corresponding to a future loss of 45133 ha (24.61%) over a period of 30 years. Anthropogenic factors (mainly agriculture and industrial logging) and natural factors (excess rainfall) were responsible for the degradation of the area. Regardless of the limitations of the CA-Markov model due to the non integration of socio-economic factors, this study is a crucial alert to decison and policy makers to undergo protection procedures for this area to be protected, thereby involving the local communities in the management and restoration of the area through participatory management.
This study analyzed ambient seismic noise using the MSNoise package to monitor temporal changes in the underground seismic wave velocity in Mining Area 6 of the Dongtan Coal Mine in China.The data was recorded continuously over 76 days by 7 three-component stations and 10 single-component microseismic stations deployed in Dongtan Coal Mine,with station spacing ranging from 0.1 km to approximately 3 km.Using the causal and non-causal components of the Z-component cross-correlation function,along with moving-window cross-spectrum analysis and cumulative calculations with a 5-day window overlay,stable seismic velocity changes were obtained in the frequency band of 0.1 to 2 Hz.We found a correlation between the timing of average velocity changes and seismic events caused by underground mining processes.In particular,when the relative seismic velocity increased by 0.23%,larger energy minequakes typically occurred.This study shows that ambient noise correlation has great potential for predicting minequakes,guiding pressure-relief production,and providing warnings about the impact of overburden pressure.
Nuclear DNA, which is essential for the transmission of genetic information, is constantly damaged by external stresses and is subsequently repaired by the removal of the damaged region, followed by resynthesis of the excised region. Accumulation of DNA damage with failure of repair processes leads to fatal diseases such as cancer. Recent studies have suggested that intra- and extra-nuclear environments play essential roles in DNA damage. However, numerous questions regarding the role of the nuclear mechanical environment in DNA damage remain unanswered. In this study, we investigated the effects of cell confluency (cell crowding) on the morphology of cell nuclei, and cytoskeletal structures, and DNA damage in NIH3T3 skin fibroblasts and HeLa cervical cancer cells. Although nuclear downsizing was observed in both NIH3T3 and HeLa cells with cell crowding, intracellular mechanical changes in the two cell types displayed opposite tendencies. Cell crowding in NIH3T3 cells induced reinforcement of actin filament structures, cell stiffening, and nuclear downsizing, resulting in a significant decrease in endogenous DNA damage, whereas cell crowding in HeLa cells caused partial depolymerization of actin filaments and cell softening, inducing endogenous DNA damage. Ultraviolet (UV) radiation significantly increased DNA damage in NIH3T3;however, this response did not change with cell crowding. In contrast, UV radiation did not cause DNA damage in HeLa cells under either sparse or confluent conditions. These results suggested that cell crowding significantly influenced endogenous DNA damage in cells and was quite different in NIH3T3 and HeLa cells. However, cell crowding did not affect the UV-induced DNA damage in either cell type.
Epigenetic regulation is critical to multiple physiological and pathological processes.However,little is known regarding the epigenetic changes during neonatal skin development and skin aging,and in response to ultraviolet(UV)exposure.The transcriptomes of human skin samples from different ages or irradiated with different types and doses of UV light were analyzed using R(version 4.0.3)software.The epigenetic landscape of the skin,including histone modifications,genetic imprinting and m^(6)A modification,which are mainly involved in collagen formation,extracellular matrix organization,immune function and keratinization,underwent significant changes during neonatal to adult development.Epigenetic effectors such as IGF2BP2,GATA2,GATA3,CPA4 and CDK1 were significantly correlated with extracellular matrix organization,and VEGFA,CDK1 and PRKCB with skin immune function.The m^(6)A readers such as IGF2BP2,IGF2BP3,HNRNPA2B1 and EIF3G showed significant correlation with extracellular matrix organization,metabolism,or antigen processing and presentation.Small doses of UV exposure only induced changes in the expression levels of some epigenetic effectors,without any significant effect on the overall epigenetic landscape.However,the minimal erythema dose of UV exposure altered multiple epigenetic effectors regulating extracellular matrix organization,cell-matrix adhesion,innate immune response,mitochondrial function and mRNA processing.In addition,epigenetic changes following UV exposure were more pronounced in the elderly skin compared to the younger skin.In conclusion,histone modifications,genetic imprinting and m^(6)A modification play critical roles during skin development,and a large dose of UV exposure can significantly change the expression of multiple epigenetic effectors.
Li LeiLing JiangYibo HuMenglu ChenJinhua HuangJing ChenQinghai Zeng
