Intensifying spatially compound heatwaves: Global implications to crop production and human population.

Recent research has provided crucial insights on regional heatwaves, including their causal mechanisms and changes under global warming. However, detailed research on global-scale spatially compound heatwaves (SCHs) (concurrent heatwaves over multiple regions) is lacking. Here, we find statistically significant teleconnections in heatwaves and show that the frequency of global-scale SCHs and their areal extent have increased significantly, which has led to 50 % increase in the population exposed to extreme heat stresses in the two most recent decades. Crop yields were reduced in most of the years of anomalous heatwaves, which often happen during El-Niños. The internal climate variability appears to significantly influence the inter-annual variability of regional and global heatwave extents. Insights gained here are critical in better quantifying heat stress risks inflicted on socioecological systems.

Recent changes in heatwaves and maximum temperatures over a complex terrain in the Himalayas.

The temperature response to anthropogenic global warming and forest cover changes is dependent on regional climatic characteristics. It is challenging to segregate the impacts of the two anthropogenic changes on local temperatures and heatwaves over complex mountainous regions. Here we present estimates of regional and local heat stress responses to the recent global climate change and local forest cover loss in complex terrain in the Himalayas using a satellite-based high-resolution land-surface temperature dataset. We find large-scale decreasing trends in the observed frequency of heatwaves and heat days, and localized increases in urbanized and high-elevation regions. Our results show large-scale significant decreasing trends in annual maximum and mean surface temperatures over the period 2003-2019. In locations that have witnessed large-scale forest losses, the declines in the surface temperatures were steeper compared to no-loss regions. We develop a regional multiple linear regression model to estimate the regional and local temperature responses to global climatic change and to segregate them from the response to forest cover losses. Our model estimates a regional decrease of about 2.0 °C in annual maximum temperature over the recent 2003-2019 period, which is locally modulated by the extent of urbanization, forest cover, and elevation. At the locations of intense deforestation, our model successfully predicts a steeper decrease in maximum surface temperature, and estimates the temperature response due to forest loss, after controlling for elevation and initial forest cover. The local cooling effect due to deforestation was reaffirmed by comparing the regions with contrasting forest cover losses. The results suggest that forest clearing amplifies the anthropogenic climate change over the region.

Role of adipose-derived stem cells in wound healing.

Impaired wound healing remains a challenge to date and causes debilitating effects with tremendous suffering. Recent advances in tissue engineering approaches in the area of cell therapy have provided promising treatment options to meet the challenges of impaired skin wound healing such as diabetic foot ulcers. Over the last few years, stem cell therapy has emerged as a novel therapeutic approach for various diseases including wound repair and tissue regeneration. Several different types of stem cells have been studied in both preclinical and clinical settings such as bone marrow-derived stem cells, adipose-derived stem cells (ASCs), circulating angiogenic cells (e.g., endothelial progenitor cells), human dermal fibroblasts, and keratinocytes for wound healing. Adipose tissue is an abundant source of mesenchymal stem cells, which have shown an improved outcome in wound healing studies. ASCs are pluripotent stem cells with the ability to differentiate into different lineages and to secrete paracrine factors initiating tissue regeneration process. The abundant supply of fat tissue, ease of isolation, extensive proliferative capacities ex vivo, and their ability to secrete pro-angiogenic growth factors make them an ideal cell type to use in therapies for the treatment of nonhealing wounds. In this review, we look at the pathogenesis of chronic wounds, role of stem cells in wound healing, and more specifically look at the role of ASCs, their mechanism of action and their safety profile in wound repair and tissue regeneration.