High-speed downflows have been observed in the solar transition region (TR) and lower corona for many decades. Despite their abundance, it has hard to find signatures of such chromosphere. In this work, we target an enhanced network that shows ample occurrences rapid spicular \halpha\ spectral line could potentially be linked high-speed TR downflowing counterparts. We used $k$-means algorithm c...

The micromeres that arise at the fourth cell division in developing sea urchin embryos give rise to primary mesenchyme, which in turn differentiates and produces calcareous endoskeletal spicules. These spicules have been isolated and purified from pluteus larvae by washing in combinations of ionic and nonionic detergents followed by brief exposure to sodium hypochlorite. The spicules may be dem...