We used metacontrast masking, a type of backward masking where a briefly presented simple visual target stimulus is rapidly followed by a nonoverlapping mask that shares a contour with the target.
Hereafter, mainly undercutting word is used for the lateral etching at any type of mask edge and corner.
Of the 102 healthcare workers from whom complete data were available, 45 (44%) reported exposure without any type of mask; 72 (70%) had exposure without eye protection (Table 3).
Autopsy data have suggested that CHI is a primary hemorrhage [ 18] or possibly due to alterations in venous drainage [ 17], however, the goal of the latter study was to test the potential impact of a type of ventilation mask attachment that is no longer in use, rather than study CHI itself.
These performers included all the miscellaneous stage arts in their repertoire and created from the various court dances and masked plays a type of folk masked play usually termed sandae togam gug.
Each group wore a single type of mask for a period of three hours, being either a FFP2 mask (4 males, 4 females), a surgical mask (3 males, 4 females) or a home-made mask (3 males, 4 females), similar to the masks used in the short-term experiment described above.
My biggest – and most ludicrous – purchase was a special type of mask that cost me over £300".
At Ughoton, to the southwest of Benin, a different type of mask is used, in the cult of the water spirit Igbile.
The Japanese preparedness plan and guidelines do not recommend a specific type of mask, and published recommendations regarding the use of specific types of masks are not consistent [ 29].
