Jika-tabi shoes in some industries, many workers prefer them for the softness of their soles. This gives wearers tactile contact with the ground, and the concomitant gripping ability lets them use their feet more agilely than rigid-soled shoes allow. This is useful for workers who traverse girders on construction sites and need to be sure what is under their feet. Carpenters and gardeners wearing these boots can, if they wish, use their feet as an extra pair of hands, for example to hold objects in place. There is also a line of knee-high all-rubber jika-tabi that is used by workers in
Effect of spaceflight on the human body lymphocytes. As these cells are central to the immune system, any damage weakens the immune system, which means that in addition to increased vulnerability to new exposures, viruses already present in the body—which would normally be suppressed—become active. In space, T-cells (a form of lymphocyte) are less able to reproduce properly, and the T-cells that do reproduce are less able to fight off infection. Over time immunodeficiency results in the rapid spread of infection among crew members, especially in the confined areas of space flight systems. On 31 May 2013, The NASA scientists reported that a possible manned mission to