Dr Sai Sudarsan (MCh, FRCS)

Filtering effect for small droplets (aerosols) by various masks; home made of tea cloth, surgical mask (3M "Tie-On") and a FFp2 (N95) respirator mask. The numbers are scaled to the reference of 100 (Source of droplets) for illustrative purposes, calculated from the PF (Protection Factor) values in table 2. Measurement was performed with a portacount counter that registers particles in the air with sizes in the range between 0.02 and 1 micrometer at the end of a 3-hour wearing period with no physical activity. The number for the protection are medians of 7 (or 8) adult volunteers per group. Protection at the beginning of the test was similar for the Tea Cloth and Surgical Mask, but for FFP2 the protection was double. Children experienced substantially less protection.

LIMBIC SYSTEM Limbic system is associated with emotion, memory and basic instincts. It is a cluster of organs in the center of the brain. Its major structures form a group of modules that pass signals between the cortex and bodies of the lower brain. The limbic system mediates instinctive drives such as aggression, fear and appetite with learning, memory and higher mental functions. SMELL: It is the only sense handled by the limbic system MAMILLARY BODIES: They act as relay station for new memories AMYGDALA: Associated with fear conditioning and rage. It is also involved in memory and emotional response PARA HIPPOCAMPAL GYRUS: it helps us recognize and to recall things. It is also involved in forming and retrieving memories. HIPPOCAMPUS: it is associated with creating episodic memories and creating spatial awareness. REWARD AND PUNISHMENT: The limbic system is closely linked to feelings of rage and contentment. Both are due to stimulation of reward