We guarantee our supplements to be the freshest and purest: Our powders and capsules contain only pure active ingredient with absolutely no additives. Other manufacturers, in an effort to keep costs down, dilute their products with cheap fillers and add chemical excipients to their products to speed up their manufacturing output. These practices cheat you out of the active ingredient. At NutraBio, we've perfected our manufacturing technology so that excipients aren't needed, that means no microcrystalline cellulose, magnesium stearate, silica or other fillers, just 100% pure active ingredient. NutraBio supplements are manufactured under the strictest standards producing the highest quality and purest supplements available anywhere. Our raw ingredients undergo state of the art HPLC analysis to insure zero tolerance for impurities and we manufacture our products every 2 weeks.
Arginine's side chain is amphipathic , because at physiological pH it contains a positively charged guanidinium group, which is highly polar, at the end of a hydrophobic aliphatic hydrocarbon chain. Because globular proteins have hydrophobic interiors and hydrophilic surfaces,  arginine is typically found on the outside of the protein, where the hydrophilic head group can interact with the polar environment, for example taking part in hydrogen bonding and salt bridges.  For this reason, it is frequently found at the interface between two proteins.  The aliphatic part of the side chain sometimes remains below the surface of the protein. 
The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".   Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.  The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.  Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.