In contrast to division of work, division of labour is the specialization of an individual workers' or organizations' skills, through education, training, and practice.
AR15 Trigger Upgrades. 1  The trigger is one of the most crucial elements in achieving the highest level of accuracy from any firearm. Installation of a quality trigger will permit a light pull with little or no creep and overtravel.
Aortic regurgitation (AR) is the diastolic flow of blood from the aorta into the left ventricle (LV). Regurgitation is due to incompetence of the aortic valve or any disturbance of the valvular apparatus (eg, leaflets, annulus of the aorta) resulting in the diastolic flow of blood into the left ventricular chamber. Abnormalities of the ascending aorta, in the absence of valve pathology, may also cause AR.