Diffusion Across a Cell Membrane. Diffusion is the movement of a substance across a membrane. Substances diffuse across cell membranes in a process known as passive transport. This means that the cell does not expend any energy in transporting substances across the cell membrane. Instead, substances move down their concentration gradient as a result of random thermal motion.
401k and profit sharing plans are both forms of retirement plans. They allow employees to make pre-tax contributions to an account where contributions and earnings are not taxed until distributed. Some 401k plans require an employer to make contributions to a plan.
Profit sharing. Profit sharing refers to various incentive plans introduced by businesses that provide direct or indirect payments to employees that depend on company's profitability in addition to employees' regular salary and bonuses. In publicly traded companies these plans typically amount to allocation of shares to employees. The profit sharing plans are based on predetermined economic sharing rules that define the split of gains between the company as a principal and the employee as an agent. For example, suppose the profits are x, which might be a random variable.