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The U.S. military presently manages about 88 billion dollars in spare and repair parts, consumables, and other support items. Department of Defense (DOD) inventory models which help wholesale item managers make inventory decisions concerning these items are based on the assumption that mean demand remains constant over time. In DOD this assumption is rarely met. During periods of declining demand, such as that associated with force reduction or equipment retirement, the inventory models usually keep stock levels too high, generating excess material. Recently, the amount of excess in DOD was estimated to be as high as 40 billion dollars. On the other extreme, during periods of increasing demand, the models generally provide too little stock, resulting in poor weapons system support. The purpose of this research was to develop an inventory model which does not rely on the assumption that mean demand is stationary. Use of the model would be appropriate when a known or predictable increase or decrease in mean demand is forecasted. Through simulation the model's performance was evaluated and compared with that of the Navy's Uniform Inventory Control Program (UICP) model. The results indicate that the proposed model significantly outperforms the existing model when mean demand is non- stationary. Additionally, the results indicate that the proposed model's performance is equal to or better than the existing Navy model under many stationary mean demand scenarios.http://archive.org/details/awholesalelevelc1094530557NANAU.S. Navy (U.S.N.) author

A Wholesale Level Consumable Item Inventory Model for Non-Stationary Demand Patterns

REPORT NUMBER 10. SPONSOFUNGR\.IIONITORING AGENCY REPORT NUMBE

Beyond the Paradigm: Novel Functions of Renin-Producing Cells

The juxtaglomerular renin-producing cells (RPC) of the kidney are referred to as the major source of circulating renin. Renin is the limiting factor in renin-angiotensin system (RAS), which represents a proteolytic cascade in blood plasma that plays a central role in the regulation of blood pressure. Further cells disseminated in the entire organism express renin at a low level as part of tissue RASs, which are thought to locally modulate the effects of systemic RAS. In recent years, it became increasingly clear that the renal RPC are involved in developmental, physiological, and pathophysiological processes outside RAS. Based on recent experimental evidence, a novel concept emerges postulating that next to their traditional role, the RPC have non-canonical RAS-independent progenitor and renoprotective functions. Moreover, the RPC are part of a widespread renin lineage population, which may act as a global stem cell pool coordinating homeostatic, stress, and regenerative responses throughout the organism. This review focuses on the RAS-unrelated functions of RPC - a dynamic research area that increasingly attracts attention