Biological Cell Identification by Integrating Micro-fluidics, Electrical Impedance Spectroscopy and Stochastic Estimation

The integration of micro-fluidics, electrical impedance spectroscopy and stochastic estimation will lead to a device with enhanced detection capabilities. The goal of this thesis was to build a micro-fluidic electrical impedance measurement device that can be used in combination with a stochastic estimator to accurately identify living cells. A microdevice capable of making impedance measurements on individual living cells was designed and built using a series of standard microelectronic fabrication techniques. A microchannel was patterned in SU-8 photoresist between two gold microelectrodes on a two inch Pyrex 7740 wafer. The design process, the fabrication techniques for the microchannel, the fluid port fabrication and the cover slip bonding processes are described in detail. Small glass cover slips were bonded to the wafer using Loctite 3301 adhesive. Impedance measurements of single cells, in the microchannel device, were made using a HP4194A impedance analyzer. Preliminary analysis of the impedance data suggests that Jurkat cells have characteristic impedance signatures, corresponding to their cell type. The microdevice that was designed and built for this project should facilitate future work to implement a stochastic estimation algorithm capable of single cell identification

Toward Agent-based Modeling of the U.S. Department of Defense Acquisition System

The systems development, procurement and sustainment of a nation\u27s military equipment is vital to its national interests, but the process is complex, constantly changing and highly adaptive, as well as time consuming and costly. The U.S. Department of Defense (DoD) expends both large amounts of capital and manpower to equip its armed forces. This research seeks to identify opportunities to gain better insight into the functioning of the defense acquisition system, building on previous simulations. A case is made that the DoD Requirements, Planning Acquisition, Technology and Logistics System is a complex adaptive system that has characteristics appropriate for exploration with agent-based modeling. This paper reviews relevant literature, existing models and presents preliminary analysis on an agent-based simulation of the DoD acquisition system. This research finds that agent-based modeling can provide insights to inform new acquisition theory

A Case–Control Study of Smoking and Bladder Cancer Risk: Emergent Patterns Over Time

jnci.oxfordjournals.org JNCI | Articles 1553 Cigarette smoking accounts for about 65 % of bladder cancer risk in men and 20 % – 30 % in women ( 1). Studies have consistently shown a two- to threefold risk of bladder cancer among regular cigarette smokers, defined as those who smoked at least one cig-arette per day for at least 6 months, compared with those who never smoked ( 1). Experimental evidence has suggested that 2-naphthylamine and 4-aminobiphenyl may be the bladder car-cinogens in cigarette smoke ( 1 – 8). Numerous studies have demonstrated that bladder cancer risk increases with increasing duration and intensity (cigarettes per day) of smoking, although risk levels off at higher intensity but not at higher duration ( 1, 9). Bladder cancer risk decreases as time since quitting increases ( 10 – 12), but it is unclear whether risk eventually returns to that of never-smokers ( 1). Moreover, previous bladde