A three-dimensional flow control concept for single-cell experiments on a microchip. 1. Cell selection, cell retention, cell culture, cell balancing, and cell scanning

An ideal microchip for single-cell experiments should be able to allow us to culture cells, to select any desired single cell from a group, to retain the cell for convenient cellular signal detection, and to deliver any buffer or reagent directly to the cell at any time during continual detection and observation. Most importantly, any negative impact on the live cell should be minimized. To accomplish all these functions, we developed a three-dimensional liquid flow control concept and employed special liquid flow fields to manipulate and retain a single yeast cell freely in the chip. A zero-speed point was controlled to retain the cell for three-dimensional cell balancing and cell scanning. A dispersive flow delivered reagents at a high speed to very near the cell and provided them to the cell at a low speed. No force stronger than its gravitational force was exerted on the cell, which could be balanced on different positions on an arc-sloping wall, thus minimizing any negative impact on the cell due to strong liquid flows. Specifically, we demonstrate on-chip single-cell culture, cell wall removal, and reagent delivery. Subsequently, single-cell fluorescence detection was performed, and noise filtering and background correction were applied for data processing.     

Calibration method for measurement of linear nanometric distances by scattered total internal reflection

Scattered total internal reflection of visible light is used to measure linear nanometric distance to as small as 10 nm. Specifically, we measure the height of magnetic transducer heads above a rotating glass disk. A breakthrough in the approach to calibration, based on combining the second derivative of the transmittance of the scattered light and parameter fitting, substantially improves the quality of the measurement relative to previous demonstrations of this method. The results agree to 1 nm with an industry-standard three-color interferometer to and including the lowest values measured. The technique in principle remains robust to as low as the zero height. Furthermore the calibration point can be as low as 10 nm, which is especially attractive in practice.     

Minimization of combined sewer overflows by large-scale mathematical programming

There is a critical need for the development and implementation of control strategies for minimizing receiving water pollution caused by overflows from urban combined sewer systems. Automation and control of such systems has risen as a viable approach to this problem. Control is carried out through regulation of ambient and/or auxiliary storage in the system. The goal is to detain storm flows in the system long enough to prevent flows of a magnitude that exceeds treatment plant capacity, thereby reducing overflow into receiving waters. The problem is first attacked by dividing the large combined sewer system into several mildly interconnected subsystems for which control logic can be developed from application of mathematical programming algorithms consistent with the special characteristics of each subsystem. A flow-projection technique is developed for subsystems not amenable to direct solution by standard optimization techniques.     

Psychodynamics, behavior therapy, and the implacable experimenter: An inquiry into the consistency of personality.

Considers that possible integrations of dynamic and behavioral approaches to theory and therapy have been obscured by polemics. One area of confusion concerns the degree of generality or specificity in personality. Variability in behavior from situation to situation has been misleadingly construed by some behavioral critics as casting doubt upon psychodynamic theories. This view is refuted, and a number of factors that account for the differing viewpoints of psychodynamic and behaviorally oriented approaches are considered. Among these are differences in Ss from which original ideas were generated, differences in phenomena of central interest (with special focus on the implications of psychodynamic concern with ambiguous affective phenomena), and the consequences of an experimental strategy (the "implacable experimenter") which limits the ways in which S may structure the environment in which he behaves. (58 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On finding minimal-length test sets for diagnosing faults in combinational circuits

A fault-detection matrix contains sufficient information for finding minimal-length, fault-diagnosis test sets. The necessary and sufficient condition is that the submatrix of the fault-detection matrix must not contain equal rows. Cited examples demonstrate that characteristics in the fault-detection matrix can be used to facilitate the search for tests.     

Determining subsea permafrost characteristics with a cone penetrometer — Prudhoe Bay,Alaska

Sediments beneath the Beaufort Sea near Prudhoe Bay, Alaska, were probed at 27 sites using a static cone penetrometer to determine engineering properties and distribution of material types, including ice-bonded sediments. The probe, designed and constructed at the Cold Regions Research and Engineering Laboratory, provided both point and casing resistance data and thermal profiles. At five sites these data were correlated with information from adjacent drilled and sampled holes. These control data and the quality of the probe information permitted profiles of sediment type and occurrence of ice-bonded material to be developed along three lines that included various geological features and depositional environments.Material properties were quite variable in the upper 14 m of sediments probed. In general, softer, finer-grained sediments occurred in the upper layers, while penetration refusal was met in stiff gravels 10 to 12 m below the seabed.Seabed temperatures during the study were all below 0°C. However, because of uncertainties in freezing point values caused by brines, evaluation of the penetration resistance data was required to identify the occurrence of ice-bonded sediments. The coupling of thermal and penetration resistance data revealed that seasonally ice-bonded sediments occurred where the sea ice froze back to or near the seabed. Deeper, perennially frozen sediments also appeared to be present at several probe sites.