A Novel Cartesian Plot Analysis for Fixed Monolayers That Relates Cell Phenotype to Transfer of Contents between Fibroblasts and Cancer Cells by Cell-Projection Pumping

We recently described cell-projection pumping as a mechanism transferring cytoplasm between cells. The uptake of fibroblast cytoplasm by co-cultured SAOS-2 osteosarcoma cells changes SAOS-2 morphology and increases cell migration and proliferation, as seen by single-cell tracking and in FACS separated SAOS-2 from co-cultures. Morphological changes in SAOS-2 seen by single cell tracking are consistent with previous observations in fixed monolayers of SAOS-2 co-cultures. Notably, earlier studies with fixed co-cultures were limited by the absence of a quantitative method for identifying sub-populations of co-cultured cells, or for quantitating transfer relative to control populations of SAOS-2 or fibroblasts cultured alone. We now overcome that limitation by a novel Cartesian plot analysis that identifies individual co-cultured cells as belonging to one of five distinct cell populations, and also gives numerical measure of similarity to control cell populations. We verified the utility of the method by first confirming the previously established relationship between SAOS-2 morphology and uptake of fibroblast contents, and also demonstrated similar effects in other cancer cell lines including from melanomas, and cancers of the ovary and colon. The method was extended to examine global DNA methylation, and while there was no clear effect on SAOS-2 DNA methylation, co-cultured fibroblasts had greatly reduced DNA methylation, similar to cancer associated fibroblasts.     

An artificial neural network based decision support system for solving the buffer allocation problem in reliable production lines

One of the major design problems in the context of manufacturing systems is the well-known Buffer Allocation Problem (BAP). This problem arises from the cost involved in terms of space requirements on the production floor and the need to keep in mind the decoupling impact of buffers in increasing the throughput of the line. Production line designers often need to solve the Buffer Allocation Problem (BAP), but this can be difficult, especially for large production lines, because the task is currently highly time consuming. Designers would be interested in a tool that would rapidly provide the solution to the BAP, even if only a near optimal solution is found, especially when they have to make their decisions at an operational level (e.g. hours). For decisions at a strategic level (e.g. years), such a tool would provide preliminary results that would be useful, before attempting to find the optimal solution with a specific search algorithm.     

Magnetic Damping Effects in Forced-Oscillation Vibrating-Wire Viscometers

Vibrating wire viscometers rely on the principle that the viscosity of the fluid surrounding the wire provides the dominant damping action on the motion of the wire. However, some residual damping is always present due to other effects such as internal friction of the wire (anelastic relaxation), losses through the wire supports, and magnetic damping. Magnetic damping is a physical mechanism that has received relatively less attention than internal friction in the context of viscometers. The phenomenon arises because the current induced by the motion of the wire contributes to the magnetic field in such a way as to oppose its own motion. For a test circuit using a 40 μm diameter tungsten wire in a 0.3 T magnetic field, surprisingly, the effect of magnetic damping was found to be of a similar order of magnitude to other non-viscous damping effects. The effect can be accounted for by including the internal impedance of the oscillating voltage source in the model and it disappears completely for a perfect oscillating current source.     

Undermining the Corrective Effects of Media‐Based Political Fact Checking? The Role of Contextual Cues and Naïve Theory

Media‐based fact checking contributes to more accurate political knowledge, but its corrective effects are limited. We argue that biographical information included in a corrective message, which is often unrelated to the inaccurate claim itself, can activate misperception‐congruent naïve theories, increasing confidence in a misperception's plausibility and inducing skepticism toward denials. Resistance to corrections occurs regardless of initial belief accuracy, but the effect is strongest among those who find the contextual information objectionable or threatening. We test these claims using an online survey‐embedded experiment (N = 750) conducted in the wake of the controversy over the proposed Islamic cultural center in New York City near the site of the 9/11 attacks, and find support for our predictions. Theoretical and practical implications are discussed.     

Microstructure and Electrical Properties of Low Temperature Processed Ohmic Contacts to p‐Type GaN

With Ni/Au and Pd/Au metal schemes and low temperature processing, we formed low resistance stable Ohmic contacts to p‐type GaN. Our investigation was preceded by conventional cleaning, followed by treatment in boiling HNO₃:HCl (1:3). Metallization was by thermally evaporating 30 nm Ni/15 nm Au or 25 nm Pd/15 nm Au. After heat treatment in O₂ + N₂ at various temperatures, the contacts were subsequently cooled in liquid nitrogen. Cryogenic cooling following heat treatment at 600 ·C decreased the specific contact resistance from 9.84·10^?4 Ωcm² to 2.65·10^?4 Ωcm² for the Ni/Au contacts, while this increased it from 1.80·10^?4 Ωcm² to 3.34·10^?4 Ωcm² for the Pd/Au contacts. The Ni/Au contacts showed slightly higher specific contact resistance than the Pd/Au contacts, although they were more stable than the Pd contacts. X‐ray photoelectron spectroscopy depth profiling showed the Ni contacts to be NiO followed by Au at the interface for the Ni/Au contacts, whereas the Pd/Au contacts exhibited a Pd:Au solid solution. The contacts quenched in liquid nitrogen following sintering were much more uniform under atomic force microscopy examination and gave a 3 times lower contact resistance with the Ni/Au design. Current‐voltage‐temperature analysis revealed that conduction was predominantly by thermionic field emission.     

Demonstration of an Analog IC Function Maintenance Strategy, Including Direct Calibration, Built-in Self-test, and Commutation of Redundant Functional Blocks

A new analog subsystem maintenance strategy is presented that can be used to improve the accuracy, reliability, yield, and testability of analog and mixed-signal ICs. This scheme is a generally applicable design approach that combines hybrid redundancy, direct subcircuit parameter adjustment (calibration), and on-chip analog function verification (built-in self-test). Improvements are realized in a system-transparent fashion through careful function block commutation. The cost is a moderate die area increase. This design strategy is applicable to a wide range of moderately complex analog functions. An example analog function is used here to illustrate this new maintenance approach. Experimental data demonstrate the capabilities of this new approach to analog IC design fortestability.