Results of modifying the difference of the growth rates.

<p>The parameter measures the difference of the growth rates of the fully favored and fully unfavored phenotypes. The growth rate increases with . The curves correspond to . Other parameters are , , , and .</p

Convergence of the growth rate to the Lyapunov exponent.

<p>A typical evolution of the time average of the growth rate (8) over the increasing time interval from 0 to . For the process asymptotically approaches a stationary value (6). Deviations are within . The plot was obtained using system (7) with OU input (4).</p

Dependence of the Lyapunov's exponent on the parameter for alternative environmental inputs.

<p>A: Results for model (1) with the stochastic input (5). The curves correspond to . For negative the growth rate decreases with . B: Results for model (1) with the periodic environmental input . The curves correspond to . Again, for negative the growth rate decreases with . Other parameters are the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103241#pone-0103241-g004" target="_blank">Figure 4</a>.</p

The effect of changes in the parameters and on the Lyapunov's exponent .

<p>Each plot demonstrates a positive optimal value of the threshold parameter , which maximizes for model (1). A: The effect of altering the average lag time . The curves correspond to . The growth rate increases with . Solid lines are plotted for , a relatively slow transition rate; dashed lines are plotted for , a high transition rate. Other parameters are , , and . B: The effect of varying the stiffness of the potential well . The lines correspond to . The growth rate decreases with . Other parameters are , , , and .</p

Illustration of random phenotype switching.

<p>The S-shaped curve consists of two horizontal segments and a slanted segment whose slope may be randomly changing. Stable phenotype states can be found on the horizontal segments of this curve. For a given value of the environmental input , the transition from the state on the lower part of the curve to the upper part occurs when the meeting point of the slanted segment with the lower state line shifts to the left of ; the transition from the upper to the lower branch occurs when the meeting point of the slanted segment with the upper state line shifts to the right of . When , transitions from state 0 to state 1 occur with higher probability than transitions from state 1 to the state 0. When , transitions from state 0 to state 1 are less likely than transitions from state 1 to state 0.</p

The Lyapunov's exponent for different values.

<p>Plots on panels A and B were obtained for systems (9) and (1), respectively, with OU environmental input (4). A: The curves correspond to . For the growth rate increases with . B: The curves are for . For negative the growth rate decreases with . Other parameters are , , , , .</p

Carbon Pipette-Based Electrochemical Nanosampler

Sampling ultrasmall volumes of liquids for analysis is essential in a number of fields from cell biology to microfluidics to nanotechnology and electrochemical energy storage. In this article, we demonstrate the possibility of using nanometer-sized quartz pipettes with a layer of carbon deposited on the inner wall for sampling attoliter-to-picoliter volumes of fluids and determining redox species by voltammetry and coulometry. Very fast mass-transport inside the carbon-coated nanocavity allows for rapid exhaustive electrolysis of the sampled material. By using a carbon pipette as the tip in the scanning electrochemical microscope (SECM), it can be precisely positioned at the sampling location. The developed device is potentially useful for solution sampling from biological cells, micropores, and other microscopic objects

Open Carbon Nanopipettes as Resistive-Pulse Sensors, Rectification Sensors, and Electrochemical Nanoprobes

Nanometer-sized glass and quartz pipettes have been widely used as a core of chemical sensors, patch clamps, and scanning probe microscope tips. Many of those applications require the control of the surface charge and chemical state of the inner pipette wall. Both objectives can be attained by coating the inner wall of a quartz pipette with a nanometer-thick layer of carbon. In this letter, we demonstrate the possibility of using open carbon nanopipettes (CNP) produced by chemical vapor deposition as resistive-pulse sensors, rectification sensors, and electrochemical nanoprobes. By applying a potential to the carbon layer, one can change the surface charge and electrical double-layer at the pipette wall, which, in turn, affect the ion current rectification and adsorption/desorption processes essential for resistive-pulse sensors. CNPs can also be used as versatile electrochemical probes such as asymmetric bipolar nanoelectrodes and dual electrodes based on simultaneous recording of the ion current through the pipette and the current produced by oxidation/reduction of molecules at the carbon nanoring

Cytotoxicity of non-thermal plasma on prostate DU145 cancer and PrEC normal cells.

<p>The cells were exposed to PBS treated with different plasma doses for 1 and 10 minutes, followed by dilution with growth medium and incubation for 24 and 48 hours. To simplify the understanding of non-thermal plasma doses, the plasma obtained at different physical parameters (<b><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156818#pone.0156818.t001" target="_blank">Table 1</a></b>) was named numerically as Dose 1, 2, etc. As seen from the graphs <b>A</b> and <b>D</b> the highest cytotoxic dose was Dose 7 (D7). (<b>B,E</b>) The quantitative graphs of the plasma induced cytotoxicity for both prostate cancer and normal cells. (<b>C,F</b>) The data and images obtained from the colony formation assay. The benign PrECs treated with plasma D7 for 1 and 10 minutes followed by PBS dilution with growth medium were cultivated for 6 days. They retain their proliferative activity while the cancer cells treated in the same way lose the ability to form colonies. Data presented as mean±SEM (n = 3).</p

Plasma induced modulations of cytosolic calcium in PrEC and DU145 cells.

<p>Representative confocal microscopy spectral records of DU145 cells. After 10 minutes of incubation with or without plasma treated PBS cells were challenged with 50μM ATP. (A) IP₃-mediated intracellular calcium oscillations induced by ATP were produced in control cells. (B) In plasma treated DU145 cells this amount of ATP provoked sustained cytosolic calcium response, while non-thermal plasma treated PBS itself did not cause calcium modulations. In PrECs the high calcium signal was observed right after addition of non-thermal plasma treated PBS (D7) (C). The representative original records demonstrate the data collected from about 50 cells evaluated in each of 5 experiments.</p