The influence of micro and macro porosity of paper on wet repellence mottling in offset printing

Fountain solution induced mottling in offset printing manifests as nonhomogenous printing area with optical variation has several influencing factors. One mechanism is that the fountain solution from the previous printing unit has no time to absorb into the coating before ink transfer or the ink cannot emulsify the water and stays on top of the ink surface as an additional hydrophilic layer. In paper coating development, the paper chemistry influences the surface chemistry features of the inkpaper coating interaction and can cause water repellency. Porosity and the absorbing capacity of paper and its coating is of great importance to avoid press related problems. In this paper, we have examined paper substrates which were reported to cause wet repellence mottling and tested their porosity ratio of micro and macro pores and their water/ ink absorption properties. The micro macro porosity was determined by using easy and low-cost proprietary technique for the porosity ratio determination. We have measured ink stabilization values, penetration dynamics, wet repellence mottling and micro and macro porosity on paper samples printed with laboratory sheet-fed offset printing. We have found that the lower number of macropores and non-optimal micro and macropore distribution influenced the occurrence of water induced wet repellence and lowered the optical homogeneity of the samples

Noise at public event

Recent years the noise is one of the leading pollutants in working and living environment. Although in some cases the noise levels do not exceed proposed levels, people often have the opposite impression. While for the most activities noise regulation exists, for public events this is not the case. There are certain guidelines, however established levels differ from country to country. In order to determine the noise level during public events the equivalent level of noise was measured at one public event on which approximately 50,000 people was present. The results show significantly high levels of noise, especially during rock concert and firework, when certain protective measures should be implemented

Decoding the Bell-Shaped Calcium Spikes in Phosphorylation Cycles of Flagella

We investigate the messenger role of calcium ions implicated in the regulation of wave-like bending dynamics of flagella. The emphasis is on microtubules of flagellar axoneme serving as nonlinear transmission lines for bell-shaped spikes of calcium ions. The calcium sensitive proteins, such as calmodulin, exhibit activation dependence on the spike train frequency and amplitude. Here, we analyze a Ca2+ decoding module IDA-I1 whose activity is controlled by Ca2+ activated kinase. We find that trains of Ca2+ spikes are advantageous compared to a constant rise in Ca2+ concentration as being more efficient and much less prone to noisy fluctuations

Decoding the Bell-Shaped Calcium Spikes in Phosphorylation Cycles of Flagella

We investigate the messenger role of calcium ions implicated in the regulation of wave-like bending dynamics of flagella. The emphasis is on microtubules of flagellar axoneme serving as nonlinear transmission lines for bell-shaped spikes of calcium ions. The calcium sensitive proteins, such as calmodulin, exhibit activation dependence on the spike train frequency and amplitude. Here, we analyze a Ca2+ decoding module IDA-I1 whose activity is controlled by Ca2+ activated kinase. We find that trains of Ca2+ spikes are advantageous compared to a constant rise in Ca2+ concentration as being more efficient and much less prone to noisy fluctuations

Calcium messages in flagella are faster than messenger particles

Calcium is one of the most versatile messengers for intracellular signaling. In the case of cilia and flagella calcium has the central role in transfer of communications between extracellular stimuli and intracellular formation of frequency modulated signal and their deciphering by target proteins. In this paper, the diffusion of fluorescently or otherwise tagged and un-tagged Ca2＋ particles is analyzed by solving the system of pertaining reaction–diffusion equations. We used Fourier transform tools to get asymptotic eigenfunctions for tagged (un-tagged) free and buffered Ca2＋ ions. We made some numerical estimations for diffusion coefficients corroborating the fact that messages diffuse faster than Ca2＋ messengers. From the best of our knowledge, this is the first time that Ca2＋ signaling in living cells is biophysically elaborated within the framework of model presented here. We suggest the experimental assay on the basis of radioactive Ca2＋ as tagged probe

Calcium ions tune the beats of cilia and flagella

The cytoskeleton of cilia and flagella is so called axoneme a stable cylindrical architecture of nine microtubule doublets. Axoneme performs periodic bending motion by utilizing specific dynein motor family powered by ATP hydrolysis. It is still unclear how this highly organized “ciliary beat” is being initiated and strongly coordinated by the combined action of hundreds dynein motors. Based on the experimental evidences we here elaborate a plausible scenario in which actually calcium ions play the roles of catalytic activators and coordinators of dynein attachments doing it in superposition with already known mechanical control tools of “ciliary beat”. Polyelectrolyte properties of microtubules incorporated in axoneme doublets enable the formation and propagation of soliton-like “ionic clouds” of Ca2+ ions along these “coaxial nanocables”. The sliding speed of such Ca2+ “clouds” along microtubule doublets is comparable with the speed of propagation of “ciliary beat” itself. We elaborated the interplay between influx of Ca2+ ions in ciliary based body and the sliding of microtubule triplets therein. In second segment we considered how the dynein motors activated by Ca2+ ions contained within solitonic “ionic clouds” in competition with axoneme curvature regulate ciliary and flagellar beating

Calcium signaling modulates the dynamics of cilia and flagella

To adapt to changing environments cells must signal and signaling requires messengers whose concentration varies with time in space. We here consider the messenger role of calcium ions implicated in regulation of the wave-like bending dynamics of cilia and flagella. The emphasis is on microtubules as polyelectrolytes serving as transmission lines for the flow of Ca2+ signals in the axoneme. This signaling is superimposed with a geometric clutch mechanism for the regulation of flagella bending dynamics and our modeling produces results in agreement with experimental data