Stationary Cell Research Articles

A role for organ level dynamics in morphogenesis of the C. elegans hermaphrodite distal tip cell.

The morphology of cells in vivo can arise from a variety of mechanisms. In the Caenorhabditis elegans hermaphrodite gonad, the distal tip cell (DTC) elaborates into a complex plexus over a relatively short developmental time period, but the mechanisms underlying this change in cell morphology are not well defined. We correlated the time of DTC elaboration with the L4-to-adult molt, but ruled out a relevant heterochronic pathway as a cue for DTC elaboration. Instead, we found that the timing of gonad elongation and aspects of underlying germline flux influence DTC elaboration. We propose a 'hitch and tow' aspect of organ-level dynamics that contributes to cellular morphogenesis, whereby germline flux drags the flexible DTC cell cortex away from its stationary cell body. More broadly, we speculate that this mechanism may contribute to cell shape changes in other contexts with implications for development and disease.

Big Brother Is Watching You: Leveraging Artificial Intelligence for Automated Fuel Cell Monitoring (Technical Report)

In this technical report, we present our second-generation digital twin model for monitoring of fuel cells. This digital twin combines two data-driven machine learning models: a stationary model for stationary cell voltage prediction and a degradation model for degradation correction. This combination of both models results in a precise probabilistic prediction of the cell voltage over time.Furthermore, we present a web-based framework for automated fuel cell monitoring in real time. This framework allows training a digital twin on existing data and subsequently applying the twin to automatically check new data for anomalies.

Big Brother Is Watching You: Leveraging Artificial Intelligence for Automated Fuel Cell Monitoring (Technical Report)

In this technical report, we present our second-generation digital twin model for monitoring of fuel cells. This digital twin combines two data-driven machine learning models: a stationary model for stationary cell voltage prediction and a degradation model for degradation correction. This combination of both models results in a precise probabilistic prediction of the cell voltage over time.Furthermore, we present a web-based framework for automated fuel cell monitoring in real time. This framework allows training a digital twin on existing data and subsequently applying the twin to automatically check new data for anomalies.

A modular and flexible open source cell incubator system for mobile and stationary use

Culturing living cells in vitro requires the maintenance of physiological conditions for extended periods of time. Here, we introduce a versatile and affordable incubation system, addressing the limitations of traditional incubation systems. Conventionally, stationary cell incubators maintain constant temperature and gas levels for in vitro cell culturing. Combining such incubators with additional lab equipment proves challenging. The presented platform offers modularity and adaptability, enabling customization to diverse experimental needs. The system includes a main unit with a user-friendly interface as well as an interchangeable incubation chamber. We present two incubation chambers targeting two completely different use cases. The first chamber, named “inkugo” facilitates the transportation of cells for up to two hours without external power and for more than a day without an external CO2 source. The second chamber termed “inkubox” was designed to enable continuous electrophysiological recordings. Recordings from up to four neural cultures growing on high-density microelectrode arrays can be performed in parallel. The system’s unique feature lies in its separability of control and incubation components, allowing one control unit to manage various custom chambers. The design’s simplicity and the use of widely accessible components make the here proposed incubation system replicable for any laboratory. This platform fosters collaboration and experimentation in both decentralized and traditional laboratory settings, making it an invaluable addition to any cell culturing pipeline.

VUV absorption spectra of water and nitrous oxide by a double-duty differentially pumped gas filter.

The differentially pumped rare-gas filter at the end of the VUV beamline of the Swiss Light Source has been adapted to house a windowless absorption cell for gases. Absorption spectra can be recorded from 7 eV to up to 21 eV photon energies routinely, as shown by a new water and nitrous oxide absorption spectrum. By and large, the spectra agree with previously published ones both in terms of resonance energies and absorption cross sections, but that of N2O exhibits a small shift in the {\tilde{\bf D}} band and tentative fine structures that have not yet been fully described. This setup will facilitate the measurement of absorption spectra in the VUV above the absorption edge of LiF and MgF2 windows. It will also allow us to carry out condensed-phase measurements on thin liquid sheets and solid films. Further development options are discussed, including the recording of temperature-dependent absorption spectra, a stationary gas cell for calibration measurements, and the improvement of the photon energy resolution.

Why freshwater hydra does not get Alzheimer’s disease

The history of research into the basic mechanisms of the pathogenesis of Alzheimer’s disease (AD) is briefly considered. Concepts are analyzed in which a decisive role in the development of this disease was attributed to aluminum or free radicals. The lack of reliable data to date to support these concepts is emphasized. The point of view of the author is presented, according to which almost all the results indicating the feasibility of using antioxidants (as well as other potential drugs for AD) for the prevention and treatment of AD were obtained on model animals with certain pathologies (for example, with severe oxidative stress), which contribute to the formation of symptoms similar to those of AD in humans. In this regard, parallels are drawn with experimental gerontological research aimed at studying the effect of a calorie-restricted diet on aging and life span. It is noted that in these studies, animals were used that were either not completely normal or were in unfavorable conditions. According to the author, the lack of significant progress in the development of effective geroprotectors or drugs for the prevention/ treatment of AD is due to the fact that most specialists ignore the principles of classical gerontology, in particular, the definitions of aging and age-related diseases, as well as the correct approaches to the selection of control objects for their studies. It is emphasized that humans, unfortunately, cannot use the freshwater hydra method to combat aging and age-related diseases. Under certain conditions, it continuously renews all cells (including nerve ones) of its body and thereby ensures its “immortality.” In humans, the replacement of “old” neurons can lead to the loss of personality/individuality, and the “repair” of these cells today seems impossible. In this regard, the author considers it expedient to study the aging of postmitotic cells in experiments on stationary cell cultures, which can accelerate, in particular, the deciphering of the mechanisms of accumulation of beta-amyloid and senile pigments such as lipofuscin in neurons. The need for clinical studies of AD is noted as complementary to experimental work, although the first ones are much more expensive and time-consuming. Only confirmation in human studies of the effectiveness of drugs developed in experiments on model animals will allow them to be recommended for use in the clinical practice.

Concept for the automated adaption of abstract planning domains for specific application cases in skills-based industrial robotics

AbstractHigh product diversity, dynamic market conditions, and a lack of skilled workers are current challenges in manufacturing. Industrial robots autonomously planning and completing upcoming production tasks can help companies address these challenges. In this publication, we focus on autonomous task planning within industrial robotics and investigate how to facilitate the use of automated planning techniques from the field of artificial intelligence for this purpose. First, we present a novel methodology to automatically adapt abstractly modeled planning domains to the characteristics of individual application cases a user intends to implement. A planning domain is a formalized representation of the robot’s working environment that builds the basis for automated planning. Second, we integrate this approach into the procedure for developing skills-based industrial robotic applications to enable them to perform autonomous task planning. Finally, we demonstrate the use of the methodology within the application field kitting in two reference scenarios with a mobile robot and a stationary robot cell. Using our methodology, persons without expertise in automated planning can enable a robot for autonomous task planning without much extra effort.

A novel method of determining the active drag profile in swimming via data manipulation of multiple tension force collection methods

A novel method aimed at evaluating the active drag profile during front-crawl swimming is proposed. Fourteen full trials were conducted with each trial using a stationary load cell set-up and a commercial resistance trainer to record the tension force in a rope, caused by an athlete swimming. Seven different stroke cycles in each experiment were identified for resampling time dependent data into position dependent data. Active drag was then calculated by subtracting resistance trainer force data away from the stationary load cell force data. Mean active drag values across the stroke cycle were calculated for comparison with existing methods, with mean active drag values calculated between 76 and 140 N depending on the trial. Comparing results with established active drag methods, such as the Velocity Perturbation Method (VPM), shows agreement in the magnitude of the mean active drag forces. Repeatability was investigated using one athlete, repeating the load cell set-up experiment, indicating results collected could range by 88 N depending on stroke cycle position. Variation in results is likely due to inconsistencies in swimmer technique and power output, although further investigation is required. The method outlined is proposed as a representation of the active drag profile over a full stroke cycle.

Reconsidering Dogmas about the Growth of Bacterial Populations.

The growth of bacterial populations has been described as a dynamic process of continuous reproduction and cell death. However, this is far from the reality. In a well fed, growing bacterial population, the stationary phase inevitably occurs, and it is not due to accumulated toxins or cell death. A population spends the most time in the stationary phase, where the phenotype of the cells alters from the proliferating ones, and only the colony forming unit (CFU) decreases after a while, not the total cell concentration. A bacterial population can be considered as a virtual tissue as a result of a specific differentiation process, in which the exponential-phase cells develop to stationary-phase cells and eventually reach the unculturable form. The richness of the nutrient had no effect on growth rate or on stationary cell density. The generation time seems not to be a constant value, but it depended on the concentration of the starter cultures. Inoculations with serial dilutions of stationary populations reveal a so-called minimal stationary cell concentration (MSCC) point, up to which the cell concentrations remain constant upon dilutions; that seems to be universal among unicellular organisms.

Analysis of the efficiency of a double-axis control system of a PV power plant in a solar tracking system

A prototype control system for a PV power plant was constructed with the movement following the position of the Sun, where the position control takes place in two planes. The principle of operation is based on comparing the voltage values of small PV modules constituting the measurement system. With the use of this stand, the dynamics of changes in light intensity as a function of electricity production using a PV cell was analyzed. The value of energy from two PV cells was compared with the determined efficiency index as the ratio of energy obtained from a follow-motion controlled PV cell to the energy obtained from a stationary cell. The amount of energy generated from the follow-up PV system in the analyzed period exceeds the stationary system in the range from 5% to 74%, depending on the climatic conditions on the observed day.

Design and performance study of a dual-axis solar tracker system for the climate of Eastern Libya

Fossil fuels are non-renewable, finite, and exhausting. Therefore, it is necessary to find alternative sources of energy. Solar energy is abundant in nature, so it can be considered as the best alternative to meet the energy demand. It is sustainable, renewable, and scalable. Increasing the efficiency of harnessing solar energy should be one of our top concerns because it is a renewable resource. The challenge in utilizing this energy is to increase efficiency as well as reduce production costs. So, a dual-axis solar tracker was developed in this study to ensure that the tracked solar cells create more electrical energy than stationary solar cells, improving the performance of the solar panels and expanding their ability to make the most of the solar radiation. The experiment yielded great results. Due to its constant exposure to sunlight, the temperature of the mobile cell is higher than that of the stationary cell. The radiation intensity of the tracked cell is more than that of the fixed cell. The radiation intensity for the traced cell is more than that of the fixed cell and peaks at 1282 W/m2 on September 10 and 1028 W/m3 on September 11. For day 10, there was a daily rate of rise in radiation intensity on the tracker cell of 42 % compared to the fixed. Day 11 saw a difference of 210 W/m2/h, or 61 percent. The results are almost same from midday until dusk. During the day, the tension in the vacuum is somewhat different for stationary cells and tracking cells, with the value of the tracker being marginally lower than the fixed value. The increased temperature in the cell caused by more solar radiation and a warmer environment is thought to be the reason for the lower energy gain in the tracker

Tumor–neuron interactions: A novel concept contributor to glioblastoma invasion

Tumor–neuron interactions: A novel concept contributor to glioblastoma invasion

A repertoire of repulsive Keller–Segel models with logarithmic sensitivity: Derivation, traveling waves, and quasi‐stationary dynamics

In this paper, we show how the chemotactic model introduced in Alejo and López (2021), which accounts for a chemical production–degradation operator of Hamilton–Jacobi type involving first‐ and second‐order derivatives of the logarithm of the cell concentration, namely, with , can be formally reduced to a repulsive Keller–Segel model with logarithmic sensitivity whenever the chemotactic parameters are appropriately chosen and the cell concentration keeps strictly positive. In this way, some explicit solutions (namely, traveling waves and stationary cell density profiles) of the former system can be transferred to a number of variants of the the latter by means of an adequate change of variables.

The Soul Is a Biophysical Reality: Review of the Experimental Evidence

Introduction: In the present report, we studied the responses of a dwarf form of the unicellular organism, Stentor coeruleus, at the life/ death interphase. Methods: Uncovered deep well slides were filled with culture media containing the large forms of Stentor coeruleus. On evaporation of the culture medium, the cell membrane of these larger forms disrupted. When rehydrated 24 hours later the micronuclei previously released from the dying cells showed the formation of numerous, mobile dwarf cells. Chlorinated tap water added to the medium was used to induce cell death. Results: The initial indication of the dying dwarf cell is “blebbing,” a signature of programmed cell death known as apoptosis. Within 8-12min, the stationary dwarf cell progressively released a morphological replicate of the dead cell before the replicate faded into the ambient environment. In other experiments, just prior to fading, the slide was exposed to a magnetic field (75 milligaus) which caused a retraction of the replicate back into the dwarf cell. Subsequently, the cells resumed their previously mobile activity. Conclusions: These findings support the hypothesis that a phenomenon analogous to the characteristics ascribed to the soul in the metaphysical literature can be demonstrated in the laboratory. We suggest that the responses shown by this unicellular organism at the life/death interphase may be conserved across the evolutionary spectrum.

Environmental Impacts Analysis of Stationary Fuel Cell Combined Heat and Power Generation Systems

Environmental Impacts Analysis of Stationary Fuel Cell Combined Heat and Power Generation Systems

Characteristic signatures of Northern Hemisphere blocking events in a Lagrangian flow network representation of the atmospheric circulation.

In the past few decades, boreal summers have been characterized by an increasing number of extreme weather events in the Northern Hemisphere extratropics, including persistent heat waves, droughts and heavy rainfall events with significant social, economic, and environmental impacts. Many of these events have been associated with the presence of anomalous large-scale atmospheric circulation patterns, in particular, persistent blocking situations, i.e., nearly stationary spatial patterns of air pressure. To contribute to a better understanding of the emergence and dynamical properties of such situations, we construct complex networks representing the atmospheric circulation based on Lagrangian trajectory data of passive tracers advected within the atmospheric flow. For these Lagrangian flow networks, we study the spatial patterns of selected node properties prior to, during, and after different atmospheric blocking events in Northern Hemisphere summer. We highlight the specific network characteristics associated with the sequence of strong blocking episodes over Europe during summer 2010 as an illustrative example. Our results demonstrate the ability of the node degree, entropy, and harmonic closeness centrality based on outgoing links to trace important spatiotemporal characteristics of atmospheric blocking events. In particular, all three measures capture the effective separation of the stationary pressure cell forming the blocking high from the normal westerly flow and the deviation of the main atmospheric currents around it. Our results suggest the utility of further exploiting the Lagrangian flow network approach to atmospheric circulation in future targeted diagnostic and prognostic studies.

Lysis of cells of diverse bacteria by l,d-peptidases of Escherichia coli bacteriophages RB43, RB49 and T5.

The objective of this work was to study the antibacterial specificity and antibacterial effect of endolysins isolated from colibacteriophages RB43, RB49 and T5-as manifested on the exponential and stationary cell cultures of diverse bacteria depending on the growth stage, structure of peptidoglycan (PG) and antibiotic resistance. Enzyme activity was assayed by the spectrophotometric method. Antimicrobial activity was estimated by the number of colony forming units (CFUs), with the results represented as logarithmic units. Morphological examination of bacterial cells was conducted using phase-contrast and scanning electron microscopy. The enzymes EndoT5, endolysin of bacteriophage T5, EndoRB43, endolysin of bacteriophage RB43 and EndoRB49, endolysin of bacteriophage RB49 turned out to be much less bacteriospecific than the corresponding Escherichia coli phages; they lysed bacteria of the genera Bacillus, Cellulomonas and Sporosarcina, whose PGs had different structures (A1γ, A4α and A4β) and chemical modifications (amidation). The specific lytic activity of phage enzymes was independent of the antibiotic resistance of bacterial cells and was higher when the cells were in the exponential, rather than stationary, growth phase. The analysis of morphological changes showed that the intermediate stage of the endolysin-induced lysis of bacterial cells was the formation of spheroplasts and protoplasts. Endolysins of colibacteriophages RB49, RB43 and T5 have a wide spectrum of antibacterial action, which includes a number of diverse micro-organisms with different PG structures. This is a study of the bacterial selectivity of enzymes degrading bacterial cell wall in relation to the chemical structure of PG. It is shown that endolysins of bacteriophages RB49 and RB43 efficiently lyse cell wall of Gram-positive bacteria of the genus Bacillus and Gram-negative bacteria of the genus Pseudomonas (including an antibiotic-resistant strain). The number of bacterial cells is reduced by 3-6 orders of magnitude, which indicates good prospects for using these enzymes in biotechnology.

Morphofunctional features of mucosa-associated lymphoid tissue of intestine as an organ of immune system and its role in the development of diseases

Reticuloendothelial system (RES) is considered one of the local immune response regulation centers. It takes part in most physiological and pathological processes, namely, in local homeostasis, in regulation of trophism and immunological responses of both primary and secondary immune responses. The main cell population of (RES) is a macrophage, which is a stationary cell that can move only within the tissue layer. Dendritic cells as representatives of (RES) as well are under direct control of macrophages. Up to 80% of all immunocompetent cells are concentrated in the intestinal mucosa. For adequate interaction with the intestinal microbiota and ensuring immunological tolerance to normal commensals, there is a lymphoid tissue associated with the intestinal mucosa (gut-associated lymphoid tissue – GALT), in which mononuclear phagocytes perform their most significant functions. When pathogenic microorganisms enter the mucosa, the network of resident macrophages as an immune barrier triggers an inflammatory response to further stabilize homeostasis. However, a pronounced microbial and antigenic load in the gut requires the mandatory presence of specific immune cells – lymphocytes, whose immature forms are located in GALT structures and specialize under the guidance of mononuclear phagocytes. After the final differentiation, lymphocytes expressing integrin α4β7 are able to return from the systemic bloodstream to the intestinal mucosa to perform highly specific functions. This phenomenon is called the homing effect. It was noted that in non-specific ulcerative colitis and Crohn's disease, both the number of regulatory T-lymphocytes and their expression of integrin α4β7 increases. The pathology of the homing effect, according to some researchers, explains the possibility of follow-up secondary lesions in chronic inflammatory bowel diseases with the development of systemic pathology.

A simple model of Keratocyte membrane dynamics: The case of motionless living cell

We perform an analytical investigation of the cell interface dynamics in the framework of a minimal phase field model of cell motility suggested in Ziebert et al. (2012), which consists of two coupled evolution equations for the order parameter and a two-dimensional vector field describing the actin network polarization (orientation). We derive a closed evolutionary integro-differential equation governing the cell interface dynamics. The equation includes the normal velocity of the membrane, curvature, volume relaxation, and a parameter that is determined by the non-equilibrium effects in the cytoskeleton. This equation can be simplified to obtain a Burgers-like equation. A condition on the system parameters for the existence of a stationary cell shape is obtained.

The Immortality of the Germ Line: The Neverending Story

This is a short review concerning the problem of germ line “immortality,” which was already formulated by A. Weismann at the end of the 19th century. Over the following years, it attracted the attention of many gerontologists, who tried to understand the mechanisms of infinite transfer of genetic information from generation to generation with the help of germ cells, which, in contrast to somatic cells, avoid aging in this way. However, it remained unclear how the germ cells of women, which are in fact a population of non-dividing cells (it is similar to stationary phase aging non-subcultured cell culture), provide the mentioned immortality of the germ line. Distinguished Russian gerontologist Zh.A. Medvedev, who passed away recently, published in 1981 his brilliant work “On the Immortality of the Germ Line: Genetic and Biochemical Mechanisms. A Review,” the main points of which are relevant up to today. His paper just discusses the possible mechanisms of such “immortality.” They are analyzed in detail in the current article and can be reduced mainly to the existence of a number of barriers that, in most cases, do not allow progeny to emerge from “old” germ cells (although certain “rejuvenating” processes in the gametes still go). Therefore, children are “born young.” Some alternative approaches to explaining the immortality of the germ line are also considered. Special attention is paid to the “parental age effect” and the role of eggs and sperm cells in this phenomenon.