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Amoeboid movement is one of the most widespread forms of cell motility that plays a key role in numerous biological contexts. While many aspects of this process are well investigated, the large cell-to-cell variability in the motile characteristics of an otherwise uniform population remains an open question that was largely ignored by previous models. In this article, we present a mathematical model of amoeboid motility that combines noisy bistable kinetics with a dynamic phase field for the cell shape. To capture cell-to-cell variability, we introduce a single parameter for tuning the balance between polarity formation and intracellular noise. We compare numerical simulations of our model to experiments with the social amoeba Dictyostelium discoideum. Despite the simple structure of our model, we found close agreement with the experimental results for the center-of-mass motion as well as for the evolution of the cell shape and the overall intracellular patterns. We thus conjecture that the building blocks of our model capture essential features of amoeboid motility and may serve as a starting point for more detailed descriptions of cell motion in chemical gradients and confined environments.

Cytokinesis—the division of a cell into two daughter cells—is a key step in cell growth and proliferation. It typically occurs in synchrony with the cell cycle to ensure that a complete copy of the genetic information is passed on to the next generation of daughter cells. In animal cells, cytokinesis commonly relies on an actomyosin contractile ring that drives equatorial furrowing and separation into the two daughter cells. However, also contractile ring-independent forms of cell division are known that depend on substrate-mediated traction forces. Here, we report evidence of an as yet unknown type of contractile ring-independent cytokinesis that we termed wave-mediated cytofission. It is driven by self-organized cortical actin waves that travel across the ventral membrane of oversized, multinucleated Dictyostelium discoideum cells. Upon collision with the cell border, waves may initiate the formation of protrusions that elongate and eventually pinch off to form separate daughter cells. They are composed of a stable elongated wave segment that is enclosed by a cell membrane and moves in a highly persistent fashion. We rationalize our observations based on a noisy excitable reaction–diffusion model in combination with a dynamic phase field to account for the cell shape and demonstrate that daughter cells emerging from wave-mediated cytofission exhibit a well-controlled size.

Within digital finance, CBDCs are booming. As there are currently four operational CBDCs and as many as ninety-four central banks, jurisdictions or currency areas are testing or investigating the launch of a retail CBDC. The study was based on a sample of 34 countries or currency areas, which were classified into three groups. This research aimed to answer the following research questions: 1. Can CBDCs be considered green and sustainable? 2. How can we determine whether a CBDC is green and sustainable? 3. Which countries are closest to having green CBDCs? It has been calculated the total and the percentage of CBDCs that could be considered green or sustainable according to each country or currency area; in this model, it has been considered one monetary unit issued in a green/sustainable CBDC format for each point that a country obtains in this model that is adjusted according to four variables: Electricity prices for households and for businesses, renewable electricity production and CO 2 emissions. The countries that could launch a higher percentage of green/sustainable CBDCs in circulation would be the countries in the Eurozone and the United Kingdom, with these countries exceeding 70%. This was followed by Sweden (60%), Australia (58%) and the Bahamas (close to 54%). Only the Bahamas has its CBDC already launched and operational. Jamaica is also in the top ten and has its CBDC up and running. Japan closes the top 10 with just over 51%. Those countries with cleaner sources of power generation will be able to keep their CBDCs operating more sustainably. The environmental impact, however, will vary depending on the design choices of a CBDC and the country where it operates, according to the variables of this model.

The ability to access quality financial services and cash has been indicated by various organizations, such as the World Bank or UN, as a fundamental aspect to guarantee regional sustainable development. However, access to cash is not always guaranteed, especially in rural regions. The present study is based in the Ávila region of Spain. A parameter called the “access to cash index” is constructed here. It is used to detect rural areas where the ability to access cash and banking services is more difficult. Based on the “access to cash index”, two sustainable solutions are proposed: The first (in the short term), based on extending access to cash, takes advantage of the existing pharmacy network. With this measure, a notable reduction of more than 55% of the average distance required to access this service is verified here. The second is based on the implementation of a central bank digital currency. Here, the results show an acceptance of 75%. However, it is known that elderly people and those without relevant education and/or low incomes would reject its widespread use. Such a circumstance would require the development of training and information policies on the safety and effectiveness of this type of currency.

In recent years, there has been increasing investment in the deployment of massive commercial Low Earth Orbit (LEO) constellations to provide global Internet connectivity. These constellations, now equipped with inter-satellite links, can serve as low-latency Internet backbones, requiring LEO satellites to act not only as access nodes for ground stations, but also as in-orbit core routers. Due to their high velocity and the resulting frequent handovers of ground gateways, LEO networks highly stress mobility procedures at both the sender and receiver endpoints. On the other hand, a growing trend in networking is the use of technologies based on the Information Centric Networking (ICN) paradigm for servicing IoT networks and sensor networks in general, as its addressing, storage, and security mechanisms are usually a good match for IoT needs. Furthermore, ICN networks possess additional characteristics that are beneficial for the massive LEO scenario. For instance, the mobility of the receiver is helped by the inherent data-forwarding procedures in their architectures. However, the mobility of the senders remains an open problem. This paper proposes a comprehensive solution to the mobility problem for massive LEO constellations using the Named-Data Networking (NDN) architecture, as it is probably the most mature ICN proposal. Our solution includes a scalable method to relate content to ground gateways and a way to address traffic to the gateway that does not require cooperation from the network routing algorithm. Moreover, our solution works without requiring modifications to the actual NDN protocol itself, so it is easy to test and deploy. Our results indicate that, for long enough handover lengths, traffic losses are negligible even for ground stations with just one satellite in sight.

The great advances produced in the field of artificial intelligence and, more specifically, in deep learning allow us to classify images automatically with a great margin of reliability. This research consists of the validation and development of a methodology that allows, through the use of convolutional neural networks and image identification, the automatic recycling of materials such as paper, plastic, glass, and organic material. The validity of the study is based on the development of a methodology capable of implementing a convolutional neural network to validate a reliability in the recycling process that is much higher than simple human interaction would have. The method used to obtain this better precision will be transfer learning through a dataset using the pre-trained networks Visual Geometric Group 16 (VGG16), Visual Geometric Group 19 (VGG19), and ResNet15V2. To implement the model, the Keras framework is used. The results conclude that by using a small set of images, and thanks to the later help of the transfer learning method, it is possible to classify each of the materials with a 90% reliability rate. As a conclusion, a model is obtained with a performance much higher than the performance that would be reached if this type of technique were not used, with the classification of a 100% reusable material such as organic material.

The development of modeling structures at the channel level that can integrate subcellular and cell models and properly reproduce different experimental data is of utmost importance in cardiac electrophysiology. In contrast to gate-based models, Markov Chain models are well suited to promote the integration of the subcellular level of the cardiomyocyte to the whole cell. In this paper, we develop Markov Chain models for the L-type Calcium current that can reproduce the electrophysiology of two established human models for the ventricular and Purkinje cells. In addition, instead of presenting a single set of parameters, we present a collection of set of parameters employing Differential Evolution algorithms that can properly reproduce very different protocol data. We show the importance of using an ensemble of a set of parameter values to obtain proper results when considering a second protocol that suppresses calcium inactivation and mimics a pathological condition. We discuss how model discrepancy, data availability, and parameter identifiability can influence the choice of the size of the collection. In summary, we have modified two cardiac models by proposing new Markov Chain models for the L-type Calcium. We keep the original whole-cell dynamics by reproducing the same characteristic action potential and calcium dynamics, whereas the Markov chain-based description of the L-type Calcium channels allows novel small spatial scale simulations of subcellular processes. Finally, the use of collections of parameters was crucial for addressing model discrepancy, identifiability issues, and avoiding fitting parameters overly precisely, i.e., overfitting.

This study analyses the current debate around central bank-backed digital currency (CBDC). A comparative study was carried out considering countries for and against implementing a CBDC and their reasons, looking for common causes, differences, etc. The conclusion was that there are opposite tendencies between defenders and detractors of establishing a CBDC. However, today-and taking into account the positions of three large banking institutions (the Federal Reserve of the United States of America, the Bank of Japan and the Bank of England) on establishing (at least in the short term) a CBDC)-it seems that large-scale implementation is still far off. On the contrary, the Chinese Central Bank and banking systems of other countries that have less weight in the world, such as Uruguay, Lithuania and the Bahamas, seem to go against the trend of rejection and are seriously considering its implementation. Although this matter has been dealt with in the theoretical field, more pilot tests such as the one carried out by Uruguay are necessary in order to understand specific effects on the economy, on one hand, and on acceptance of its use by the population, on the other.

This article describes research that was carried out regarding the tax incentives in Spain associated with the “eco-friendly car,” which are reflected in its share of taxes on motor-driven vehicles. The study focused on the electric vehicle, the hybrid, and the liquefied petroleum gas vehicle. First, the current regulatory framework was addressed. The maximum bonus limits were considered, as well as how each of 68 cities examined the incentives. The qualitative and quantitative differences among the Spanish cities were discussed. Next, the annual tax savings on the Tax on motor vehicles (IVTM) quota were calculated, and the differences in the tax savings depending on the municipality and type of vehicle were noted, as well as the temporal duration of the bonus. Finally, the average tax savings were calculated based on the type of vehicle, power and municipality. It is clear that, although the tax incentives are positive, they must be complemented by other measures if the public authorities in Spain want to achieve a change in mentality and an increase in the acquisition of “eco-friendly cars” that eliminate pollutants (powered by the combustion of gasoline or diesel).

Streptomyces species are prolific producers of bioactive natural products, yet their genetic manipulation remains constrained by inefficient DNA delivery methods in many strains. Conjugation from methylation-deficient Escherichia coli has become the preferred approach for introducing plasmids into Streptomyces , relying on the presence of the oriT sequence within the mobilizable plasmid and the conjugation machinery ( tra genes) encoded on the non-mobilizable helper plasmid pUZ8002. Among these, traJ encodes an essential component of the relaxosome. An additional copy of traJ is present downstream of oriT in some mobilizable plasmids, whereas many other commonly used plasmids lack traJ . Here, we investigated the impact of including traJ in mobilizable plasmids on conjugation efficiency by engineering two oriT -containing plasmids that initially lacked traJ : the ΦC31 integrative vector pRASK-SP44 and the non-replicative transposon delivery vector pHL734. We also examined the effect of introducing a second copy of traJ into the recombination-based chromosomal end-removal vector pCER. Incorporation of traJ into pRASK-SP44 and pHL734 resulted in tenfold and 100-fold increases in transconjugant numbers, respectively. Furthermore, introducing a second copy of traJ into pCER led to a fivefold improvement in plasmid transfer. Our data suggest that the inclusion of traJ improves transfer efficiency and may help overcome limiting steps in conjugation from E. coli to Streptomyces . Modulating the presence and copy number of traJ could represent a simple yet effective strategy to enhance genetic accessibility in Streptomyces . These findings have broad implications for the optimisation of genetic tools used in Streptomyces genome engineering and natural product discovery. Key points • traj in mobilizable plasmids enhances conjugation to S. coelicolor. • traj increases plasmid transfer efficiency up to 100-fold in S. coelicolor. • traj may aid development of genetic tools for genome engineering in Streptomyces.