Role of the particle's stepping cycle in an asymmetric exclusion process: A model of mRNA translation

Messenger RNA translation is often studied by means of statistical-mechanical models based on the Asymmetric Simple Exclusion Process (ASEP), which considers hopping particles (the ribosomes) on a lattice (the polynucleotide chain). In this work we extend this class of models and consider the two fundamental steps of the ribosome's biochemical cycle following a coarse-grained perspective. In order to achieve a better understanding of the underlying biological processes and compare the theoretical predictions with experimental results, we provide a description lying between the minimal ASEP-like models and the more detailed models, which are analytically hard to treat. We use a mean-field approach to study the dynamics of particles associated with an internal stepping cycle. In this framework it is possible to characterize analytically different phases of the system (high density, low density or maximal current phase). Crucially, we show that the transitions between these different phases occur at different parameter values than the equivalent transitions in a standard ASEP, indicating the importance of including the two fundamental steps of the ribosome's biochemical cycle into the model.Comment: 9 pages, 9 figure

Ribosome recycling induces optimal translation rate at low ribosomal availability

Funding statement The authors thank BBSRC (BB/F00513/X1, BB/I020926/1 and DTG) and SULSA for funding. Acknowledgement The authors thank R. Allen, L. Ciandrini, B. Gorgoni and P. Greulich for very helpful discussions and careful reading of the manuscript.Peer reviewedPublisher PD

Elongated theropod tracks from the Cretaceous Apenninic Carbonate Platform of southern Latium (central Italy)

New dinosaur footprints were recently discovered in southern Latium (Italy). The tracks all appear slightly differently preserved and are characterized by elongated metatarsal impressions, recording the complex locomotor behaviour of a medium-sized theropod. The spatial distribution and the features of the footprints indicate that the trackmaker adopted a “crouched” position as part of an activity as well as a resting phase suggested by sub-parallel, calcigrade tracks. These new data once again highlight the great potential of ichnological evidence in the study of the biology and behaviour of extinct tetrapods

Control of magnetism in singlet-triplet superconducting heterostructures

We analyze the magnetization at the interface between singlet and triplet superconductors and show that its direction and dependence on the phase difference across the junction are strongly tied to the structure of the triplet order parameter as well as to the pairing interactions. We consider equal spin helical, opposite spin chiral, and mixed symmetry pairing on the triplet side and show that the magnetization vanishes at $\phi=0$ only in the first case, follows approximately a $\cos\phi$ behavior for the second, and shows higher harmonics for the last configuration. We trace the origin of the magnetization to the magnetic structure of the Andreev bound states near the interface, and provide a symmetry-based explanation of the results. Our findings can be used to control the magnetization in superconducting heterostructures and to test symmetries of spin-triplet superconductors.Comment: 5 pages, 3 figure

Segmenting the Italian coffee market: marketing opportunities for economic agents working along the international coffee chain

Globalization, either directly or indirectly (e.g. through structural adjustment reforms), has called for profound changes in the previously existing institutional order. Some changes adversely impacted the production and market environment of many coffee producers in developing countries resulting in more risky and less remunerative coffee transactions. This paper focuses on customization of a tropical commodity, fair-trade coffee, as an approach to mitigating the effects of worsened market conditions for small-scale coffee producers in less developed countries. fair-trade labeling is viewed as a form of “de-commodification” of coffee through product differentiation on ethical grounds. This is significant not only as a solution to the market failure caused by pervasive information asymmetries along the supply chain, but also as a means of revitalizing the agricultural-commodity-based trade of less developed countries (LDCs) that has been languishing under globalization. More specifically, fair-trade is an example of how the same strategy adopted by developed countries’ producers/ processors (i.e. the sequence product differentiation - institutional certification - advertisement) can be used by LDC producers to increase the reputation content of their outputs by transforming them from mere commodities into “decommodified” (i.e. customized and more reputed) goods. The resulting segmentation of the world coffee market makes possible to meet the demand by consumers with preference for this “(ethically) customized” coffee and to transfer a share of the accruing economic rents backward to the Fair-trade coffee producers in LDCs. It should however be stressed that this outcome cannot be taken for granted since investments are needed to promote the required institutional innovations. In Italy FTC is a niche market with very few private brands selling this product. However, an increase of FTC market share could be a big commercial opportunity for farmers in LDCs and other economic agents involved along the international coffee chain. Hence, this research explores consumers’ knowledge of labels promoting quality products, consumption coffee habits, brand loyalty, willingness to pay and market segmentation according to the heterogeneity of preferences for coffee products. The latter was assessed developing a D-efficient design where stimuli refinement was tested during two focus groups.fair-trade coffee, product decommodification, choice experiments, International Relations/Trade,

Strategi Pengembangan Kluster Perkebunan Kopi dan Tebu untuk Pengembangan Ekonomi Kabupaten Aceh Tengah

. The purpose of this stady is not indentifiying the cluster and economic strategic development cluster for economic growth supported at Aceh Tengah residence. The study conducted in the Aceh Tengah residence using direct primary data and secondary data. Primary data collection was based of observasing through the objective of stady. Secondary data was taken from literature study and the data from similar institution like Dinas Badan Pusat Statistik Aceh Tengah which has correlation with this study. Analysis that used in this study is the analysis that using Location Quotient (LQ) technical and SWOT analysis. The result of this study show based on Location Quotient (LQ) analysis tekhnical, could identified the comodities that has value LQ>1 showed production Existing Condition and Coffe Development Potencial in Linge district, Atu Lintang, Jagong Jeget, Bintang, Lut Tawar, Kebayakan, Pegasing, Bies, Bebesan, Kute Pinang, Silih Nara, Celala, Rusip Antara, while sugar cane just in Ketol District as a strategic comodities for advance development at Aceh Tengah residence. Meanwhile the strategic position of coffee and sugar cane investors placed at aggressive strategic position which supported investors policy, this strategy could be used if the investors has chances and strengths until they could used it coith the strengtht they have, bicause both of it has different value that cunted as positive such about 1,34 and 1,31

Using neuroscience evidence to train pre-service physics teachers on the concepts of heat and cold

Journal of Physics: Conference Series PAPER • THE FOLLOWING ARTICLE ISOPEN ACCESS Using neuroscience evidence to train pre-service physics teachers on the concepts of heat and cold A Ezquerra1 and I Ezquerra-Romano2 Published under licence by IOP Publishing Ltd Journal of Physics: Conference Series, Volume 1287, GIREP-MPTL 2018 9–13 July 2018, San Sebastian, Spain Citation A Ezquerra and I Ezquerra-Romano 2019 J. Phys.: Conf. Ser. 1287 012038 DownloadArticle PDF References Download PDF 150 Total downloads 11 citation on Dimensions. Turn on MathJax Share this article Share this content via email Share on Facebook (opens new window) Share on Twitter (opens new window) Share on Mendeley (opens new window) Hide article information Author affiliations 1 Department of Didactics of Experimental Sciences, Social Sciences and Mathematics. Faculty of Education. Universidad Complutense Madrid, Spain 2 Institute of Cognitive Neuroscience, University College London, UK DOI https://doi.org/10.1088/1742-6596/1287/1/012038 Buy this article in print Sign up for new issue notifications Create citation alert Abstract Teachers must identify, manage and modify alternative conceptions in their students. However, research consistently highlights that future teachers prioritise disciplines' requirements rather than the educational needs of children. Moreover, some researchers have proposed that the way our senses work shapes the development of children's ideas. Neuroscientists have only recently started to understand how the senses transduce and transmit stimuli. In this study, we show an innovative initial training course of Didactics of Physics, which includes the latest understanding of the thermosensory system. We analysed the progression of the educational proposals written by future teachers. This analysis revealed the effect of integrating neuroscience contents in the initial training. We found that the neuroscience insights helped future teachers incorporating children's misconceptions in their proposals. Additionally, they lowered their expectations and became less frustrated. They understood that it is not expected to quickly modify pupils' alternative conceptions because they have a physiological component

Highway to thermosensation: a traced review, from the proteins to the brain

Temperature maintenance and detection are essential for the survival and perpetuation of any species. This review is focused on thermosensation; thus a detailed and traced explanation of the anatomical and physiological characteristics of each component of this sensation is given. First, the proteins that react to temperature changes are identified; next, the nature of the neurons involved in thermosensation is described; and then, the pathways from the skin through the spinal cord to the brain are outlined. Finally, the areas of the brain and their interconnections where thermoperception arises are explained. Transduction of the external and internal temperature information is essentially mediated by the transient receptor potential ion channels (TRPs). These proteins are embedded in the neurons’ membrane and they hyper- or de-polarize neurons in function of the intrinsic voltage and the temperature changes. There are distinct TRP sensors for different temperature ranges. Interestingly, the primary afferent neurons have either cold or hot receptors, so they are dedicated separately to cold or hot sensation. The information is transmitted by different pathways from the skin to the brain, where it either remains separated or is integrated to generate a response. It seems that both the determination of how thermoperception is produced and how we interact with the world are dependent on the particular arrangement and nature of the components, the way of transduction of information and the communication between these elements