59 research outputs found

    Computers from plants we never made. Speculations

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    We discuss possible designs and prototypes of computing systems that could be based on morphological development of roots, interaction of roots, and analog electrical computation with plants, and plant-derived electronic components. In morphological plant processors data are represented by initial configuration of roots and configurations of sources of attractants and repellents; results of computation are represented by topology of the roots' network. Computation is implemented by the roots following gradients of attractants and repellents, as well as interacting with each other. Problems solvable by plant roots, in principle, include shortest-path, minimum spanning tree, Voronoi diagram, α\alpha-shapes, convex subdivision of concave polygons. Electrical properties of plants can be modified by loading the plants with functional nanoparticles or coating parts of plants of conductive polymers. Thus, we are in position to make living variable resistors, capacitors, operational amplifiers, multipliers, potentiometers and fixed-function generators. The electrically modified plants can implement summation, integration with respect to time, inversion, multiplication, exponentiation, logarithm, division. Mathematical and engineering problems to be solved can be represented in plant root networks of resistive or reaction elements. Developments in plant-based computing architectures will trigger emergence of a unique community of biologists, electronic engineering and computer scientists working together to produce living electronic devices which future green computers will be made of.Comment: The chapter will be published in "Inspired by Nature. Computing inspired by physics, chemistry and biology. Essays presented to Julian Miller on the occasion of his 60th birthday", Editors: Susan Stepney and Andrew Adamatzky (Springer, 2017

    Maze solvers demystified and some other thoughts

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    There is a growing interest towards implementation of maze solving in spatially-extended physical, chemical and living systems. Several reports of prototypes attracted great publicity, e.g. maze solving with slime mould and epithelial cells, maze navigating droplets. We show that most prototypes utilise one of two phenomena: a shortest path in a maze is a path of the least resistance for fluid and current flow, and a shortest path is a path of the steepest gradient of chemoattractants. We discuss that substrates with so-called maze-solving capabilities simply trace flow currents or chemical diffusion gradients. We illustrate our thoughts with a model of flow and experiments with slime mould. The chapter ends with a discussion of experiments on maze solving with plant roots and leeches which show limitations of the chemical diffusion maze-solving approach.Comment: This is a preliminary version of the chapter to be published in Adamatzky A. (Ed.) Shortest path solvers. From software to wetware. Springer, 201

    An updated revision of shortfin mako size distributions in the Atlantic

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    As part of an ongoing cooperative program for fisheries and biological data collection within the ICCAT Sharks Working Group, information collected by fishery observers and scientific projects from several fishing nations in the Atlantic were analyzed. Datasets included information on geographic location, size and sex. A total of 42,979 shortfin mako records collected between 1989 and 2017 were compiled. Sizes considered ranged between 60 and 353 cm FL (fork length). Of those, sex information was available for 24,316 specimens. Considerable variability was observed in the size distribution by region and season, with larger sizes tending to occur in equatorial and tropical regions and smaller sizes in higher latitudes. Variability between coastal and more oceanic waters is also likely. Most fleets showed unimodal distributions, but in some cases there were bimodal patterns. The distributional patterns presented in this study provide an advance in the understanding of shortfin mako size distribution in the Atlantic, and can be used in the next update of the ICCAT shortfin mako stock assessment.info:eu-repo/semantics/publishedVersio

    Is the tiger shark (Galeocerdo cuvier) a coastal species? Expanding its distribution range in the Atlantic Ocean using at-sea observer data

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    captura asociada a la pesquería de palangre de superficie dirigida a pez espadaThe occurrence of tiger shark (Galeocerdo cuvier) in the Atlantic Ocean was assessed using at-sea observer data from multiple pelagic longline fisheries (Japan, Portugal, Spain, United States and Uruguay). Geographic positions of 2,764 tiger sharks, recorded between 1993 and 2013 and covering a wide area of the Atlantic were compared with the currently accepted distribution ranges of the species. Most of our records fell outside the accepted distribution ranges in both the Southern and Northern hemispheres. These results strongly suggest that the distribution range of the tiger shark is considerably wider than previously described, particularly over the open oceanEn prensa1,834

    Distributional and reproductive aspects of the bigeye thresher shark (Alopias superciliosus) in the Atlantic ocean

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    Captura asociada a la pesquería de palangre de superficie dirigida a pez espadaThe bigeye thresher shark, Alopias supercilious is sometimes caught as bycatch in pelagic longline fisheries targeting tunas and swordfish in the Atlantic Ocean. As part of an ongoing cooperative program for fisheries and biological data collection, fishery observer data from various fishing nations and projects were compiled and analyzed. Those data sets include information on geographic location of the observations, as well as size, sex and in some cases maturity stage. A total of 4371 bigeye threshers were recorded throughout the Atlantic Ocean between 1992 and 2013, with the sizes ranging from 70 to 305 cm FL (fork length). Considerable variability was observed in the catchat- size, with particular emphasis on the tropical region where the mean sizes tended to be smaller than in the other regions. The expected distribution of juvenile and adult specimens also showed considerable variability, and the sex-ratios varied between regions and size classes. Maturity ogives were fitted to data from 642 specimens, with the median sizes at maturity estimated at 208.6 cm FL (corresponding to 349.1 cm TL) for females and 159.2 cm FL (corresponding to 269.8 cm TL) for males. In addition, a segmented regression model (SRM) was used for males, and two breakpoints (Bk1: 122.5cm FL, Bk2: 173.3cm FL) estimated, identifying transitions between the three different maturity stages for male sharks (immature, maturing and mature). Only a few pregnant females were recorded, always with the presence of two embryos (one per uterus), and were distributed predominantly in the tropical northeast Atlantic closer the African continent, and in the southwest region, with those regions possibly serving as nursery areas for this species. These reproductive parameters, and especially the estimated median sizes at maturity and low fecundity, highlight the vulnerability of this species, reinforcing that the bigeye thresher tends to mature at a larger size than the other species of the Alopiidae family. The biological and distributional patterns presented can help managers adopt more informed and efficient conservation measures for this species.En prensa0,000

    Impact of severe coronary disease associated or not associated with diabetes mellitus on outcome of interventional treatment using stents: Results from HERZ (heart research group of Kanazawa) analyses

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    金沢大学医薬保健研究域医学系Percutaneous coronary intervention (PCI) using a drug-eluting stent (DES) leads to less re-stenosis than PCI using a bare metal stent (BMS), however there is still controversy whether use of a DES for severe coronary disease leads to an acceptable outcome in patients with diabetes mellitus (DM). In this study 8159 lesions were treated in 6739 patients (mean age 68.9 years) with coronary artery disease. Use of a DES significantly decreased the re-stenosis rate compared with BMS in both DM (9.6% versus 21.3%) and non-DM (9.5% versus 17.1%) patients. The re-stenosis rate was significantly higher in DM than in non-DM patients in the BMS group but not in the DES group. There was no statistically significant difference in event-free survival after stenting of patients with left main coronary artery (LMCA) disease between the BMS and DES groups. It was concluded that, compared with BMS, DES reduced re-stenosis in patients with DM, however, we advise careful treatment after using DES for severe coronary disease, including LMCA lesions, in patients with DM. © 2011 Field House Publishing LLP

    Increased Anion Channel Activity Is an Unavoidable Event in Ozone-Induced Programmed Cell Death

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    Ozone is a major secondary air pollutant often reaching high concentrations in urban areas under strong daylight, high temperature and stagnant high-pressure systems. Ozone in the troposphere is a pollutant that is harmful to the plant. generation by salicylic and abscisic acids. Anion channel activation was also shown to promote the accumulation of transcripts encoding vacuolar processing enzymes, a family of proteases previously reported to contribute to the disruption of vacuole integrity observed during programmed cell death.-induced programmed cell death. Because ion channels and more specifically anion channels assume a crucial position in cells, an understanding about the underlying role(s) for ion channels in the signalling pathway leading to programmed cell death is a subject that warrants future investigation

    Allozyme differentiation of sixteen species of ommastrephid squid (Mollusca, Cephalopoda)

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