scholarly journals The evolutionary ecology of molecular replicators

2016 ◽  
Vol 3 (8) ◽  
pp. 160235 ◽  
Author(s):  
Sean Nee
Keyword(s):  
Evolutionary Theory ◽  
Evolutionary Ecology ◽  
Great Power ◽  
Price Equation ◽  
Current View ◽  
Unified Approach ◽  
Chronic Infections ◽  
New Class ◽  
The Earth ◽  
Primary Literature

By reasonable criteria, life on the Earth consists mainly of molecular replicators. These include viruses, transposons, transpovirons, coviruses and many more, with continuous new discoveries like Sputnik Virophage. Their study is inherently multidisciplinary, spanning microbiology, genetics, immunology and evolutionary theory, and the current view is that taking a unified approach has great power and promise. We support this with a new, unified, model of their evolutionary ecology, using contemporary evolutionary theory coupling the Price equation with game theory, studying the consequences of the molecular replicators' promiscuous use of each others' gene products for their natural history and evolutionary ecology. Even at this simple expository level, we can make a firm prediction of a new class of replicators exploiting viruses such as lentiviruses like SIVs, a family which includes HIV: these have been explicitly stated in the primary literature to be non-existent. Closely connected to this departure is the view that multicellular organism immunology is more about the management of chronic infections rather than the elimination of acute ones and new understandings emerging are changing our view of the kind of theatre we ourselves provide for the evolutionary play of molecular replicators. This study adds molecular replicators to bacteria in the emerging field of sociomicrobiology.

scholarly journals A Large Toxin from Pathogenic Escherichia coli Strains That Inhibits Lymphocyte Activation

2000 ◽  
Vol 68 (4) ◽  
pp. 2148-2155 ◽  
Author(s):  
Jan-Michael A. Klapproth ◽  
Isabel C. A. Scaletsky ◽  
Barry P. McNamara ◽  
Li-Ching Lai ◽  
Carol Malstrom ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lymphocyte Proliferation ◽  
Interleukin 2 ◽  
Lymphocyte Activation ◽  
Chronic Infections ◽  
E Coli ◽  
New Class ◽  
Large Gene ◽  
Pathogenic Escherichia Coli ◽  
Nonpathogenic Strain

ABSTRACT The mechanisms by which bacteria resist cell-mediated immune responses to cause chronic infections are largely unknown. We report the identification of a large gene present in enteropathogenic strains of Escherichia coli (EPEC) that encodes a toxin that specifically inhibits lymphocyte proliferation and interleukin-2 (IL-2), IL-4, and gamma interferon production in response to a variety of stimuli. Lymphostatin, the product of this gene, is predicted to be 366 kDa and shares significant homology with the catalytic domains of the large clostridial cytotoxins. A mutant EPEC strain that has a disruption in this gene lacks the ability to inhibit lymphokine production and lymphocyte proliferation. Enterohemorrhagic E. coli strains of serotype O157:H7 possess a similar gene located on a large plasmid. Loss of the plasmid is associated with loss of the ability to inhibit IL-2 expression while transfer of the plasmid to a nonpathogenic strain of E. coli is associated with gain of this activity. Among 89 strains of E. coli and related bacteria tested, lifA sequences were detected exclusively in strains capable of attaching and effacing activity. Lymphostatin represents a new class of large bacterial toxins that blocks lymphocyte activation.

Diamonds in the Sky!

2019 ◽  
pp. 101-109
Author(s):  
Nicholas Mee
Keyword(s):  
Nuclear Fuel ◽  
White Dwarf ◽  
White Dwarfs ◽  
Star Trek ◽  
The Sun ◽  
New Class ◽  
The Earth ◽  
Night Sky

After consuming their nuclear fuel, most stars lose their outer envelopes and all that remains is the collapsed core of the star, an object known as a white dwarf. Ever since Galileo pointed a telescope at the night sky, each advance in telescope making has resulted in sensational discoveries. Alvan Clark & Sons ground some of the biggest telescope lenses ever made. Alvan Graham Clark discovered Sirius B while testing one of these lenses. Eddington deduced that Sirius B has a size similar to that of the Earth, but with the mass of the Sun, and was an example of a new class of stars—white dwarfs. The easiest white dwarf to see with a telescope orbits the star Keid. In Star Trek, the planet Vulcan orbits the star Keid A.

A unified approach to the representation of seismic sources

1973 ◽  
Vol 331 (1587) ◽  
pp. 525-551 ◽  
Keyword(s):  
Spherical Surface ◽  
Theoretical Studies ◽  
Unified Approach ◽  
Concentrated Force ◽  
Elastic Fields ◽  
Earthquake Sources ◽  
The Earth ◽  
Unbounded Medium ◽  
Navier Equation ◽  
Dipolar Source

An attempt is made to give a unified treatment to the problem of the representation of various sources commonly used in theoretical studies in seismology. Beginning with the Stokes-Love solution for a concentrated force, the displacement field due to a dipolar source in a homogeneous, isotropic, unbounded medium is expressed in terms of the eigen­vector solutions of the vector Navier equation. This field is transformed to a spherical co­ordinate system having its origin at the centre of the Earth. The transformed field is then used to calculate the jumps in the displacements and stresses across the concentric spherical surface passing through the source. These jumps constitute a convenient representation of the source. Since it exhibits the properties of the source and not that of the medium, the above representation is also valid when the medium under consideration is bounded and inhomo­geneous. A similar representation is obtained in the case of the circular cylinder coordinate system. This representation can be conveniently applied to investigate the excitation of various elastic fields in the Earth by earthquake sources such as the free oscillations, surface waves and residual static deformation.

Panbiogeography 1981-91: development of an earth/life synthesis

1991 ◽  
Vol 15 (4) ◽  
pp. 331-363 ◽  
Author(s):  
J.R. Grehan
Keyword(s):  
New Zealand ◽  
Geographic Distribution ◽  
Evolutionary Theory ◽  
Evolutionary Ecology ◽  
Evolutionary Relationship ◽  
New Developments ◽  
Geological Processes ◽  
Statistical Measures ◽  
Biogeographic Regions ◽  
Tectonic Features

Contributions to the method and theory of panbiogeography are reviewed in relation to a New Zealand interest that arose from the late 1970s and early 1980s. Panbiogeography was developed by Leon Croizat in the 1950s, but ignored by prominent evolutionary theorists in favour of traditional explanations of geographic distribution established from Darwin's time. The New Zealand interest has provided a critical reappraisal of Croizat's work and its continued relevance to evolutionary theory through new developments in method and synthesis. Panbiogeography is presented in this review as an exploration of Hooker's paradox - the problem of integrating contradictory aspects of earth and life in space/time. Croizat's approach to biogeography involved analyses of geographic distribution by linking localities together to form line graphs called tracks. Analysis and interpretation of tracks has been developed by application of graph theory techniques for quantitative and statistical measures of track inter-relationships and their biogeog raphic significance. Panbiogeographic approaches have developed the application of defining features called 'baselines' that represent spatial characters for biogeographic homology. Ocean basins comprise important biogeographic features for the baseline orientation of tracks. This approach has resulted in a new classification system where ocean basins are the natural biogeographic regions while major landmasses are located at regional boundaries. This subsumes the conflicts and contradictions inherent in the geographic classifications developed from Wallace onwards. Panbiogeographic correlation of tracks with tectonic features provides a geographic basis for interpreting the evolutionary relationship between earth and life. Different standard tracks are compared in reference to the associated tectonic features such as spreading ridges, fault systems and suture zones. Novel geological predictions generated from distributional and tectonic congruence illustrated for the Americas, and for New Zealand where a novel parallel arcs model has been proposed for its natural history and evolution. The conceptual implications for evolutionary ecology are explored in terms of life evolving as a 'geological' layer where organism-environment relationships evolve through coconstruction of interdependent processes rather than by interaction of organisms and environments as separately preformed entities. Progress in panbiogeography over the last decade provides a significant contribution to evolutionary theory through the continued development of a spatiotemporal synthesis for understanding biological and geological processes responsible for local and global biodiversity.

scholarly journals Photo-Electrochemical Oxygen Evolution Reaction by Biomimetic CaMn2O4 Catalyst

2019 ◽  
Vol 9 (11) ◽  
pp. 2196
Author(s):  
Ankita Gagrani ◽  
Mohammed Alsultan ◽  
Gerhard F. Swiegers ◽  
Takuya Tsuzuki
Keyword(s):  
Control Sample ◽  
Structural Similarity ◽  
Oxygen Evolving Complex ◽  
New Class ◽  
Irregular Shapes ◽  
The Earth ◽  
Earth Abundant ◽  
The Difference ◽  
Oxygen Evolving ◽  
Electrochemical Oxygen

Calcium manganese oxide catalysts are a new class of redox catalysts with significant importance because of their structural similarity to natural oxygen-evolving complex in plant cells and the earth-abundant elemental constituents. In the present study, the photo-electrocatalytic properties of CaMn2O4 in water-splitting were investigated. CaMn2O4 powders with irregular shapes and nanowire shapes were synthesised using mechanochemical processing and a hydrothermal method, respectively. The anode in a photo-electrochemical cell was fabricated by embedding CaMn2O4 powders within polypyrrole. The results showed that CaMn2O4 induced a higher dark and light current in comparison to the control sample (polypyrrole alone). CaMn2O4 nanowires exhibited higher dark and light current in comparison to irregular-shaped CaMn2O4 powders. The difference was attributable to the higher surface area of nanowires compared to the irregular-shaped particles, rather than the difference in exposed crystal facets.

scholarly journals Poems in Prose by I.S. Turgenev: the Cycle’s Title as a Historical Literary Issue

2021 ◽  
Vol 26 (1) ◽  
pp. 7-15
Author(s):  
Yulia D. Burmistrova
Keyword(s):  
Sequential Analysis ◽  
World View ◽  
Fear Of Death ◽  
Creative Work ◽  
Unified Approach ◽  
Foreign Publication ◽  
Life After Death ◽  
French Edition ◽  
The Earth ◽  
Death Experience

The article deals with the I.S. Turgenevs last cycle Poems in prose which title has been changed several times throughout his work on it. The cycle put together the main aspects of writers previous creative works which led to the continuous search for the most suitable title to fully express authors intentions: from the original Posthuma which is focused on the life after death experience to the last Poems in prose which additionally underlines the uniqueness of the form used for Turgenevs last creative work. The study reveals the main theories on the cycles titles and the reasons behind their changes as well as suggests the own vision of the evolution of concepts after death and senile which are seemed to be bound in writers world view. The sequential analysis of the existing cycles titles undertaken in the current research finds the logic of Turgenevs title transformations where the fear of death is gradually replaced by the thoughts of future new life which will be continued beyond the Earth life. The significance of the research lies in the absence of the unified approach to the naming and understanding of the Turgenevs last cycle while the title of the book was considered to change the works perception even by Turgenevs contemporaries. The scientific novelty of the work is added by using the authors French edition of Poems in prose which up until now hasnt been studied properly. It allows to expand the material of the research and look thoroughly into Turgenevs strategy of naming his final cycle which was preserved for the foreign publication as well.

scholarly journals On application of asymmetric Kan-like exact equilibria to the Earth magnetotail modeling

2018 ◽  
Author(s):  
Daniil B. Korovinskiy ◽  
Darya I. Kubyshkina ◽  
Vladimir S. Semenov ◽  
Marina V. Kubyshkina ◽  
Nikolai V. Erkaev ◽  
...  
Keyword(s):  
Maxwell Equations ◽  
Vertical Plane ◽  
Empirical Models ◽  
Magnetic Flux Tube ◽  
Two Dimensional ◽  
New Class ◽  
The Earth ◽  
Sheet Bending ◽  
Wide Range ◽  
Radial Propagation

Abstract. A new class of solutions of the Vlasov-Maxwell equations is developed by means of generalization of the well-known Harris-Fadeev-Kan-Manankova family of exact two-dimensional equilibria. The new model reproduces the current sheet bending and shifting in the vertical plane, arising from the Earth dipole tilting and the solar wind non-radial propagation. The generalized model allows magnetic configurations with equatorial magnetic field decreasing in tailward direction as slow as 1/x, contrary to the original Kan model (1/x3); magnetic configurations with a single X-point are also available. The analytical solution is compared with the empirical T96 model in terms of the magnetic flux tube volume. It is found that parameters of the analytical model may be adjusted to fit a wide range of realistic current sheets. The best agreement between analytical and empirical models is obtained for the midtail at distances beyond 10–15 RE at high levels of magnetospheric activity.

Meridian section projections: a new class of the triaxial ellipsoid projections

2021 ◽  
Vol 968 (2) ◽  
pp. 11-22
Author(s):  
M.V. Nyrtsov ◽  
M.E. Fleis ◽  
A.I. Sokolov
Keyword(s):  
Triaxial Ellipsoid ◽  
International Astronomical Union ◽  
Small Bodies ◽  
New Class ◽  
The Earth ◽  
Meridian Section ◽  
International Astronomical ◽  
Global Mapping ◽  
Ellipsoid Of Revolution ◽  
Celestial Bodies

Historically the conformal projections have been used for mapping not only the Earth, but other celestial bodies as well. Their application enables preserving the shape of the relief features on the maps, which is extremely important for various analyses of celestial bodies’ surfaces. For many small bodies of the Solar system the International Astronomical Union recommends to apply a triaxial ellipsoid as a reference surface. But if the conformal projections for the reference surfaces of a sphere and an ellipsoid of revolution already exist, obtaining these projections for a triaxial ellipsoid will be significantly complicated, and the task of preserving the shape of relief features still actual. In general, the article deals with cylindrical and azimuthal projections of the meridian section for global mapping the celestial body surface in accordance with the idea formulated by prof. L. M. Bugaevsky. The projections are implemented for mapping of Phobos, moon of Mars.

scholarly journals Potential Synergy Activity of the Novel Ceragenin, CSA-13, against Carbapenem-ResistantAcinetobacter baumanniiStrains Isolated from Bacteremia Patients

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Cagla Bozkurt-Guzel ◽  
Paul B. Savage ◽  
Alper Akcali ◽  
Berna Ozbek-Celik
Keyword(s):  
Antimicrobial Agents ◽  
Pharmacokinetic Parameters ◽  
The Novel ◽  
Chronic Infections ◽  
New Class ◽  
Synergistic Interactions ◽  
Carbapenem Resistant ◽  
Potential Synergy ◽  
Blood Specimens

Carbapenem-resistantAcinetobacter baumanniiis an important cause of nosocomial infections, particularly in patients in the intensive care units. As chronic infections are difficult to treat, attempts have been made to discover new antimicrobials. Ceragenins, designed to mimic the activities of antimicrobial peptides, are a new class of antimicrobial agents. In this study, the in vitro activities of CSA-13 either alone or in combination with colistin (sulphate), tobramycin, and ciprofloxacin were investigated using 60 carbapenem-resistantA. baumanniistrains isolated from bacteremia patients blood specimens. MICs and MBCs were determined by microbroth dilution technique. Combinations were assessed by using checkerboard technique. The MIC50values (mg/L) of CSA-13, colistin, tobramycin, and ciprofloxacin were 2, 1, 1.25, and 80, respectively. The MIC90(mg/L) of CSA-13 and colistin were 8 and 4. The MBCs were equal to or twice greater than those of the MICs. Synergistic interactions were mostly seen with CSA-13-colistin (55%), whereas the least synergistic interactions were observed in the CSA-13-tobramycin (35%) combination. No antagonism was observed. CSA-13 appears to be a good candidate for further investigations in the treatment ofA. baumanniiinfections. However, future studies should be performed to correlate the safety, efficacy, and pharmacokinetic parameters of this molecule.

Version

1950 ◽  
Vol 19 (57) ◽  
pp. 137-138
Author(s):  
A. G. Street
Keyword(s):  
Great Power ◽  
East Side ◽  
The West ◽  
The Earth ◽  
Flexible Instrument

The plough, which looks so clumsy and uncouth, changes its character. In conjunction with your team of horses, it becomes a glorious galleon, which you steer proudly over the rolling fields like some mariner of old. It is no longer an ugly, awkward, inanimate thing, but a delicately flexible instrument, which responds to your lightest touch … Not that the poesy of ploughing is continuous. The length of the lines is determined by the head-lands; it is broken into verses by each strike-out, and, if you wish to continue the simile, into different poems by the different fields. Such a nuisance these breaks are! Why cannot one plough one long straight furrow for ever without these petty hindrances ? But, this being impossible, one is forced to turn, to let the plough grate clumsily along the head-land, then to turn again into the work, and swing away on a new tack, happy and interested once more.'Tis true I am no physician, but I would suggest in all sincerity that three months’ steady ploughing would cure any man of a nervous break-down. For ploughing is a mental tonic of great power. The ploughman is master of the situation. Nothing can stop him. Little by little he changes the surface of the earth. The plough may be slow, but it is so very sure. As the strip of black on the east side of that piece of prairie grew slowly wider and wider until it neared the west boundary, I was forced to marvel at the relentless power of the plough.

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