scholarly journals Protein translocons in photosynthetic organelles of Paulinella chromatophora

2014 ◽  
Vol 83 (4) ◽  
pp. 399-407 ◽  
Author(s):  
Przemysław Gagat ◽  
Paweł Mackiewicz
Keyword(s):  
Protein Import ◽  
Nuclear Genome ◽  
Vesicular Trafficking ◽  
Plastid Gene ◽  
Endosymbiotic Gene Transfer ◽  
Redox Sensor ◽  
Proposed Model ◽  
Number Of Genes ◽  
The Common ◽  
Chromatophore Membrane

The rhizarian amoeba <em>Paulinella chromatophora</em> harbors two photosynthetic cyanobacterial endosymbionts (chromatophores), acquired independently of primary plastids of glaucophytes, red algae and green plants. These endosymbionts have lost many essential genes, and transferred substantial number of genes to the host nuclear genome via endosymbiotic gene transfer (EGT), including those involved in photosynthesis. This indicates that, similar to primary plastids, <em>Paulinella</em> endosymbionts must have evolved a transport system to import their EGT-derived proteins. This system involves vesicular trafficking to the outer chromatophore membrane and presumably a simplified Tic-like complex at the inner chromatophore membrane. Since both sequenced <em>Paulinella</em> strains have been shown to undergo differential plastid gene losses, they do not have to possess the same set of Toc and Tic homologs. We searched the genome of <em>Paulinella</em> FK01 strain for potential Toc and Tic homologs, and compared the results with the data obtained for <em>Paulinella</em> CCAC 0185 strain, and 72 cyanobacteria, eight Archaeplastida as well as some other bacteria. Our studies revealed that chromatophore genomes from both <em>Paulinella</em> strains encode the same set of translocons that could potentially create a simplified but fully-functional Tic-like complex at the inner chromatophore membranes. The common maintenance of the same set of translocon proteins in two <em>Paulinella</em> strains suggests a similar import mechanism and/or supports the proposed model of protein import. Moreover, we have discovered a new putative Tic component, Tic62, a redox sensor protein not identified in previous comparative studies of <em>Paulinella</em> translocons.

scholarly journals The economics of endosymbiotic gene transfer and the evolution of organellar genomes

2020 ◽  
Author(s):  
Steven Kelly
Keyword(s):  
Gene Transfer ◽  
Host Cell ◽  
Protein Import ◽  
Nuclear Genome ◽  
Selective Advantage ◽  
Endosymbiotic Gene Transfer ◽  
Organellar Genomes ◽  
Evolution Of Life ◽  
A Cell ◽  
Life On Earth

AbstractThe endosymbiosis of the bacterial progenitors of mitochondrion and the chloroplast are landmark events in the evolution of life on earth. While both organelles have retained substantial proteomic and biochemical complexity, this complexity is not reflected in the content of their genomes. Instead, the organellar genomes encode fewer than 5% of genes found in living relatives of their ancestors. While some of the 95% of missing organellar genes have been discarded, many have been transferred to the host nuclear genome through a process known as endosymbiotic gene transfer. Here we demonstrate that the energy liberated or consumed by a cell as a result of endosymbiotic gene transfer can be sufficient to provide a selectable advantage for retention or nuclear-transfer of organellar genes in eukaryotic cells. We further demonstrate that for realistic estimates of protein abundances, organellar protein import costs, host cell sizes, and cellular investment in organelles that it is energetically favourable to transfer the majority of organellar genes to the nuclear genome. Moreover, we show that the selective advantage of such transfers is sufficiently large to enable such events to rapidly reach fixation. Thus, endosymbiotic gene transfer can be advantageous in the absence of any additional benefit to the host cell, providing new insight into the processes that have shaped eukaryotic genome evolution.One sentence summaryThe high copy number of organellar genomes renders endosymbiotic gene transfer energetically favourable for the vast majority of organellar genes.

scholarly journals Research of reliability and efficiency of technological processes of mechanical assembly production on the basis of the common semi-Markov model

2018 ◽  
Vol 224 ◽  
pp. 01138
Author(s):  
Yuri Rapatskiy ◽  
Mikhail Zamorenov ◽  
Vadim Kopp ◽  
Yuri Obzherin ◽  
Vladimir Gusev ◽  
...  
Keyword(s):  
Distribution Functions ◽  
Mechanical Assembly ◽  
Renewal Equations ◽  
Technological Processes ◽  
Threaded Connections ◽  
Proposed Model ◽  
The Common ◽  
Semi Markov Processes ◽  
Simulation Parameters ◽  
Assembly Production

In the article a common semi-Markov mathematical model is considered that allows one to investigate the productivity and reliability of various technological processes of mechanical assembly production. The proposed model allows to study, inter alia, technological processes of manufacturing parts with screw and assemblies of threaded connections. Mathematical apparatus of the research is the theory of semi-Markov processes with a common phase space, which operates with a common kind of random variables distribution functions. If the considering process in the system is a subsystem located on a higher level of hierarchy, the hierarchical model for compatibility with each other levels as output simulation parameters required distribution functions. In the proposed model, based on the decision of the Markov renewal equations depend not only on the torque characteristics, but also the distribution function of time per unit of output service according to different kinds of undervalued failures.

scholarly journals Measurements and Computations of Internal Temperatures of the IGBT and the Diode Situated in the Common Case

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 210
Author(s):  
Paweł Górecki ◽  
Krzysztof Górecki
Keyword(s):  
Thermal Properties ◽  
Measurement Error ◽  
Thermal Model ◽  
Bipolar Transistor ◽  
Internal Temperature ◽  
Self Heating ◽  
Factors Influencing ◽  
Proposed Model ◽  
The Common ◽  
Transient Thermal

This article proposes effective methods of measurements and computations of internal temperature of the dies of the Insulted Gate Bipolar Transistor (IGBT) and the diode mounted in the common case. The nonlinear compact thermal model of the considered device is proposed. This model takes into account both self-heating phenomena in both dies and mutual thermal couplings between them. In the proposed model, the influence of the device internal temperature on self and transfer thermal resistances is taken into account. Methods of measurements of each self and transfer transient thermal impedances occurring in this model are described and factors influencing the measurement error of these methods are analysed. Some results illustrating thermal properties of the investigated devices including the IGBT and the antiparallel diode in the common case are shown and discussed. Computations illustrating the usefulness of the proposed compact thermal model are presented and compared to the results of measurements. It is proved that differences between internal temperature of both dies included in the TO-247 case can exceed even 15 K.

scholarly journals Introgression from Gorilla caused the Human-Chimpanzee split

2018 ◽  
Author(s):  
Johan Nygren
Keyword(s):  
Common Ancestor ◽  
Nuclear Genome ◽  
Genome Project ◽  
Lineage Sorting ◽  
Chromosome 5 ◽  
Speciation Model ◽  
Introgression Event ◽  
The Common

ABSTRACT: The Gorilla Genome Project (Scally, 2012) showed that 30% of the gorilla genome introgressed into the ancestor of humans and chimpanzees, and that the two species diverged through lineage sorting with 15% ending up in Pan and another 15% in Homo. That introgression is the Pan-Homo split, hybridization, which led to speciation as the new hybrid lineages became reproductively isolated from one another. The NUMT on chromosome 5 (“ps5”) (Popadin, 2017) fits perfectly with the introgression speciation model, it was formed from mtDNA that had diverged from the common ancestor of Pan-Homo for 1.8 Myr at the time of insertion into the nuclear genome, and originated in the Gorilla lineage. The ps5 pseudogene was transferred to Pan and Homo during the introgression event that led to the Pan-Homo split, 6 million years ago.

Reliability of nonrepairable phased-mission systems with common bus performance sharing

2018 ◽  
Vol 232 (6) ◽  
pp. 647-660 ◽  
Author(s):  
Huan Yu ◽  
Jun Yang ◽  
Yu Zhao
Keyword(s):  
Genetic Algorithm ◽  
Reliability Analysis ◽  
Evaluation Method ◽  
Optimal Allocation ◽  
Recursive Algorithm ◽  
Entire System ◽  
Allocation Algorithm ◽  
Proposed Model ◽  
The Common ◽  
Multi Phase

This article considers the reliability analysis of phased-mission systems with common bus performance sharing. The whole system consists of client nodes, service elements, and a common bus redistribution system and it undertakes a multi-phase mission. In each phase, the service elements must satisfy the demands of the prespecified client nodes set. The service elements can share their surplus performance with other client nodes through the common bus. In any phase, the system fails if the demands of the prespecified client nodes set are not satisfied. In other words, the entire system succeeds if the demands of the prespecified client nodes set are satisfied in all phases. The reliability of the proposed model is analyzed by the backward recursive algorithm. The optimal allocation problem is solved by the genetic algorithm. Two examples are presented to demonstrate the proposed reliability evaluation method and optimal allocation algorithm.

A Model of Metabolic Supply-Demand Mismatch Leading to Secondary Brain Injury

2021 ◽  
Author(s):  
Jiangling Song ◽  
Jennifer A. Kim ◽  
Aaron Frank Struck ◽  
Rui Zhang ◽  
M. Brandon Westover
Keyword(s):  
Brain Injury ◽  
Mechanistic Model ◽  
Acute Brain Injury ◽  
Extracellular Potassium ◽  
Secondary Brain Injury ◽  
Proposed Model ◽  
The Common ◽  
High Level ◽  
The Brain ◽  
Common Association

Secondary brain injury (SBI) is defined as new or worsening injury to the brain after an initial neurologic insult, such as hemorrhage, trauma, ischemic stroke, or infection. It is a common and potentially preventable complication following many types of primary brain injury (PBI). However, mechanistic details about how PBI leads to additional brain injury and evolves into SBI are poorly characterized. In this work, we propose a mechanistic model for the metabolic supply demand mismatch hypothesis (MSDMH) of SBI. Our model, based on the Hodgkin-Huxley model, supplemented with additional dynamics for extracellular potassium, oxygen concentration and excitotoxity, provides a high-level unified explanation for why patients with acute brain injury frequently develop SBI. We investigate how decreased oxygen, increased extracellular potassium, excitotoxicity, and seizures can induce SBI, and suggest three underlying paths for how events following PBI may lead to SBI. The proposed model also helps explain several important empirical observations, including the common association of acute brain injury with seizures, the association of seizures with tissue hypoxia and so on. In contrast to current practices which assume that ischemia plays the predominant role in SBI, our model suggests that metabolic crisis involved in SBI can also be non-ischemic. Our findings offer a more comprehensive understanding of the complex interrelationship among potassium, oxygen, excitotoxicity, seizures and SBI.

scholarly journals A Study on Trend Analysis of Applicants Based on Patent Classification Systems

Information ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 364 ◽  
Author(s):  
Soohyeon Chae ◽  
Jangwon Gim
Keyword(s):  
Intellectual Property Rights ◽  
New Technologies ◽  
Classification Systems ◽  
International Patent Classification ◽  
Ripple Effects ◽  
Patent Classification ◽  
Proposed Model ◽  
International Patent ◽  
The Social ◽  
The Common

In recent times, with the development of science and technology, new technologies have been rapidly emerging, and innovators are making efforts to acquire intellectual property rights to preserve their competitive advantage as well as to enhance innovative competitiveness. As a result, the number of patents being acquired increases exponentially every year, and the social and economic ripple effects of developed technologies are also increasing. Now, innovators are focusing on evaluating existing technologies to develop more valuable ones. However, existing patent analysis studies mainly focus on discovering core technologies amongst the technologies derived from patents or analyzing trend changes for specific techniques; the analysis of innovators who develop such core technologies is insufficient. In this paper, we propose a model for analyzing the technical inventions of applicants based on patent classification systems such as international patent classification (IPC) and cooperative patent classification (CPC). Through the proposed model, the common invention patterns of applicants are extracted and used to analyze their technical inventions. The proposed model shows that patent classification systems can be used to extract the trends in applicants’ technological inventions and to track changes in their innovative patterns.

scholarly journals Nash Equilibrium Investment-Reinsurance Strategies for an Insurer and a Reinsurer with Intertemporal Restrictions and Common Interests

Mathematics ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 139
Author(s):  
Yanfei Bai ◽  
Zhongbao Zhou ◽  
Rui Gao ◽  
Helu Xiao
Keyword(s):  
Nash Equilibrium ◽  
Value Premium ◽  
Insurance Company ◽  
Common Goal ◽  
General Insurance ◽  
Proposed Model ◽  
Common Interests ◽  
The Common ◽  
Mean Variance ◽  
Theoretical Results

This paper investigates the generalized multi-period mean-variance investment-reinsurance optimization model in a discrete-time framework for a general insurance company that contains a reinsurer and an insurer. The intertemporal restrictions and the common interests of the reinsurer and the insurer are considered. The common goal of the reinsurer and the insurer is to maximize the expectation of the weighted sum of their wealth processes and minimize the corresponding variance. Based on the game method, we obtain the Nash equilibrium investment-reinsurance strategies for the above-proposed model and find out the equilibrium strategies when unilateral interest is considered. In addition, the Nash equilibrium investment-reinsurance strategies are deduced under two special premium calculated principles (i.e., the expected value premium principle and the variance value premium principle). We theoretically study the effect of the intertemporal restrictions on Nash equilibrium investment-reinsurance strategies and find the effect depends on the value of some parameters, which differs from the previous researches that generally believed that intertemporal restrictions would make investors avoid risks. Finally, we perform corresponding numerical analyses to verify our theoretical results.

scholarly journals Optimization a new mathematical model of hybrid flow shop work order problem by the Genetic Algorithm

2012 ◽  
Vol 1 (3) ◽  
pp. 192
Author(s):  
Nasser Shahsavari Pour ◽  
Hamed Asadi ◽  
Mansoor Kheradmand
Keyword(s):  
Genetic Algorithm ◽  
Flow Shop ◽  
Production Costs ◽  
Hybrid Flow Shop ◽  
Inventory Cost ◽  
Order Problem ◽  
Proposed Model ◽  
Production Environments ◽  
Task Processing ◽  
The Common

In competitive business, one of the challenges of management in industrial units is reducing the prime cost. Hybrid flow shop is one of the common production environments which lead to a significant decrease in production costs if it has a good and appropriate scheduling in production. Hybrid flow-shop problems overcome one of the limitations of the classical flow-shop model by allowing parallel processors at each stage of task Processing. In this paper we study the hybrid flow shop work order problems. A brief enumeration of the essential constraints that characterize this kind of organization is given. Problem is minimizing the production and inventory cost in Hybrid flow-shop organization. To solve problem we used the genetic algorithm to obtain the minimum of production cost. An illustrative example explains in detail the feature of the proposed model.

Slow subduction initiation forces fast ophiolite formation

2020 ◽  
Author(s):  
Mathieu Soret ◽  
Guillaume Bonnet ◽  
Philippe Agard ◽  
Kyle Larson ◽  
John Cottle ◽  
...  
Keyword(s):  
Large Scale ◽  
Time Lag ◽  
Deformation Pattern ◽  
Far Field ◽  
Common Belief ◽  
Plate Interface ◽  
Subduction Initiation ◽  
Proposed Model ◽  
Modelling Studies ◽  
The Common

&lt;p&gt;Metamorphic soles are m to ~500 m thick tectonic slices welded beneath most large- scale ophiolites (usually ~20 km thick). They typically show a steep inverted metamorphic structure where the pressure and temperature (T) conditions of crystallization increase upward, from the base of the sole (500 &amp;#177; 100&amp;#176;C at 0.5 &amp;#177; 0.2 GPa) to the contact with the overlying peridotite (800 &amp;#177; 100&amp;#176;C at 1.0 &amp;#177; 0.2 GPa). The inverted &amp;#160;T gradient was historically interpreted as a result of heat transfer from the incipient mantle wedge toward the nascent slab synchronously with the overlying ophiolite formation (within only 1-2 Myrs). Their mineralogical assemblage and deformation pattern provide major constraints on the nature and the timing of the processes controlling the dynamics of the plate interface during early subduction.&lt;/p&gt;&lt;p&gt;Soret et al. (2017, 2019) recently reappraised the tectonic&amp;#8211;petrological model for the formation of metamorphic soles below ophiolites, showing that the present-day structure of the sole results from the successive stacking of several homogeneous oceanic crustal slivers (without internal T gradient). This stacking marks the evolution of rheological properties of slab material and peridotites of the upper plate as the plate interface progressively cools (Agard et al., 2016). These findings outline the thermal and mechanical complexity of early subduction dynamics, and highlight the need for refined numerical modelling studies.&lt;/p&gt;&lt;p&gt;Lu-Hf geochronology on garnet from the Oman metamorphic sole has recently shown that the earliest accreted subunit, found directly against the upper plate mantle, was initially buried &amp;#8805; 8 Ma earlier than previously estimated (Guilmette et al., 2017). These results imply initiation &amp;#8805; 8 Ma before the formation of the ophiolite, which underscores the common belief that ophiolite-sole couples record spontaneous subduction initiation and rather indicates far-field forcing long before upper plate extension and mantle upwelling.&lt;/p&gt;&lt;p&gt;We herein present new U-Pb titanite and monazite petrochronology across the different sub-units of the Oman metamorphic sole. Our results confirm the time lag of several million years between subduction initiation and the ophiolite formation, therefore supporting the recently proposed model of far-field forced subduction initiation. They also reveal a significant time lag between the underplating and exhumation of each sub-unit of the sole.&lt;/p&gt;

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