Sample records for dag fjeld iwan

  1. A six-parameter Iwan model and its application

    NASA Astrophysics Data System (ADS)

    Li, Yikun; Hao, Zhiming

    2016-02-01

    Iwan model is a practical tool to describe the constitutive behaviors of joints. In this paper, a six-parameter Iwan model based on a truncated power-law distribution with two Dirac delta functions is proposed, which gives a more comprehensive description of joints than the previous Iwan models. Its analytical expressions including backbone curve, unloading curves and energy dissipation are deduced. Parameter identification procedures and the discretization method are also provided. A model application based on Segalman et al.'s experiment works with bolted joints is carried out. Simulation effects of different numbers of Jenkins elements are discussed. The results indicate that the six-parameter Iwan model can be used to accurately reproduce the experimental phenomena of joints.

  2. Investigation into discretization methods of the six-parameter Iwan model

    NASA Astrophysics Data System (ADS)

    Li, Yikun; Hao, Zhiming; Feng, Jiaquan; Zhang, Dingguo

    2017-02-01

    Iwan model is widely applied for the purpose of describing nonlinear mechanisms of jointed structures. In this paper, parameter identification procedures of the six-parameter Iwan model based on joint experiments with different preload techniques are performed. Four kinds of discretization methods deduced from stiffness equation of the six-parameter Iwan model are provided, which can be used to discretize the integral-form Iwan model into a sum of finite Jenkins elements. In finite element simulation, the influences of discretization methods and numbers of Jenkins elements on computing accuracy are discussed. Simulation results indicate that a higher accuracy can be obtained with larger numbers of Jenkins elements. It is also shown that compared with other three kinds of discretization methods, the geometric series discretization based on stiffness provides the highest computing accuracy.

  3. A reduced Iwan model that includes pinning for bolted joint mechanics

    DOE PAGES

    Brake, M. R. W.

    2016-10-28

    Bolted joints are prevalent in most assembled structures; however, predictive models for their behavior do not exist. Calibrated models, such as the Iwan model, are able to predict the response of a jointed structure over a range of excitations once calibrated at a nominal load. The Iwan model, though, is not widely adopted due to the high computational expense of implementation. To address this, an analytical solution of the Iwan model is derived under the hypothesis that for an arbitrary load reversal, there is a new distribution of dry friction elements, which are now stuck, that approximately resemble a scaledmore » version of the original distribution of dry friction elements. The dry friction elements internal to the Iwan model do not have a uniform set of parameters and are described by a distribution of parameters, i.e., which internal dry friction elements are stuck or slipping at a given load, that ultimately governs the behavior of the joint as it transitions from microslip to macroslip. This hypothesis allows the model to require no information from previous loading cycles. Additionally, the model is extended to include the pinning behavior inherent in a bolted joint. Modifications of the resulting framework are discussed to highlight how the constitutive model for friction can be changed (in the case of an Iwan–Stribeck formulation) or how the distribution of dry friction elements can be changed (as is the case for the Iwan plasticity model). Finally, the reduced Iwan plus pinning model is then applied to the Brake–Reuß beam in order to discuss methods to deduce model parameters from experimental data.« less

  4. A stochastic Iwan-type model for joint behavior variability modeling

    NASA Astrophysics Data System (ADS)

    Mignolet, Marc P.; Song, Pengchao; Wang, X. Q.

    2015-08-01

    This paper focuses overall on the development and validation of a stochastic model to describe the dissipation and stiffness properties of a bolted joint for which experimental data is available and exhibits a large scatter. An extension of the deterministic parallel-series Iwan model for the characterization of the force-displacement behavior of joints is first carried out. This new model involves dynamic and static coefficients of friction differing from each other and a broadly defined distribution of Jenkins elements. Its applicability is next investigated using the experimental data, i.e. stiffness and dissipation measurements obtained in harmonic testing of 9 nominally identical bolted joints. The model is found to provide a very good fit of the experimental data for each bolted joint notwithstanding the significant variability of their behavior. This finding suggests that this variability can be simulated through the randomization of only the parameters of the proposed Iwan-type model. The distribution of these parameters is next selected based on maximum entropy concepts and their corresponding parameters, i.e. the hyperparameters of the model, are identified using a maximum likelihood strategy. Proceeding with a Monte Carlo simulation of this stochastic Iwan model demonstrates that the experimental data fits well within the uncertainty band corresponding to the 5th and 95th percentiles of the model predictions which well supports the adequacy of the modeling effort.

  5. A numerical study on the limitations of modal Iwan models for impulsive excitations

    NASA Astrophysics Data System (ADS)

    Lacayo, Robert M.; Deaner, Brandon J.; Allen, Matthew S.

    2017-03-01

    Structures with mechanical joints are difficult to model accurately. Even if the natural frequencies of the system remain essentially constant, the damping introduced by the joints is often observed to change dramatically with amplitude. Although models for individual joints have been employed with some success, accurately modeling a structure with many joints remains a significant obstacle. To this end, Segalman proposed a modal Iwan model, which simplifies the analysis by modeling a system with a linear superposition of weakly-nonlinear, uncoupled single degree-of-freedom systems or modes. Given a simulation model with discrete joints, one can identify the model for each mode by selectively exciting each mode one at a time and observing how the transient response decays. However, in the environment of interest several modes may be excited simultaneously, such as in an experiment when an impulse is applied at a discrete point. In this work, the modal Iwan model framework is assessed numerically to understand how well it captures the dynamic response of typical structures with joints when they are excited with impulsive forces applied at point locations. This is done by comparing the effective natural frequency and modal damping of the uncoupled modal models with those of truth models that include nonlinear modal coupling. These concepts are explored for two structures, a simple spring-mass system and a finite element model of a beam, both of which contain physical Iwan elements to model joint nonlinearity. The results show that modal Iwan models can effectively capture the variations in frequency and damping with amplitude, which, for damping, can increase by as much as two orders of magnitude in the microslip regime. However, even in the microslip regime the accuracy of a modal Iwan model is found to depend on whether the mode in question is dominant in the response; in some cases the effective damping that the uncoupled model predicts is found to be in error by

  6. Simulation of dynamics of beam structures with bolted joints using adjusted Iwan beam elements

    NASA Astrophysics Data System (ADS)

    Song, Y.; Hartwigsen, C. J.; McFarland, D. M.; Vakakis, A. F.; Bergman, L. A.

    2004-05-01

    Mechanical joints often affect structural response, causing localized non-linear stiffness and damping changes. As many structures are assemblies, incorporating the effects of joints is necessary to produce predictive finite element models. In this paper, we present an adjusted Iwan beam element (AIBE) for dynamic response analysis of beam structures containing joints. The adjusted Iwan model consists of a combination of springs and frictional sliders that exhibits non-linear behavior due to the stick-slip characteristic of the latter. The beam element developed is two-dimensional and consists of two adjusted Iwan models and maintains the usual complement of degrees of freedom: transverse displacement and rotation at each of the two nodes. The resulting element includes six parameters, which must be determined. To circumvent the difficulty arising from the non-linear nature of the inverse problem, a multi-layer feed-forward neural network (MLFF) is employed to extract joint parameters from measured structural acceleration responses. A parameter identification procedure is implemented on a beam structure with a bolted joint. In this procedure, acceleration responses at one location on the beam structure due to one known impulsive forcing function are simulated for sets of combinations of varying joint parameters. A MLFF is developed and trained using the patterns of envelope data corresponding to these acceleration histories. The joint parameters are identified through the trained MLFF applied to the measured acceleration response. Then, using the identified joint parameters, acceleration responses of the jointed beam due to a different impulsive forcing function are predicted. The validity of the identified joint parameters is assessed by comparing simulated acceleration responses with experimental measurements. The capability of the AIBE to capture the effects of bolted joints on the dynamic responses of beam structures, and the efficacy of the MLFF parameter

  7. DAG tales: the multiple faces of diacylglycerol--stereochemistry, metabolism, and signaling.

    PubMed

    Eichmann, Thomas Oliver; Lass, Achim

    2015-10-01

    The neutral lipids diacylglycerols (DAGs) are involved in a plethora of metabolic pathways. They function as components of cellular membranes, as building blocks for glycero(phospho)lipids, and as lipid second messengers. Considering their central role in multiple metabolic processes and signaling pathways, cellular DAG levels require a tight regulation to ensure a constant and controlled availability. Interestingly, DAG species are versatile in their chemical structure. Besides the different fatty acid species esterified to the glycerol backbone, DAGs can occur in three different stereo/regioisoforms, each with unique biological properties. Recent scientific advances have revealed that DAG metabolizing enzymes generate and distinguish different DAG isoforms, and that only one DAG isoform holds signaling properties. Herein, we review the current knowledge of DAG stereochemistry and their impact on cellular metabolism and signaling. Further, we describe intracellular DAG turnover and its stereochemistry in a 3-pool model to illustrate the spatial and stereochemical separation and hereby the diversity of cellular DAG metabolism.

  8. DAG1, no gene for RNA regulation?

    PubMed

    Brancaccio, Andrea

    2012-04-10

    DAG1 encodes for a precursor protein that liberates the two subunits featured by the dystroglycan (DG) adhesion complex that are involved in an increasing number of cellular functions in a wide variety of cells and tissues. Aside from the proteolytic events producing the α and β subunits, especially the former undergoes extensive "post-production" modifications taking place within the ER/Golgi where its core protein is both N- and O-decorated with sugars. These post-translational events, that are mainly orchestrated by a plethora of certified, or putative, glycosyltransferases, prelude to the excocytosis-mediated trafficking and targeting of the DG complex to the plasma membrane. Extensive genetic and biochemical evidences have been accumulated so far on α-DG glycosylation, while little is know on possible regulatory events underlying the chromatine activation, transcription or post-transcription (splicing and escape from the nucleus) of DAG1 or of its mRNA. A scenario is envisaged in which cells would use a sort of preferential, and scarcely regulated, route for DAG1 activation, that would imply fast mRNA transcription, maturation and export to the cytosol, and would prelude to the multiple time-consuming enzymatic post-translational activities needed for its glycosylation. Such a provocative view might be helpful to trigger future work aiming at disclosing the complete molecular mechanisms underlying DAG1 activation and at improving our knowledge of any pre-translational step that is involved in dystroglycan regulation. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. VPipe: Virtual Pipelining for Scheduling of DAG Stream Query Plans

    NASA Astrophysics Data System (ADS)

    Wang, Song; Gupta, Chetan; Mehta, Abhay

    There are data streams all around us that can be harnessed for tremendous business and personal advantage. For an enterprise-level stream processing system such as CHAOS [1] (Continuous, Heterogeneous Analytic Over Streams), handling of complex query plans with resource constraints is challenging. While several scheduling strategies exist for stream processing, efficient scheduling of complex DAG query plans is still largely unsolved. In this paper, we propose a novel execution scheme for scheduling complex directed acyclic graph (DAG) query plans with meta-data enriched stream tuples. Our solution, called Virtual Pipelined Chain (or VPipe Chain for short), effectively extends the "Chain" pipelining scheduling approach to complex DAG query plans.

  10. Eastern Anatolia Observatory (DAG): Recent developments and a prospective observing site for robotic telescopes

    NASA Astrophysics Data System (ADS)

    Yesilyaprak, C.; Yerli, S. K.; Keskin, O.

    2016-12-01

    This document (Eastern Anatolia Observatory (DAG) is the new observatory of Turkey with the optical and near-infrared largest telescope (4 m class) and its robust observing site infrastructure. This national project consists of three phases with DAG (Telescope, Enclosure, Buildings and Infrastructures), FPI (Focal Plane Instruments and Adaptive Optics) and MCP (Mirror Coating Plant) and is supported by the Ministry of Development of Turkey. The tenders of telescope and enclosure have been made and almost all the infrastructure (roads, geological and atmospherical surveys, electricity, fiber optics, cable car, water, generator, etc.) of DAG site (Erzurum/Turkey, 3,170 m altitude) have been completed. This poster is about the recent developments of DAG and about the future possible collaborations for various robotic telescopes which can be set up in DAG site.

  11. Directed acyclic graphs (DAGs): an aid to assess confounding in dental research.

    PubMed

    Merchant, Anwar T; Pitiphat, Waranuch

    2002-12-01

    Confounding, a special type of bias, occurs when an extraneous factor is associated with the exposure and independently affects the outcome. In order to get an unbiased estimate of the exposure-outcome relationship, we need to identify potential confounders, collect information on them, design appropriate studies, and adjust for confounding in data analysis. However, it is not always clear which variables to collect information on and adjust for in the analyses. Inappropriate adjustment for confounding can even introduce bias where none existed. Directed acyclic graphs (DAGs) provide a method to select potential confounders and minimize bias in the design and analysis of epidemiological studies. DAGs have been used extensively in expert systems and robotics. Robins (1987) introduced the application of DAGs in epidemiology to overcome shortcomings of traditional methods to control for confounding, especially as they related to unmeasured confounding. DAGs provide a quick and visual way to assess confounding without making parametric assumptions. We introduce DAGs, starting with definitions and rules for basic manipulation, stressing more on applications than theory. We then demonstrate their application in the control of confounding through examples of observational and cross-sectional epidemiological studies.

  12. DAG telescope site studies and infrastructure for possible international co-operations

    NASA Astrophysics Data System (ADS)

    Yerli, Sinan K.; Yeşilyaprak, Cahit; Keskin, Onur; Alis, Sinan

    2016-07-01

    The selected site for the 4 m DAG (Eastern Anatolian Observatory in Turkish) telescope is at "Karakaya Ridge", at 3170 m altitude (3150 m after summit management). The telescope's optical design is performed by the DAG technical team to allow infrared observation at high angular resolution, with its adaptive optics system to be built in Turkey. In this paper; a brief introduction about DAG telescope design; planned instrumentation; the meteorological data collected from 2008, clear night counts, short-term DIMM observations; current infrastructure to hold auxiliary telescopes; auxiliary buildings to assist operations; the observatory design; and coating unit plans will be presented along with possible collaboration possibilities in terms of instrumentation and science programs.

  13. A DAG Scheduling Scheme on Heterogeneous Computing Systems Using Tuple-Based Chemical Reaction Optimization

    PubMed Central

    Jiang, Yuyi; Shao, Zhiqing; Guo, Yi

    2014-01-01

    A complex computing problem can be solved efficiently on a system with multiple computing nodes by dividing its implementation code into several parallel processing modules or tasks that can be formulated as directed acyclic graph (DAG) problems. The DAG jobs may be mapped to and scheduled on the computing nodes to minimize the total execution time. Searching an optimal DAG scheduling solution is considered to be NP-complete. This paper proposed a tuple molecular structure-based chemical reaction optimization (TMSCRO) method for DAG scheduling on heterogeneous computing systems, based on a very recently proposed metaheuristic method, chemical reaction optimization (CRO). Comparing with other CRO-based algorithms for DAG scheduling, the design of tuple reaction molecular structure and four elementary reaction operators of TMSCRO is more reasonable. TMSCRO also applies the concept of constrained critical paths (CCPs), constrained-critical-path directed acyclic graph (CCPDAG) and super molecule for accelerating convergence. In this paper, we have also conducted simulation experiments to verify the effectiveness and efficiency of TMSCRO upon a large set of randomly generated graphs and the graphs for real world problems. PMID:25143977

  14. A DAG scheduling scheme on heterogeneous computing systems using tuple-based chemical reaction optimization.

    PubMed

    Jiang, Yuyi; Shao, Zhiqing; Guo, Yi

    2014-01-01

    A complex computing problem can be solved efficiently on a system with multiple computing nodes by dividing its implementation code into several parallel processing modules or tasks that can be formulated as directed acyclic graph (DAG) problems. The DAG jobs may be mapped to and scheduled on the computing nodes to minimize the total execution time. Searching an optimal DAG scheduling solution is considered to be NP-complete. This paper proposed a tuple molecular structure-based chemical reaction optimization (TMSCRO) method for DAG scheduling on heterogeneous computing systems, based on a very recently proposed metaheuristic method, chemical reaction optimization (CRO). Comparing with other CRO-based algorithms for DAG scheduling, the design of tuple reaction molecular structure and four elementary reaction operators of TMSCRO is more reasonable. TMSCRO also applies the concept of constrained critical paths (CCPs), constrained-critical-path directed acyclic graph (CCPDAG) and super molecule for accelerating convergence. In this paper, we have also conducted simulation experiments to verify the effectiveness and efficiency of TMSCRO upon a large set of randomly generated graphs and the graphs for real world problems.

  15. DAG-TM Concept Element 11 CNS Performance Assessment: ADS-B Performance in the TRACON

    NASA Technical Reports Server (NTRS)

    Raghavan, Rajesh S.

    2004-01-01

    Distributed Air/Ground (DAG) Traffic Management (TM) is an integrated operational concept in which flight deck crews, air traffic service providers and aeronautical operational control personnel use distributed decision-making to enable user preferences and increase system capacity, while meeting air traffic management (ATM) safety requirements. It is a possible operational mode under the Free Flight concept outlined by the RTCA Task Force 3. The goal of DAG-TM is to enhance user flexibility/efficiency and increase system capacity, without adversely affecting system safety or restricting user accessibility to the National Airspace System (NAS). DAG-TM will be accomplished with a human-centered operational paradigm enabled by procedural and technological innovations. These innovations include automation aids, information sharing and Communication, Navigation, and Surveillance (CNS) / ATM technologies. The DAG-TM concept is intended to eliminate static restrictions to the maximum extent possible. In this paradigm, users may plan and operate according to their preferences - as the rule rather than the exception - with deviations occurring only as necessary. The DAG-TM concept elements aim to mitigate the extent and impact of dynamic NAS constraints, while maximizing the flexibility of airspace operations

  16. DAG: a new observatory and a prospective observing site for other potential telescopes

    NASA Astrophysics Data System (ADS)

    Yeşilyaprak, Cahit; Yerli, Sinan K.; Keskin, Onur; Güçsav, B. Bülent

    2016-07-01

    DAG (Eastern Anatolia Observatory is read as "Doğu Anadolu Gözlemevi" in Turkish) is the newest and largest observatory of Turkey, constructed at an altitude of 3150 m in Konaklı/Erzurum provenience, with an optical and nearinfrared telescope (4 m in diameter) and its robust observing site infrastructure. This national project consists of three main phases: DAG (Telescope, Enclosure, Buildings and Infrastructures), FPI (Focal Plane Instruments and Adaptive Optics) and MCP (Mirror Coating Plant). All these three phases are supported by the Ministry of Development of Turkey and funding is awarded to Atatürk University. Telescope, enclosure and building tenders were completed in 2014, 2015 and 2016, respectively. The final design of telescope, enclosure and building and almost all main infrastructure components of DAG site have been completed; mainly: road work, geological and atmospheric surveys, electric and fiber cabling, water line, generator system, cable car to summit. This poster explains recent developments of DAG project and talks about the future possible collaborations for various telescopes which can be constructed at the site.

  17. Application of viscous and Iwan modal damping models to experimental measurements from bolted structures

    DOE PAGES

    Deaner, Brandon J.; Allen, Matthew S.; Starr, Michael James; ...

    2015-01-20

    Measurements are presented from a two-beam structure with several bolted interfaces in order to characterize the nonlinear damping introduced by the joints. The measurements (all at force levels below macroslip) reveal that each underlying mode of the structure is well approximated by a single degree-of-freedom (SDOF) system with a nonlinear mechanical joint. At low enough force levels, the measurements show dissipation that scales as the second power of the applied force, agreeing with theory for a linear viscously damped system. This is attributed to linear viscous behavior of the material and/or damping provided by the support structure. At larger forcemore » levels, the damping is observed to behave nonlinearly, suggesting that damping from the mechanical joints is dominant. A model is presented that captures these effects, consisting of a spring and viscous damping element in parallel with a four-parameter Iwan model. As a result, the parameters of this model are identified for each mode of the structure and comparisons suggest that the model captures the stiffness and damping accurately over a range of forcing levels.« less

  18. Diagnostic Analyzer for Gearboxes (DAG): User's Guide. Version 3.1 for Microsoft Windows 3.1

    NASA Technical Reports Server (NTRS)

    Jammu, Vinay B.; Kourosh, Danai

    1997-01-01

    This documentation describes the Diagnostic Analyzer for Gearboxes (DAG) software for performing fault diagnosis of gearboxes. First, the user would construct a graphical representation of the gearbox using the gear, bearing, shaft, and sensor tools contained in the DAG software. Next, a set of vibration features obtained by processing the vibration signals recorded from the gearbox using a signal analyzer is required. Given this information, the DAG software uses an unsupervised neural network referred to as the Fault Detection Network (FDN) to identify the occurrence of faults, and a pattern classifier called Single Category-Based Classifier (SCBC) for abnormality scaling of individual vibration features. The abnormality-scaled vibration features are then used as inputs to a Structure-Based Connectionist Network (SBCN) for identifying faults in gearbox subsystems and components. The weights of the SBCN represent its diagnostic knowledge and are derived from the structure of the gearbox graphically presented in DAG. The outputs of SBCN are fault possibility values between 0 and 1 for individual subsystems and components in the gearbox with a 1 representing a definite fault and a 0 representing normality. This manual describes the steps involved in creating the diagnostic gearbox model, along with the options and analysis tools of the DAG software.

  19. Reducing Response Time Bounds for DAG-Based Task Systems on Heterogeneous Multicore Platforms

    DTIC Science & Technology

    2016-01-01

    synchronous parallel tasks on multicore platforms. In 25th ECRTS, 2013. [10] U. Devi. Soft Real - Time Scheduling on Multiprocessors. PhD thesis...report, Washington University in St Louis, 2014. [18] C. Liu and J. Anderson. Supporting soft real - time DAG-based sys- tems on multiprocessors with...analysis for DAG-based real - time task systems im- plemented on heterogeneous multicore platforms. The spe- cific analysis problem that is considered was

  20. The Dag Hammarskjold Library Reaches Out to the World.

    ERIC Educational Resources Information Center

    Chepesiuk, Ron

    1998-01-01

    Describes services offered at the Dag Hammarskjold Library at the United Nations (UN). Highlights include adopting new technology for a virtual library; the international law collection which is now accessible through the World Wide Web; UN depository libraries; material available on the Internet; the Optical Disk System, a storage/retrieval…

  1. Production of DagA and ethanol by sequential utilization of sugars in a mixed-sugar medium simulating microalgal hydrolysate.

    PubMed

    Park, Juyi; Hong, Soon-Kwang; Chang, Yong Keun

    2015-09-01

    A novel two-step fermentation process using a mixed-sugar medium mimicking microalgal hydrolysate has been proposed to avoid glucose repression and thus to maximize substrate utilization efficiency. When DagA, a β-agarase was produced in one step in the mixed-sugar medium by using a recombinant Streptomyces lividans, glucose was found to have negative effects on the consumption of the other sugars and DagA biosynthesis causing low substrate utilization efficiency and low DagA productivity. To overcome such difficulties, a new strategy of sequential substrate utilization was developed. In the first step, glucose was consumed by Saccharomyces cerevisiae together with galactose and mannose producing ethanol, after which DagA was produced from the remaining sugars of xylose, rhamnose and ribose. Fucose was not consumed. By adopting this two-step process, the overall substrate utilization efficiency was increased approximately 3-fold with a nearly 2-fold improvement of DagA production, let alone the additional benefit of ethanol production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Deleting the DAG Kinase Dgk1 Augments Yeast Vacuole Fusion Through In-creased Ypt7 Activity and Altered Membrane Fluidity

    PubMed Central

    Miner, Gregory E.; Starr, Matthew L.; Hurst, Logan R.; Fratti, Rutilio A.

    2017-01-01

    Diacylglycerol (DAG) is a fusogenic lipid that can be produced through phospholipase C activity on phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], or through phosphatidic acid (PA) phosphatase activity. The fusion of Saccharomyces cerevisiae vacuoles requires DAG, PA and PI(4,5)P2, and the production of these lipids is thought to provide temporally specific stoichiometries that are critical for each stage of fusion. Furthermore, DAG and PA can be interconverted by the DAG kinase Dgk1 and the PA phosphatase Pah1. Previously we found that pah1Δ vacuoles were fragmented, blocked in SNARE priming and showed arrested endosomal maturation. In other pathways the effects of deleting PAH1 can be compensated for by additionally deleting DGK1, however deleting both genes did not rescue the pah1Δ vacuolar defects. Deleting DGK1 alone caused a marked increase in vacuole fusion that was attributed to elevated DAG levels. This was accompanied by a gain in resistance to the inhibitory effects of PA as well as inhibitors of Ypt7 activity. Together these data show that Dgk1 function can act as a negative regulator of vacuole fusion through the production of PA at the cost of depleting DAG and reducing Ypt7 activity. PMID:28276191

  3. The DAG project, a 4m class telescope: the telescope main structure performances

    NASA Astrophysics Data System (ADS)

    Marchiori, G.; Busatta, A.; Ghedin, L.; Marcuzzi, E.; Manfrin, C.; Battistel, C.; Pirnay, O.; Flebus, Carlo; Yeşilyaprak, C.; Keskin, O.; Yerli, S.

    2016-07-01

    Dogu Anatolu Gözlemevi (DAG-Eastern Anatolia Observatory) Project is a 4m class optical, near-infrared Telescope and suitable enclosure which will be located at an altitude of 3.170m in Erzurum, Turkey. The DAG telescope is a project fully funded by Turkish Ministry of Development and the Atatürk University of Astrophysics Research Telescope - ATASAM. The Project is being developed by the Belgian company AMOS (project leader), which is also the optics supplier and EIE GROUP, the Telescope Main Structure supplier and responsible for the final site integration. The design of the Telescope Main Structure fits in the EIE TBO Program which aims at developing a Dome/Telescope systemic optimization process for both performances and competitive costs based on previous project commitments like NTT, VLT, VST and ASTRI. The optical Configuration of the DAG Telescope is a Ritchey-Chretien with two Nasmyth foci and a 4m primary thin mirror controlled in shape and position by an Active Optic System. The main characteristics of the Telescope Main Structure are an Altitude-Azimuth light and rigid structure system with Direct Drive Systems for both axis, AZ Hydrostatic Bearing System and Altitude standard bearing system; both axes are equipped with Tape Encoder System. An innovative Control System characterizes the telescope performance.

  4. Novel mutations in RASGRP2, which encodes CalDAG-GEFI, abrogate Rap1 activation, causing platelet dysfunction

    PubMed Central

    Lozano, María Luisa; Cook, Aaron; Bastida, José María; Paul, David S.; Iruin, Gemma; Cid, Ana Rosa; Adan-Pedroso, Rosa; Ramón González-Porras, José; Hernández-Rivas, Jesús María; Fletcher, Sarah J.; Johnson, Ben; Morgan, Neil; Ferrer-Marin, Francisca; Vicente, Vicente; Sondek, John; Watson, Steve P.; Bergmeier, Wolfgang

    2016-01-01

    In addition to mutations in ITG2B or ITGB3 genes that cause defective αIIbβ3 expression and/or function in Glanzmann’s thrombasthenia patients, platelet dysfunction can be a result of genetic variability in proteins that mediate inside-out activation of αIIbβ3. The RASGRP2 gene is strongly expressed in platelets and neutrophils, where its encoded protein CalDAG-GEFI facilitates the activation of Rap1 and subsequent activation of integrins. We used next-generation sequencing (NGS) and whole-exome sequencing (WES) to identify 2 novel function-disrupting mutations in RASGRP2 that account for bleeding diathesis and platelet dysfunction in 2 unrelated families. By using a panel of 71 genes, we identified a homozygous change (c.1142C>T) in exon 10 of RASGRP2 in a 9-year-old child of Chinese origin (family 1). This variant led to a p.Ser381Phe substitution in the CDC25 catalytic domain of CalDAG-GEFI. In 2 Spanish siblings from family 2, WES identified a nonsense homozygous variation (c.337C>T) (p.Arg113X) in exon 5 of RASGRP2. CalDAG-GEFI expression was markedly reduced in platelets from all patients, and by using a novel in vitro assay, we found that the nucleotide exchange activity was dramatically reduced in CalDAG-GEFI p.Ser381Phe. Platelets from homozygous patients exhibited agonist-specific defects in αIIbβ3 integrin activation and aggregation. In contrast, α- and δ-granule secretion, platelet spreading, and clot retraction were not markedly affected. Integrin activation in the patients’ neutrophils was also impaired. These patients are the first cases of a CalDAG-GEFI deficiency due to homozygous RASGRP2 mutations that are linked to defects in both leukocyte and platelet integrin activation. PMID:27235135

  5. Structured DAG oil ameliorates renal injury in streptozotocin-induced diabetic rats through inhibition of NF-κB and activation of Nrf2 pathway.

    PubMed

    Das, Kankana; Ghosh, Mahua

    2017-02-01

    Accumulating evidence suggested that inflammatory processes are involved in the development of diabetic nephropathy (DN). Here, we have tested the hypothesis that Caprylic Acid (Cy)-diacylglycerol (DAG) oil (Cy-DAG), a novel structurally formulated lipid with high nutritional value, ameliorated DN in streptozotocin (STZ)-induced diabetic rats through the anti-inflammatory mechanisms. Basic hematological, biochemical parameters, immunoblotting, immunofluorescence and flow cytometry analysis were performed to observe the anti-inflammatory potential of Cy-DAG oil. The data revealed that STZ significantly increased the renal oxidative stress markers and decreased the levels of renal enzymatic and non-enzymatic antioxidants. Moreover, renal nitric oxide (NO), tissue necrosis factor-α (TNF-α), interleukin-6 (IL-6) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were also increased in the renal tissue of STZ-treated rats. Further, DAG oil pretreatment produced a significant improvement in renal antioxidant status, reduced the lipid peroxidation and the levels of inflammatory markers in STZ-treated kidney. Similarly, results of protein expression showed that DAG oil pretreatment normalized the renal expression of Nrf2/Keap1 and its downstream regulatory proteins in STZ-treated condition. Immunohistochemical observations provided further evidence that DAG oil effectively protected the kidney from STZ-mediated oxidative damage. These results suggested that the DAG oil ameliorated STZ-induced oxidative renal injury by the activation of AKT/Nrf2/HO-1 pathway and the inhibition of ROS/MAPK/NF-κB pathway. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Calcium diacylglycerol guanine nucleotide exchange factor I (CalDAG-GEFI) gene mutations in a thrombopathic Simmental calf.

    PubMed

    Boudreaux, M K; Schmutz, S M; French, P S

    2007-11-01

    Simmental thrombopathia is an inherited platelet disorder that closely resembles the platelet disorders described in Basset Hounds and Eskimo Spitz dogs. Recently, two different mutations in the gene encoding calcium diacylglycerol guanine nucleotide exchange factor I (CalDAG-GEFI) were described to be associated with the Basset Hound and Spitz thrombopathia disorders, and a third distinct mutation was identified in CalDAG-GEFI in thrombopathic Landseers of European Continental Type. The gene encoding CalDAG-GEFI was sequenced using DNA obtained from normal cattle and from a thrombopathic calf studied in Canada. The affected calf was found to have a nucleotide change (c.701 T>C), which would result in the substitution of a proline for a leucine within structurally conserved region two (SCR2) of the catalytic domain of the protein. This change is likely responsible for the thrombopathic phenotype observed in Simmental cattle and underscores the critical nature of this signal transduction protein in platelets.

  7. Agile development approach for the observatory control software of the DAG 4m telescope

    NASA Astrophysics Data System (ADS)

    Güçsav, B. Bülent; ćoker, Deniz; Yeşilyaprak, Cahit; Keskin, Onur; Zago, Lorenzo; Yerli, Sinan K.

    2016-08-01

    Observatory Control Software for the upcoming 4m infrared telescope of DAG (Eastern Anatolian Observatory in Turkish) is in the beginning of its lifecycle. After the process of elicitation-validation of the initial requirements, we have been focused on preparation of a rapid conceptual design not only to see the big picture of the system but also to clarify the further development methodology. The existing preliminary designs for both software (including TCS and active optics control system) and hardware shall be presented here in brief to exploit the challenges the DAG software team has been facing with. The potential benefits of an agile approach for the development will be discussed depending on the published experience of the community and on the resources available to us.

  8. Quantification of TAG and DAG in lesquerella (Physaria fendleri) oil by HPLC and MS

    USDA-ARS?s Scientific Manuscript database

    Castor oil has many industrial uses because of its high content (90%) of the hydroxy fatty acid, ricinoleic acid (OH1218:19). Lesquerella oil containing lesquerolic acid (Ls, OH1420:111, 56.5%) is potentially useful in industry. Ten diacylglycerols (DAG) and 74 triacylglycerols (TAG) in the seed oil...

  9. Unusual occurrence of a DAG motif in the Ipomovirus Cassava brown streak virus and implications for its vector transmission.

    PubMed

    Ateka, Elijah; Alicai, Titus; Ndunguru, Joseph; Tairo, Fred; Sseruwagi, Peter; Kiarie, Samuel; Makori, Timothy; Kehoe, Monica A; Boykin, Laura M

    2017-01-01

    Cassava is the main staple food for over 800 million people globally. Its production in eastern Africa is being constrained by two devastating Ipomoviruses that cause cassava brown streak disease (CBSD); Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), with up to 100% yield loss for smallholder farmers in the region. To date, vector studies have not resulted in reproducible and highly efficient transmission of CBSV and UCBSV. Most virus transmission studies have used Bemisia tabaci (whitefly), but a maximum of 41% U/CBSV transmission efficiency has been documented for this vector. With the advent of next generation sequencing, researchers are generating whole genome sequences for both CBSV and UCBSV from throughout eastern Africa. Our initial goal for this study was to characterize U/CBSV whole genomes from CBSD symptomatic cassava plants sampled in Kenya. We have generated 8 new whole genomes (3 CBSV and 5 UCBSV) from Kenya, and in the process of analyzing these genomes together with 26 previously published sequences, we uncovered the aphid transmission associated DAG motif within coat protein genes of all CBSV whole genomes at amino acid positions 52-54, but not in UCBSV. Upon further investigation, the DAG motif was also found at the same positions in two other Ipomoviruses: Squash vein yellowing virus (SqVYV), Coccinia mottle virus (CocMoV). Until this study, the highly-conserved DAG motif, which is associated with aphid transmission was only noticed once, in SqVYV but discounted as being of minimal importance. This study represents the first comprehensive look at Ipomovirus genomes to determine the extent of DAG motif presence and significance for vector relations. The presence of this motif suggests that aphids could potentially be a vector of CBSV, SqVYV and CocMov. Further transmission and ipomoviral protein evolutionary studies are needed to confirm this hypothesis.

  10. CQPSO scheduling algorithm for heterogeneous multi-core DAG task model

    NASA Astrophysics Data System (ADS)

    Zhai, Wenzheng; Hu, Yue-Li; Ran, Feng

    2017-07-01

    Efficient task scheduling is critical to achieve high performance in a heterogeneous multi-core computing environment. The paper focuses on the heterogeneous multi-core directed acyclic graph (DAG) task model and proposes a novel task scheduling method based on an improved chaotic quantum-behaved particle swarm optimization (CQPSO) algorithm. A task priority scheduling list was built. A processor with minimum cumulative earliest finish time (EFT) was acted as the object of the first task assignment. The task precedence relationships were satisfied and the total execution time of all tasks was minimized. The experimental results show that the proposed algorithm has the advantage of optimization abilities, simple and feasible, fast convergence, and can be applied to the task scheduling optimization for other heterogeneous and distributed environment.

  11. Actinomycetal complex of light sierozem on the Kopet-Dag piedmont plain

    NASA Astrophysics Data System (ADS)

    Zenova, G. M.; Zvyagintsev, D. G.; Manucharova, N. A.; Stepanova, O. A.; Chernov, I. Yu.

    2016-10-01

    The population density of actinomycetes in the samples of light sierozem from the Kopet Dag piedmont plain (75 km from Ashkhabad, Turkmenistan) reaches hundreds of thousand CFU/g soil. The actinomycetal complex is represented by two genera: Streptomyces and Micromonospora. Representatives of the Streptomyces genus predominate and comprise 73 to 87% of the actinomycetal complex. In one sample, representatives of the Micromonospora genus predominated in the complex (75%). The Streptomyces genus in the studied soil samples is represented by the species from several sections and series: the species of section Helvolo-Flavus series Helvolus represent the dominant component of the streptomycetal complex; their portion is up to 77% of all isolated actinomycetes. The species of other sections and series are much less abundant. Thus, the percentage of the Cinereus Achromogenes section in the actinomycetal complex does not exceed 28%; representatives of the Albus section Albus series, Roseus section Lavendulae-Roseus series, and Imperfectus section belong to rare species; they have been isolated not from all the studied samples of light sierozem, and their portion does not exceed 10% of the actinomycetal complex.

  12. The tale wagged by the DAG: broadening the scope of causal inference and explanation for epidemiology.

    PubMed

    Krieger, Nancy; Davey Smith, George

    2016-12-01

    'Causal inference', in 21st century epidemiology, has notably come to stand for a specific approach, one focused primarily on counterfactual and potential outcome reasoning and using particular representations, such as directed acyclic graphs (DAGs) and Bayesian causal nets. In this essay, we suggest that in epidemiology no one causal approach should drive the questions asked or delimit what counts as useful evidence. Robust causal inference instead comprises a complex narrative, created by scientists appraising, from diverse perspectives, different strands of evidence produced by myriad methods. DAGs can of course be useful, but should not alone wag the causal tale. To make our case, we first address key conceptual issues, after which we offer several concrete examples illustrating how the newly favoured methods, despite their strengths, can also: (i) limit who and what may be deemed a 'cause', thereby narrowing the scope of the field; and (ii) lead to erroneous causal inference, especially if key biological and social assumptions about parameters are poorly conceived, thereby potentially causing harm. As an alternative, we propose that the field of epidemiology consider judicious use of the broad and flexible framework of 'inference to the best explanation', an approach perhaps best developed by Peter Lipton, a philosopher of science who frequently employed epidemiologically relevant examples. This stance requires not only that we be open to being pluralists about both causation and evidence but also that we rise to the challenge of forging explanations that, in Lipton's words, aspire to 'scope, precision, mechanism, unification and simplicity'. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  13. The Story of a Seminar in Applied Communication. The Dag Hammarskjold Seminar on "Communication--An Essential Component in Development Work" (Uppsala, Sweden, August 27-September 9, 1972).

    ERIC Educational Resources Information Center

    Fuglesang, Andreas, Ed.

    The objective of the two week long 1972 Dag Hammarskjold Seminar was to break away from traditional and theoretical concepts of information work in order to gain a practical insight into communication, especially as it applies to social and economic development. Fifty participants and lecturers from developed and developing countries in Europe and…

  14. The use of bioelectrical impedance analysis to estimate total body water in young children with cerebral palsy.

    PubMed

    Bell, Kristie L; Boyd, Roslyn N; Walker, Jacqueline L; Stevenson, Richard D; Davies, Peter S W

    2013-08-01

    Body composition assessment is an essential component of nutritional evaluation in children with cerebral palsy. This study aimed to validate bioelectrical impedance to estimate total body water in young children with cerebral palsy and determine best electrode placement in unilateral impairment. 55 young children with cerebral palsy across all functional ability levels were included. Height/length was measured or estimated from knee height. Total body water was estimated using a Bodystat 1500MDD and three equations, and measured using the gold standard, deuterium dilution technique. Comparisons were made using Bland Altman analysis. For children with bilateral impairment, the Fjeld equation estimated total body water with the least bias (limits of agreement): 0.0 L (-1.4 L to 1.5 L); the Pencharz equation produced the greatest: 2.7 L (0.6 L-4.8 L). For children with unilateral impairment, differences between measured and estimated total body water were lowest on the unimpaired side using the Fjeld equation 0.1 L (-1.5 L to 1.6 L)) and greatest for the Pencharz equation. The ability of bioelectrical impedance to estimate total body water depends on the equation chosen. The Fjeld equation was the most accurate for the group, however, individual results varied by up to 18%. A population specific equation was developed and may enhance the accuracy of estimates. Australian New Zealand Clinical Trials Registry (ANZCTR) number: ACTRN12611000616976. Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  15. 77 FR 25538 - Quarterly Publication of Individuals, Who Have Chosen To Expatriate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... CHARLES FJELD SONJA NORENE FLEMING JAY LYNNE FLOUTY ANTOINE NICHOLAS FOO ANGELA WEI-QIN FORD GLENORA... KELLER PATRICIA DORIS KELLY ALEXANDER ANTHONY KELLY VIRGINIA RAE KEMPE TOBY NICHOLAS KESSLER CHRISTIAN... CHRISTIAN MARTIN SYZ ISABEL SUSAN TAN CHUAN LIONG TAN WEI-EE BEVERLY [[Page 25544

  16. ASTRONAUT KERWIN, JOSEPH P. - ART CONCEPTS

    NASA Image and Video Library

    1975-02-05

    S75-21432 (March 1975) --- An artist's concept illustrating a scene during the June 7, 1973 Skylab 2 extravehicular activity in Earth orbit when astronauts Joseph P. Kerwin (larger figure) and Charles Conrad Jr. cut the aluminum strapping which prevented the Skylab Orbital Workshop solar array system wing from deploying. The solar panel was successfully deployed. The painting is by artist Paul Fjeld. The action portrayed here is about two to four seconds after using the beam erection tether, the two crewmen broke the frozen SAS beam actuators. This artistic effort took weeks to research and a day and a half to paint. Fjeld said that he needed some hundred or so photographs to get all the details for the painting. He struggled through about 300 pages of transcripts from the flight. Also, he used several pages of teleprinter messages which were the actual instructions on the EVA that the two astronauts used in flight. Photo credit: NASA

  17. 3D Orthorhombic Elastic Wave Propagation Pre-Test Simulation of SPE DAG-1 Test

    NASA Astrophysics Data System (ADS)

    Jensen, R. P.; Preston, L. A.

    2017-12-01

    A more realistic representation of many geologic media can be characterized as a dense system of vertically-aligned microfractures superimposed on a finely-layered horizontal geology found in shallow crustal rocks. This seismic anisotropy representation lends itself to being modeled as an orthorhombic elastic medium comprising three mutually orthogonal symmetry planes containing nine independent moduli. These moduli can be determined by observing (or prescribing) nine independent P-wave and S-wave phase speeds along different propagation directions. We have developed an explicit time-domain finite-difference (FD) algorithm for simulating 3D elastic wave propagation in a heterogeneous orthorhombic medium. The components of the particle velocity vector and the stress tensor are governed by a set of nine, coupled, first-order, linear, partial differential equations (PDEs) called the velocity-stress system. All time and space derivatives are discretized with centered and staggered FD operators possessing second- and fourth-order numerical accuracy, respectively. Additionally, we have implemented novel perfectly matched layer (PML) absorbing boundary conditions, specifically designed for orthorhombic media, to effectively suppress grid boundary reflections. In support of the Source Physics Experiment (SPE) Phase II, a series of underground chemical explosions at the Nevada National Security Site, the code has been used to perform pre-test estimates of the Dry Alluvium Geology - Experiment 1 (DAG-1). Based on literature searches, realistic geologic structure and values for orthorhombic P-wave and S-wave speeds have been estimated. Results and predictions from the simulations are presented.

  18. Mineralogical and Geochemical Analysis of Howardite DaG 779: understanding geological evolution of asteroid (4) Vesta

    NASA Astrophysics Data System (ADS)

    Marcel Müller, Christian; Mengel, Kurt; Singh Thangjam, Guneshwar; Weckwerth, Gerd

    2016-04-01

    The HED meteorites, a clan of stony achondrites, are believed to originate from asteroid (4) Vesta (e.g. Mittlefehldt et al. (2015)). Recent evolution models (e.g. Toplis et al. (2013)) and observations from Dawn spacecraft data (e.g., Prettyman et al. (2013)) indicate that diogenites form the lower crust and uppermost mantle of (4) Vesta. Deep seated material excavated by large impacts such as the Rheasilvia- and Veneneiaforming event should be present in howardites. We analysed a slice of howardite DaG 779 which had been recovered from the Libyan Desert in 1999 and was briefly described by Grossmann (2000). The data presented here include electron microprobe, bulk-rock XRD and XRF as well as trace element analysis by ICP-MS and INA. The petrographic results confirm earlier observations that DaG 779 is polymict and mainly contains diogenite and eucrite clasts. Mass balance calculations using bulk-rock and microprobe major element data reveal a modal mineralogy of 77% orthopyroxene, 8% plagioclase, 7% clinopyroxene and 2% spinels, the rest being olivine, SiO2-phases, sulphides, and native Fe(Ni). When compared with the element compilation recently reported by Mittlefehldt (2015) the 39 trace element analysed here (including REE and PGE) confirm that this howardite is clearly dominated by diogenite. Beside the modal petrographic information, a number of more detailed observations obtained from microprobe investigations reveal fresh and recrystallized glasses, troilite-orthopyroxene symplectites from a mixed silicate-sulphide melt giving rise to graphic intergrowths as well as vermicular and reticular FeS in highly disrupted clasts. While the origin of the FeS in these clasts is not clear yet, its particular shape and distribution indicates that this mineral has been (partially) molten and recrystallized from a sulphide melt. The silicate minerals around these FeS occurrences are recrystallized but there is no indication for a partial silicate melt. Further

  19. Artist's concept of scene in Earth orbit during transposition and docking

    NASA Technical Reports Server (NTRS)

    1975-01-01

    An artist's concept depicting a scene in Earth orbit during the Apollo transposition and docking maneuvers of the Apollo Soyuz Test Project (ASTP) mission. The Command/Service Module is moving into position to dock with the Docking Module. This scene will take place some one hour and twenty-three minutes after the Apollo-Saturn 1B liftoff from the Kennedy Space Center on July 15, 1975. The artwork is by Paul Fjeld.

  20. A cladistically based reinterpretation of the taxonomy of two Afrotropical tenebrionid genera Ectateus Koch, 1956 and Selinus Mulsant & Rey, 1853 (Coleoptera, Tenebrionidae, Platynotina).

    PubMed

    Kamiński, Marcin Jan

    2014-01-01

    On the basis of a newly performed cladistic analysis a new classification of the representatives of two Afrotropical tenebrionid genera, Ectateus Koch, 1956 and Selinus Mulsant & Rey, 1853 sensu Iwan 2002a, is provided. Eleoselinus is described as a new genus. The genus Monodius, previously synonymized with Selinus by Iwan (2002), is redescribed and considered as a separate genus. Following new combinations are proposed: Ectateus calcaripes (Gebien, 1904), Monodius laevistriatus (Fairmaire, 1897), Monodius lamottei (Gridelli, 1954), Monodius plicicollis (Fairmaire, 1897), Eleoselinus villiersi (Ardoin, 1965) and Eleoselinus ursynowiensis (Kamiński, 2011). Neotype for Ectateus calcaripes and lectotypes for E. crenatus (Fairmaire, 1897), E. ghesquierei Koch, 1956 and Monodius malaisei malaisei Koch, 1956 are designated to fix the taxonomic status of these taxa. The following synonymies are proposed: Selinus monardi Kaszab, 1951 and Ectateus latipennis Koch, 1956 with E. crenatus (Fairmaire, 1897). Identification keys are provided to all known species of Ectateus sensu novum, Eleoselinus, Monodius and Selinus sensu novum.

  1. Systems Engineering Applications for Small Business Innovative Research (SBIR) Projects

    DTIC Science & Technology

    2012-09-01

    7 2. DAG Processes and Roles of the PM and SE................................................................8 3. DAG SE Processes...also defines the role of the Program Manager and Chief Engineer illustrated in figure 2 below. The DAG also separates the above 16 SE processes...into two areas shown in figure 3. Table 2: DAG Processes and Roles of the PM and SE (DAG Table 4.1.1T1, 2012) 9 Table 3: DAG SE Processes (DAG

  2. Reduced-order modeling approach for frictional stick-slip behaviors of joint interface

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Xu, Chao; Fan, Xuanhua; Wan, Qiang

    2018-03-01

    The complex frictional stick-slip behaviors of mechanical joint interface have a great effect on the dynamic properties of assembled structures. In this paper, a reduced-order modeling approach based on the constitutive Iwan model is proposed to describe the stick-slip behaviors of joint interface. An improved Iwan model is developed to describe the non-zero residual stiffness at macro-slip regime and smooth transition of joint stiffness from micro-slip to macro-slip regime, and the power-law relationship of energy dissipation during the micro-slip regime. In allusion to these nonlinear behaviors, the finite element method is used to calculate the recycle force under monolithic loading and the energy dissipation per cycle under oscillatory loading. The proposed model is then used to predict the nonlinear stick-slip behaviors of joint interface by curve-fitting to the results of finite element analysis, and the results show good agreements with the finite element analysis. A comparison with the experiment results in literature is also made. The proposed model agrees very well with the experiment results.

  3. The Significance of Different Diacylgycerol Synthesis Pathways on Plant Oil Composition and Bioengineering

    PubMed Central

    Bates, Philip D.; Browse, John

    2012-01-01

    The unique properties of vegetable oils from different plants utilized for food, industrial feedstocks, and fuel is dependent on the fatty acid (FA) composition of triacylglycerol (TAG). Plants can use two main pathways to produce diacylglycerol (DAG), the immediate precursor molecule to TAG synthesis: (1) De novo DAG synthesis, and (2) conversion of the membrane lipid phosphatidylcholine (PC) to DAG. The FA esterified to PC are also the substrate for FA modification (e.g., desaturation, hydroxylation, etc.), such that the FA composition of PC-derived DAG can be substantially different than that of de novo DAG. Since DAG provides two of the three FA in TAG, the relative flux of TAG synthesis from de novo DAG or PC-derived DAG can greatly affect the final oil FA composition. Here we review how the fluxes through these two alternate pathways of DAG/TAG synthesis are determined and present evidence that suggests which pathway is utilized in different plants. Additionally, we present examples of how the endogenous DAG synthesis pathway in a transgenic host plant can produce bottlenecks for engineering of plant oil FA composition, and discuss alternative strategies to overcome these bottlenecks to produce crop plants with designer vegetable oil compositions. PMID:22783267

  4. Nutritionally enriched 1,3-diacylglycerol-rich oil: Low calorie fat with hypolipidemic effects in rats.

    PubMed

    Prabhavathi Devi, B L A; Gangadhar, K N; Prasad, R B N; Sugasini, D; Rao, Y Poorna Chandra; Lokesh, B R

    2018-05-15

    An enzymatic process was developed for the preparation of a nutritionally enriched 1,3-diacylglycerol(DAG)-rich oil from a blend of refined sunflower and rice bran oils. The process involves hydrolysis of vegetable oil blend using Candida cylindracea followed by esterification with glycerol using Lipozyme RM1M. The resultant DAG-rich oil contains 84% of DAG (66% of 1,3-DAG, 18% of 1,2-DAG) and 16% of triacylglycerol (TAG) along with micro nutrients like γ-oryzanol, tocotrienols, tocopherols and phytosterols. Nutritional studies of the DAG-rich oil were conducted in Wistar rats and compared with sunflower oil (SFO). The calorific value of the DAG-rich oil was estimated to be 6.45 Kcals/g as against 9.25 Kcals/g for SFO. The serum and liver cholesterol and TAG levels in rats fed with 1,3-DAG-rich oil were found to be significantly reduced as compared to rats fed diet containing SFO. We conclude that 1,3-DAG-rich oil is a low calorie fat and exhibits hypolipidemic effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Morphological differentiation of N1E-115 neuroblastoma cells by dimethyl sulfoxide activation of lipid second messengers.

    PubMed

    Clejan, S; Dotson, R S; Wolf, E W; Corb, M P; Ide, C F

    1996-04-10

    Quantitative changes in the lipid second messenger diacylglycerol (DAG) were studied in the rat neuroblastoma N1E-115 following exposure to the differentiating agent dimethylsulfoxide (DMSO). Relatively high basal levels of DAG are present in these cells, and addition of 2% DMSO elicited a biphasic increase in DAG levels, dependent on the presence of extracellular Ca2+. Exposure to DMSO also elicited a rapid increase in inositol phosphate and a slight increase in phosphatidic acid (PA), trailing that of DAG. The molecular species (MS) of DAG were analyzed. Within 60 s of DMSO application there were transient increases of DAG representative of phosphatidylinositol (PI) hydrolysis. At longer intervals, more DAG originated from phosphatidylcholine. The MS composition of newly formed PA resembled that of PI and native DAG. Inhibition studies indicated that DAG is formed in the DMSO-treated cells by phospholipases C and that PA formed later is a result of DAG phosphorylation and not activity of phospholipase D (PLD). Undifferentiated cells exhibited an active PLD pathway. In contrast, PLD in DMSO-differentiated cells was not active. In examining the involvement of the sphingomyelin pathway, DMSO exposure was found to increase ceramide levels with a concomitant decrease in sphingomyelin. Addition of the exogenous, soluble analog C6-ceramide to undifferentiated cells resulted in dramatic reductions in DAG and PA levels and PLD activity. These results indicate that DMSO treatment inactivates PLD while activating phospholipases C and the sphingomyelin pathway, suggesting a "switch" between signal transduction pathways in the undifferentiated and differentiated states of N1E-115.

  6. Airborne Conflict Management within Confined Airspace in a Piloted Simulation of DAG-TM Autonomous Aircraft Operations

    NASA Technical Reports Server (NTRS)

    Barmore, Bryan; Johnson, Edward; Wing, David J.; Barhydt, Richard

    2003-01-01

    A human-in-the-loop experiment was performed at the NASA Langley Research Center to study the feasibility of Distributed Air/Ground Traffic Management (DAG-TM) autonomous aircraft operations in highly constrained airspace. The airspace was constrained by a pair of special use airspace (SUA) regions on either side of the pilot s planned route. The available airspace was further varied by changing the separation standard for lateral separation between 3 nm and 5 nm. The pilot had to maneuver through the corridor between the SUA s, avoid other traffic and meet flow management constraints. Traffic flow management (TFM) constraints were imposed as a required time of arrival and crossing altitude at an en route fix. This is a follow-up study to work presented at the 4th USA/Europe Air Traffic Management R&D Seminar in December 2001. Nearly all of the pilots were able to meet their TFM constraints while maintaining adequate separation from other traffic. In only 3 out of 59 runs were the pilots unable to meet their required time of arrival. Two loss of separation cases are studied and it is found that the pilots need conflict prevention information presented in a clearer manner. No degradation of performance or safety was seen between the wide and narrow corridors. Although this was not a thorough study of the consequences of reducing the en route lateral separation, nothing was found that would refute the feasibility of reducing the separation requirement from 5 nm to 3 nm. The creation of additional, second-generation conflicts is also investigated. Two resolution methods were offered to the pilots: strategic and tactical. The strategic method is a closed-loop alteration to the Flight Management System (FMS) active route that considers other traffic as well as TFM constraints. The tactical resolutions are short-term resolutions that leave avoiding other traffic conflicts and meeting the TFM constraints to the pilot. Those that made use of the strategic tools avoided

  7. A 90-day repeated-dose toxicity study of dietary alpha linolenic acid-enriched diacylglycerol oil in rats.

    PubMed

    Bushita, Hiroto; Ito, Yuichi; Saito, Tetsuji; Nukada, Yuko; Ikeda, Naohiro; Nakagiri, Hideaki; Saito, Kazutoshi; Morita, Osamu

    2018-05-31

    Diets supplemented with alpha-linolenic acid (ALA)-enriched diacylglycerol (DAG) oil-which mainly consists of oleic and linolenic, linoleic acids-have potential health benefits in terms of preventing or managing obesity. Although safety of DAG oil has been extensively investigated, toxicity of ALA-DAG oil has not been well understood. Hence, the present study was conducted to clarify the potential adverse effects, if any, of ALA-DAG oil in rats (10/sex/group) fed diets containing 1.375%, 2.75%, or 5.5% ALA-DAG oil for 90 days. Compared to control rats fed rapeseed oil or ALA-triacylglycerol oil (flaxseed oil), rats receiving ALA-DAG oil did not reveal any toxicologically significant treatment-related changes as evaluated by clinical signs, functional observational battery, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, organ weight, necropsy and histopathology. The no observed adverse effect levels for dietary exposure to ALA-DAG oil for male and female rats were 2916 and 3326 mg/kg body weight/day, respectively, the highest dose tested. The findings from this study suggest that consumption of ALA-DAG oil is unlikely to cause adverse effects. Copyright © 2018. Published by Elsevier Inc.

  8. Ultrastructural localization of the C-terminus of the 43-kd dystrophin-associated glycoprotein and its relation to dystrophin in normal murine skeletal myofiber.

    PubMed Central

    Wakayama, Y.; Shibuya, S.; Takeda, A.; Jimi, T.; Nakamura, Y.; Oniki, H.

    1995-01-01

    We used single and double immunogold labeling electron microscopy to investigate ultrastructural localization of the C terminus of the 43-kd dystrophin-associated glycoprotein (43-DAG) and its relationship to dystrophin in normal murine skeletal myofibers. Single immunolabeling localized the antibody against the C terminus of 43-DAG to the inside surface of the muscle plasma membrane and the sarcoplasmic side of plasma membrane invaginations. Double immunolabeling co-localized antibodies against dystrophin and the C terminus of 43-DAG to the same site noted in the single immunolabeling localization of 43-DAG. In particular, dystrophin and the C-terminal 43-DAG antibody signals were often observed as doublets separated by less than 30 nm. We compared these results with those obtained from double immunogold labeling with anti-dystrophin and anti-beta-spectrin, as well as anti-C-terminal 43-DAG and anti-beta-spectrin antibodies. The antibodies against dystrophin and beta-spectrin, or beta-spectrin and 43-DAG, also co-localized to similar sites in skeletal muscle fibers. Signals of doublet formations were noted but their frequency was significantly lower than the doublet frequency of antidystrophin and anti-43-DAG antibodies. The results support the presence of dystrophin and 43-DAG linkage at the inside surface of the murine skeletal muscle plasma membrane. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:7856727

  9. Both acyl and des-acyl ghrelin regulate adiposity and glucose metabolism via central nervous system ghrelin receptors.

    PubMed

    Heppner, Kristy M; Piechowski, Carolin L; Müller, Anne; Ottaway, Nickki; Sisley, Stephanie; Smiley, David L; Habegger, Kirk M; Pfluger, Paul T; Dimarchi, Richard; Biebermann, Heike; Tschöp, Matthias H; Sandoval, Darleen A; Perez-Tilve, Diego

    2014-01-01

    Growth hormone secretagogue receptors (GHSRs) in the central nervous system (CNS) mediate hyperphagia and adiposity induced by acyl ghrelin (AG). Evidence suggests that des-AG (dAG) has biological activity through GHSR-independent mechanisms. We combined in vitro and in vivo approaches to test possible GHSR-mediated biological activity of dAG. Both AG (100 nmol/L) and dAG (100 nmol/L) significantly increased inositol triphosphate formation in human embryonic kidney-293 cells transfected with human GHSR. As expected, intracerebroventricular infusion of AG in mice increased fat mass (FM), in comparison with the saline-infused controls. Intracerebroventricular dAG also increased FM at the highest dose tested (5 nmol/day). Chronic intracerebroventricular infusion of AG or dAG increased glucose-stimulated insulin secretion (GSIS). Subcutaneously infused AG regulated FM and GSIS in comparison with saline-infused control mice, whereas dAG failed to regulate these parameters even with doses that were efficacious when delivered intracerebroventricularly. Furthermore, intracerebroventricular dAG failed to regulate FM and induce hyperinsulinemia in GHSR-deficient (Ghsr(-/-)) mice. In addition, a hyperinsulinemic-euglycemic clamp suggests that intracerebroventricular dAG impairs glucose clearance without affecting endogenous glucose production. Together, these data demonstrate that dAG is an agonist of GHSR and regulates body adiposity and peripheral glucose metabolism through a CNS GHSR-dependent mechanism.

  10. Does des-acyl ghrelin improve glycemic control in obese diabetic subjects by decreasing acylated ghrelin levels?

    PubMed

    Özcan, Behiye; Neggers, Sebastian J C M M; Miller, Anne Reifel; Yang, Hsiu-Chiung; Lucaites, Virginia; Abribat, Thierry; Allas, Soraya; Huisman, Martin; Visser, Jenny A; Themmen, Axel P N; Sijbrands, Eric J G; Delhanty, Patric J D; van der Lely, Aart Jan

    2014-06-01

    The objective of this study was to assess the effects of a continuous overnight infusion of des-acyl ghrelin (DAG) on acylated ghrelin (AG) levels and glucose and insulin responses to a standard breakfast meal (SBM) in eight overweight patients with type 2 diabetes. Furthermore, in the same patients and two additional subjects, the effects of DAG infusion on AG concentrations and insulin sensitivity during a hyperinsulinemic-euglycemic clamp (HEC) were assessed. A double-blind, placebo-controlled cross-over study design was implemented, using overnight continuous infusions of 3 and 10  μg DAG/kg per h and placebo to study the effects on a SBM. During a HEC, we studied the insulin sensitivity. We observed that, compared with placebo, overnight DAG administration significantly decreased postprandial glucose levels, both during continuous glucose monitoring and at peak serum glucose levels. The degree of improvement in glycemia was correlated with baseline plasma AG concentrations. Concurrently, DAG infusion significantly decreased fasting and postprandial AG levels. During the HEC, 2.5  h of DAG infusion markedly decreased AG levels, and the M-index, a measure of insulin sensitivity, was significantly improved in the six subjects in whom we were able to attain steady-state euglycemia. DAG administration was not accompanied by many side effects when compared with placebo. DAG administration improves glycemic control in obese subjects with type 2 diabetes through the suppression of AG levels. DAG is a good candidate for the development of compounds in the treatment of metabolic disorders or other conditions with a disturbed AG:DAG ratio, such as type 2 diabetes mellitus or Prader-Willi syndrome. © 2014 European Society of Endocrinology.

  11. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Edwards, Harold C.; Ibanez, Daniel Alejandro

    This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Taskmore » DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.« less

  12. Viscosity and compressibility of diacylglycerol under high pressure

    NASA Astrophysics Data System (ADS)

    Malanowski, Aleksander; Rostocki, A. J.; Kiełczyński, P.; Szalewski, M.; Balcerzak, A.; Kościesza, R.; Tarakowski, R.; Ptasznik, S.; Siegoczyński, R. M.

    2013-03-01

    The influence of high pressure on viscosity and compressibility of diacylglycerol (DAG) oil has been presented in this paper. The investigated DAG oil was composed of 82% of DAGs and 18% TAGs (triacylglycerols). The dynamic viscosity of DAG was investigated as a function of the pressure up to 400 MPa. The viscosity was measured by means of the surface acoustic wave method, where the acoustic waveguides were used as sensing elements. As the pressure was rising, the larger ultrasonic wave attenuation was observed, whereas amplitude decreased with the liquid viscosity augmentation. Measured changes of physical properties were most significant in the pressure range near the phase transition. Deeper understanding of DAG viscosity and compressibility changes versus pressure could shed more light on thermodynamic properties of edible oils.

  13. Gender-Specific Association of Desacylated Ghrelin with Subclinical Atherosclerosis in the Metabolic Syndrome.

    PubMed

    Zanetti, Michela; Gortan Cappellari, Gianluca; Semolic, Annamaria; Burekovic, Ismet; Fonda, Maurizio; Cattin, Luigi; Barazzoni, Rocco

    2017-07-01

    Ghrelin, a gastric hormone with pleiotropic effects modulates vascular function and may influence atherosclerosis. Plasma ghrelin is reduced in the metabolic syndrome (MS), which is also characterized by early atherosclerosis. Ghrelin circulates in acylated (AG) and desacylated (DAG) forms. Their relative impact and that of gender on subclinical atherosclerosis in MS is unknown. To investigate potential associations of total, AG and DAG with carotid atherosclerosis and with gender in the MS. Plasma total ghrelin, AG, DAG and carotid artery IMT (cIMT) were measured in 46 MS patients (NCEP-ATP III criteria, 22M/24F). Compared with males, females had higher (p <0.05) total and DAG. In the association analysis, age and plasma glucose were positively (p <0.05) correlated with cIMT in all MS patients. The positive (p <0.05) association between cIMT and age was also confirmed in males, while that between cIMT and glucose was significant in women. In contrast, neither total ghrelin nor AG and DAG were associated with cIMT in all MS patients nor in the male subgroup. In females, a negative (p <0.05) association between carotid artery IMT, DAG and glucose was detected, but not between cIMT, total ghrelin and AG. In multivariate modeling, DAG remained negatively (p <0.05) associated with cIMT after adjusting for plasma glucose and cardiovascular risk factors. These data indicate a negative independent association between DAG and cIMT in middle-aged women with the MS and suggest a gender-specific modulatory function of DAG in the development of atherosclerosis. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  14. Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol

    DOE PAGES

    Yang, Wenyu; Wang, Geliang; Li, Jia; ...

    2017-03-21

    Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG), successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be limited by flux through the enzymatic reactions that supply DAG. In this study, two Arabidopsis phospholipase Dζ genes (AtPLDζ 1 and AtPLDζ 2) were coexpressed in Camelina sativa to test whether the conversion of phosphatidylcholine to DAG impacts TAG levels in seeds. The resulting transgenic plants produced 2% to 3% more TAG as amore » component of total seed biomass and had increased 18:3 and 20:1 fatty acid levels relative to wild type. Increased DAG and decreased PC levels were examined through the kinetics of lipid assembly by [ 14C]acetate and [ 14C]glycerol incorporation into glycerolipids. [ 14C]acetate was rapidly incorporated into TAG in both wild-type and overexpression lines, indicating a significant flux of nascent and elongated acyl-CoAs into the sn-3 position of TAG. Stereochemical analysis revealed that newly synthesized fatty acids were preferentially incorporated into the sn-2 position of PC, but the sn-1 position of de novo DAG and indicated similar rates of nascent acyl groups into the Kennedy pathway and acyl editing. [ 14C]glycerol studies demonstrated PC-derived DAG is the major source of DAG for TAG synthesis in both tissues. The results emphasize that the interconversions of DAG and PC pools can impact oil production and composition.« less

  15. Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Wenyu; Wang, Geliang; Li, Jia

    Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG), successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be limited by flux through the enzymatic reactions that supply DAG. In this study, two Arabidopsis phospholipase Dζ genes (AtPLDζ 1 and AtPLDζ 2) were coexpressed in Camelina sativa to test whether the conversion of phosphatidylcholine to DAG impacts TAG levels in seeds. The resulting transgenic plants produced 2% to 3% more TAG as amore » component of total seed biomass and had increased 18:3 and 20:1 fatty acid levels relative to wild type. Increased DAG and decreased PC levels were examined through the kinetics of lipid assembly by [ 14C]acetate and [ 14C]glycerol incorporation into glycerolipids. [ 14C]acetate was rapidly incorporated into TAG in both wild-type and overexpression lines, indicating a significant flux of nascent and elongated acyl-CoAs into the sn-3 position of TAG. Stereochemical analysis revealed that newly synthesized fatty acids were preferentially incorporated into the sn-2 position of PC, but the sn-1 position of de novo DAG and indicated similar rates of nascent acyl groups into the Kennedy pathway and acyl editing. [ 14C]glycerol studies demonstrated PC-derived DAG is the major source of DAG for TAG synthesis in both tissues. The results emphasize that the interconversions of DAG and PC pools can impact oil production and composition.« less

  16. Identification of a Common R-Chondrite Impactor on the Ureilite Parent Body

    NASA Technical Reports Server (NTRS)

    Downes, H.; Mittlefehldt, D. W.

    2006-01-01

    Polymict ureilites are brecciated ultramafic meteorites that contain a variety of single mineral and lithic clasts. They represent the surface debris from a small, differentiated asteroid. We are continuing a detailed petrological study of several polymict ureilites including EET 87720, EET 83309 and FRO93008 (from Antarctica), North Haig, Nilpena (Australia), DaG 976, DaG 999, DaG 1000 and DaG 1023 (Libya). The latter four stones are probably paired. Clast sizes can be 10 mm in diameter, so a thin-section can consist of a single lithic clast.

  17. Characterization of acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) enzyme of human small intestine.

    PubMed

    Hiramine, Yasushi; Tanabe, Toshizumi

    2011-06-01

    Acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) enzyme plays a significant role in dietary triacylglycerol (TAG) absorption in the small intestine. However, the characteristics of human intestinal DGAT enzyme have not been examined in detail. The aim of our study was to characterize the human intestinal DGAT enzyme by examining acyl-CoA specificity, temperature dependency, and selectivity for 1,2-diacylglycerol (DAG) or 1,3-DAG. We detected DGAT activity of human intestinal microsome and found that the acyl-CoA specificity and temperature dependency of intestinal DGAT coincided with those of recombinant human DGAT1. To elucidate the selectivity of human intestinal DGAT to 1,2-DAG or 1,3-DAG, we conducted acyl-coenzyme A:monoacylglycerol acyltransferase assays using 1- or 2-monoacylglycerol (MAG) as substrates. When 2-MAG was used as acyl acceptor, both 1,2-DAG and TAG were generated; however, when 1-MAG was used, 1,3-DAG was predominantly observed and little TAG was detected. These findings suggest that human small intestinal DGAT, which is mainly encoded by DGAT1, utilizes 1,2-DAG as the substrate to form TAG. This study will contribute to understand the lipid absorption profile in the small intestine.

  18. Label-free measurement of the yeast short chain TAG lipase activity by ESI-MS after one-step esterification.

    PubMed

    Ham, Hye Jin; Seo, Jongcheol; Yoon, Hye-Joo; Shin, Seung Koo

    2017-03-01

    Triacylglycerol (TAG) lipases hydrolyze ester bonds in TAG and release diacylglycerol (DAG), monoacylglycerol (MAG), and FA. We present a one-step chemical derivatization method for label-free quantification of a mixture of TAG, DAG, and MAG following lipase assay by ESI-MS. Because the ionization efficiencies of TAG, DAG, and MAG are not identical, lipase reaction products, DAG and MAG, are derivatized to TAG species by esterifying their hydroxyl groups using acyl chloride, whose acyl chain contains one less (or one more) -CH 2 group than that of substrate TAG. This resulted in three TAG species that were separated by 14 Da from one another and exhibited similar ion responses representing their molar amounts in the mass spectra. A good linear correlation was observed between peak intensity ratios and molar ratios in calibration curve. This method enables simultaneous quantification of TAG, DAG, and MAG in lipase assay and, in turn, allows stoichiometric determination of the concentrations of FAs released from TAG and DAG separately. By applying this strategy to measure both TAG and DAG lipolytic activities of the yeast Tgl2 lipase, we demonstrated its usefulness in studying enzymatic catalysis, as lipase enzymes often show dissimilar activities toward these lipids. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  19. The role of PIP2 and the IP3/DAG pathway in intracellular calcium release and cell survival during nanosecond electric pulse exposures

    NASA Astrophysics Data System (ADS)

    Steelman, Zachary A.; Tolstykh, Gleb P.; Estlack, Larry E.; Roth, Caleb C.; Ibey, Bennett L.

    2015-03-01

    Phosphatidylinositol4,5-biphosphate (PIP2) is a membrane phospholipid of particular importance in cell-signaling pathways. Hydrolysis of PIP2 releases inositol-1,4,5-triphosphate (IP3) from the membrane, activating IP3 receptors on the smooth endoplasmic reticulum (ER) and facilitating a release of intracellular calcium stores and activation of protein kinase C (PKC). Recent studies suggest that nanosecond pulsed electric fields (nsPEF) cause depletion of PIP2 in the cellular membrane, activating the IP3 signaling pathway. However, the exact mechanism(s) causing this observed depletion of PIP2 are unknown. Complicating the matter, nsPEF create nanopores in the plasma membrane, allowing calcium to enter the cell and thus causing an increase in intracellular calcium. While elevated intracellular calcium can cause activation of phospholipase C (PLC) (a known catalyst of PIP2 hydrolysis), PIP2 depletion has been shown to occur in the absence of both extracellular and intracellular calcium. These observations have led to the hypothesis that the high electric field itself may be playing a direct role in the hydrolysis of PIP2 from the plasma membrane. To support this hypothesis, we used edelfosine to block PLC and prevent activation of the IP3/DAG pathway in Chinese Hamster Ovarian (CHO) cells prior to applying nsPEF. Fluorescence microscopy was used to monitor intracellular calcium bursts during nsPEF, while MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) survivability assays were utilized to determine whether edelfosine improved cell survival during nsPEF exposure. This work is critical to refine the role of PIP2 in the cellular response to nsPEF, and also to determine the fundamental biological effects of high electric field exposures.

  20. Effect of Chimaerins, Novel Receptors for Phorbol Esters, on Breast Cancer Cell Proliferation and Cell Cycle Progression

    DTIC Science & Technology

    2006-07-01

    that is responsible for the phosphorylation of DAG to generate phosphatidic acid . DGKs might be key molecules in a negative feedback aimed at turning off...C2 Neurotransmitter release KinaseT PH PKCs EF DAG Phosphatidic acid EF C1 KinaseC2 C1 C1 KinaseC2C1 C1 C1 C1 C1 C1 C1 C1 C1 Rac–GTP Rac–GDP Protein...generate phosphatidic acid , and thus it decreases DAG levels. It is possible that DAG-regulated DGKs might serve as negative feedback molecules that turn

  1. Mechanisms whereby insulin increases diacylglycerol in BC3H-1 myocytes.

    PubMed Central

    Farese, R V; Cooper, D R; Konda, T S; Nair, G; Standaert, M L; Davis, J S; Pollet, R J

    1988-01-01

    We previously suggested that insulin increases diacylglycerol (DAG) in BC3H-1 myocytes, both by increases in synthesis de novo of phosphatidic acid (PA) and by hydrolysis of non-inositol-containing phospholipids, such as phosphatidylcholine (PC) and phosphatidylethanolamine (PE). We have now evaluated these insulin effects more thoroughly, and several potential mechanisms for their induction. In studies of the effect on PA synthesis de novo, insulin stimulated [2-3H]glycerol incorporation into PA, DAG, PC/PE and total glycerolipids of BC3H-1 myocytes, regardless of whether insulin was added simultaneously with, or after 2 h or 3 or 10 days of prelabelling with, [2-3H]glycerol. In prelabelled cells, time-related changes in [2-3H]glycerol labelling of DAG correlated well with increases in DAG content: both were maximal in 30-60 s and persisted for 20-30 min. [2-3H]Glycerol labelling of glycerol 3-phosphate, on the other hand, was decreased by insulin, presumably reflecting increased utilization for PA synthesis. Glycerol 3-phosphate concentrations were 0.36 and 0.38 mM before and 1 min after insulin treatment, and insulin effects could not be explained by increases in glycerol 3-phosphate specific radioactivity. In addition to that of [2-3H]glycerol, insulin increased [U-14C]glucose and [1,2,3-3H]glycerol incorporation into DAG and other glycerolipids. Effects of insulin on [2-3H]glycerol incorporation into DAG and other glycerolipids were half-maximal and maximal at 2 nM- and 20 nM-insulin respectively, and were not dependent on glucose concentration in the medium, extracellular Ca2+ or protein synthesis. Despite good correlation between [3H]DAG and DAG content, calculated increases in DAG content from glycerol 3-phosphate specific radioactivity (i.e. via the pathway of PA synthesis de novo) could account for only 15-30% of the observed increases in DAG content. In addition to increases in [3H]glycerol labelling of PC/PE, insulin rapidly (within 30 s) increased PC

  2. Alpha-linolenic acid-enriched diacylglycerol oil does not promote tumor development in tongue and gastrointestinal tract tissues in a medium-term multi-organ carcinogenesis bioassay using male F344 rat.

    PubMed

    Honda, Hiroshi; Kawamoto, Taisuke; Doi, Yuko; Matsumura, Shoji; Ito, Yuichi; Imai, Norio; Ikeda, Naohiro; Mera, Yukinori; Morita, Osamu

    2017-08-01

    Alpha-linolenic acid (ALA)-enriched diacylglycerol (DAG) oil is an edible oil enriched with DAG (>80%) and ALA (>50%). The present study investigated whether ALA-DAG oil promotes tumorigenesis in the tongue and gastrointestinal tract, using a rat medium-term multi-organ carcinogenesis bioassay model. Rats were treated with five genotoxic carcinogens to induce multi-organ tumorigenesis until week 4, and from 1 week after withdrawal, fed a semi-synthetic diet (AIN-93G) containing ALA-DAG oil at concentrations of 0, 13,750, 27,500, and 55,000 ppm. Rats fed AIN-93G containing 55,000 ppm ALA-triacylglycerol or a standard basal diet served as reference and negative control groups, respectively. Animals were euthanized at week 30. ALA-DAG oil was shown to have no effects on survival, general condition, body weight, food consumption, or organ weight. More discolored spots were observed in the stomachs of the 13,750- and 55,000-ppm ALA-DAG groups than in those of the control groups; however, there were no differences in the frequency of histopathological findings across groups. There were no meaningful increases in the incidence of pre-neoplastic and neoplastic lesions in the tongue and gastrointestinal tract among the groups. We therefore conclude that ALA-DAG oil does not promote tumor development in the digestive system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Tracking Diacylglycerol and Phosphatidic Acid Pools in Budding Yeast

    PubMed Central

    Ganesan, Suriakarthiga; Shabits, Brittney N.; Zaremberg, Vanina

    2015-01-01

    Phosphatidic acid (PA) and diacylglycerol (DAG) are key signaling molecules and important precursors for the biosynthesis of all glycerolipids found in eukaryotes. Research conducted in the model organism Saccharomyces cerevisiae has been at the forefront of the identification of the enzymes involved in the metabolism and transport of PA and DAG. Both these lipids can alter the local physical properties of membranes by introducing negative curvature, but the anionic nature of the phosphomonoester headgroup in PA sets it apart from DAG. As a result, the mechanisms underlying PA and DAG interaction with other lipids and proteins are notoriously different. This is apparent from the analysis of the protein domains responsible for recognition and binding to each of these lipids. We review the current evidence obtained using the PA-binding proteins and domains fused to fluorescent proteins for in vivo tracking of PA pools in yeast. In addition, we present original results for visualization of DAG pools in yeast using the C1 domain from mammalian PKCδ. An emerging first cellular map of the distribution of PA and DAG pools in actively growing yeast is discussed. PMID:27081314

  4. Safety assessment of dietary diacylglycerol oil: a two-generation reproductive toxicity study in rats.

    PubMed

    Morita, Osamu; Knapp, John F; Tamaki, Yasushi; Nemec, Mark D; Varsho, Bennett J; Stump, Donald G

    2008-09-01

    Diacylglycerol (DAG) oil is a novel edible oil with similar taste and usability characteristics as conventional edible oils. Recent studies suggest that DAG oil may be helpful in the prevention and management of obesity. The objective of the present two-generation study was to evaluate potential adverse effects of DAG oil on reproductive processes. DAG oil was administered via gavage to rats (30/sex/group) for at least 70 days prior to mating, at dose levels of 0, 1.25, 2.5 or 5.0 ml/kg/day (0, 1160, 2320 and 4630 mg/kg/day). An additional group received a triacylglycerol (TAG) oil with a similar fatty acid composition to DAG oil. The rats were treated throughout the mating, gestation and lactation periods. Administration of DAG or TAG oil did not reveal any toxicologically significant effects on reproductive performance (mating, fertility and copulation/conception indices). DAG oil did not affect mean gestation lengths, the process of parturition, spermatogenic parameters, organ weights, histopathologic findings, mean numbers of pups born, implantation sites and unaccounted sites. F1 and F2 pup viability, live litter sizes, body weights, mean age of attainment of balanopreputial separation and vaginal patency were similar to those in the control group. Based on the results of this study, a dose level of 5.0 ml/kg (4630 mg/kg/day) was considered as the no-observed-adverse-effect level for reproductive and systemic toxicity, and neonatal toxicity.

  5. Channeling of eukaryotic diacylglycerol into the biosynthesis of plastidial phosphatidylglycerol.

    PubMed

    Fritz, Markus; Lokstein, Heiko; Hackenberg, Dieter; Welti, Ruth; Roth, Mary; Zähringer, Ulrich; Fulda, Martin; Hellmeyer, Wiebke; Ott, Claudia; Wolter, Frank P; Heinz, Ernst

    2007-02-16

    Plastidial glycolipids contain diacylglycerol (DAG) moieties, which are either synthesized in the plastids (prokaryotic lipids) or originate in the extraplastidial compartment (eukaryotic lipids) necessitating their transfer into plastids. In contrast, the only phospholipid in plastids, phosphatidylglycerol (PG), contains exclusively prokaryotic DAG backbones. PG contributes in several ways to the functions of chloroplasts, but it is not known to what extent its prokaryotic nature is required to fulfill these tasks. As a first step toward answering this question, we produced transgenic tobacco plants that contain eukaryotic PG in thylakoids. This was achieved by targeting a bacterial DAG kinase into chloroplasts in which the heterologous enzyme was also incorporated into the envelope fraction. From lipid analysis we conclude that the DAG kinase phosphorylated eukaryotic DAG forming phosphatidic acid, which was converted into PG. This resulted in PG with 2-3 times more eukaryotic than prokaryotic DAG backbones. In the newly formed PG the unique Delta3-trans-double bond, normally confined to 3-trans-hexadecenoic acid, was also found in sn-2-bound cis-unsaturated C18 fatty acids. In addition, a lipidomics technique allowed the characterization of phosphatidic acid, which is assumed to be derived from eukaryotic DAG precursors in the chloroplasts of the transgenic plants. The differences in lipid composition had only minor effects on measured functions of the photosynthetic apparatus, whereas the most obvious phenotype was a significant reduction in growth.

  6. Studies on the substrate and stereo/regioselectivity of adipose triglyceride lipase, hormone-sensitive lipase, and diacylglycerol-O-acyltransferases.

    PubMed

    Eichmann, Thomas O; Kumari, Manju; Haas, Joel T; Farese, Robert V; Zimmermann, Robert; Lass, Achim; Zechner, Rudolf

    2012-11-30

    Adipose triglyceride lipase (ATGL) is rate-limiting for the initial step of triacylglycerol (TAG) hydrolysis, generating diacylglycerol (DAG) and fatty acids. DAG exists in three stereochemical isoforms. Here we show that ATGL exhibits a strong preference for the hydrolysis of long-chain fatty acid esters at the sn-2 position of the glycerol backbone. The selectivity of ATGL broadens to the sn-1 position upon stimulation of the enzyme by its co-activator CGI-58. sn-1,3 DAG is the preferred substrate for the consecutive hydrolysis by hormone-sensitive lipase. Interestingly, diacylglycerol-O-acyltransferase 2, present at the endoplasmic reticulum and on lipid droplets, preferentially esterifies sn-1,3 DAG. This suggests that ATGL and diacylglycerol-O-acyltransferase 2 act coordinately in the hydrolysis/re-esterification cycle of TAGs on lipid droplets. Because ATGL preferentially generates sn-1,3 and sn-2,3, it suggests that TAG-derived DAG cannot directly enter phospholipid synthesis or activate protein kinase C without prior isomerization.

  7. Skeletal Muscle Triglycerides, Diacylglycerols, and Ceramides in Insulin Resistance

    PubMed Central

    Amati, Francesca; Dubé, John J.; Alvarez-Carnero, Elvis; Edreira, Martin M.; Chomentowski, Peter; Coen, Paul M.; Switzer, Galen E.; Bickel, Perry E.; Stefanovic-Racic, Maja; Toledo, Frederico G.S.; Goodpaster, Bret H.

    2011-01-01

    OBJECTIVE Chronic exercise and obesity both increase intramyocellular triglycerides (IMTGs) despite having opposing effects on insulin sensitivity. We hypothesized that chronically exercise-trained muscle would be characterized by lower skeletal muscle diacylglycerols (DAGs) and ceramides despite higher IMTGs and would account for its higher insulin sensitivity. We also hypothesized that the expression of key skeletal muscle proteins involved in lipid droplet hydrolysis, DAG formation, and fatty-acid partitioning and oxidation would be associated with the lipotoxic phenotype. RESEARCH DESIGN AND METHODS A total of 14 normal-weight, endurance-trained athletes (NWA group) and 7 normal-weight sedentary (NWS group) and 21 obese sedentary (OBS group) volunteers were studied. Insulin sensitivity was assessed by glucose clamps. IMTGs, DAGs, ceramides, and protein expression were measured in muscle biopsies. RESULTS DAG content in the NWA group was approximately twofold higher than in the OBS group and ~50% higher than in the NWS group, corresponding to higher insulin sensitivity. While certain DAG moieties clearly were associated with better insulin sensitivity, other species were not. Ceramide content was higher in insulin-resistant obese muscle. The expression of OXPAT/perilipin-5, adipose triglyceride lipase, and stearoyl-CoA desaturase protein was higher in the NWA group, corresponding to a higher mitochondrial content, proportion of type 1 myocytes, IMTGs, DAGs, and insulin sensitivity. CONCLUSIONS Total myocellular DAGs were markedly higher in highly trained athletes, corresponding with higher insulin sensitivity, and suggest a more complex role for DAGs in insulin action. Our data also provide additional evidence in humans linking ceramides to insulin resistance. Finally, this study provides novel evidence supporting a role for specific skeletal muscle proteins involved in intramyocellular lipids, mitochondrial oxidative capacity, and insulin resistance. PMID

  8. Effect of Acylglycerol Composition and Fatty Acyl Chain Length on Lipid Digestion in pH-Stat Digestion Model and Simulated In Vitro Digestion Model.

    PubMed

    Qi, Jin F; Jia, Cai H; Shin, Jung A; Woo, Jeong M; Wang, Xiang Y; Park, Jong T; Hong, Soon T; Lee, K-T

    2016-02-01

    In this study, a pH-stat digestion model and a simulated in vitro digestion model were employed to evaluate the digestion degree of lipids depending on different acylglycerols and acyl chain length (that is, diacylglycerol [DAG] compared with soybean oil representing long-chain triacylglycerol compared with medium-chain triacylglycerol [MCT]). In the pH-stat digestion model, differences were observed among the digestion degrees of 3 oils using digestion rate (k), digestion half-time (t1/2 ), and digestion extent (Φmax). The results showed the digestion rate order was MCT > soybean oil > DAG. Accordingly, the order of digestion half-times was MCT < soybean oil < DAG. In simulated in vitro digestion model, digestion rates (k') and digestion half-times (t'1/2 ) were also obtained and the results showed a digestion rate order of MCT (k' = 0.068 min(-1) ) > soybean oil (k' = 0.037 min(-1) ) > DAG (k' = 0.024 min(-1) ). Consequently, the order of digestion half-times was MCT (t'1/2 = 10.20 min) < soybean oil (t'1/2 = 18.74 min) < DAG (t'1/2 = 29.08 min). The parameters obtained using the 2 models showed MCT was digested faster than soybean oil, and that soybean oil was digested faster than DAG. © 2015 Institute of Food Technologists®

  9. Serum retinol, alpha-tocopherol, and beta-carotene levels are not altered by excess ingestion of diacylglycerol-containing plant sterol esters.

    PubMed

    Saito, Shinichiro; Tomonobu, Kazuichi; Kudo, Naoto; Shiiba, Daisuke; Hase, Tadashi; Tokimitsu, Ichiro

    2006-01-01

    Diacylglycerol (DAG) suppresses the postprandial increase in serum triglycerides, and has antiobesity effects. On the other hand, plant sterol esters (PSE) lower serum cholesterol levels in hypercholesterolemia. Thus, DAG-containing PSE (PSE/DAG) would be expected to maintain an appropriate serum cholesterol level and decrease the risk of arteriosclerotic disorders. Several recent studies, however, report negative effects of PSE on serum fat-soluble (pro)vitamin levels. The objective of this study was to investigate the effect of PSE/DAG on serum retinol, beta-carotene, and alpha-tocopherol levels using a threefold excess of the effective dose obtained in our previous study. A randomized placebo-controlled double-blind parallel study was performed in healthy and mildly hypercholesterolemic subjects, in which the subjects ingested 1.2 g PSE/30 g DAG for 2 weeks in the form of mayonnaise-type products. Triacylglycerol (TAG) mayonnaise was used as a control. There were no subjective adverse effects or changes in serum retinol, alpha-tocopherol, and beta-carotene levels, abdominal symptoms, hematologic values, or blood biochemical values. Ingestion of a threefold excess of PSE/DAG for 2 weeks had no adverse effects compared to ingestion of conventional TAG mayonnaise. Copyright 2006 S. Karger AG, Basel.

  10. Acute Depletion of Diacylglycerol from the Cis-Golgi Affects Localised Nuclear Envelope Morphology During Mitosis.

    PubMed

    Chung, Gary Hong Chun; Domart, Marie Charlotte; Peddie, Christopher; Mantell, Judith; Mclaverty, Kieran; Arabiotorre, Angela; Hodgson, Lorna; Byrne, Richard D; Verkade, Paul; Arkill, Kenton; Collinson, Lucy M; Larijani, Banafshe

    2018-06-12

    Dysregulation of nuclear envelope (NE) assembly results in various cancers; for example, renal and some lung carcinomas ensue due to NE malformation. The NE is a dynamic membrane compartment and its completion during mitosis, is a highly regulated process but the detailed mechanism still remains incompletely understood. Previous studies have found isolated diacylglycerol (DAG) containing vesicles are essential for completing the fusion of NE in non-somatic cells. We investigated the impact of DAG depletion from cis-Golgi in mammalian cells on NE reassembly. Using advanced electron microscopy, we observed an enriched DAG population of vesicles at the vicinity of the NE gaps of telophase mammalian cells. We applied a miniSOG-C1-domain tag that localized DAG-enriched vesicles at the perinuclear region, which suggested the existence of NE fusogenic vesicles. We quantified the impact of Golgi-DAG depletion by measuring the in situ NE rim curvature of the re-forming NE. The rim curvature in these cells was significantly reduced compared with controls, which indicated a localized defect in NE morphology. Our novel results demonstrate the significance of the role of DAG from cis-Golgi for the regulation of NE assembly. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Diacylglycerol lipase regulates lifespan and oxidative stress response by inversely modulating TOR signaling in Drosophila and C. elegans

    PubMed Central

    Lin, Yen-Hung; Chen, Yi-Chun; Kao, Tzu-Yu; Lin, Yi-Chun; Hsu, Tzu-En; Wu, Yi-Chun; Ja, William W; Brummel, Theodore J; Kapahi, Pankaj; Yuh, Chiou-Hwa; Yu, Lin-Kwei; Lin, Zhi-Han; You, Ru-Jing; Jhong, Yi-Ting; Wang, Horng-Dar

    2014-01-01

    Target of rapamycin (TOR) signaling is a nutrient-sensing pathway controlling metabolism and lifespan. Although TOR signaling can be activated by a metabolite of diacylglycerol (DAG), phosphatidic acid (PA), the precise genetic mechanism through which DAG metabolism influences lifespan remains unknown. DAG is metabolized to either PA via the action of DAG kinase or 2-arachidonoyl-sn-glycerol by diacylglycerol lipase (DAGL). Here, we report that in Drosophila and Caenorhabditis elegans, overexpression of diacylglycerol lipase (DAGL/inaE/dagl-1) or knockdown of diacylglycerol kinase (DGK/rdgA/dgk-5) extends lifespan and enhances response to oxidative stress. Phosphorylated S6 kinase (p-S6K) levels are reduced following these manipulations, implying the involvement of TOR signaling. Conversely, DAGL/inaE/dagl-1 mutants exhibit shortened lifespan, reduced tolerance to oxidative stress, and elevated levels of p-S6K. Additional results from genetic interaction studies are consistent with the hypothesis that DAG metabolism interacts with TOR and S6K signaling to affect longevity and oxidative stress resistance. These findings highlight conserved metabolic and genetic pathways that regulate aging. PMID:24889782

  12. Identification of the gene for disaggregatase from Methanosarcina mazei.

    PubMed

    Osumi, Naoki; Kakehashi, Yoshihiro; Matsumoto, Shiho; Nagaoka, Kazunari; Sakai, Junichi; Miyashita, Kiyotaka; Kimura, Makoto; Asakawa, Susumu

    2008-12-01

    The gene sequences encoding disaggregatase (Dag), the enzyme responsible for dispersion of cell aggregates of Methanosarcina mazei to single cells, were determined for three strains of M. mazei (S-6(T), LYC and TMA). The dag genes of the three strains were 3234 bp in length and had almost the same sequences with 97% amino acid sequence identities. Dag was predicted to comprise 1077 amino acid residues and to have a molecular mass of 120 kDa containing three repeats of the DNRLRE domain in the C terminus, which is specific to the genus Methanosarcina and may be responsible for structural organization and cell wall function. Recombinant Dag was overexpressed in Escherichia coli and preparations of the expressed protein exhibited enzymatic activity. The RT-PCR analysis showed that dag was transcribed to mRNA in M. mazei LYC and indicated that the gene was expressed in vivo. This is the first time the gene involved in the morphological change of Methanosarcina spp. from aggregate to single cells has been identified.

  13. Synthesis of docosapentaenoic acid-enriched diacylglycerols by enzymatic glycerolysis of Schizochytrium sp. oil.

    PubMed

    Wang, Xiaosan; Wang, Xiaohan; Wang, Wei; Jin, Qingzhe; Wang, Xingguo

    2018-04-17

    Utilization of algae oil and glycerol for preparation of value-added products is vital for sustainable development of related industries. In this study, we aimed to prepare highly pure diacylglycerols (DAG) rich in docosapentaenoic acid (DPA). First, content of DPA in form of triacylglycerols (TAG) increased from 16.4% to 28.1% after low-temperature crystallization of Schizochytrium sp. oil at -80 °C for 6 h. Subsequently, DPA-enriched DAG was prepared by the enzymatic glycerolysis of the enriched oil. Under the optimum conditions, there was 48.4% DAG produced in the crude mixture. To remove polar impurities from the crude product, a novel two-step purification was developed and the final product consisted of 75.1% DAG and 24.9% TAG with a low peroxide value. The current method for the synthesis of DAG rich DPA is effective and relatively mild and the successful preparation of value-added product will reduce production costs for algae and biodiesel industries. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Defective in Cuticular Ridges (DCR) of Arabidopsis thaliana, a Gene Associated with Surface Cutin Formation, Encodes a Soluble Diacylglycerol Acyltransferase*

    PubMed Central

    Rani, Sapa Hima; Krishna, T. H. Anantha; Saha, Saikat; Negi, Arvind Singh; Rajasekharan, Ram

    2010-01-01

    A key step in the triacylglycerol (TAG) biosynthetic pathway is the final acylation of diacylglycerol (DAG) by DAG acyltransferase. In silico analysis has revealed that the DCR (defective in cuticular ridges) (At5g23940) gene has a typical HX4D acyltransferase motif at the N-terminal end and a lipid binding motif VX2GF at the middle of the sequence. To understand the biochemical function, the gene was overexpressed in Escherichia coli, and the purified recombinant protein was found to acylate DAG specifically in an acyl-CoA-dependent manner. Overexpression of At5g23940 in a Saccharomyces cerevisiae quadruple mutant deficient in DAG acyltransferases resulted in TAG accumulation. At5g23940 rescued the growth of this quadruple mutant in the oleate-containing medium, whereas empty vector control did not. Lipid particles were localized in the cytosol of At5g23940-transformed quadruple mutant cells, as observed by oil red O staining. There was an incorporation of 16-hydroxyhexadecanoic acid into TAG in At5g23940-transformed cells of quadruple mutant. Here we report a soluble acyl-CoA-dependent DAG acyltransferase from Arabidopsis thaliana. Taken together, these data suggest that a broad specific DAG acyltransferase may be involved in the cutin as well as in the TAG biosynthesis by supplying hydroxy fatty acid. PMID:20921218

  15. Defective in cuticular ridges (DCR) of Arabidopsis thaliana, a gene associated with surface cutin formation, encodes a soluble diacylglycerol acyltransferase.

    PubMed

    Rani, Sapa Hima; Krishna, T H Anantha; Saha, Saikat; Negi, Arvind Singh; Rajasekharan, Ram

    2010-12-03

    A key step in the triacylglycerol (TAG) biosynthetic pathway is the final acylation of diacylglycerol (DAG) by DAG acyltransferase. In silico analysis has revealed that the DCR (defective in cuticular ridges) (At5g23940) gene has a typical HX(4)D acyltransferase motif at the N-terminal end and a lipid binding motif VX(2)GF at the middle of the sequence. To understand the biochemical function, the gene was overexpressed in Escherichia coli, and the purified recombinant protein was found to acylate DAG specifically in an acyl-CoA-dependent manner. Overexpression of At5g23940 in a Saccharomyces cerevisiae quadruple mutant deficient in DAG acyltransferases resulted in TAG accumulation. At5g23940 rescued the growth of this quadruple mutant in the oleate-containing medium, whereas empty vector control did not. Lipid particles were localized in the cytosol of At5g23940-transformed quadruple mutant cells, as observed by oil red O staining. There was an incorporation of 16-hydroxyhexadecanoic acid into TAG in At5g23940-transformed cells of quadruple mutant. Here we report a soluble acyl-CoA-dependent DAG acyltransferase from Arabidopsis thaliana. Taken together, these data suggest that a broad specific DAG acyltransferase may be involved in the cutin as well as in the TAG biosynthesis by supplying hydroxy fatty acid.

  16. Positional-Species Composition of Diacylglycerol Acetates from Mature Euonymus Seeds.

    PubMed

    Sidorov, Roman A; Pchelkin, Vasily P; Zhukov, Anatoly V; Tsydendambaev, Vladimir D

    2016-06-01

    The positional-species composition (PSC) of 3-acetyl-1,2-diacyl-sn-glycerols (AcDAGs) from the seeds of mature fruits of 14 species of the genus Euonymus L. was established. The residues of six major fatty acids (FAs), palmitic (P), stearic (St), hexadecenoic (H), octadecenoic (O), linoleic (L), and linolenic (Ln), were present in the AcDAGs. Here, we demonstrated that the profile of PSC of AcDAGs could serve as chemotaxonomic factor to divide euonymus species studied here into groups which completely correlate with the present day systematic of the genus. In particular, the Euonymus section greatly exceeded other sections of the Euonymus subgenus as well as the Kalonymus one in the total levels of AcDAGs positional species having one and two O residues and was characterized by significantly lesser concentrations of species with one and two L residues. Moreover, in seed, AcDAGs of almost all Euonymus species EFL values were slightly higher than EFO ones, but all EFL and EFO values were higher than 1.0, and therefore, it can be concluded that both FAs mainly esterified sn-2-position of the glycerol moiety and saturated FAs residues were always virtually absent in the sn-2 position of Euonymus seed AcDAGs, as it is also the case in nearly all TAGs molecules of plant origin. © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

  17. In Vivo Imaging of Diacylglycerol at the Cytoplasmic Leaflet of Plant Membranes.

    PubMed

    Vermeer, Joop E M; van Wijk, Ringo; Goedhart, Joachim; Geldner, Niko; Chory, Joanne; Gadella, Theodorus W J; Munnik, Teun

    2017-07-01

    Diacylglycerol (DAG) is an important intermediate in lipid biosynthesis and plays key roles in cell signaling, either as a second messenger itself or as a precursor of phosphatidic acid. Methods to identify distinct DAG pools have proven difficult because biochemical fractionation affects the pools, and concentrations are limiting. Here, we validate the use of a genetically encoded DAG biosensor in living plant cells. The sensor is composed of a fusion between yellow fluorescent protein and the C1a domain of protein kinase C (YFP-C1aPKC) that specifically binds DAG, and was stably expressed in suspension-cultured tobacco BY-2 cells and whole Arabidopsis thaliana plants. Confocal imaging revealed that the majority of the YFP-C1aPKC fluorescence did not locate to membranes but was present in the cytosol and nucleus. Treatment with short-chain DAG or PMA (phorbol-12-myristate-13-acetate), a phorbol ester that binds the C1a domain of PKC, caused the recruitment of the biosensor to the plasma membrane. These results indicate that the biosensor works and that the basal DAG concentration in the cytoplasmic leaflet of membranes (i.e. accessible to the biosensor) is in general too low, and confirms that the known pools in plastids, the endoplasmic reticulum and mitochondria are located at the luminal face of these compartments (i.e. inaccessible to the biosensor). Nevertheless, detailed further analysis of different cells and tissues discovered four novel DAG pools, namely at: (i) the trans-Golgi network; (ii) the cell plate during cytokinesis; (iii) the plasma membrane of root epidermal cells in the transition zone, and (iv) the apex of growing root hairs. The results provide new insights into the spatiotemporal dynamics of DAG in plants and offer a new tool to monitor this in vivo. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Rapid desensitization of vasopressin-stimulated phosphatidylinositol 4,5-bisphosphate and phosphatidylcholine hydrolysis questions the role of these pathways in sustained diacylglycerol formation in A10 vascular-smooth-muscle cells.

    PubMed

    Plevin, R; Wakelam, M J

    1992-08-01

    The kinetics of vasopressin-stimulated PtdIns(4,5)P2 and phosphatidylcholine (PtdCho) hydrolysis in relation to sustained diacylglycerol (DAG) formation was investigated in A10 vascular-smooth-muscle cells in culture. Vasopressin stimulated a transient increase in Ins(1,4,5)P3 mass formation, which was mirrored by a decrease in PtdIns(4,5)P2 mass levels. Vasopressin stimulated sustained accumulation of total [3H]inositol phosphates ([3H]IP) in the presence of Li+; however, this was significantly decreased by adding a vasopressin-receptor antagonist at different times after initial stimulation. Vasopressin-stimulated phospholipase D (PLD) activity was found to be a transient phenomenon lasting approx. 2 min. Experiments involving agonist preincubation with subsequent addition of butanol confirmed that vasopressin-stimulated PLD activity was desensitized. Vasopressin stimulated an increase in formation of choline, but not of phosphocholine, suggesting that PLD was the major catalytic route of PtdCho hydrolysis in this cell line. The roles of choline and inositol phospholipid hydrolysis in the prolonged phase of DAG formation was examined by comparing vasopressin-stimulated changes in DAG levels in the presence of butanol, the protein kinase C inhibitor Ro-31-8220 or a V1a-receptor antagonist. Vasopressin-stimulated DAG formation was decreased by 40-50% in the presence of butanol between 1 and 10 min; however, during more prolonged stimulation butanol was without significant effect. In cells pretreated with Ro-31-8220, vasopressin-stimulated DAG formation was decreased by approx. 30% at 2 min, but was significantly potentiated at later times. This coincided with an enhancement of vasopressin-stimulated [3H]IP accumulation. In cells exposed to the V1a-receptor antagonist 5 min after addition of vasopressin, subsequent DAG formation was significantly decreased, indicating that sustained formation of DAG, like [3H]IP accumulation, was dependent on continual agonist

  19. Prolactin-stimulated ornithine decarboxylase induction in rat hepatocytes: Coupling to diacylglycerol generation and protein kinase C

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Buckley, A.R.; Buckley, D.J.

    1991-01-01

    The trophic effects of prolactin (PRL) in rat liver have been linked to activation of protein kinase C (PKC). Since alterations in PKC activity imply its activation by 1,2-diacylglycerol (DAG), we tested whether PRL treatment stimulated DAG generation coupled to induction of a growth response in primary hepatocytes. Addition of PRL to hepatocyte cultures significantly increased ({sup 3}H)-glycerol incorporation into DAG within 5 minutes which was followed by a loss of cytosolic PKC activity by 10 minutes. Prolactin also significantly enhanced radiolabel incorporation into triacylglycerol and phospholipids within 10 minutes and induced ODC activity at 6 hours. Therefore, prolactin-stimulated alterationsmore » in PKC activity are preceded by enhanced DAG generation. Moreover, these events appear to be coupled to PRL-stimulated entry of hepatocytes into cell cycle.« less

  20. ESI-MS/MS and MALDI-IMS Localization Reveal Alterations in Phosphatidic Acid, Diacylglycerol, and DHA in Glioma Stem Cell Xenografts.

    PubMed

    Wildburger, Norelle C; Wood, Paul L; Gumin, Joy; Lichti, Cheryl F; Emmett, Mark R; Lang, Frederick F; Nilsson, Carol L

    2015-06-05

    Glioblastoma (GBM) is the most common adult primary brain tumor. Despite aggressive multimodal therapy, the survival of patients with GBM remains dismal. However, recent evidence has demonstrated the promise of bone marrow-derived mesenchymal stem cells (BM-hMSCs) as a therapeutic delivery vehicle for anti-glioma agents due to their ability to migrate or home to human gliomas. While several studies have demonstrated the feasibility of harnessing the homing capacity of BM-hMSCs for targeted delivery of cancer therapeutics, it is now also evident, based on clinically relevant glioma stem cell (GSC) models of GBMs, that BM-hMSCs demonstrate variable tropism toward these tumors. In this study, we compared the lipid environment of GSC xenografts that attract BM-hMSCs (N = 9) with those that do not attract (N = 9) to identify lipid modalities that are conducive to homing of BM-hMSC to GBMs. We identified lipids directly from tissue by matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) and electrospray ionization-tandem mass spectrometry (ESI-MS/MS) of lipid extracts. Several species of signaling lipids, including phosphatidic acid (PA 36:2, PA 40:5, PA 42:5, and PA 42:7) and diacylglycerol (DAG 34:0, DAG 34:1, DAG 36:1, DAG 38:4, DAG 38:6, and DAG 40:6), were lower in attracting xenografts. Molecular lipid images showed that PA (36:2), DAG (40:6), and docosahexaenoic acid (DHA) were decreased within tumor regions of attracting xenografts. Our results provide the first evidence for lipid signaling pathways and lipid-mediated tumor inflammatory responses in the homing of BM-hMSCs to GSC xenografts. Our studies provide new fundamental knowledge on the molecular correlates of the differential homing capacity of BM-hMSCs toward GSC xenografts.

  1. Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae.

    PubMed

    Qiu, Yixuan; Hassaninasab, Azam; Han, Gil-Soo; Carman, George M

    2016-12-16

    In the yeast Saccharomyces cerevisiae, Dgk1 diacylglycerol (DAG) kinase catalyzes the CTP-dependent phosphorylation of DAG to form phosphatidic acid (PA). The enzyme in conjunction with Pah1 PA phosphatase controls the levels of PA and DAG for the synthesis of triacylglycerol and membrane phospholipids, the growth of the nuclear/endoplasmic reticulum membrane, and the formation of lipid droplets. Little is known about how DAG kinase activity is regulated by posttranslational modification. In this work, we examined the phosphorylation of Dgk1 DAG kinase by casein kinase II (CKII). When phosphate groups were globally reduced using nonspecific alkaline phosphatase, Triton X-100-solubilized membranes from DGK1-overexpressing cells showed a 7.7-fold reduction in DAG kinase activity; the reduced enzyme activity could be increased 5.5-fold by treatment with CKII. Dgk1(1-77) expressed heterologously in Escherichia coli was phosphorylated by CKII on a serine residue, and its phosphorylation was dependent on time as well as on the concentrations of CKII, ATP, and Dgk1(1-77). We used site-specific mutagenesis, coupled with phosphorylation analysis and phosphopeptide mapping, to identify Ser-45 and Ser-46 of Dgk1 as the CKII target sites, with Ser-46 being the major phosphorylation site. In vivo, the S46A and S45A/S46A mutations of Dgk1 abolished the stationary phase-dependent stimulation of DAG kinase activity. In addition, the phosphorylation-deficient mutations decreased Dgk1 function in PA production and in eliciting pah1Δ phenotypes, such as the expansion of the nuclear/endoplasmic reticulum membrane, reduced lipid droplet formation, and temperature sensitivity. This work demonstrates that the CKII-mediated phosphorylation of Dgk1 regulates its function in the production of PA. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Synergistic control of protein kinase Cgamma activity by ionotropic and metabotropic glutamate receptor inputs in hippocampal neurons.

    PubMed

    Codazzi, Franca; Di Cesare, Alessandra; Chiulli, Nino; Albanese, Alberto; Meyer, Tobias; Zacchetti, Daniele; Grohovaz, Fabio

    2006-03-29

    Conventional protein kinase C (PKC) isoforms are abundant neuronal signaling proteins with important roles in regulating synaptic plasticity and other neuronal processes. Here, we investigate the role of ionotropic and metabotropic glutamate receptor (iGluR and mGluR, respectively) activation on the generation of Ca2+ and diacylglycerol (DAG) signals and the subsequent activation of the neuron-specific PKCgamma isoform in hippocampal neurons. By combining Ca2+ imaging with total internal reflection microscopy analysis of specific biosensors, we show that elevation of both Ca2+ and DAG is necessary for sustained translocation and activation of EGFP (enhanced green fluorescent protein)-PKCgamma. Both DAG production and PKCgamma translocation were localized processes, typically observed within discrete microdomains along the dendritic branches. Markedly, intermediate-strength NMDA receptor (NMDAR) activation or moderate electrical stimulation generated Ca2+ but no DAG signals, whereas mGluR activation generated DAG but no Ca2+ signals. Both receptors were needed for PKCgamma activation. This suggests that a coincidence detection process exists between iGluRs and mGluRs that relies on a molecular coincidence detection process based on the corequirement of Ca2+ and DAG for PKCgamma activation. Nevertheless, the requirement for costimulation with mGluRs could be overcome for maximal NMDAR stimulation through a direct production of DAG via activation of the Ca2+-sensitive PLCdelta (phospholipase Cdelta) isoform. In a second important exception, mGluRs were sufficient for PKCgamma activation in neurons in which Ca2+ stores were loaded by previous electrical activity. Together, the dual activation requirement for PKCgamma provides a plausible molecular interpretation for different synergistic contributions of mGluRs to long-term potentiation and other synaptic plasticity processes.

  3. A study of the influence of charged residues on β-hairpin formation by nuclear magnetic resonance and molecular dynamics.

    PubMed

    Makowska, Joanna; Zmudzińska, Wioletta; Uber, Dorota; Chmurzyński, Lech

    2014-12-01

    Chain reversals are often nucleation sites in protein folding. The β-hairpins of FBP28 WW domain and IgG are stable and have been proved to initiate the folding and are, therefore, suitable for studying the influence of charged residues on β-hairpin conformation. In this paper, we carried out NMR examination of the conformations in solution of two fragments from the FPB28 protein (PDB code: 1E0L) (N-terminal part) namely KTADGKT-NH2 (1E0L 12-18, D7) and YKTADGKTY-NH2 (1E0L 11-19, D9), one from the B3 domain of the protein G (PDB code: 1IGD), namely DDATKT-NH2 (1IGD 51-56) (Dag1), and three variants of Dag1 peptide: DVATKT-NH2 (Dag2), OVATKT-NH2 (Dag3) and KVATKT-NH2 (Dag4), respectively, in which the original charged residue were replaced with non-polar residues or modified charged residues. It was found that both the D7 and D9 peptides form a large fraction bent conformations. However, no hydrophobic contacts between the terminal Tyr residues of D9 occur, which suggests that the presence of a pair of like-charged residues stabilizes chain reversal. Conversely, only the Dag1 and Dag2 peptides exhibit some chain reversal; replacing the second aspartic-acid residue with a valine and the first one with a basic residue results in a nearly extended conformation. These results suggest that basic residues farther away in sequence can result in stabilization of chain reversal owing to screening of the non-polar core. Conversely, smaller distance in sequence prohibits this screening, while the presence oppositely-charged residues can stabilize a turn because of salt-bridge formation.

  4. Interfacial Partitioning of a Loop Hinge Residue Contributes to Diacylglycerol Affinity of Conserved Region 1 Domains*

    PubMed Central

    Stewart, Mikaela D.; Cole, Taylor R.; Igumenova, Tatyana I.

    2014-01-01

    Conventional and novel isoenzymes of PKC are activated by the membrane-embedded second messenger diacylglycerol (DAG) through its interactions with the C1 regulatory domain. The affinity of C1 domains to DAG varies considerably among PKCs. To gain insight into the origin of differential DAG affinities, we conducted high-resolution NMR studies of C1B domain from PKCδ (C1Bδ) and its W252Y variant. The W252Y mutation was previously shown to render C1Bδ less responsive to DAG (Dries, D. R., Gallegos, L. L., and Newton, A. C. (2007) A single residue in the C1 domain sensitizes novel protein kinase C isoforms to cellular diacylglycerol production. J. Biol. Chem. 282, 826–830) and thereby emulate the behavior of C1B domains from conventional PKCs that have a conserved Tyr at the equivalent position. Our data revealed that W252Y mutation did not perturb the conformation of C1Bδ in solution but significantly reduced its propensity to partition into a membrane-mimicking environment in the absence of DAG. Using detergent micelles doped with a paramagnetic lipid, we determined that both the residue identity at position 252 and complexation with diacylglycerol influence the geometry of C1Bδ-micelle interactions. In addition, we identified the C-terminal helix α1 of C1Bδ as an interaction site with the head groups of phosphatidylserine, a known activator of PKCδ. Taken together, our studies (i) reveal the identities of C1Bδ residues involved in interactions with membrane-mimicking environment, DAG, and phosphatidylserine, as well as the affinities associated with each event and (ii) suggest that the initial ligand-independent membrane recruitment of C1B domains, which is greatly facilitated by the interfacial partitioning of Trp-252, is responsible, at least in part, for the differential DAG affinities. PMID:25124034

  5. Diacylglycerol oil does not affect portal vein transport of nonesterified fatty acids but decreases the postprandial plasma lipid response in catheterized pigs.

    PubMed

    Kristensen, Janni Brogaard; Jørgensen, Henry; Mu, Huiling

    2006-07-01

    Studies have shown several beneficial effects of dietary diacylglycerol oil (DAG oil), but the mechanism behind these effects is still not clear. One hypothesis is that an increase in portal vein transport of nonesterified fatty acids (NEFA) with subsequent oxidation in the liver might be responsible for the positive effects. We examined the portal vein transport of NEFA and other lipid related variables, in response to DAG and triacylglycerol (TAG) bolus feeding and a bolus of standard pig feed in 4 portal vein and mesenteric artery catheterized pigs. Also, the effect of the boluses on postprandial lipid variables was examined. Portal vein transport of NEFA did not differ when pigs were administered the 2 oil bolus diets, consistent with the similar portal plasma concentrations of oleic and linolenic acids during h 1 after feeding. Glycerol, on the contrary, was transported by the portal vein to a much higher degree after intake of DAG oil (P < 0.001; 20, 40, and 60 min). The postprandial arterial TAG response at 5 and 6 h postprandially was significantly lower after the DAG bolus intake. Analysis of Delta AUC for the 6-h postprandial period of selected and total fatty acids showed a lower concentration of vaccenic acid (P = 0.002) after the DAG bolus diet. In conclusion, DAG bolus feeding did not increase the portal transport of NEFA, but it did increase the portal transport of glycerol and lower the postprandial lipid concentration in arterial plasma.

  6. Desacyl Ghrelin Decreases Anxiety-like Behavior in Male Mice.

    PubMed

    Mahbod, Parinaz; Smith, Eric P; Fitzgerald, Maureen E; Morano, Rachel L; Packard, Benjamin A; Ghosal, Sriparna; Scheimann, Jessie R; Perez-Tilve, Diego; Herman, James P; Tong, Jenny

    2018-01-01

    Ghrelin is a 28-amino acid polypeptide that regulates feeding, glucose metabolism, and emotionality (stress, anxiety, and depression). Plasma ghrelin circulates as desacyl ghrelin (DAG) or, in an acylated form, acyl ghrelin (AG), through the actions of ghrelin O-acyltransferase (GOAT), exhibiting low or high affinity, respectively, for the growth hormone secretagogue receptor (GHSR) 1a. We investigated the role of endogenous AG, DAG, and GHSR1a signaling on anxiety and stress responses using ghrelin knockout (Ghr KO), GOAT KO, and Ghsr stop-floxed (Ghsr null) mice. Behavioral and hormonal responses were tested in the elevated plus maze and light/dark (LD) box. Mice lacking both AG and DAG (Ghr KO) increased anxiety-like behaviors across tests, whereas anxiety reactions were attenuated in DAG-treated Ghr KO mice and in mice lacking AG (GOAT KO). Notably, loss of GHSR1a (Ghsr null) did not affect anxiety-like behavior in any test. Administration of AG and DAG to Ghr KO mice with lifelong ghrelin deficiency reduced anxiety-like behavior and decreased phospho-extracellular signal-regulated kinase phosphorylation in the Edinger-Westphal nucleus in wild-type mice, a site normally expressing GHSR1a and involved in stress- and anxiety-related behavior. Collectively, our data demonstrate distinct roles for endogenous AG and DAG in regulation of anxiety responses and suggest that the behavioral impact of ghrelin may be context dependent. Copyright © 2018 Endocrine Society.

  7. Suaahara in Nepal: An at-scale, multi-sectoral nutrition program influences knowledge and practices while enhancing equity.

    PubMed

    Cunningham, Kenda; Singh, Akriti; Pandey Rana, Pooja; Brye, Laura; Alayon, Silvia; Lapping, Karin; Gautam, Bindu; Underwood, Carol; Klemm, Rolf D W

    2017-10-01

    The burden of undernutrition in South Asia is greater than anywhere else. Policies and programmatic efforts increasingly address health and non-health determinants of undernutrition. In Nepal, one large-scale integrated nutrition program, Suaahara, aimed to reduce undernutrition among women and children in the 1,000-day period, while simultaneously addressing inequities. In this study, we use household-level process evaluation data (N = 480) to assess levels of exposure to program inputs and levels of knowledge and practices related to health, nutrition, and water, sanitation, and hygiene (WASH). We also assess Suaahara's effect on the differences between disadvantaged (DAG) and non-disadvantaged households in exposure, knowledge, and practice indicators. All regression models were adjusted for potential confounders at the child-, maternal-, and household levels, as well as clustering. We found a higher prevalence of almost all exposure and knowledge indicators and some practice indicators in Suaahara areas versus comparison areas. A higher proportion of DAG households in Suaahara areas reported exposure, were knowledgeable, and practiced optimal behaviors related to nearly all maternal and child health, nutrition, and WASH indicators than DAG households in non-Suaahara areas and sometimes even than non-DAG households in Suaahara areas. Moreover, differences in some of these indicators between DAG and non-DAG households were significantly smaller in Suaahara areas than in comparison areas. These results indicate that large-scale integrated interventions can influence nutrition-related knowledge and practices, while simultaneously reducing inequities. © 2017 John Wiley & Sons Ltd.

  8. Fact Sheets of CTAS and NASA Decision-Support Tools and Concepts

    NASA Technical Reports Server (NTRS)

    Lee, Katharine

    2004-01-01

    Distributed Air/Ground (DAG) Traffic Management (TM) is an integrated operational concept in which flight deck crews, air traffic service providers and aeronautical operational control personnel use distributed decision-making to enable user preferences and increase system capacity, while meeting air traffic management (ATM) requirements. It is a possible operational mode under the Free Flight concept outlined by the RTCA Task Force 3. The goal of DAG-TM is to enhance user flexibility/efficiency and increase system capacity, without adversely affecting system safety or restricting user accessibility to the National Airspace System (NAS). DAG-TM will be accomplished with a human-centered operational paradigm enabled by procedural and technological innovations. These innovations include automation aids, information sharing and Communication, Navigation, and Surveillance (CNS) / ATM technologies. The DAG-TM concept is intended to eliminate static restrictions to the maximum extent possible. In this paradigm, users may plan and operate according to their preferences - as the rule rather than the exception - with deviations occumng eyond the year 2015. Out of a total of 15 concept elements, 4 have been selected for initial sutidies (see Key Elements in sidebar). DAG-TM research is being performed at Ames, Glenn, and Langley Research Centers.

  9. Cholesterol blocks spontaneous insertion of membrane proteins into liposomes of phosphatidylcholine.

    PubMed

    Nakamura, Shota; Suzuki, Sonomi; Saito, Hiroaki; Nishiyama, Ken-Ichi

    2018-04-01

    Spontaneous insertion of membrane proteins into liposomes formed from Escherichia coli polar phospholipids is blocked by diacylglycerol (DAG) at a physiological level. We found that cholesterol also blocks this spontaneous insertion, although a much larger amount is necessary for sufficient blockage. Reversely, sphingomyelin enhanced the spontaneous insertion. DAG at a physiological level was found not to block spontaneous insertion into liposomes formed from phosphatidylcholine (PC), while non-physiologically high concentrations of DAG reduced it. On the other hand, cholesterol blocked the spontaneous insertion into PC liposomes at a physiological level, explaining that both PC and cholesterol are absent in E. coli. While sphingomyelin did not enhance spontaneous insertion into PC liposomes, the effect of cholesterol on blockage of spontaneous insertion was dominant over that of sphingomyelin, suggesting that cholesterol functions as a blocker of disordered spontaneous insertion in eukaryotic cells. Lower amount of cholesterol was necessary to block spontaneous insertion into ER-mimic liposomes, explaining that ER membranes contain less amount of cholesterol. These results also explain that cholesterol, but not DAG, is involved in blockage of spontaneous insertion in eukaryotic cells, since DAG plays an important role as a second messenger in signal transduction.

  10. Physicochemical properties of peanut oil-based diacylglycerol and their derived oil-in-water emulsions stabilized by sodium caseinate.

    PubMed

    Long, Zhao; Zhao, Mouming; Liu, Ning; Liu, Daolin; Sun-Waterhouse, Dongxiao; Zhao, Qiangzhong

    2015-10-01

    High purity peanut oil-based diacylglycerol (PO-DAG) (94.95 wt%) was prepared via enzymatic glycerolysis from peanut oil (PO). The resulting dominance of DAGs was proven to greatly influence the properties of corresponding fresh or frozen-thawed emulsions. Stable fresh oil-in-water emulsions were produced using either PO-DAG or PO, with stability enhanced by increased concentrations of Na-CN. The lower equilibrium interfacial tension along with greater negative ζ-potential of PO revealed that Na-CN was preferentially adsorbed to the PO interface. Adding 0.05 mol/L NaCl to the PO emulsions minimized depletion flocculation caused by the unadsorbed Na-CN, but further NaCl addition increased oil droplet size and concomitant coalescence. For the PO-DAG emulsions, adding 0.2 mol/L NaCl did not significantly (p>0.05) affect their ζ-potential but adding 0.05 or 0.1 mol/L NaCl lowered ζ-potential, although NaCl at these concentrations increased oil droplet size and coalescence. Freezing-thawing process considerably weakened the stability of PO-DAG emulsions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Thermal Stability of Gun Propellants from Munition Articles That Returned from Cambodia.

    DTIC Science & Technology

    1998-02-01

    0482 0661 0312 0472 EMZ 79- 11 MEN 80-8 DAG 86-2 MEN 88-57 DAG 89- 11 DAG 90-3 IMI91-4 7% 9 % 12% 15% 17% 18% 16% CTG.50 inch Ball LKD...5. Peltierelement, 6. diffe- rentiemeetpunt, 7. aluminium binnenblok, 8. referentievat, 9 . isolatie, 10. verwarmingsman- tel, 11 . isolatie, 12...W/TR CTG 7,62 mm NATO Ball CTG.50 inch Med RNG Ball LKD, W/TR CTG 7,62 mm NATO Ball CTG 9 mm NATO Ball CTG 7,62 mm NATO Ball CTG 7,62 mm NATO

  12. The Abundance and Isotopic Composition of Water in Howardite-Eucrite-Diogenite Meteorites

    NASA Astrophysics Data System (ADS)

    Barrett, T. J.; Tartèse, R.; Anand, M.; Franchi, I. A.; Grady, M. M.; Greenwood, R. C.; Charlier, B. L. A.

    2014-09-01

    Using SIMs techniques we measure OH abundances and D/H ratios in apatite grains from two Eucrites (DaG 945, DaG 844).The average δD values of these two samples are also similar to carbonaceous chondrites, the Earth and the Moon.

  13. Glycidyl esters in refined palm (Elaeis guineensis) oil and related fractions. Part II: practical recommendations for effective mitigation.

    PubMed

    Craft, Brian D; Nagy, Kornél; Seefelder, Walburga; Dubois, Mathieu; Destaillats, Frédéric

    2012-05-01

    In a previous work, it was shown that at high temperatures (up to 280°C) glycidyl esters (GE) are formed from diacylglycerols (DAG) via elimination of free fatty acid (FFA). In the present study, the impact of DAG content and temperature on the formation of GE using a model vacuum system mimicking industrial edible oil deodorization is investigated. These deodorization experiments confirmed that the formation of GE from DAG is extensive at temperatures above 230-240°C, and therefore, this value should be considered as an upper limit for refining operations. Furthermore, experimental data suggest that the formation of GE accelerates in particular when the DAG levels in refined oils exceed 3-4% of total lipids. Analysis of the lipid composition of crude palm oil (CPO) samples allowed the estimation that this critical DAG content corresponds to about 1.9-2.5% of FFA, which is the conventional quality marker of CPO. Moreover, high levels (>100ppm) of GE were also found in palm fatty acid distillate samples, which may indicate that the level of GE in fully refined palm oils also depends on the elimination rate of GE into the fatty acid distillate. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Phospholipase D¿ enhances diacylglycerol flux into triacylglycerol

    USDA-ARS?s Scientific Manuscript database

    Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG) successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be lim...

  15. Phosphatidic Acid-Mediated Signaling Regulates Microneme Secretion in Toxoplasma.

    PubMed

    Bullen, Hayley E; Jia, Yonggen; Yamaryo-Botté, Yoshiki; Bisio, Hugo; Zhang, Ou; Jemelin, Natacha Klages; Marq, Jean-Baptiste; Carruthers, Vern; Botté, Cyrille Y; Soldati-Favre, Dominique

    2016-03-09

    The obligate intracellular lifestyle of apicomplexan parasites necessitates an invasive phase underpinned by timely and spatially controlled secretion of apical organelles termed micronemes. In Toxoplasma gondii, extracellular potassium levels and other stimuli trigger a signaling cascade culminating in phosphoinositide-phospholipase C (PLC) activation, which generates the second messengers diacylglycerol (DAG) and IP3 and ultimately results in microneme secretion. Here we show that a delicate balance between DAG and its downstream product, phosphatidic acid (PA), is essential for controlling microneme release. Governing this balance is the apicomplexan-specific DAG-kinase-1, which interconverts PA and DAG, and whose depletion impairs egress and causes parasite death. Additionally, we identify an acylated pleckstrin-homology (PH) domain-containing protein (APH) on the microneme surface that senses PA during microneme secretion and is necessary for microneme exocytosis. As APH is conserved in Apicomplexa, these findings highlight a potentially widely used mechanism in which key lipid mediators regulate microneme exocytosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Short-Term Effects of Dietary Fatty Acids on Muscle Lipid Composition and Serum Acylcarnitine Profile in Human Subjects

    PubMed Central

    Kien, C. Lawrence; Everingham, Karen I.; Stevens, Robert D.; Fukagawa, Naomi K.; Muoio, Deborah M.

    2010-01-01

    In cultured cells, palmitic acid (PA) and oleic acid (OA) confer distinct metabolic effects, yet, unclear, is whether changes in dietary fat intake impact cellular fatty acid (FA) composition. We hypothesized that short-term increases in dietary PA or OA would result in corresponding changes in the FA composition of skeletal muscle diacylglycerol (DAG) and triacylglycerol (TAG) and/or the specific FA selected for β-oxidation. Healthy males (N = 12) and females (N = 12) ingested a low-PA diet for 7 days. After fasting measurements of the serum acylcarnitine (AC) profile, subjects were randomized to either high-PA (HI PA) or low-PA/high-OA (HI OA) diets. After 7 days, the fasting AC measurement was repeated and a muscle/fat biopsy obtained. FA composition of intramyocellular DAG and TAG and serum AC was measured. HI PA increased, whereas HI OA decreased, serum concentration of 16:0 AC (P < 0.001). HI OA increased 18:1 AC (P = 0.005). HI PA was associated with a higher PA/OA ratio in muscle DAG and TAG (DAG: 1.03 ± 0.24 vs. 0.46 ± 0.08, P = 0.04; TAG: 0.63 ± 0.07 vs. 0.41 ± 0.03, P = 0.01). The PA concentration in the adipose tissue DAG (μg/mg adipose tissue) was 0.17 ± 0.02 in those receiving the HI PA diet (n = 6), compared to 0.11 ± 0.02 in the HI OA group (n = 4) (P = 0.067). The relative PA concentration in muscle DAG and TAG and the serum palmitoylcarnitine concentration was higher in those fed the high-PA diet. PMID:20559306

  17. Short-term effects of dietary fatty acids on muscle lipid composition and serum acylcarnitine profile in human subjects.

    PubMed

    Kien, C Lawrence; Everingham, Karen I; D Stevens, Robert; Fukagawa, Naomi K; Muoio, Deborah M

    2011-02-01

    In cultured cells, palmitic acid (PA) and oleic acid (OA) confer distinct metabolic effects, yet, unclear, is whether changes in dietary fat intake impact cellular fatty acid (FA) composition. We hypothesized that short-term increases in dietary PA or OA would result in corresponding changes in the FA composition of skeletal muscle diacylglycerol (DAG) and triacylglycerol (TAG) and/or the specific FA selected for β-oxidation. Healthy males (N = 12) and females (N = 12) ingested a low-PA diet for 7 days. After fasting measurements of the serum acylcarnitine (AC) profile, subjects were randomized to either high-PA (HI PA) or low-PA/high-OA (HI OA) diets. After 7 days, the fasting AC measurement was repeated and a muscle/fat biopsy obtained. FA composition of intramyocellular DAG and TAG and serum AC was measured. HI PA increased, whereas HI OA decreased, serum concentration of 16:0 AC (P < 0.001). HI OA increased 18:1 AC (P = 0.005). HI PA was associated with a higher PA/OA ratio in muscle DAG and TAG (DAG: 1.03 ± 0.24 vs. 0.46 ± 0.08, P = 0.04; TAG: 0.63 ± 0.07 vs. 0.41 ± 0.03, P = 0.01). The PA concentration in the adipose tissue DAG (µg/mg adipose tissue) was 0.17 ± 0.02 in those receiving the HI PA diet (n = 6), compared to 0.11 ± 0.02 in the HI OA group (n = 4) (P = 0.067). The relative PA concentration in muscle DAG and TAG and the serum palmitoylcarnitine concentration was higher in those fed the high-PA diet.

  18. Prefission Constriction of Golgi Tubular Carriers Driven by Local Lipid Metabolism: A Theoretical Model

    PubMed Central

    Shemesh, Tom; Luini, Alberto; Malhotra, Vivek; Burger, Koert N. J.; Kozlov, Michael M.

    2003-01-01

    Membrane transport within mammalian cells is mediated by small vesicular as well as large pleiomorphic transport carriers (TCs). A major step in the formation of TCs is the creation and subsequent narrowing of a membrane neck connecting the emerging carrier with the initial membrane. In the case of small vesicular TCs, neck formation may be directly induced by the coat proteins that cover the emerging vesicle. However, the mechanism underlying the creation and narrowing of a membrane neck in the generation of large TCs remains unknown. We present a theoretical model for neck formation based on the elastic model of membranes. Our calculations suggest a lipid-driven mechanism with a central role for diacylglycerol (DAG). The model is applied to a well-characterized in vitro system that reconstitutes TC formation from the Golgi complex, namely the pearling and fission of Golgi tubules induced by CtBP/BARS, a protein that catalyzes the conversion of lysophosphatidic acid into phosphatidic acid. In view of the importance of a PA-DAG cycle in the formation of Golgi TCs, we assume that the newly formed phosphatidic acid undergoes rapid dephosphorylation into DAG. DAG possesses a unique molecular shape characterized by an extremely large negative spontaneous curvature, and it redistributes rapidly between the membrane monolayers and along the membrane surface. Coupling between local membrane curvature and local lipid composition results, by mutual enhancement, in constrictions of the tubule into membrane necks, and a related inhomogeneous lateral partitioning of DAG. Our theoretical model predicts the exact dimensions of the constrictions observed in the pearling Golgi tubules. Moreover, the model is able to explain membrane neck formation by physiologically relevant mole fractions of DAG. PMID:14645071

  19. Blood lipid-lowering and antioxidant effects of a structured lipid containing monoacylglyceride enriched with monounsaturated fatty acids in C57BL/6 mice.

    PubMed

    Cho, Kyung-Hyun; Lee, Jeung-Hee; Kim, Jin-Man; Park, Sang Hyun; Choi, Myung-Sook; Lee, Yun-Mi; Choi, Inho; Lee, Ki-Teak

    2009-04-01

    We recently reported that a synthetic edible oil-containing monoacylglyceride (MAG) and diacylglyceride (DAG) exerted anti-atherosclerotic effects. In order to further investigate the activities and individual effects of MAG and DAG on the atherosclerotic process, we prepared a structured oil with various MAG and DAG contents and tested them both in vitro and in vivo, using C57BL/6 mice. The structured oil to be tested was mixed (final concentration 5%, wt/wt) with a high-cholesterol high-fat diet (1.2% cholesterol/15% fat/0.5% sodium cholate) and provided to the mice for 7 weeks. After administration, the mice consuming MAG97%-oil and DAG50%/MAG10%-oil evidenced 17% and 24% decreases in plasma total cholesterol (TC) level, respectively, as compared to a group of mice fed on lard. The experimental mice also had reduced plasma triglyceride concentrations and elevated high-density lipoprotein-cholesterol to TC ratios, by up to 31% in the case of the DAG50%/MAG10%-oil fed mice. The mice fed on MAG97%-oil exhibited elevated plasma antioxidant activity and lecithin:cholesterol acyltransferase activity. Histological assessments of the livers of the mice showed that the consumption of MAG-containing oil attenuated the adhesion of inflammatory cells and also ameliorated fatty liver changes, as compared to what was observed in the case of DAG85%-oil consumption. In conclusion, the MAG-containing oil exhibited anti-inflammatory and antioxidant activities in vivo, as well as in vitro inhibitory activity against human cholesteryl ester transfer protein. These results provide us with new insights into MAG-containing oil in terms of hypocholesterolemic effects and antioxidant activities.

  20. NLP-12 engages different UNC-13 proteins to potentiate tonic and evoked release.

    PubMed

    Hu, Zhitao; Vashlishan-Murray, Amy B; Kaplan, Joshua M

    2015-01-21

    A neuropeptide (NLP-12) and its receptor (CKR-2) potentiate tonic and evoked ACh release at Caenorhabditis elegans neuromuscular junctions. Increased evoked release is mediated by a presynaptic pathway (egl-30 Gαq and egl-8 PLCβ) that produces DAG, and by DAG binding to short and long UNC-13 proteins. Potentiation of tonic ACh release persists in mutants deficient for egl-30 Gαq and egl-8 PLCβ and requires DAG binding to UNC-13L (but not UNC-13S). Thus, NLP-12 adjusts tonic and evoked release by distinct mechanisms. Copyright © 2015 the authors 0270-6474/15/351038-05$15.00/0.

  1. Differential effects of pertussis toxin on insulin-stimulated phosphatidylcholine hydrolysis and glycerolipid synthesis de novo. Studies in BC3H-1 myocytes and rat adipocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hoffman, J.M.; Standaert, M.L.; Nair, G.P.

    1991-04-02

    Insulin-induced increases in diacylglycerol (DAG) have been suggested to result from stimulation of de novo phosphatidic acid (PA) synthesis and phosphatidylcholine (PC) hydrolysis. Presently, the authors found that insulin decreased PC levels of BC3H-1 myocytes and rat adipocytes by approximately 10-25% within 30 s. These decreases were rapidly reversed in both cell types, apparently because of increased PC synthesis de novo. In BC3H-1 myocytes, pertussis toxin inhibited PC resynthesis and insulin effects on the pathway of de novo PA-DAG-PC synthesis, as evidenced by changes in ({sup 3}H)glycerol incorporation, but did not inhibit insulin-stimulated PC hydrolysis. Pertussis toxin also blocked themore » later, but not the initial, increase in DAG production in the myocytes. Phorbol esters activated PC hydrolysis in both myocytes and adipocytes, but insulin-induced stimulation of PC hydrolysis was not dependent upon activation of PKC, since this hydrolysis was not inhibited by 500 {mu}M sangivamycin, an effective PKC inhibitor. The results indicate that insulin increases DAG by pertussis toxin sensitive and insensitive (PC hydrolysis) mechanisms, which are mechanistically separate, but functionally interdependent and integrated. PC hydrolysis may contribute importantly to initial increases in DAG, but later sustained increases are apparently largely dependent on insulin-induced stimulation of the pathway of de novo phospholipid synthesis.« less

  2. Defining the extreme substrate specificity of Euonymus alatus diacylglycerol acetyltransferase, an unusual membrane-bound O-acyltransferase

    DOE PAGES

    Bansal, Sunil; Durrett, Timothy P.

    2016-11-08

    Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) synthesizes the unusually structured 3-acetyl-1,2-diacylglycerols (acetyl-TAG) found in the seeds of a few plant species. A member of the membrane-bound O-acyltransferase (MBOAT) family, EaDAcT transfers the acetyl group from acetyl-CoA to sn-1,2-diacylglycerol (DAG) to produce acetyl-TAG. In vitro assays demonstrated that the enzyme is also able to utilize butyryl-CoA and hexanoyl-CoA as acyl donors, though with much less efficiency compared with acetyl-CoA. Acyl-CoAs longer than eight carbons were not used by EaDAcT. This extreme substrate specificity of EaDAcT distinguishes it from all other MBOATs which typically catalyze the transfer of much longer acyl groups. Inmore » vitro selectivity experiments revealed that EaDAcT preferentially acetylated DAG molecules containing more double bonds over those with less. However, the enzyme was also able to acetylate saturated DAG containing medium chain fatty acids, albeit with less efficiency. Interestingly, EaDAcT could only acetylate the free hydroxyl group of sn-1,2-DAG but not the available hydroxyl groups in sn-1,3-DAG or in monoacylglycerols (MAG). Consistent with its similarity to the jojoba wax synthase, EaDAcT could acetylate fatty alcohols in vitro to produce alkyl acetates. Likewise, when coexpressed in yeast with a fatty acyl-CoA reductase capable of producing fatty alcohols, EaDAcT synthesized alkyl acetates although the efficiency of production was low. As a result, this improved understanding of EaDAcT specificity confirms that the enzyme preferentially utilizes acetyl-CoA to acetylate sn-1,2-DAGs and will be helpful in engineering the production of acetyl-TAG with improved functionality in transgenic plants.« less

  3. Defining the extreme substrate specificity of Euonymus alatus diacylglycerol acetyltransferase, an unusual membrane-bound O-acyltransferase

    PubMed Central

    Bansal, Sunil; Durrett, Timothy P.

    2016-01-01

    Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) synthesizes the unusually structured 3-acetyl-1,2-diacylglycerols (acetyl-TAG) found in the seeds of a few plant species. A member of the membrane-bound O-acyltransferase (MBOAT) family, EaDAcT transfers the acetyl group from acetyl-CoA to sn-1,2-diacylglycerol (DAG) to produce acetyl-TAG. In vitro assays demonstrated that the enzyme is also able to utilize butyryl-CoA and hexanoyl-CoA as acyl donors, though with much less efficiency compared with acetyl-CoA. Acyl-CoAs longer than eight carbons were not used by EaDAcT. This extreme substrate specificity of EaDAcT distinguishes it from all other MBOATs which typically catalyze the transfer of much longer acyl groups. In vitro selectivity experiments revealed that EaDAcT preferentially acetylated DAG molecules containing more double bonds over those with less. However, the enzyme was also able to acetylate saturated DAG containing medium chain fatty acids, albeit with less efficiency. Interestingly, EaDAcT could only acetylate the free hydroxyl group of sn-1,2-DAG but not the available hydroxyl groups in sn-1,3-DAG or in monoacylglycerols (MAG). Consistent with its similarity to the jojoba wax synthase, EaDAcT could acetylate fatty alcohols in vitro to produce alkyl acetates. Likewise, when coexpressed in yeast with a fatty acyl-CoA reductase capable of producing fatty alcohols, EaDAcT synthesized alkyl acetates although the efficiency of production was low. This improved understanding of EaDAcT specificity confirms that the enzyme preferentially utilizes acetyl-CoA to acetylate sn-1,2-DAGs and will be helpful in engineering the production of acetyl-TAG with improved functionality in transgenic plants. PMID:27688773

  4. Defining the extreme substrate specificity of Euonymus alatus diacylglycerol acetyltransferase, an unusual membrane-bound O-acyltransferase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bansal, Sunil; Durrett, Timothy P.

    Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) synthesizes the unusually structured 3-acetyl-1,2-diacylglycerols (acetyl-TAG) found in the seeds of a few plant species. A member of the membrane-bound O-acyltransferase (MBOAT) family, EaDAcT transfers the acetyl group from acetyl-CoA to sn-1,2-diacylglycerol (DAG) to produce acetyl-TAG. In vitro assays demonstrated that the enzyme is also able to utilize butyryl-CoA and hexanoyl-CoA as acyl donors, though with much less efficiency compared with acetyl-CoA. Acyl-CoAs longer than eight carbons were not used by EaDAcT. This extreme substrate specificity of EaDAcT distinguishes it from all other MBOATs which typically catalyze the transfer of much longer acyl groups. Inmore » vitro selectivity experiments revealed that EaDAcT preferentially acetylated DAG molecules containing more double bonds over those with less. However, the enzyme was also able to acetylate saturated DAG containing medium chain fatty acids, albeit with less efficiency. Interestingly, EaDAcT could only acetylate the free hydroxyl group of sn-1,2-DAG but not the available hydroxyl groups in sn-1,3-DAG or in monoacylglycerols (MAG). Consistent with its similarity to the jojoba wax synthase, EaDAcT could acetylate fatty alcohols in vitro to produce alkyl acetates. Likewise, when coexpressed in yeast with a fatty acyl-CoA reductase capable of producing fatty alcohols, EaDAcT synthesized alkyl acetates although the efficiency of production was low. As a result, this improved understanding of EaDAcT specificity confirms that the enzyme preferentially utilizes acetyl-CoA to acetylate sn-1,2-DAGs and will be helpful in engineering the production of acetyl-TAG with improved functionality in transgenic plants.« less

  5. Dependency graph for code analysis on emerging architectures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shashkov, Mikhail Jurievich; Lipnikov, Konstantin

    Direct acyclic dependency (DAG) graph is becoming the standard for modern multi-physics codes.The ideal DAG is the true block-scheme of a multi-physics code. Therefore, it is the convenient object for insitu analysis of the cost of computations and algorithmic bottlenecks related to statistical frequent data motion and dymanical machine state.

  6. Modified Gas Chromatographic Method to Determine Monoacylglycerol and Diacylglycerol Contents in Edible Fats and Oils.

    PubMed

    Satou, Chiemi; Goto, Hirofumi; Yamazaki, Yuya; Saitou, Katsuyoshi; Matsumoto, Shoji; Takahashi, Ou; Miyazaki, Yosuke; Ikuta, Keiichi; Yajima, Yosuke

    2017-06-01

    Monoacylglycerol (MAG) and diacylglycerol (DAG) are minor components of edible fats and oils, and they relate to the quality of these foods. The AOCS official method Cd 11b-91 has been used to determine MAG and DAG contents in fats and oils. There are, however, difficulties in the determination of MAG and DAG using this analytical procedure. Therefore, we improved this method by modifying the trimethylsilyl derivatization procedure and replacing the internal standard (IS) material. In our modified method, TMS-HT (mixture of hexamethyldisilazane and trimethylchlorosilane) was used for derivatization of MAG and DAG, which was followed by liquid-liquid extraction with water and n-hexane solution containing the IS, tricaprin. Using the modified method, we demonstrated superior repeatability in comparison with that of the AOCS method by reducing procedural difficulties. The relative standard deviation of distearin peak areas was 1.8% or 2.9% in the modified method, while it was 5.6% in the AOCS method. In addition, capillary columns, such as DB-1ht and DB-5ht could be used in this method.

  7. Formation of diacylglycerol by a phospholipase D-phosphatidate phosphatase pathway specific for phosphatidylcholine in endothelial cells.

    PubMed

    Martin, T W

    1988-10-14

    The conversion of phosphatidylcholine (PC) to diacylglycerol (DAG) was studied in sonicated endothelial cells and in subcellular fractions in the presence of 0.05% Triton X-100 and 2 mM EDTA. DAG formation occurred predominantly in an organelle fraction that sedimented at 15,000 x g. In parallel reactions with exogenous 1-oleoyl-2-[3H]oleoyl-PC (sn-2-[3H]DOPC) and phosphatidyl[3H]choline ([choline-3H]PC), [3H]DAG was formed by a reaction pathway in which [3H]choline was the only product derived from [choline-3H]PC. [3H]Choline was not formed secondarily from [3H]glycerophosphocholine or [3H]phosphocholine. Small amounts of [3H]phosphatidate ([3H]PA) were isolated from reactions with sn-2-[3H]DOPC at short incubation times, and substantial PA phosphatase activity was demonstrated. These data, taken together, supported a phospholipase D-PA phosphatase pathway of DAG formation. Kinetic data established that the low ratio of [3H]PA/[3H]DAG formed in reactions with sn-2-[3H]DOPC was due to a 15-fold higher Vmax and 7-fold lower apparent Km of the PA phosphatase. The [3H]PA/[3H]DAG product ratio was increased by addition of unlabeled PA or by selective extraction of phospholipase D with Triton X-100. The characteristics of the phospholipase D indicated a unique enzyme. Activity was optimal in the presence of EDTA and was almost totally dependent upon Triton X-100. The pH profile displayed a peak at 7.0. Of particular significance was the stringent substrate specificity. Phosphatidylinositol was not hydrolyzed, and activities towards phosphatidylethanolamine and sphingomyelin were at most 30- to 50-fold lower than those towards PC. Phospholipase D and PA phosphatase were identified in a number of rat tissues and other cells. The highest activities of phospholipase D were present in lung and endothelial cells. Phospholipase D was partially purified from rat lung by Triton X-100 extraction and anion exchange chromatography. When linked with PA phosphatase, the phospholipase

  8. The Production of the AGARD Multilingual Aeronautical Dictionary Using Computer Techniques,

    DTIC Science & Technology

    1981-04-01

    INl 10161 AnfliigknapuN if) 1 6877 Abatugalau (t) 10068 Ahkjntut, . fiI 10642 Anftigkannolfea (I1867 Ah.ug nng ft) 10062 skususocl, Aussabiohung 111...jA jin00 I.... (. . 167 ipndn I10063 ni-- M--1 M 13632 dAjinn!,-O In -1611’nn .*,.oIi P67 ,n . , 10062 d..-0a~ 1-014~~ /V *A 10064 .. n.lj If).t~ 1016...oilnn~nnn (0621 I) 10062 dnp4In.,l*tI0q 18891 aalln’." I/) IWAn.,0I 104s 16 0 ......nln In) )-d/ IVAann.. 14606 ipinO n W66 eggs~ l d n/njf l (If) d~p

  9. The Crucial Role of C18-Cer in Fat-Induced Skeletal Muscle Insulin Resistance.

    PubMed

    Blachnio-Zabielska, Agnieszka U; Chacinska, Marta; Vendelbo, Mikkel H; Zabielski, Piotr

    2016-01-01

    Muscle bioactive lipids accumulation leads to several disorder states. The most common are insulin resistance (IR) and type 2 diabetes. There is an ongoing debate which of the lipid species plays the major role in induction of muscle IR. Our aim was to elucidate the role of particular lipid group in induction of muscle IR. The analyses were performed on muscle from the following groups of rats: 1. Control, fed standard diet, 2 HFD, fed high fat diet, 3. HFD/Myr, fed HFD and treated with myriocin (Myr), an inhibitor of ceramide de novo synthesis. We utilized [U13C] palmitate isotope tracer infusion and mass spectrometry to measure content and synthesis rate of muscle long-chain acyl-CoA (LCACoA), diacylglycerols (DAG) and ceramide (Cer). HFD led to intramuscular accumulation of LCACoA, DAG and Cer and skeletal muscle IR. Myr-treatment caused decrease in Cer (most noticeable for stearoyl-Cer and oleoyl-Cer) and accumulation of DAG, possibly due to re-channeling of excess of intramuscular LCACoA towards DAG synthesis. An improvement in insulin sensitivity at both systemic and muscular level coincided with decrease in ceramide, despite elevated intramuscular DAG. The improved insulin sensitivity was associated with decreased muscle stearoyl- and oleoyl-ceramide content. The results indicate that accumulation of those ceramide species has the greatest impact on skeletal muscle insulin sensitivity in rats. © 2016 The Author(s) Published by S. Karger AG, Basel.

  10. Membrane-Surface Anchoring of Charged Diacylglycerol-Lactones Correlates with Biological Activities | Center for Cancer Research

    Cancer.gov

    The inside cover picture shows the molecular structure of a DAG lactone derivative on top of the inner leaflet of a DMPC bilayer. The confocal microscopy image illustrates DAG-lactone-stimulated membrane localization of PKCδ-ECFP in living cells, while the space-filling model shows the surface of the C1B domain of PKCδ, the target of the lactone.

  11. Quantization of the Kadomtsev-Petviashvili equation

    NASA Astrophysics Data System (ADS)

    Kozlowski, K.; Sklyanin, E. K.; Torrielli, A.

    2017-08-01

    We propose a quantization of the Kadomtsev-Petviashvili equation on a cylinder equivalent to an infinite system of nonrelativistic one-dimensional bosons with the masses m = 1, 2,.... The Hamiltonian is Galilei-invariant and includes the split and merge terms Ψ _{{m_1}}^\\dag Ψ _{{m_2}}^\\dag {Ψ _{{m_1} + {m_2}}} and Ψ _{{m_1} + {m_2}}^\\dag {Ψ _{{m_1}}}{Ψ _{{m_2}}} for all combinations of particles with masses m 1, m 2, and m 1 + m 2 for a special choice of coupling constants. We construct the Bethe eigenfunctions for the model and verify the consistency of the coordinate Bethe ansatz and hence the quantum integrability of the model up to the mass M=8 sector.

  12. Diacylglycerol levels modulate the cellular distribution of the nicotinic acetylcholine receptor.

    PubMed

    Kamerbeek, Constanza B; Mateos, Melina V; Vallés, Ana S; Pediconi, María F; Barrantes, Francisco J; Borroni, Virginia

    2016-05-01

    Diacylglycerol (DAG), a second messenger involved in different cell signaling cascades, activates protein kinase C (PKC) and D (PKD), among other kinases. The present work analyzes the effects resulting from the alteration of DAG levels on neuronal and muscle nicotinic acetylcholine receptor (AChR) distribution. We employ CHO-K1/A5 cells, expressing adult muscle-type AChR in a stable manner, and hippocampal neurons, which endogenously express various subtypes of neuronal AChR. CHO-K1/A5 cells treated with dioctanoylglycerol (DOG) for different periods showed augmented AChR cell surface levels at short incubation times (30min-4h) whereas at longer times (18h) the AChR was shifted to intracellular compartments. Similarly, in cultured hippocampal neurons surface AChR levels increased as a result of DOG incubation for 4h. Inhibition of endogenous DAG catabolism produced changes in AChR distribution similar to those induced by DOG treatment. Specific enzyme inhibitors and Western blot assays revealed that DAGs exert their effect on AChR distribution through the modulation of the activity of classical PKC (cPKC), novel PKC (nPKC) and PKD activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Thermal profiles, crystallization behaviors and microstructure of diacylglycerol-enriched palm oil blends with diacylglycerol-enriched palm olein.

    PubMed

    Xu, Yayuan; Zhao, Xiaoqing; Wang, Qiang; Peng, Zhen; Dong, Cao

    2016-07-01

    To elucidate the possible interaction mechanisms between DAG-enriched oils, this study investigated how mixtures of DAG-enriched palm-based oils influenced the phase behavior, thermal properties, crystallization behaviors and the microstructure in binary fat blends. DAG-enriched palm oil (PO-DAGE) was blended with DAG-enriched palm olein (POL-DAGE) in various percentages (0%, 10%, 30%, 50%, 70%, 90%, 100%). Based on the observation of iso-solid diagram and phase diagram, the binary mixture of PO-DAGE/POL-DAGE showed a better compatibility in comparison with their corresponding original blends. DSC thermal profiles exhibited that the melting and crystallization properties of PO-DAGE/POL-DAGE were distinctively different from corresponding original blends. Crystallization kinetics revealed that PO-DAGE/POL-DAGE blends displayed a rather high crystallization rate and exhibited no spherulitic crystal growth. From the results of polarized light micrographs, PO-DAGE/POL-DAGE blends showed more dense structure with very small needle-like crystals than PO/POL. X-ray diffraction evaluation revealed when POL-DAGE was added in high contents to PO-DAGE, above 30%, β-polymorph dominated, and the mount of β' forms crystals was decreasing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Stage-Specific Fatty Acid Fluxes Play a Regulatory Role in Glycerolipid Metabolism during Seed Development in Jatropha curcas L.

    PubMed

    Chaitanya, Bharatula Sri Krishna; Kumar, Sumit; Kaki, Shiva Shanker; Balakrishna, Marrapu; Karuna, Mallampalli Sri Lakshmi; Prasad, Rachapudi Badari Narayana; Sastry, Pidaparty Seshadri; Reddy, Attipalli Ramachandra

    2015-12-23

    The present study describes the changes in lipid profile as well as fatty acid fluxes during seed development in Jatropha curcas L. Endosperm from 34, 37, and 40 days after anthesis (DAA), incubated with [(14)C]acetate, showed significant synthesis of phosphatidylcholine (PC) at seed maturation. The fatty acid methyl ester profile showed PC from 34 DAA was rich in palmitic acid (16:0), whereas PC from 37 and 40 DAA was rich in oleic acid (18:1n-9). Molecular species analysis of diacylglycerol (DAG) indicated DAG (16:0/18:2n-6) was in abundance at 34 DAA, whereas DAG (18:1n-9/18:2n-6) was significantly high at 40 DAA. Triacylglycerol (TAG) analysis revealed TAG (16:0/18:2n-6/16:0) was abundant at 34 DAA, whereas TAG (18:1n-9/18:2n-6/18:1n-9) formed the majority at 40 DAA. Expression of two types of diacylglycerol acyltransferases varied with seed maturation. These data demonstrate stage-specific distinct pools of PC and DAG synthesis during storage TAG accumulation in Jatropha seed.

  15. Regulation of Cellular Diacylglycerol through Lipid Phosphate Phosphatases Is Required for Pathogenesis of the Rice Blast Fungus, Magnaporthe oryzae

    PubMed Central

    Mir, Albely Afifa; Choi, Jaeyoung; Choi, Jaehyuk; Lee, Yong-Hwan

    2014-01-01

    Considering implication of diacylglycerol in both metabolism and signaling pathways, maintaining proper levels of diacylglycerol (DAG) is critical to cellular homeostasis and development. Except the PIP2-PLC mediated pathway, metabolic pathways leading to generation of DAG converge on dephosphorylation of phosphatidic acid catalyzed by lipid phosphate phosphatases. Here we report the role of such enzymes in a model plant pathogenic fungus, Magnaporthe oryzae. We identified five genes encoding putative lipid phosphate phosphatases (MoLPP1 to MoLPP5). Targeted disruption of four genes (except MoLPP4) showed that MoLPP3 and MoLPP5 are required for normal progression of infection-specific development and proliferation within host plants, whereas MoLPP1 and MoLPP2 are indispensable for fungal pathogenicity. Reintroduction of MoLPP3 and MoLPP5 into individual deletion mutants restored all the defects. Furthermore, exogenous addition of saturated DAG not only restored defect in appressorium formation but also complemented reduced virulence in both mutants. Taken together, our data indicate differential roles of lipid phosphate phosphatase genes and requirement of proper regulation of cellular DAGs for fungal development and pathogenesis. PMID:24959955

  16. Preparation of Diacylglycerol from Lard by Enzymatic Glycerolysis and Its Compositional Characteristics

    PubMed Central

    Diao, Xiaoqin; Guan, Haining

    2017-01-01

    The aim of this study was to prepare diacylglycerol (DAG) by enzymatic glycerolysis of lard. The effects of reaction parameters such as lipase type, reaction temperature, enzyme amount, substrate molar ratio (lard/glycerol), reaction time, and magnetic stirring speed were investigated. Lipozyme RMIM was found to be a more active biocatalyst than Novozym 435, and the optimal reaction conditions were 14:100 (W/W) of enzyme to lard substrate ratio, 1:1 of lard to glycerol molar ratio, and 500 rpm magnetic stirring speed. The reaction mixture was first incubated at 65℃ for 2 h and then transferred to 45℃ for 8 h. At the optimum reaction conditions, the conversion rate of triacylglycerol (TAG) and the content of DAG in the reaction mixture reached 76.26% and 61.76%, respectively, and the DAG content in purified glycerolized lard was 82.03% by molecular distillation. The distribution of fatty acids and Fourier transform infrared spectra in glycerolized lard samples were similar to those in lard samples. The results revealed that enzymatic glycerolysis and molecular distillation can be used to prepare more highly purified DAG from lard. PMID:29725202

  17. Caloric restriction and intermittent fasting alter hepatic lipid droplet proteome and diacylglycerol species and prevent diabetes in NZO mice.

    PubMed

    Baumeier, Christian; Kaiser, Daniel; Heeren, Jörg; Scheja, Ludger; John, Clara; Weise, Christoph; Eravci, Murat; Lagerpusch, Merit; Schulze, Gunnar; Joost, Hans-Georg; Schwenk, Robert Wolfgang; Schürmann, Annette

    2015-05-01

    Caloric restriction and intermittent fasting are known to improve glucose homeostasis and insulin resistance in several species including humans. The aim of this study was to unravel potential mechanisms by which these interventions improve insulin sensitivity and protect from type 2 diabetes. Diabetes-susceptible New Zealand Obese mice were either 10% calorie restricted (CR) or fasted every other day (IF), and compared to ad libitum (AL) fed control mice. AL mice showed a diabetes prevalence of 43%, whereas mice under CR and IF were completely protected against hyperglycemia. Proteomic analysis of hepatic lipid droplets revealed significantly higher levels of PSMD9 (co-activator Bridge-1), MIF (macrophage migration inhibitor factor), TCEB2 (transcription elongation factor B (SIII), polypeptide 2), ACY1 (aminoacylase 1) and FABP5 (fatty acid binding protein 5), and a marked reduction of GSTA3 (glutathione S-transferase alpha 3) in samples of CR and IF mice. In addition, accumulation of diacylglycerols (DAGs) was significantly reduced in livers of IF mice (P=0.045) while CR mice showed a similar tendency (P=0.062). In particular, 9 DAG species were significantly reduced in response to IF, of which DAG-40:4 and DAG-40:7 also showed significant effects after CR. This was associated with a decreased PKCε activation and might explain the improved insulin sensitivity. In conclusion, our data indicate that protection against diabetes upon caloric restriction and intermittent fasting associates with a modulation of lipid droplet protein composition and reduction of intracellular DAG species. Copyright © 2015. Published by Elsevier B.V.

  18. Long non-coding RNA NEAT1-modulated abnormal lipolysis via ATGL drives hepatocellular carcinoma proliferation.

    PubMed

    Liu, Xirui; Liang, Yingjian; Song, Ruipeng; Yang, Guangchao; Han, Jihua; Lan, Yaliang; Pan, Shangha; Zhu, Mingxi; Liu, Yao; Wang, Yan; Meng, Fanzheng; Cui, Yifeng; Wang, Jiabei; Zhang, Bo; Song, Xuan; Lu, Zhaoyang; Zheng, Tongsen; Liu, Lianxin

    2018-05-15

    Abnormal metabolism, including abnormal lipid metabolism, is a hallmark of cancer cells. Some studies have demonstrated that the lipogenic pathway might promote the development of hepatocellular carcinoma (HCC). However, the role of the lipolytic pathway in HCC has not been elucidated. We compared levels of adipose triglyceride lipase (ATGL) in human HCC and healthy liver tissues by real time PCR, western blot and immunohistochemistry. We measured diacylglycerol(DAG) and free fatty acid (FFA) levels in HCC cells driven by the NEAT1-ATGL axis and in HCC tissues. We also assessed the effects of ATGL, DAG, FFA, and NEAT1 on HCC cells proliferation in vitro and in an orthotopic xenograft HCC mouse model. We also performed a luciferase reporter assay to investigate the interaction between NEAT1/ATGL and miR-124-3p. We found that the lipolytic enzyme, ATGL is highly expressed in human HCC tissues and predicts poor prognosis. We also found that high levels of DAG and FFA are present in HCC tissues. Furthermore, the lncRNA-NEAT1 was found to modulate ATGL expression and disrupt lipolysis in HCC cells via ATGL. Notably, ATGL and its products, DAG and FFA, were shown to be responsible for NEAT1-mediated HCC cell growth. NEAT1 regulated ATGL expression by binding miR-124-3p. Additionally, NEAT1 knockdown attenuated HCC cell growth through miR-124-3p/ATGL/DAG+FFA/PPARα signaling. Our results reveal that NEAT1-modulates abnormal lipolysis via ATGL to drive HCC proliferation.

  19. Fragile X syndrome: Are signaling lipids the missing culprits?

    PubMed

    Tabet, Ricardos; Vitale, Nicolas; Moine, Hervé

    2016-11-01

    Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and autism. FXS results from the absence of FMRP, an RNA binding protein associated to ribosomes that influences the translation of specific mRNAs in post-synaptic compartments of neurons. The main molecular consequence of the absence of FMRP is an excessive translation of neuronal protein in several areas of the brain. This local protein synthesis deregulation is proposed to underlie the defect in synaptic plasticity responsible for FXS. Recent findings in neurons of the fragile X mouse model (Fmr1-KO) uncovered another consequence of the lack of FMRP: a deregulation of the diacylglycerol (DAG)/phosphatidic acid (PA) homeostasis. DAG and PA are two interconvertible lipids that influence membrane architecture and that act as essential signaling molecules that activate various downstream effectors, including master regulators of local protein synthesis and actin polymerization. As a consequence, DAG and PA govern a variety of cellular processes, including cell proliferation, vesicle/membrane trafficking and cytoskeletal organization. At the synapse, the level of these lipids is proposed to influence the synaptic activation status. FMRP appears as a master regulator of this neuronal process by controlling the translation of a diacylglycerol kinase enzyme that converts DAG into PA. The deregulated levels of DAG and PA caused by the absence of FMRP could represent a novel therapeutic target for the treatment of FXS. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. Endurance exercise training and high-fat diet differentially affect composition of diacylglycerol molecular species in rat skeletal muscle.

    PubMed

    Kawanishi, Noriaki; Takagi, Kana; Lee, Hyeon-Cheol; Nakano, Daiki; Okuno, Toshiaki; Yokomizo, Takehiko; Machida, Shuichi

    2018-06-01

    Insulin resistance of peripheral muscle is implicated in the etiology of metabolic syndrome in obesity. Although accumulation of glycerolipids, such as triacylglycerol and diacylglycerol (DAG), in muscle contributes to insulin resistance in obese individuals, endurance-trained athletes also have higher glycerolipid levels but normal insulin sensitivity. We hypothesized that the difference in insulin sensitivity of skeletal muscle between athletes and obese individuals stems from changes in fatty acid composition of accumulated lipids. Here, we evaluated the effects of intense endurance exercise and high-fat diet (HFD) on the accumulation and composition of lipid molecular species in rat skeletal muscle using a lipidomic approach. Sprague-Dawley female rats were randomly assigned to three groups and received either normal diet (ND) in sedentary conditions, ND plus endurance exercise training, or HFD in sedentary conditions. Rats were fed ND or HFD between 4 and 12 wk of age. Rats in the exercise group ran on a treadmill for 120 min/day, 5 days/wk, for 8 wk. Soleus muscle lipidomic profiles were obtained using liquid chromatography/tandem mass spectrometry. Total DAG levels, particularly those of palmitoleate-containing species, were increased in muscle by exercise training. However, whereas the total DAG level in the muscle was also increased by HFD, the levels of DAG molecular species containing palmitoleate were decreased by HFD. The concentration of phosphatidylethanolamine molecular species containing palmitoleate was increased by exercise but decreased by HFD. Our results indicate that although DAG accumulation was similar levels in trained and sedentary obese rats, specific changes in molecular species containing palmitoleate were opposite.

  1. Interhospital transfer of liver trauma in New Mexico: a state of austere resources.

    PubMed

    Szoka, Nova; Murray-Krezan, Cristina; Miskimins, Richard; Greenbaum, Alissa; Tobey, David; Faizi, Syed; West, Sonlee; Lu, Stephen; Howdieshell, Thomas; Demarest, Gerald; Nir, Itzhak

    2014-09-01

    There is debate in the trauma literature regarding the effect of prolonged prehospital transport on morbidity and mortality. This study analyzes the management of hepatic trauma patients requiring surgery and compares the outcomes of the group that was transferred to the University of New Mexico Hospital (UNMH) from outside institutions, to the directly admitted group. The UNMH Trauma Database was queried from 2005-2012. Of 674 patients who sustained liver injuries, 163 required surgery: 46 patients (28.2%) underwent interhospital transfer, and 117 (71.8%) were directly admitted. Variables examined included transfer status, trauma mechanism, transport type, injury severity score (ISS), liver injury grade, and associated injuries. Outcome variables included length of stay (LOS) and 30-day mortality. Outcomes of the transfer group (TG) and direct admit group (DAG) were compared. Both TG and DAG had the same median age (31 y, P = 0.33). The blunt-to-penetrating ratio was the same for each group (48% blunt: 52% penetrating, P = 1.0). Median ISS was 25 for the TG and 26 for the DAG. Grade III or higher injury occurred in 29 (63%) of the TG and in 68 (58%) of the DAG (P = 0.56). Median hospital LOS was 14 d for TG and 9 d for DAG (P = 0.15). Median intensive care unit LOS was 4 d for both groups (P = 0.71). Thirty-day mortality was 20% in each group (P = 0.27). Using a multiple logistic regression model for the outcome of mortality, only age, ISS, and liver injury grade, not transfer status or transport type, had a significant effect on mortality. There was no significant difference in liver injury grade, ISS, LOS, and mortality between TG and DAG. In the patient population of our study, transfer status did not affect outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification

    PubMed Central

    Wen, Cuihong; Zhang, Jing; Rebelo, Ana; Cheng, Fanyong

    2016-01-01

    Optical Music Recognition (OMR) has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM). The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM), which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs) and Neural Networks (NNs). PMID:26985826

  3. A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification.

    PubMed

    Wen, Cuihong; Zhang, Jing; Rebelo, Ana; Cheng, Fanyong

    2016-01-01

    Optical Music Recognition (OMR) has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM). The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM), which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs) and Neural Networks (NNs).

  4. Mutation of a single residue in the S2-S3 loop of CNG channels alters the gating properties and sensitivity to inhibitors.

    PubMed

    Crary, J I; Dean, D M; Maroof, F; Zimmerman, A L

    2000-12-01

    We previously found that native cyclic nucleotide-gated (CNG) cation channels from amphibian rod cells are directly and reversibly inhibited by analogues of diacylglycerol (DAG), but little is known about the mechanism of this inhibition. We recently determined that, at saturating cGMP concentrations, DAG completely inhibits cloned bovine rod (Brod) CNG channels while only partially inhibiting cloned rat olfactory (Rolf) channels (Crary, J.I., D.M. Dean, W. Nguitragool, P.T. Kurshan, and A.L. Zimmerman. 2000. J. Gen. Phys. 116:755-768; in this issue). Here, we report that a point mutation at position 204 in the S2-S3 loop of Rolf and a mouse CNG channel (Molf) found in olfactory epithelium and heart, increased DAG sensitivity to that of the Brod channel. Mutation of this residue from the wild-type glycine to a glutamate (Molf G204E) or aspartate (Molf G204D) gave dramatic increases in DAG sensitivity without changing the apparent cGMP or cAMP affinities or efficacies. However, unlike the wild-type olfactory channels, these mutants demonstrated voltage-dependent gating with obvious activation and deactivation kinetics. Interestingly, the mutants were also more sensitive to inhibition by the local anesthetic, tetracaine. Replacement of the position 204 glycine with a tryptophan residue (Rolf G204W) not only gave voltage-dependent gating and an increased sensitivity to DAG and tetracaine, but also showed reduced apparent agonist affinity and cAMP efficacy. Sequence comparisons show that the glycine at position 204 in the S2-S3 loop is highly conserved, and our findings indicate that its alteration can have critical consequences for channel gating and inhibition.

  5. Oxidation Stability of O/W Emulsion Prepared with Linolenic Acid Enriched Diacylglycerol.

    PubMed

    Shin, Jung-Ah; Lee, Mi-Young; Lee, Ki-Teak

    2016-10-01

    The sn-1,3-regiospecific Rhizomucor miehei lipase (Lipozyme RM IM) was employed to produce structured diacylglycerol (SL-DAG), which contained 67.3 mol% DAG with 27.2 area% of C18:3. To investigate the oxidative stability of the SL-DAG in emulsion form, 5% oil-in-water (O/W) emulsions were prepared with 200 and 400 ppm sinapic acid. It was shown that the hydroperoxide values of the control (without any antioxidant) was the highest (117.7 meq/L) on day 43 of storage and thereafter the value decreased. However, the emulsions with 200 and 400 ppm sinapic acid resulted in slow oxidation degree until day 64 of storage (30.3 and 7.3 meq/L, respectively). Aldehyde measurements for the 200 ppm sinapic acid emulsion (12.8 mmol/mol) and the 400 ppm sinapic acid emulsion (7.5 mmol/mol) also showed better oxidative stability than that for the 200 ppm catechin emulsion (27.4 mmol/mol) and the control (52.7 mmol/mol). Although the SL-DAG in the emulsions contains high levels of polyunsaturated fatty acids, the degree of oxidation in the emulsions can be reduced when sinapic acid is used as an antioxidant. © 2016 Institute of Food Technologists®.

  6. Abrogating Monoacylglycerol Acyltransferase Activity in Liver Improves Glucose Tolerance and Hepatic Insulin Signaling in Obese Mice

    PubMed Central

    Soufi, Nisreen; Chambers, Kari T.; Chen, Zhouji; Schweitzer, George G.; McCommis, Kyle S.; Erion, Derek M.; Graham, Mark J.; Su, Xiong; Finck, Brian N.

    2014-01-01

    Monoacylglycerol acyltransferase (MGAT) enzymes convert monoacylglycerol to diacylglycerol (DAG), a lipid that has been linked to the development of hepatic insulin resistance through activation of protein kinase C (PKC). The expression of genes that encode MGAT enzymes is induced in the livers of insulin-resistant human subjects with nonalcoholic fatty liver disease, but whether MGAT activation is causal of hepatic steatosis or insulin resistance is unknown. We show that the expression of Mogat1, which encodes MGAT1, and MGAT activity are also increased in diet-induced obese (DIO) and ob/obmice. To probe the metabolic effects of MGAT1 in the livers of obese mice, we administered antisense oligonucleotides (ASOs) against Mogat1 to DIO and ob/ob mice for 3 weeks. Knockdown of Mogat1 in liver, which reduced hepatic MGAT activity, did not affect hepatic triacylglycerol content and unexpectedly increased total DAG content. Mogat1 inhibition also increased both membrane and cytosolic compartment DAG levels. However, Mogat1 ASO treatment significantly improved glucose tolerance and hepatic insulin signaling in obese mice. In summary, inactivation of hepatic MGAT activity, which is markedly increased in obese mice, improved glucose tolerance and hepatic insulin signaling independent of changes in body weight, intrahepatic DAG and TAG content, and PKC signaling. PMID:24595352

  7. Evidence of Strict Stereospecificity in the Structure of sn-1,2-Diacyl-3-Acetyl-Glycerols from Euonymus maximowiczianus Seeds Using Nuclear Magnetic Resonance Spectroscopy.

    PubMed

    Sidorov, Roman A; Shashkov, Alexander S; Solovyev, Pavel A; Gorshkova, Elena N; Tsydendambaev, Vladimir D

    2018-05-02

    Asymmetric, optically active sn-1,2-diacyl-3-acetyl-glycerols (AcDAG) have been known to scientists for several decades. However, to date, the problem of their structure has not been definitely resolved, which has led to a vast diversity of terms used for their designation in the literature. Using two-dimensional nuclear magnetic resonance, we have investigated AcDAG from the mature seeds of Euonymus maximowiczianus, from which we have been able to both identify a correlation of the methyl group in acetic acid residue with protons at the carbon atom at sn-3 position in the glycerol residue of the AcDAG molecule and, for the first time, demonstrate that this correlation is observed exclusively with one carbon atom at the α-position, but not with two as would have been expected in case of a racemic mixture. Moreover, results of our analysis of AcDAG isolated from the seeds of E. maximowiczianus directly confirm that diacylglycerol-3-acetyl-transferase is responsible for their biosynthesis, which reveals a strict specificity not only to acetyl-CoA as one of the substrates but also to the sn-3-position of the glycerol residue in sn-1,2-diacylglycerol during their biosynthesis. © 2018 AOCS.

  8. A Convenient and Safer Synthesis of Diaminoglyoxime

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, Eric C.; Sabatini, Jesse J.; Zuckerman, Nathaniel B.

    A new procedure for the synthesis and isolation of diaminoglyoxime (DAG) is described. A previous procedure involved treating glyoxal with two equivalents each of hydroxylammonium chloride and sodium hydroxide to form glyoxime, followed by further treatment of this intermediate with two additional equivalents of hydroxylammonium chloride and sodium hydroxide at 95 °C to form DAG. Two recrystallizations were needed to obtain the desired product in pure form. Another previous procedure employed glyoxal in the presence of four equivalents each of hydroxylammonium chloride and sodium hydroxide at 95 °C to form DAG. Though this latter procedure gives product after a fewmore » hours, yields do not exceed 40%, and the reaction is prone to thermal runaway. Furthermore, the use of decolorizing carbon, and recrystallization of the crude solid is necessary to obtain a pure product. The new disclosed procedure involves treating a preheated aqueous hydroxylamine solution (50 wt. %, ten equivalents) with aqueous glyoxal (40 wt. %), followed by heating at 95 °C for 72-96 h. The reaction is cooled to room temperature, and then to 0-5 °C to obtain DAG in pure form, without recrystallization or decolorizing carbon in 77-80% yield. The exothermic nature of the reaction is also minimized by this updated process.« less

  9. A Convenient and Safer Synthesis of Diaminoglyoxime

    DOE PAGES

    Johnson, Eric C.; Sabatini, Jesse J.; Zuckerman, Nathaniel B.

    2017-11-29

    A new procedure for the synthesis and isolation of diaminoglyoxime (DAG) is described. A previous procedure involved treating glyoxal with two equivalents each of hydroxylammonium chloride and sodium hydroxide to form glyoxime, followed by further treatment of this intermediate with two additional equivalents of hydroxylammonium chloride and sodium hydroxide at 95 °C to form DAG. Two recrystallizations were needed to obtain the desired product in pure form. Another previous procedure employed glyoxal in the presence of four equivalents each of hydroxylammonium chloride and sodium hydroxide at 95 °C to form DAG. Though this latter procedure gives product after a fewmore » hours, yields do not exceed 40%, and the reaction is prone to thermal runaway. Furthermore, the use of decolorizing carbon, and recrystallization of the crude solid is necessary to obtain a pure product. The new disclosed procedure involves treating a preheated aqueous hydroxylamine solution (50 wt. %, ten equivalents) with aqueous glyoxal (40 wt. %), followed by heating at 95 °C for 72-96 h. The reaction is cooled to room temperature, and then to 0-5 °C to obtain DAG in pure form, without recrystallization or decolorizing carbon in 77-80% yield. The exothermic nature of the reaction is also minimized by this updated process.« less

  10. Absence of cross-resistance between two alkylating agents: BCNU vs bifunctional galactitol.

    PubMed

    Institóris, E; Szikla, K; Otvös, L; Gál, F

    1989-01-01

    Dianhydrogalactitol (DAG) increased the life span of both BCNU-sensitive and -resistant L1210 tumor-bearing mice. However, the BCNU-resistant strain showed slightly lower sensitivity against DAG, which could be overcome by an increase in drug dose of ca. 20%. The somewhat lower sensitivity was proportional to a slightly reduced DNA cross-linking formation induced by DAG in BCNU-resistant cells. The amount of DNA cross-links was determined by measurement of the 1,6-di(guaninyl)-galactitol content of DNA. The slight reduction in cross-links is not attributable to DNA repair but rather to other factors that seem to prevent the formation of DNA-drug adducts. The absence of cross-resistance is explained by different kinds of DNA damage caused by the two alkylating agents and the presumably different defense mechanisms developed by cells against these lesions.

  11. Identification of the In Vivo Phosphorylation Sites of the Ras Suppressor Rsu-1

    DTIC Science & Technology

    2000-12-11

    to phosphatidic acid (PA). Ras activation of the Raf serine/threonine kinases and activation of the MAPKs remains an important component of Ras...of either phospholipase C isofonns to yield DAG, or phospholipase D to yield phosphatidic acid and then DAG. Diacylglycerol is the key "on" switch...Rsu-I is phosphorylated in vivo in response to growth factor and TPA , a known activator of PKC. Phosphoamino acid analysis of Rsu- I suggests that

  12. A Flight Investigation of Digital Control Using Microprocessor Technology.

    DTIC Science & Technology

    1979-06-01

    software development system (Fig. 3-4) allow programs to be entered and tested efficiently. The ground chasis 3-7 pF MIRO -DFCS HOUSING I ANALOG...6E/V .125 06 La/V Lca/V/10 .200 07 L /V 100 LV/V .200 V 08 Step Gust .100 Scaling 10 D-VT V.073 11 Da-g Da.g/10o .060 12 g g/100 . 322 13 Vscale 1003x

  13. Interleukin 4 receptor signaling in human monocytes and U937 cells involves the activation of a phosphatidylcholine-specific phospholipase C: a comparison with chemotactic peptide, FMLP, phospholipase D, and sphingomyelinase

    PubMed Central

    1994-01-01

    Interleukin 4 (IL-4) diminishes cytokine activation of human macrophage. IL-4 binding to monocyte IL-4R is associated with protein kinase C (PKC) translocation to a nuclear fraction. The cleavage of diacyglycerol (DAG), an activator of PKC, from membrane phospholipids was investigated to define the proximal events of IL-4R signaling. IL-4 induced a statistically significant time-and dose-dependent generation of DAG. The IL-4-triggered production of DAG was not derived from phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis, since neither cytosolic calcium flux nor liberation of inositol phosphates was detected in response to IL-4. Experiments were performed using [14C- methyl]choline-labeled U937 cells and monocytes to determine whether IL- 4R activated phospholipase C (PLC), PLD, or PLA2 to use membrane phosphatidylcholine (PC) to form DAG. IL-4 induced a time- and dose- dependent increase of phosphocholine (pchol) with concomitant degradation of membrane PC (p < 0.05 compared with control). The finding that the peak reduction of PC was equivalent to peak production of pchol suggested that IL-4R signaling involved the activation of a PC- specific PLC. Changes in choline (chol) or lyso-PC and glycerolphosphocholine, the respective products of PC cleavage by PLD or PLA2, were not detected in IL-4-treated cells. In contrast, exogenous PLD induced an increase in chol and concomitant loss of membrane PC. Additional investigation suggested that IL-4R signaling does not involve PLD. In cells labeled with L-lyso-3-PC 1-[1- 14C]palmitoyl, PLD but not IL-4, increased the production of phosphatidic acid (PA) and phosphatidyl-ethanol when pretreated with ethanol. Propranolol, an inhibitor of phosphatidate phosphohydrolase, and calyculin A, a phosphatase 1 and 2A inhibitor, blocked DAG production in response to FMLP but not to IL-4. In propranolol pretreated cells, PMA but not IL-4 triggered the production of PA and lowered the amount of DAG. Evidence that PLA2 is not

  14. Diacylglycerol, phosphatidic acid, and their metabolic enzymes in synaptic vesicle recycling.

    PubMed

    Tu-Sekine, Becky; Goldschmidt, Hana; Raben, Daniel M

    2015-01-01

    The synaptic vesicle (SV) cycle includes exocytosis of vesicles loaded with a neurotransmitter such as glutamate, coordinated recovery of SVs by endocytosis, refilling of vesicles, and subsequent release of the refilled vesicles from the presynaptic bouton. SV exocytosis is tightly linked with endocytosis, and variations in the number of vesicles, and/or defects in the refilling of SVs, will affect the amount of neurotransmitter available for release (Sudhof, 2004). There is increasing interest in the roles synaptic vesicle lipids and lipid metabolizing enzymes play in this recycling. Initial emphasis was placed on the role of polyphosphoinositides in SV cycling as outlined in a number of reviews (Lim and Wenk, 2009; Martin, 2012; Puchkov and Haucke, 2013; Rohrbough and Broadie, 2005). Other lipids are now recognized to also play critical roles. For example, PLD1 (Humeau et al., 2001; Rohrbough and Broadie, 2005) and some DGKs (Miller et al., 1999; Nurrish et al., 1999) play roles in neurotransmission which is consistent with the critical roles for phosphatidic acid (PtdOH) and diacylglycerol (DAG) in the regulation of SV exo/endocytosis (Cremona et al., 1999; Exton, 1994; Huttner and Schmidt, 2000; Lim and Wenk, 2009; Puchkov and Haucke, 2013; Rohrbough and Broadie, 2005). PLD generates phosphatidic acid by catalyzing the hydrolysis of phosphatidylcholine (PtdCho) and in some systems this PtdOH is de-phosphorylated to generate DAG. In contrast, DGK catalyzes the phosphorylation of DAG thereby converting it into PtdOH. While both enzymes are poised to regulate the levels of DAG and PtdOH, therefore, they both lead to the generation of PtdOH and could have opposite effects on DAG levels. This is particularly important for SV cycling as PtdOH and DAG are both needed for evoked exocytosis (Lim and Wenk, 2009; Puchkov and Haucke, 2013; Rohrbough and Broadie, 2005). Two lipids and their involved metabolic enzymes, two sphingolipids have also been implicated in

  15. Ontologies and tag-statistics

    NASA Astrophysics Data System (ADS)

    Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely

    2012-05-01

    Due to the increasing popularity of collaborative tagging systems, the research on tagged networks, hypergraphs, ontologies, folksonomies and other related concepts is becoming an important interdisciplinary area with great potential and relevance for practical applications. In most collaborative tagging systems the tagging by the users is completely ‘flat’, while in some cases they are allowed to define a shallow hierarchy for their own tags. However, usually no overall hierarchical organization of the tags is given, and one of the interesting challenges of this area is to provide an algorithm generating the ontology of the tags from the available data. In contrast, there are also other types of tagged networks available for research, where the tags are already organized into a directed acyclic graph (DAG), encapsulating the ‘is a sub-category of’ type of hierarchy between each other. In this paper, we study how this DAG affects the statistical distribution of tags on the nodes marked by the tags in various real networks. The motivation for this research was the fact that understanding the tagging based on a known hierarchy can help in revealing the hidden hierarchy of tags in collaborative tagging systems. We analyse the relation between the tag-frequency and the position of the tag in the DAG in two large sub-networks of the English Wikipedia and a protein-protein interaction network. We also study the tag co-occurrence statistics by introducing a two-dimensional (2D) tag-distance distribution preserving both the difference in the levels and the absolute distance in the DAG for the co-occurring pairs of tags. Our most interesting finding is that the local relevance of tags in the DAG (i.e. their rank or significance as characterized by, e.g., the length of the branches starting from them) is much more important than their global distance from the root. Furthermore, we also introduce a simple tagging model based on random walks on the DAG, capable of

  16. The Necessary Evil of Preventive Detention: A Plan for a More Moderate and Sustainable Solution

    DTIC Science & Technology

    2008-07-01

    http://www.usdoj.gov/archive/dag/ speeches /2004/dag6104.htm (accessed November 10, 2007). 25 Ron Suskind, The One Percent Doctrine (New York: Simon...detaining suspected terrorists for purposes of interrogation and/or incapacitation but also for ultimately trying them for various war crimes or...to what extent, if any, this conflict should be thought of as a “war” as opposed to “ crime .” This chapter serves to better define the problems with

  17. Solvent-Free Lipase-Catalyzed Synthesis of Diacylgycerols as Low-Calorie Food Ingredients.

    PubMed

    Vázquez, Luis; González, Noemí; Reglero, Guillermo; Torres, Carlos

    2016-01-01

    Problems derived from obesity and overweight have recently promoted the development of fat substitutes and other low-calorie foods. On the one hand, fats with short- and medium-chain fatty acids are a source of quick energy, easily hydrolyzable and hardly stored as fat. Furthermore, 1,3-diacylglycerols are not hydrolyzed to 2-monoacylglycerols in the gastrointestinal tract, reducing the formation of chylomicron and lowers the serum level of triacylglycerols by decreasing its resynthesis in the enterocyte. In this work, these two effects were combined to synthesize short- and medium-chain 1,3-diacylglycerols, leading to a product with great potential as for their low-calorie properties. Lipase-catalyzed transesterification reactions were performed between short- and medium-chain fatty acid ethyl esters and glycerol. Different variables were investigated, such as the type of biocatalyst, the molar ratio FAEE:glycerol, the adsorption of glycerol on silica gel, or the addition of lecithin. Best reaction conditions were evaluated considering the percentage of 1,3-DAG produced and the reaction rate. Except Novozym 435 (Candida antarctica), other lipases required the adsorption of glycerol on silica gel to form acylglycerols. Lipases that gave the best results with adsorption were Novozym 435 and Lipozyme RM IM (Rhizomucor miehei) with 52 and 60.7% DAG at 32 h, respectively. Because of its specificity for sn-1 and sn-3 positions, lipases leading to a higher proportion of 1,3-DAG vs. 1,2-DAG were Lipozyme RM IM (39.8 and 20.9%, respectively) and Lipase PLG (Alcaligenes sp.) (35.9 and 19.3%, respectively). By adding 1% (w/w) of lecithin to the reaction with Novozym 435 and raw glycerol, the reaction rate was considerably increased from 41.7 to 52.8% DAG at 24 h.

  18. Solvent-Free Lipase-Catalyzed Synthesis of Diacylgycerols as Low-Calorie Food Ingredients

    PubMed Central

    Vázquez, Luis; González, Noemí; Reglero, Guillermo; Torres, Carlos

    2016-01-01

    Problems derived from obesity and overweight have recently promoted the development of fat substitutes and other low-calorie foods. On the one hand, fats with short- and medium-chain fatty acids are a source of quick energy, easily hydrolyzable and hardly stored as fat. Furthermore, 1,3-diacylglycerols are not hydrolyzed to 2-monoacylglycerols in the gastrointestinal tract, reducing the formation of chylomicron and lowers the serum level of triacylglycerols by decreasing its resynthesis in the enterocyte. In this work, these two effects were combined to synthesize short- and medium-chain 1,3-diacylglycerols, leading to a product with great potential as for their low-calorie properties. Lipase-catalyzed transesterification reactions were performed between short- and medium-chain fatty acid ethyl esters and glycerol. Different variables were investigated, such as the type of biocatalyst, the molar ratio FAEE:glycerol, the adsorption of glycerol on silica gel, or the addition of lecithin. Best reaction conditions were evaluated considering the percentage of 1,3-DAG produced and the reaction rate. Except Novozym 435 (Candida antarctica), other lipases required the adsorption of glycerol on silica gel to form acylglycerols. Lipases that gave the best results with adsorption were Novozym 435 and Lipozyme RM IM (Rhizomucor miehei) with 52 and 60.7% DAG at 32 h, respectively. Because of its specificity for sn-1 and sn-3 positions, lipases leading to a higher proportion of 1,3-DAG vs. 1,2-DAG were Lipozyme RM IM (39.8 and 20.9%, respectively) and Lipase PLG (Alcaligenes sp.) (35.9 and 19.3%, respectively). By adding 1% (w/w) of lecithin to the reaction with Novozym 435 and raw glycerol, the reaction rate was considerably increased from 41.7 to 52.8% DAG at 24 h. PMID:26904539

  19. The occurrence of domoic acid linked to a toxic diatom bloom in a new potential vector: the tunicate Pyura chilensis (piure).

    PubMed

    López-Rivera, Américo; Pinto, Maricela; Insinilla, Andrea; Suárez Isla, Benjamín; Uribe, Eduardo; Alvarez, Gonzalo; Lehane, Mary; Furey, Ambrose; James, Kevin J

    2009-11-01

    The tunicate Pyura chilensis (Molina, 1782); Phylum Chordata; Subphylum Urochordata; Class Ascidiacea, common local name "piure" or sea squirt; a filter-feeder (plankton and suspended particles) sessile species; may play an important role in monitoring domoic acid (DA) the principal toxic component of Amnesic Shellfish Poisoning (ASP). Significant DA concentrations have been determined in tunicate samples, collected during a recent ASP outbreak in Bahía Inglesa, an important scallop (Argopecten purpuratus) farming area. Several infaunal species were tested for the presence of DA, in addition to the usual scallop monitoring programme. DA was found at sub-toxic levels in filtering bivalves such as mussels (Mytilus chilensis), large mussels (Aulacomya ater) and clams (Protothaca thaca) (6.4, 5.4 and 4.7 microg DA/g tissue respectively). Of particular interest was the observation of significant accumulations of toxic Pseudo-nitzschia sp. diatoms in the internal siphon and atrium spaces of the tunicate. Toxin distribution within major tunicate organs was heterogeneous with 8.7-15.5 microg DA/g in edible tissues, 14.9-17.9 microg DA/g in the fecal material and 13.6-32.7 microg DA/g in the gut content. DA was determined by HPLC-UV and confirmed by diode-array detection and LC-MS/MS analysis. This is the first report of the presence of DA in a tunicate that is regularly consumed by coastal populations. These results confirm the need to include these organisms in sanitation programs for marine toxins.

  20. ART CONCEPTS - ASTP

    NASA Image and Video Library

    1975-04-01

    S75-27289 (May 1975) --- An artist?s concept depicting the American Apollo spacecraft docked with a Soviet Soyuz spacecraft in Earth orbit. During the joint U.S.-USSR Apollo-Soyuz Test Project mission, scheduled for July 1975, the American and Soviet crews will visit one another?s spacecraft while the Soyuz and Apollo are docked for a maximum period of two days. The mission is designed to test equipment and techniques that will establish international crew rescue capability in space, as well as permit future cooperative scientific missions. Each nation has developed separately docking systems based on a mutually agreeable single set of interface design specifications. The major new U.S. program elements are the docking module and docking system necessary to achieve compatibility of rendezvous and docking systems with the USSR-developed hardware to be used on the Soyuz spacecraft. The DM and docking system together with an Apollo Command/Service Module will be launched by a Saturn 1B launch vehicle. This artwork is by Paul Fjeld.

  1. Among Metabolic Factors, Significance of Fasting and Postprandial Increases in Acyl and Desacyl Ghrelin and the Acyl/Desacyl Ratio in Obstructive Sleep Apnea before and after Treatment.

    PubMed

    Chihara, Yuichi; Akamizu, Takashi; Azuma, Masanori; Murase, Kimihiko; Harada, Yuka; Tanizawa, Kiminobu; Handa, Tomohiro; Oga, Toru; Mishima, Michiaki; Chin, Kazuo

    2015-08-15

    There are reports suggesting that obstructive sleep apnea (OSA) may itself cause weight gain. However, recent reports showed increases in body mass index (BMI) following continuous positive airway pressure (CPAP) treatments. When considering weight changes, changes in humoral factors that have significant effects on appetite such as acyl (AG) and desacyl ghrelin (DAG), leptin, insulin, and glucose and their interactions, examples of which are AG/DAG and AG/insulin, are important. The aim of this study was to test the hypothesis that some appetite-related factors had a specific profile before and after CPAP treatment. Metabolic parameters were measured cross-sectionally while fasting and 30, 60, 90, and 120 min following breakfast in no or mild OSA (apnea-hypopnea index < 15, n = 15) and moderate-to-severe OSA (apnea-hypopnea index ≥ 15, n = 39) participants in a single institute. There were no differences in age, sex, BMI, or visceral fat accumulation between the two groups. Twenty-one patients with moderate-to-severe OSA who received CPAP treatment also prospectively underwent the same testing following 3 months of CPAP treatment. Although fasting and postprandial glucose, insulin, and leptin levels did not differ between no or mild OSA and moderate-to-severe OSA participants, AG and DAG, including AG/DAG and AG/insulin, under fasting and postprandial conditions were significantly increased in the moderate-to-severe OSA patients (p < 0.01). After 3 months of CPAP treatment in 21 of the moderate-to-severe OSA participants, AG/DAG did not change significantly, but other ghrelin-related parameters including AG/insulin significantly decreased compared with values before treatment but remained higher than in no or mild OSA. Among several important metabolic factors, ghrelin-related factors had the strongest associations with moderate-to-severe OSA. These results indicate that continuous changes in ghrelin secretion in OSA patients existed at least within 3 months of

  2. Automated interviews on clinical case reports to elicit directed acyclic graphs.

    PubMed

    Luciani, Davide; Stefanini, Federico M

    2012-05-01

    Setting up clinical reports within hospital information systems makes it possible to record a variety of clinical presentations. Directed acyclic graphs (Dags) offer a useful way of representing causal relations in clinical problem domains and are at the core of many probabilistic models described in the medical literature, like Bayesian networks. However, medical practitioners are not usually trained to elicit Dag features. Part of the difficulty lies in the application of the concept of direct causality before selecting all the causal variables of interest for a specific patient. We designed an automated interview to tutor medical doctors in the development of Dags to represent their understanding of clinical reports. Medical notions were analyzed to find patterns in medical reasoning that can be followed by algorithms supporting the elicitation of causal Dags. Clinical relevance was defined to help formulate only relevant questions by driving an expert's attention towards variables causally related to nodes already inserted in the graph. Key procedural features of the proposed interview are described by four algorithms. The automated interview comprises questions on medical notions, phrased in medical terms. The first elicitation session produces questions concerning the patient's chief complaints and the outcomes related to diseases serving as diagnostic hypotheses, their observable manifestations and risk factors. The second session focuses on questions that refine the initial causal paths by considering syndromes, dysfunctions, pathogenic anomalies, biases and effect modifiers. A case study concerning a gastro-enterological problem and one dealing with an infected patient illustrate the output produced by the algorithms, depending on the answers provided by the doctor. The proposed elicitation framework is characterized by strong consistency with medical background and by a progressive introduction of relevant medical topics. Revision and testing of the

  3. Demonstration of the sustained anthelmintic efficacy of a controlled-release capsule formulation of ivermectin in weaner lambs under field conditions in New Zealand.

    PubMed

    Gogolewski, R P; Allerton, G R; Rugg, D; Kawhia, D; Barrick, R A; Eagleson, J S

    1997-08-01

    Ten field trials were conducted in the North and South Islands of New Zealand to evaluate the anthelmintic efficacy and production responses attributable to treatment of weaner lambs with an intra-ruminal controlled-release capsule formulation of ivermectin. A total of 800 Coopworth, Perendale and Romney lambs weighing on average 20.8-34.8 kg were used. Lambs were either untreated or treated shortly after weaning with an ivermectin controlled-release capsule which delivers ivermectin at 0.8 mg per day for 100 days (minimum dose rate 20 microg/kg/day). Bodyweights, faecal nematode egg counts and dag scores (assessment of faecal soiling in the breech area) were determined before treatment and at about 4,8, 12, 14 and 16 weeks after treatment. Sheep treated with the Ivermectin capsule gained significantly more weight (11.6 kg) over the 16 weeks of the trials compared to untreated sheep (7.3 kg) (p < 0.01). Before treatment, faecal strongylid and Nematodirus spp. egg counts were equivalent (p > 0.10) but, at each time point thereafter, egg counts in ivermectin capsule-treated sheep were significantly lower (p < 0.01 or p < 0.05). Dag scores were not different at the start of the trial (p > 0.10), but at the end of the trial control sheep had significantly greater dags (p < 0.05) than sheep treated with the ivermectin capsule. These findings indicate that treated animals contributed significantly fewer nematode eggs to the contamination of pasture and therefore pasture contamination should be significantly reduced for at least 112 days. The productivity of the ivermectin capsule-treated sheep over the I6 weeks of the trials was also significantly increased compared to salvage-treated controls. Furthermore, the presence of dags, which predispose sheep to blowfly strike in the breech area and result in production losses due to the costs of dagging and downgrading of breech wool, were also significantly (p < 0.05) reduced in the ivermectin capsule-treated sheep.

  4. Petrogenesis of lunar highlands meteorites: Dhofar 025, Dhofar 081 Dar al Gani 262, and Dar al Gani 400

    NASA Astrophysics Data System (ADS)

    Cahill, J. T.; Floss, C.; Anand, M.; Taylor, L. A.; Nazarov, M. A.; Cohen, B. A.

    2004-04-01

    The petrogenesis of four lunar highlands meteorites, Dhofar 025 (Dho 025), Dhofar 081 (Dho 081), Dar al Gani 262 (DaG 262), and Dar al Gani 400 (DaG 400) were studied. For Dho 025, measured oxygen isotopic values and Fe-Mn ratios for mafic minerals provide corroboratory evidence that it originated on the Moon. Similarly, Fe-Mn ratios in the mafic minerals of Dho 081 indicate lunar origin. Lithologies in Dho 025 and Dho 081 include lithic clasts, granulites, and mineral fragments. A large number of lithic clasts have plagioclase AN# and coexisting mafic mineral Mg# that plot within the "gap" separating ferroan anorthosite suite (FAN) and high-magnesium suite (HMS) rocks. This is consistent with whole rock Ti-Sm ratios for Dho 025, Dho 081, and DaG 262, which are also intermediate compared to FAN and HMS lithologies. Although ion microprobe analyses performed on Dho 025, Dho 081, DaG 262, and DaG 400 clasts and minerals show far stronger FAN affinities than whole rock data suggest, most clasts indicate admixture of £12% HMS component based on geochemical modeling. In addition, coexisting plagioclase-pyroxene REE concentration ratios in several clasts were compared to experimentally determined plagioclase-pyroxene REE distribution coefficient ratios. Two Dho 025 clasts have concordant plagioclase-pyroxene profiles, indicating that equilibrium between these minerals has been sustained despite shock metamorphism. One clast has an intermediate FAN-HMS composition. These lunar meteorites appear to represent a type of highland terrain that differs substantially from the KREEP-signatured impact breccias that dominate the lunar database. From remote sensing data, it is inferred that the lunar far side appears to have appropriate geochemical signatures and lithologies to be the source regions for these rocks; although, the near side cannot be completely excluded as a possibility. If these rocks are, indeed, from the far side, their geochemical characteristics may have far

  5. A two-state hysteresis model from high-dimensional friction

    PubMed Central

    Biswas, Saurabh; Chatterjee, Anindya

    2015-01-01

    In prior work (Biswas & Chatterjee 2014 Proc. R. Soc. A 470, 20130817 (doi:10.1098/rspa.2013.0817)), we developed a six-state hysteresis model from a high-dimensional frictional system. Here, we use a more intuitively appealing frictional system that resembles one studied earlier by Iwan. The basis functions now have simple analytical description. The number of states required decreases further, from six to the theoretical minimum of two. The number of fitted parameters is reduced by an order of magnitude, to just six. An explicit and faster numerical solution method is developed. Parameter fitting to match different specified hysteresis loops is demonstrated. In summary, a new two-state model of hysteresis is presented that is ready for practical implementation. Essential Matlab code is provided. PMID:26587279

  6. Simultaneous production of fatty acid methyl esters and diglycerides by four recombinant Candida rugosa lipase's isozymes.

    PubMed

    Chang, Shu-Wei; Huang, Myron; Hsieh, Yu-Hsun; Luo, Ying-Ting; Wu, Tsung-Ta; Tsai, Chia-Wen; Chen, Chin-Shuh; Shaw, Jei-Fu

    2014-07-15

    In this study, the catalytic efficiency of four recombinant CRL (Candida rugosa lipase) isozymes (LIP1-LIP4) towards the production of fatty acid methyl ester (FAME) was compared and evaluated as an alternative green method for industrial applications. The results indicated that the recombinant C. rugosa LIP1 enzyme exhibited the highest catalytic efficiency for FAME production compared to the recombinant C. rugosa LIP2-LIP4 enzymes. The optimal conditions were as follows: pH 7.0, methanol/soybean oil molar ratio: 3/1, enzyme amount: 2U (1.6 μL), reaction temperature: 20°C, 22 h of reaction time, and 3 times of methanol addition (1 mol/6h), and resulted in 61.5 ± 1.5 wt.% of FAME conversion. The reaction product contained also 10 wt.% of DAG with a ratio of 1,3-DAG to 1,2-DAG of approximately 4:6, and can be potentially used in industrial applications as a food emulsifier. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Effect of the type of fat on the physicochemical, instrumental and sensory characteristics of reduced fat non-acid fermented sausages.

    PubMed

    Mora-Gallego, Héctor; Serra, Xavier; Guàrdia, Maria Dolors; Miklos, Rikke; Lametsch, René; Arnau, Jacint

    2013-03-01

    Four batches of reduced fat non-acid fermented sausages were manufactured with pork-ham lean, and the addition of no fat (Lean), 5% pork backfat (BF), 5% sunflower oil (SO) and 5% diacylglycerols (DAGs). The effect of the type of fat as pork-fat substitute on some physicochemical parameters, instrumental color and texture and sensory attributes of the sausages was studied. Results showed that reduced fat non-acid fermented sausages containing less than 12.5% of fat (BF, SO and DAGs) had a good overall sensory quality. This means a fat reduction of more than 70% compared with the average fat content of standard fermented sausages of similar characteristics. Sausages with SO showed higher sensory ratings in desirable ripened odor and flavor attributes and improved texture defined by lower hardness and chewiness (both sensory and instrumental) and higher crumbliness. Sausages with DAGs showed a similar behavior to that of BF, so they could be a good alternative to produce healthier reduced fat non-acid fermented sausages. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. In vitro stereoselective hydrolysis of diacylglycerols by hormone-sensitive lipase.

    PubMed

    Rodriguez, Jorge A; Ben Ali, Yassine; Abdelkafi, Slim; Mendoza, Lilia D; Leclaire, Julien; Fotiadu, Frédéric; Buono, Gerard; Carrière, Frédéric; Abousalham, Abdelkarim

    2010-01-01

    Hormone-sensitive lipase (HSL) contributes importantly to the mobilization of fatty acids in adipocytes and shows a substrate preference for the diacylglycerols (DAGs) originating from triacylglycerols. To determine whether HSL shows any stereopreference during the hydrolysis of diacylglycerols, racemic 1,2(2,3)-sn-diolein was used as a substrate and the enantiomeric excess (ee%) of residual 1,2-sn-diolein over 2,3-sn-diolein was measured as a function of DAG hydrolysis. Enantiomeric DAGs were separated by performing chiral-stationary-phase HPLC after direct derivatization from lipolysis product extracts. The fact that the ee% of 1,2-sn-diolein over 2,3-sn-diolein increased with the level of hydrolysis indicated that HSL has a preference for 2,3-sn-diolein as a substrate and therefore a stereopreference for the sn-3 position of dioleoylglycerol. The ee% of 1,2-sn-diolein reached a maximum value of 36% at 42% hydrolysis. Among the various mammalian lipases tested so far, HSL is the only lipolytic carboxylester hydrolase found to have a pronounced stereospecificity for the sn-3 position of dioleoylglycerol.

  9. NASA Langley and NLR Research of Distributed Air/Ground Traffic Management

    NASA Technical Reports Server (NTRS)

    Ballin, Mark G.; Hoekstra, Jacco M.; Wing, David J.; Lohr, Gary W.

    2002-01-01

    Distributed Air/Ground Traffic Management (DAG-TM) is a concept of future air traffic operations that proposes to distribute information, decision-making authority, and responsibility among flight crews, the air traffic service provider, and aeronautical operational control organizations. This paper provides an overview and status of DAG-TM research at NASA Langley Research Center and the National Aerospace Laboratory of The Netherlands. Specific objectives of the research are to evaluate the technical and operational feasibility of the autonomous airborne component of DAG-TM, which is founded on the operational paradigm of free flight. The paper includes an overview of research approaches, the airborne technologies under development, and a summary of experimental investigations and findings to date. Although research is not yet complete, these findings indicate that free flight is feasible and will significantly enhance system capacity and safety. While free flight cannot alone resolve the complex issues faced by those modernizing the global airspace, it should be considered an essential part of a comprehensive air traffic management modernization activity.

  10. Stimulation of phosphatidylcholine breakdown and diacylglycerol production by growth factors in Swiss-3T3 cells.

    PubMed Central

    Price, B D; Morris, J D; Hall, A

    1989-01-01

    The effect of a number of growth factors on phosphatidylcholine (PtdCho) turnover in Swiss-3T3 cells was studied. Phorbol 12-myristate 13-acetate (PMA), bombesin, platelet-derived growth factor (PDGF) and vasopressin rapidly stimulated PtdCho hydrolysis, diacylglycerol (DAG) production, and PtdCho synthesis. Insulin and prostaglandin F2 alpha (PGF2 alpha) stimulated PtdCho synthesis, but not its breakdown, whereas epidermal growth factor (EGF) and bradykinin were without effect. Stimulation of PtdCho hydrolysis by the above ligands resulted in increased production of phosphocholine and DAG (due to phospholipase C activity) and significant amounts of choline, suggesting activation of a phospholipase D as well. CDP-choline and glycerophosphocholine levels were unchanged. Down-regulation of protein kinase C with PMA (400 nM, 40 h) abolished the stimulation of PtdCho hydrolysis and PtdCho synthesis by PMA, bombesin, PDGF and vasopressin, but not the stimulation of PtdCho synthesis by insulin and PGF2 alpha. PtdCho hydrolysis therefore occurs predominantly by activation of protein kinase C (either by PMA or PtdIns hydrolysis) leading to elevation of DAG levels derived from non-PtdIns(4,5)P2 sources. PtdCho synthesis occurs by both a protein kinase C-dependent pathway (stimulated by PMA, PDGF, bombesin and vasopressin) and a protein kinase C-independent pathway (stimulated by insulin and PGF2 alpha). DAG production from PtdCho hydrolysis is not the primary signal to activate protein kinase C, but may contribute to long-term activation of this kinase. PMID:2690829

  11. Insulin stimulates phospholipase D-dependent phosphatidylcholine hydrolysis, Rho translocation, de novo phospholipid synthesis, and diacylglycerol/protein kinase C signaling in L6 myotubes.

    PubMed

    Standaert, M L; Bandyopadhyay, G; Zhou, X; Galloway, L; Farese, R V

    1996-07-01

    Previous studies have provided conflicting findings on whether insulin activates certain, potentially important, phospholipid signaling systems in skeletal muscle preparations. In particular, insulin effects on the hydrolysis of phosphatidylcholine (PC) and subsequent activation of protein kinase C (PKC) have not been apparent in some studies. Presently, we examined insulin effects on phospholipid signaling systems, diacylglycerol (DAG) production, and PKC translocation/activation in L6 myotubes. We found that insulin provoked rapid increases in phospholipase D (PLD)-dependent hydrolysis of PC, as evidenced by increases in choline release and phosphatidylethanol production in cells incubated in the presence of ethanol. In association with PC-PLD activation, Rho, a small G protein that is known to activate PC-PLD activation, translocated from the cytosol to the membrane fraction in response to insulin treatment. PC-PLD activation was also accompanied by increases in total DAG production and increases in the translocation of both PKC enzyme activity and DAG-sensitive PKC-alpha, -beta, -delta, and -epsilon from the cytosol to the membrane fraction. A potential role for PKC or a related protein kinase in insulin action was suggested by the finding that RO 31-8220 inhibited both PKC enzyme activity and insulin-stimulated [3H]2-deoxyglucose uptake. Our findings provide the first evidence that insulin stimulates Rho translocation and activates PC-PLD in L6 skeletal muscle cells. Moreover, this signaling system appears to lead to increases in DAG/PKC signaling, which, along with other related signaling factors, may regulate certain metabolic processes, such as glucose transport, in these cells.

  12. Phosphatidic Acid Sequesters Sec18p from cis-SNARE Complexes to Inhibit Priming.

    PubMed

    Starr, Matthew L; Hurst, Logan R; Fratti, Rutilio A

    2016-10-01

    Yeast vacuole fusion requires the activation of cis-SNARE complexes through priming carried out by Sec18p/N-ethylmaleimide sensitive factor and Sec17p/α-SNAP. The association of Sec18p with vacuolar cis-SNAREs is regulated in part by phosphatidic acid (PA) phosphatase production of diacylglycerol (DAG). Inhibition of PA phosphatase activity blocks the transfer of membrane-associated Sec18p to SNAREs. Thus, we hypothesized that Sec18p associates with PA-rich membrane microdomains before transferring to cis-SNARE complexes upon PA phosphatase activity. Here, we examined the direct binding of Sec18p to liposomes containing PA or DAG. We found that Sec18p preferentially bound to liposomes containing PA compared with those containing DAG by approximately fivefold. Additionally, using a specific PA-binding domain blocked Sec18p binding to PA-liposomes and displaced endogenous Sec18p from isolated vacuoles. Moreover, the direct addition of excess PA blocked the priming activity of isolated vacuoles in a manner similar to chemically inhibiting PA phosphatase activity. These data suggest that the conversion of PA to DAG facilitates the recruitment of Sec18p to cis-SNAREs. Purified vacuoles from yeast lacking the PA phosphatase Pah1p showed reduced Sec18p association with cis-SNAREs and complementation with plasmid-encoded PAH1 or recombinant Pah1p restored the interaction. Taken together, this demonstrates that regulating PA concentrations by Pah1p activity controls SNARE priming by Sec18p. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Estimating causal effects with a non-paranormal method for the design of efficient intervention experiments

    PubMed Central

    2014-01-01

    Background Knockdown or overexpression of genes is widely used to identify genes that play important roles in many aspects of cellular functions and phenotypes. Because next-generation sequencing generates high-throughput data that allow us to detect genes, it is important to identify genes that drive functional and phenotypic changes of cells. However, conventional methods rely heavily on the assumption of normality and they often give incorrect results when the assumption is not true. To relax the Gaussian assumption in causal inference, we introduce the non-paranormal method to test conditional independence in the PC-algorithm. Then, we present the non-paranormal intervention-calculus when the directed acyclic graph (DAG) is absent (NPN-IDA), which incorporates the cumulative nature of effects through a cascaded pathway via causal inference for ranking causal genes against a phenotype with the non-paranormal method for estimating DAGs. Results We demonstrate that causal inference with the non-paranormal method significantly improves the performance in estimating DAGs on synthetic data in comparison with the original PC-algorithm. Moreover, we show that NPN-IDA outperforms the conventional methods in exploring regulators of the flowering time in Arabidopsis thaliana and regulators that control the browning of white adipocytes in mice. Our results show that performance improvement in estimating DAGs contributes to an accurate estimation of causal effects. Conclusions Although the simplest alternative procedure was used, our proposed method enables us to design efficient intervention experiments and can be applied to a wide range of research purposes, including drug discovery, because of its generality. PMID:24980787

  14. Estimating causal effects with a non-paranormal method for the design of efficient intervention experiments.

    PubMed

    Teramoto, Reiji; Saito, Chiaki; Funahashi, Shin-ichi

    2014-06-30

    Knockdown or overexpression of genes is widely used to identify genes that play important roles in many aspects of cellular functions and phenotypes. Because next-generation sequencing generates high-throughput data that allow us to detect genes, it is important to identify genes that drive functional and phenotypic changes of cells. However, conventional methods rely heavily on the assumption of normality and they often give incorrect results when the assumption is not true. To relax the Gaussian assumption in causal inference, we introduce the non-paranormal method to test conditional independence in the PC-algorithm. Then, we present the non-paranormal intervention-calculus when the directed acyclic graph (DAG) is absent (NPN-IDA), which incorporates the cumulative nature of effects through a cascaded pathway via causal inference for ranking causal genes against a phenotype with the non-paranormal method for estimating DAGs. We demonstrate that causal inference with the non-paranormal method significantly improves the performance in estimating DAGs on synthetic data in comparison with the original PC-algorithm. Moreover, we show that NPN-IDA outperforms the conventional methods in exploring regulators of the flowering time in Arabidopsis thaliana and regulators that control the browning of white adipocytes in mice. Our results show that performance improvement in estimating DAGs contributes to an accurate estimation of causal effects. Although the simplest alternative procedure was used, our proposed method enables us to design efficient intervention experiments and can be applied to a wide range of research purposes, including drug discovery, because of its generality.

  15. ADS-B within a Multi-Aircraft Simulation for Distributed Air-Ground Traffic Management

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Palmer, Michael T.; Chung, William W.; Loveness, Ghyrn W.

    2004-01-01

    Automatic Dependent Surveillance Broadcast (ADS-B) is an enabling technology for NASA s Distributed Air-Ground Traffic Management (DAG-TM) concept. DAG-TM has the goal of significantly increasing capacity within the National Airspace System, while maintaining or improving safety. Under DAG-TM, aircraft exchange state and intent information over ADS-B with other aircraft and ground stations. This information supports various surveillance functions including conflict detection and resolution, scheduling, and conformance monitoring. To conduct more rigorous concept feasibility studies, NASA Langley Research Center s PC-based Air Traffic Operations Simulation models a 1090 MHz ADS-B communication structure, based on industry standards for message content, range, and reception probability. The current ADS-B model reflects a mature operating environment and message interference effects are limited to Mode S transponder replies and ADS-B squitters. This model was recently evaluated in a Joint DAG-TM Air/Ground Coordination Experiment with NASA Ames Research Center. Message probability of reception vs. range was lower at higher traffic levels. The highest message collision probability occurred near the meter fix serving as the confluence for two arrival streams. Even the highest traffic level encountered in the experiment was significantly less than the industry standard "LA Basin 2020" scenario. Future studies will account for Mode A and C message interference (a major effect in several industry studies) and will include Mode A and C aircraft in the simulation, thereby increasing the total traffic level. These changes will support ongoing enhancements to separation assurance functions that focus on accommodating longer ADS-B information update intervals.

  16. The Dag Hammarskjold Library and United Nations Microforms.

    ERIC Educational Resources Information Center

    Marulli-Koenig, Luciana

    1980-01-01

    Surveys the United Nations microform program's history, its current filming projects, and its future plans. Established originally to preserve UN documents for archival purposes, it has expanded to public distribution and dissemination of significant UN documents. (Author)

  17. Inhibitory effects of herbal constituents on P-glycoprotein in vitro and in vivo: Herb–drug interactions mediated via P-gp

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Xue, E-mail: lixue@imm.ac.cn; Hu, Jinping, E-mail: hujp@imm.ac.cn; Wang, Baolian, E-mail: wangbaolian@imm.ac.cn

    Modulation of drug transporters via herbal medicines which have been widely used in combination with conventional prescription drugs may result in herb–drug interactions in clinical practice. The present study was designed to investigate the inhibitory effects of 50 major herbal constituents on P-glycoprotein (P-gp) in vitro and in vivo as well as related inhibitory mechanisms. Among these herbal medicines, four constituents, including emodin, 18β-glycyrrhetic acid (18β-GA), dehydroandrographolide (DAG), and 20(S)-ginsenoside F{sub 1} [20(S)-GF{sub 1}] exhibited significant inhibition (> 50%) on P-gp in MDR1-MDCKII and Caco-2 cells. Emodin was the strongest inhibitor of P-gp (IC{sub 50} = 9.42 μM), followed bymore » 18β-GA (IC{sub 50} = 21.78 μM), 20(S)-GF{sub 1} (IC{sub 50} = 76.08 μM) and DAG (IC{sub 50} = 77.80 μM). P-gp ATPase activity, which was used to evaluate the affinity of substrates to P-gp, was stimulated by emodin and DAG with K{sub m} and V{sub max} values of 48.61, 29.09 μM and 71.29, 38.45 nmol/min/mg protein, respectively. However, 18β-GA and 20(S)-GF{sub 1} exhibited significant inhibition on both basal and verapamil-stimulated P-gp ATPase activities at high concentration. Molecular docking analysis (CDOCKER) further elucidated the mechanism for structure–inhibition relationships of herbal constituents with P-gp. When digoxin was co-administered to male SD rats with emodin or 18β-GA, the AUC{sub 0−t} and Cmax of digoxin were increased by approximately 51% and 58%, respectively. Furthermore, 18β-GA, DAG, 20(S)-GF{sub 1} and Rh{sub 1} at 10 μM significantly inhibited CYP3A4/5 activity, while emodin activated the metabolism of midazolam in human liver microsomes. In conclusion, four herbal constituents demonstrated inhibition of P-gp to specific extents in vitro and in vivo. Taken together, our findings provided the basis for the reliable assessment of the potential risks of herb–drug interactions in humans. - Highlights:

  18. PLC-mediated PI(4,5)P2 hydrolysis regulates activation and inactivation of TRPC6/7 channels

    PubMed Central

    Itsuki, Kyohei; Imai, Yuko; Hase, Hideharu; Okamura, Yasushi; Inoue, Ryuji

    2014-01-01

    Transient receptor potential classical (or canonical) (TRPC)3, TRPC6, and TRPC7 are a subfamily of TRPC channels activated by diacylglycerol (DAG) produced through the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) by phospholipase C (PLC). PI(4,5)P2 depletion by a heterologously expressed phosphatase inhibits TRPC3, TRPC6, and TRPC7 activity independently of DAG; however, the physiological role of PI(4,5)P2 reduction on channel activity remains unclear. We used Förster resonance energy transfer (FRET) to measure PI(4,5)P2 or DAG dynamics concurrently with TRPC6 or TRPC7 currents after agonist stimulation of receptors that couple to Gq and thereby activate PLC. Measurements made at different levels of receptor activation revealed a correlation between the kinetics of PI(4,5)P2 reduction and those of receptor-operated TRPC6 and TRPC7 current activation and inactivation. In contrast, DAG production correlated with channel activation but not inactivation; moreover, the time course of channel inactivation was unchanged in protein kinase C–insensitive mutants. These results suggest that inactivation of receptor-operated TRPC currents is primarily mediated by the dissociation of PI(4,5)P2. We determined the functional dissociation constant of PI(4,5)P2 to TRPC channels using FRET of the PLCδ Pleckstrin homology domain (PHd), which binds PI(4,5)P2, and used this constant to fit our experimental data to a model in which channel gating is controlled by PI(4,5)P2 and DAG. This model predicted similar FRET dynamics of the PHd to measured FRET in either human embryonic kidney cells or smooth muscle cells, whereas a model lacking PI(4,5)P2 regulation failed to reproduce the experimental data, confirming the inhibitory role of PI(4,5)P2 depletion on TRPC currents. Our model also explains various PLC-dependent characteristics of channel activity, including limitation of maximum open probability, shortening of the peak time, and the bell-shaped response of

  19. Signal-dependent hydrolysis of phosphatidylinositol 4,5-bisphosphate without activation of phospholipase C: implications on gating of Drosophila TRPL (transient receptor potential-like) channel.

    PubMed

    Lev, Shaya; Katz, Ben; Tzarfaty, Vered; Minke, Baruch

    2012-01-06

    In Drosophila, a phospholipase C (PLC)-mediated signaling cascade, couples photo-excitation of rhodopsin to the opening of the transient receptor potential (TRP) and TRP-like (TRPL) channels. A lipid product of PLC, diacylglycerol (DAG), and its metabolites, polyunsaturated fatty acids (PUFAs) may function as second messengers of channel activation. However, how can one separate between the increase in putative second messengers, change in pH, and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) depletion when exploring the TRPL gating mechanism? To answer this question we co-expressed the TRPL channels together with the muscarinic (M1) receptor, enabling the openings of TRPL channels via G-protein activation of PLC. To dissect PLC activation of TRPL into its molecular components, we used a powerful method that reduced plasma membrane-associated PI(4,5)P(2) in HEK cells within seconds without activating PLC. Upon the addition of a dimerizing drug, PI(4,5)P(2) was selectively hydrolyzed in the cell membrane without producing DAG, inositol trisphosphate, or calcium signals. We show that PI(4,5)P(2) is not an inhibitor of TRPL channel activation. PI(4,5)P(2) hydrolysis combined with either acidification or application of DAG analogs failed to activate the channels, whereas PUFA did activate the channels. Moreover, a reduction in PI(4,5)P(2) levels or inhibition of DAG lipase during PLC activity suppressed the PLC-activated TRPL current. This suggests that PI(4,5)P(2) is a crucial substrate for PLC-mediated activation of the channels, whereas PUFA may function as the channel activator. Together, this study defines a narrow range of possible mechanisms for TRPL gating.

  20. Solvent-free enzymatic synthesis of 1, 3-Diacylglycerols by direct esterification of glycerol with saturated fatty acids

    PubMed Central

    2013-01-01

    Background Pure 1, 3-diacylglycerols (1, 3-DAG) have been considered to be significant surfactants in food, cosmetics and pharmaceutical industries, as well as the effect on obesity prevention. Methods In this study, a vacuum-driven air bubbling operation mode was developed and evaluated for the enzymatic synthesis of 1, 3-DAG of saturated fatty acids, by direct esterification of glycerol with fatty acids in a solvent-free system. The employed vacuum-driven air bubbling operation mode was comparable to vacuum-driven N2 bubbling protocol, in terms of lauric acid conversion and 1, 3-dilaurin content. Results Some operation parameters were optimized, and 95.3% of lauric acid conversion and 80.3% of 1, 3-dilaurin content was obtained after 3-h reaction at 50°C, with 5 wt% of Lipozyme RM IM (based on reactants) amount. Of the lipases studied, both Lipozyme RM IM and Novozym 435 exhibited good performance in terms of lauric acid conversion. Lipozyme TL IM, however, showed low activity. Lipozyme RM IM showed good operational stability in this operation protocol, 80.2% of the original catalytic activity remained after 10 consecutive batch applications. Some other 1, 3-DAG were prepared and high content was obtained after purification: 98.5% for 1, 3-dicaprylin, 99.2% for 1, 3-dicaprin, 99.1% for 1, 3-dilaurin, 99.5 for 1, 3-dipalmitin and 99.4% for 1, 3-disterin. Conclusion The established vacuum-driven air bubbling operation protocol had been demonstrated to be a simple-operating, cost-effective, application practical and efficient methodology for 1, 3-DAG preparation. PMID:23656739

  1. Overexpression of a phosphatidic acid phosphatase type 2 leads to an increase in triacylglycerol production in oleaginous Rhodococcus strains.

    PubMed

    Hernández, Martín A; Comba, Santiago; Arabolaza, Ana; Gramajo, Hugo; Alvarez, Héctor M

    2015-03-01

    Oleaginous Rhodococcus strains are able to accumulate large amounts of triacylglycerol (TAG). Phosphatidic acid phosphatase (PAP) enzyme catalyzes the dephosphorylation of phosphatidic acid (PA) to yield diacylglycerol (DAG), a key precursor for TAG biosynthesis. Studies to establish its role in lipid metabolism have been mainly focused in eukaryotes but not in bacteria. In this work, we identified and characterized a putative PAP type 2 (PAP2) encoded by the ro00075 gene in Rhodococcus jostii RHA1. Heterologous expression of ro00075 in Escherichia coli resulted in a fourfold increase in PAP activity and twofold in DAG content. The conditional deletion of ro00075 in RHA1 led to a decrease in the content of DAG and TAG, whereas its overexpression in both RHA1 and Rhodococcus opacus PD630 promoted an increase up to 10 to 15 % by cellular dry weight in TAG content. On the other hand, expression of ro00075 in the non-oleaginous strain Rhodococcus fascians F7 promoted an increase in total fatty acid content up to 7 % at the expense of free fatty acid (FFA), DAG, and TAG fractions. Moreover, co-expression of ro00075/atf2 genes resulted in a fourfold increase in total fatty acid content by a further increase of the FFA and TAG fractions. The results of this study suggest that ro00075 encodes for a PAP2 enzyme actively involved in TAG biosynthesis. Overexpression of this gene, as single one or with an atf gene, provides an alternative approach to increase the biosynthesis and accumulation of bacterial oils as a potential source of raw material for biofuel production.

  2. Causal Analysis After Haavelmo

    PubMed Central

    Heckman, James; Pinto, Rodrigo

    2014-01-01

    Haavelmo's seminal 1943 and 1944 papers are the first rigorous treatment of causality. In them, he distinguished the definition of causal parameters from their identification. He showed that causal parameters are defined using hypothetical models that assign variation to some of the inputs determining outcomes while holding all other inputs fixed. He thus formalized and made operational Marshall's (1890) ceteris paribus analysis. We embed Haavelmo's framework into the recursive framework of Directed Acyclic Graphs (DAGs) used in one influential recent approach to causality (Pearl, 2000) and in the related literature on Bayesian nets (Lauritzen, 1996). We compare the simplicity of an analysis of causality based on Haavelmo's methodology with the complex and nonintuitive approach used in the causal literature of DAGs—the “do-calculus” of Pearl (2009). We discuss the severe limitations of DAGs and in particular of the do-calculus of Pearl in securing identification of economic models. We extend our framework to consider models for simultaneous causality, a central contribution of Haavelmo. In general cases, DAGs cannot be used to analyze models for simultaneous causality, but Haavelmo's approach naturally generalizes to cover them. PMID:25729123

  3. Kinetic study of lipase-catalyzed glycerolysis of palm olein using Lipozyme TLIM in solvent-free system

    PubMed Central

    Phuah, Eng-Tong; Lee, Yee-Ying; Tang, Teck-Kim

    2018-01-01

    Diacylglycerol (DAG) and monoacylglycerol (MAG) are two natural occurring minor components found in most edible fats and oils. These compounds have gained increasing market demand owing to their unique physicochemical properties. Enzymatic glycerolysis in solvent-free system might be a promising approach in producing DAG and MAG-enriched oil. Understanding on glycerolysis mechanism is therefore of great importance for process simulation and optimization. In this study, a commercial immobilized lipase (Lipozyme TL IM) was used to catalyze the glycerolysis reaction. The kinetics of enzymatic glycerolysis reaction between triacylglycerol (TAG) and glycerol (G) were modeled using rate equation with unsteady-state assumption. Ternary complex, ping-pong bi-bi and complex ping-pong bi-bi models were proposed and compared in this study. The reaction rate constants were determined using non-linear regression and sum of square errors (SSE) were minimized. Present work revealed satisfactory agreement between experimental data and the result generated by complex ping-pong bi-bi model as compared to other models. The proposed kinetic model would facilitate understanding on enzymatic glycerolysis for DAG and MAG production and design optimization of a pilot-scale reactor. PMID:29401481

  4. Signal-dependent Hydrolysis of Phosphatidylinositol 4,5-Bisphosphate without Activation of Phospholipase C

    PubMed Central

    Lev, Shaya; Katz, Ben; Tzarfaty, Vered; Minke, Baruch

    2012-01-01

    In Drosophila, a phospholipase C (PLC)-mediated signaling cascade, couples photo-excitation of rhodopsin to the opening of the transient receptor potential (TRP) and TRP-like (TRPL) channels. A lipid product of PLC, diacylglycerol (DAG), and its metabolites, polyunsaturated fatty acids (PUFAs) may function as second messengers of channel activation. However, how can one separate between the increase in putative second messengers, change in pH, and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) depletion when exploring the TRPL gating mechanism? To answer this question we co-expressed the TRPL channels together with the muscarinic (M1) receptor, enabling the openings of TRPL channels via G-protein activation of PLC. To dissect PLC activation of TRPL into its molecular components, we used a powerful method that reduced plasma membrane-associated PI(4,5)P2 in HEK cells within seconds without activating PLC. Upon the addition of a dimerizing drug, PI(4,5)P2 was selectively hydrolyzed in the cell membrane without producing DAG, inositol trisphosphate, or calcium signals. We show that PI(4,5)P2 is not an inhibitor of TRPL channel activation. PI(4,5)P2 hydrolysis combined with either acidification or application of DAG analogs failed to activate the channels, whereas PUFA did activate the channels. Moreover, a reduction in PI(4,5)P2 levels or inhibition of DAG lipase during PLC activity suppressed the PLC-activated TRPL current. This suggests that PI(4,5)P2 is a crucial substrate for PLC-mediated activation of the channels, whereas PUFA may function as the channel activator. Together, this study defines a narrow range of possible mechanisms for TRPL gating. PMID:22065576

  5. Phospholipid transfer protein plays a major role in the initiation of apolipoprotein B-containing lipoprotein assembly in mouse primary hepatocytes.

    PubMed

    Manchekar, Medha; Liu, Yanwen; Sun, Zhihuan; Richardson, Paul E; Dashti, Nassrin

    2015-03-27

    In this study, we tested the hypothesis that phospholipid transfer protein (PLTP) is a plausible mediator of phospholipid (PL) transfer to the N-terminal 1000 residues of apoB (apoB:1000) leading to the initiation of apoB-containing lipoprotein assembly. To this end, primary hepatocytes from wild type (WT) and PLTP knock-out (KO) mice were transduced with adenovirus-apoB:1000 with or without co-transduction with adenovirus-PLTP, and the assembly and secretion of apoB:1000-containing lipoproteins were assessed. PLTP deficiency resulted in a 65 and 72% reduction in the protein and lipid content, respectively, of secreted apoB:1000-containing lipoproteins. Particles secreted by WT hepatocytes contained 69% PL, 9% diacylglycerol (DAG), and 23% triacylglycerol (TAG) with a stoichiometry of 46 PL, 6 DAG, and 15 TAG molecules per apoB:1000. PLTP absence drastically altered the lipid composition of apoB:1000 lipoproteins; these particles contained 46% PL, 13% DAG, and 41% TAG with a stoichiometry of 27 PL, 10 DAG, and 23 TAG molecules per apoB:1000. Reintroduction of Pltp gene into PLTP-KO hepatocytes stimulated the lipidation and secretion of apoB:1000-containing lipoproteins by ∼3-fold; the lipid composition and stoichiometry of these particles were identical to those secreted by WT hepatocytes. In contrast to the WT, apoB:1000 in PLTP-KO hepatocytes was susceptible to intracellular degradation predominantly in the post-endoplasmic reticulum, presecretory compartment. Reintroduction of Pltp gene into PLTP-KO hepatocytes restored the stability of apoB:1000. These results provide compelling evidence that in hepatocytes initial recruitment of PL by apoB:1000 leading to the formation of the PL-rich apoB-containing initiation complex is mediated to a large extent by PLTP. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Phospholipid Transfer Protein Plays a Major Role in the Initiation of Apolipoprotein B-containing Lipoprotein Assembly in Mouse Primary Hepatocytes*

    PubMed Central

    Manchekar, Medha; Liu, Yanwen; Sun, Zhihuan; Richardson, Paul E.; Dashti, Nassrin

    2015-01-01

    In this study, we tested the hypothesis that phospholipid transfer protein (PLTP) is a plausible mediator of phospholipid (PL) transfer to the N-terminal 1000 residues of apoB (apoB:1000) leading to the initiation of apoB-containing lipoprotein assembly. To this end, primary hepatocytes from wild type (WT) and PLTP knock-out (KO) mice were transduced with adenovirus-apoB:1000 with or without co-transduction with adenovirus-PLTP, and the assembly and secretion of apoB:1000-containing lipoproteins were assessed. PLTP deficiency resulted in a 65 and 72% reduction in the protein and lipid content, respectively, of secreted apoB:1000-containing lipoproteins. Particles secreted by WT hepatocytes contained 69% PL, 9% diacylglycerol (DAG), and 23% triacylglycerol (TAG) with a stoichiometry of 46 PL, 6 DAG, and 15 TAG molecules per apoB:1000. PLTP absence drastically altered the lipid composition of apoB:1000 lipoproteins; these particles contained 46% PL, 13% DAG, and 41% TAG with a stoichiometry of 27 PL, 10 DAG, and 23 TAG molecules per apoB:1000. Reintroduction of Pltp gene into PLTP-KO hepatocytes stimulated the lipidation and secretion of apoB:1000-containing lipoproteins by ∼3-fold; the lipid composition and stoichiometry of these particles were identical to those secreted by WT hepatocytes. In contrast to the WT, apoB:1000 in PLTP-KO hepatocytes was susceptible to intracellular degradation predominantly in the post-endoplasmic reticulum, presecretory compartment. Reintroduction of Pltp gene into PLTP-KO hepatocytes restored the stability of apoB:1000. These results provide compelling evidence that in hepatocytes initial recruitment of PL by apoB:1000 leading to the formation of the PL-rich apoB-containing initiation complex is mediated to a large extent by PLTP. PMID:25638820

  7. Insulin-sensitive phospholipid signaling systems and glucose transport. Update II.

    PubMed

    Farese, R V

    2001-04-01

    Insulin provokes rapid changes in phospholipid metabolism and thereby generates biologically active lipids that serve as intracellular signaling factors that regulate glucose transport and glycogen synthesis. These changes include: (i) activation of phosphatidylinositol 3-kinase (PI3K) and production of PIP3; (ii) PIP3-dependent activation of atypical protein kinase Cs (PKCs); (iii) PIP3-dependent activation of PKB; (iv) PI3K-dependent activation of phospholipase D and hydrolysis of phosphatidylcholine with subsequent increases in phosphatidic acid (PA) and diacylglycerol (DAG); (v) PI3K-independent activation of glycerol-3-phosphate acylytansferase and increases in de novo synthesis of PA and DAG; and (vi) activation of DAG-sensitive PKCs. Recent findings suggest that atypical PKCs and PKB serve as important positive regulators of insulin-stimulated glucose metabolism, whereas mechanisms that result in the activation of DAG-sensitive PKCs serve mainly as negative regulators of insulin signaling through PI3K. Atypical PKCs and PKB are rapidly activated by insulin in adipocytes, liver, skeletal muscles, and other cell types by a mechanism requiring PI3K and its downstream effector, 3-phosphoinositide-dependent protein kinase-1 (PDK-1), which, in conjunction with PIP3, phosphorylates critical threonine residues in the activation loops of atypical PKCs and PKB. PIP3 also promotes increases in autophosphorylation and allosteric activation of atypical PKCs. Atypical PKCs and perhaps PKB appear to be required for insulin-induced translocation of the GLUT 4 glucose transporter to the plasma membrane and subsequent glucose transport. PKB also appears to be the major regulator of glycogen synthase. Together, atypical PKCs and PKB serve as a potent, integrated PI3K/PDK-1-directed signaling system that is used by insulin to regulate glucose metabolism.

  8. Insulin promotes diacylglycerol kinase activation by different mechanisms in rat cerebral cortex synaptosomes.

    PubMed

    Zulian, Sandra E; Ilincheta de Boschero, Mónica G; Giusto, Norma M

    2006-10-01

    The mechanism by which insulin increases diacylglycerol kinase (DAGK) activity has been studied in cerebral cortex (CC) synaptosomes from adult (3-4 months of age) rats. The purpose of this study was to identify the role of phospholipases C and D (PLC and PLD) in DAGK activation by insulin. Neomycin, an inhibitor of PLC phosphatidylinositol-bisphosphate (PIP2) specific; ethanol, an inhibitor of phosphatidic acid (PA) formation by the promotion of a transphosphatidyl reaction of phosphatidylcholine phospholipase D (PC-PLD); and DL propranolol, an inhibitor of phosphatidate phosphohydrolase (PAP), were used in this study. Insulin (0.1 microM) shielded an increase in PA synthesis by [32P] incorporation using [gamma-32P]ATP as substrate and endogenous diacylglycerol (DAG) as co-substrate. This activated synthesis was strongly inhibited either by ethanol or DL propranolol. Pulse chase experiments also showed a PIP2-PLC activation within 1 min exposure to insulin. When exogenous unsaturated 18:0-20:4 DAG was present, insulin increased PA synthesis significantly. However, this stimulatory effect was not observed in the presence of exogenous saturated (di-16:0). In the presence of R59022, a selective DAGK inhibitor, insulin exerted no stimulatory effect on [32P]PA formation, suggesting a strong relationship between increased PA formation by insulin and DAGK activity. These data indicate that the increased synthesis of PA by insulin could be mediated by the activation of both a PC-PLD pathway to provide DAG and a direct DAGK activation that is associated to the use of 18:0-20:4 DAG species. PIP2-PLC activation may contribute at least partly to the insulin effect on DAGK activity. Copyright 2006 Wiley-Liss, Inc.

  9. Three essays on price dynamics and causations among energy markets and macroeconomic information

    NASA Astrophysics Data System (ADS)

    Hong, Sung Wook

    This dissertation examines three important issues in energy markets: price dynamics, information flow, and structural change. We discuss each issue in detail, building empirical time series models, analyzing the results, and interpreting the findings. First, we examine the contemporaneous interdependencies and information flows among crude oil, natural gas, and electricity prices in the United States (US) through the multivariate generalized autoregressive conditional heteroscedasticity (MGARCH) model, Directed Acyclic Graph (DAG) for contemporaneous causal structures and Bernanke factorization for price dynamic processes. Test results show that the DAG from residuals of out-of-sample-forecast is consistent with the DAG from residuals of within-sample-fit. The result supports innovation accounting analysis based on DAGs using residuals of out-of-sample-forecast. Second, we look at the effects of the federal fund rate and/or WTI crude oil price shock on US macroeconomic and financial indicators by using a Factor Augmented Vector Autoregression (FAVAR) model and a graphical model without any deductive assumption. The results show that, in contemporaneous time, the federal fund rate shock is exogenous as the identifying assumption in the Vector Autoregression (VAR) framework of the monetary shock transmission mechanism, whereas the WTI crude oil price return is not exogenous. Third, we examine price dynamics and contemporaneous causality among the price returns of WTI crude oil, gasoline, corn, and the S&P 500. We look for structural break points and then build an econometric model to find the consistent sub-periods having stable parameters in a given VAR framework and to explain recent movements and interdependency among returns. We found strong evidence of two structural breaks and contemporaneous causal relationships among the residuals, but also significant differences between contemporaneous causal structures for each sub-period.

  10. Identification of bottlenecks in the accumulation of cyclic fatty acids in camelina seed oil

    DOE PAGES

    Yu, Xiao-Hong; Cahoon, Rebecca E.; Horn, Patrick J.; ...

    2017-09-20

    Modified fatty acids (mFA) have diverse uses, e.g., cyclopropane fatty acids (CPA) are feedstocks for producing coatings, lubricants, plastics, and cosmetics. The expression of mFA-producing enzymes in crop and model plants generally results in lower levels of mFA accumulation than in their natural-occurring source plants. In order to further our understanding of metabolic bottlenecks that limit mFA accumulation, we generated transgenic Camelina sativa lines co-expressing Escherichia coli cyclopropane synthase (EcCPS) and Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT). In contrast to transgenic CPA-accumulating Arabidopsis, CPA accumulation in camelina caused only minor changes in seed weight, germination rate, oil accumulation, and seedlingmore » development. CPA accumulated to much higher levels in membrane than storage lipids, comprising more than 60% of total fatty acid in both phosphatidylcholine (PC) and phosphatidylethanolamine (PE) versus 26% in diacylglycerol (DAG) and 12% in triacylglycerol (TAG) indicating bottlenecks in the transfer of CPA from PC to DAG and from DAG to TAG. Upon coexpression of SfLPAT with EcCPS, di-CPA-PC increased by ~50% relative to lines expressing EcCPS alone with the di-CPA-PC primarily observed in the embryonic axis and mono-CPA-PC primarily in cotyledon tissue. EcCPS-SfLPAT lines revealed a redistribution of CPA from the sn-1 to sn-2 positions within PC and PE that was associated with a doubling of CPA accumulation in both DAG and TAG. Finally, the identification of metabolic bottlenecks in acyl transfer between site of synthesis (phospholipids) and deposition in storage oils (TAGs) lays the foundation for the optimizing CPA accumulation through directed engineering of oil synthesis in target crops.« less

  11. Identification of bottlenecks in the accumulation of cyclic fatty acids in camelina seed oil

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yu, Xiao-Hong; Cahoon, Rebecca E.; Horn, Patrick J.

    Modified fatty acids (mFA) have diverse uses, e.g., cyclopropane fatty acids (CPA) are feedstocks for producing coatings, lubricants, plastics, and cosmetics. The expression of mFA-producing enzymes in crop and model plants generally results in lower levels of mFA accumulation than in their natural-occurring source plants. In order to further our understanding of metabolic bottlenecks that limit mFA accumulation, we generated transgenic Camelina sativa lines co-expressing Escherichia coli cyclopropane synthase (EcCPS) and Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT). In contrast to transgenic CPA-accumulating Arabidopsis, CPA accumulation in camelina caused only minor changes in seed weight, germination rate, oil accumulation, and seedlingmore » development. CPA accumulated to much higher levels in membrane than storage lipids, comprising more than 60% of total fatty acid in both phosphatidylcholine (PC) and phosphatidylethanolamine (PE) versus 26% in diacylglycerol (DAG) and 12% in triacylglycerol (TAG) indicating bottlenecks in the transfer of CPA from PC to DAG and from DAG to TAG. Upon coexpression of SfLPAT with EcCPS, di-CPA-PC increased by ~50% relative to lines expressing EcCPS alone with the di-CPA-PC primarily observed in the embryonic axis and mono-CPA-PC primarily in cotyledon tissue. EcCPS-SfLPAT lines revealed a redistribution of CPA from the sn-1 to sn-2 positions within PC and PE that was associated with a doubling of CPA accumulation in both DAG and TAG. Finally, the identification of metabolic bottlenecks in acyl transfer between site of synthesis (phospholipids) and deposition in storage oils (TAGs) lays the foundation for the optimizing CPA accumulation through directed engineering of oil synthesis in target crops.« less

  12. Characterization of E 471 food emulsifiers by high-performance thin-layer chromatography-fluorescence detection.

    PubMed

    Oellig, Claudia; Brändle, Klara; Schwack, Wolfgang

    2018-07-13

    Mono- and diacylglycerol (MAG and DAG) emulsifiers, also known as food additive E 471, are widely used to adjust techno-functional properties in various foods. Besides MAGs and DAGs, E 471 emulsifiers additionally comprise different amounts of triacylglycerols (TAGs) and free fatty acids (FFAs). MAGs, DAGs, TAGs and FFAs are generally determined by high-performance liquid chromatography (HPLC) or gas chromatography (GC) coupled to mass selective detection, analyzing the individual representatives of the lipid classes. In this work we present a rapid and sensitive method for the determination of MAGs, DAGs, TAGs and FFAs in E 471 emulsifiers by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD), including a response factor system for quantitation. Samples were simply dissolved and diluted with t-butyl methyl ether before a two-fold development was performed on primuline pre-impregnated LiChrospher silica gel plates with diethyl ether and n-pentane/n-hexane/diethyl ether (52:20:28, v/v/v) as the mobile phases to 18 and 75 mm, respectively. For quantitation, the plate was scanned in the fluorescence mode at UV 366/>400 nm, when the cumulative signal for each lipid class was used. Calibration was done with 1,2-distearin and amounts of lipid classes were calculated with response factors and expressed as monostearin, distearin, tristearin and stearic acid. Limits of detection and quantitation were 1 and 4 ng/zone, respectively, for 1,2-distearin. Thus, the HPTLC-FLD approach represents a simple, rapid and convenient screening alternative to HPLC and GC analysis of the individual compounds. Visual detection additionally enables an easy characterization and the direct comparison of emulsifiers through the lipid class pattern, when utilized as a fingerprint. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. The molecular products and biogeochemical significance of lipid photooxidation in West Antarctic surface waters

    NASA Astrophysics Data System (ADS)

    Collins, James R.; Fredricks, Helen F.; Bowman, Jeff S.; Ward, Collin P.; Moreno, Carly; Longnecker, Krista; Marchetti, Adrian; Hansel, Colleen M.; Ducklow, Hugh W.; Van Mooy, Benjamin A. S.

    2018-07-01

    The seasonal depletion of stratospheric ozone over the Southern Hemisphere allows abnormally high doses of ultraviolet radiation (UVR) to reach surface waters of the West Antarctic Peninsula (WAP) in the austral spring, creating a natural laboratory for the study of lipid photooxidation in the shallow mixed layer of the marginal ice zone. The photooxidation of lipids under such conditions has been identified as a significant source of stress to microorganisms and short-chain fatty acids altered by photochemical processes have been found in both marine aerosols and sinking marine particle material. However, the biogeochemical impact of lipid photooxidation has not been quantitatively compared at ecosystem scale to the many other biological and abiotic processes that can transform particulate organic matter in the surface ocean. We combined results from field experiments with diverse environmental data, including high-resolution, accurate-mass HPLC-ESI-MS analysis of lipid extracts and in situ measurements of ultraviolet irradiance, to address several unresolved questions about lipid photooxidation in the marine environment. In our experiments, we used liposomes-nonliving, cell-like aggregations of lipids-to examine the photolability of various moieties of the intact polar diacylglycerol (IP-DAG) phosphatidylcholine (PC), a structural component of membranes in a broad range of microorganisms. We observed significant rates of photooxidation only when the molecule contained the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA). As the DHA-containing lipid was oxidized, we observed the steady ingrowth of a diversity of oxylipins and oxidized IP-DAG; our results suggest both the intact IP-DAG the degradation products were amenable to heterotrophic assimilation. To complement our experiments, we used an enhanced version of a new lipidomics discovery software package to identify the lipids in water column samples and in several diatom isolates. The galactolipid

  14. Aluminum ions alter the function of non-specific phospholipase C through the changes in plasma membrane physical properties.

    PubMed

    Pejchar, Přemysl; Martinec, Jan

    2015-01-01

    The first indication of the aluminum (Al) toxicity in plants growing in acidic soils is the cessation of root growth, but the detailed mechanism of Al effect is unknown. Here we examined the impact of Al stress on the activity of non-specific phospholipase C (NPC) in the connection with the processes related to the plasma membrane using fluorescently labeled phosphatidylcholine. We observed a rapid and significant decrease of labeled diacylglycerol (DAG), product of NPC activity, in Arabidopsis seedlings treated with AlCl₃. Interestingly, an application of the membrane fluidizer, benzyl alcohol, restored the level of DAG during Al treatment. Our observations suggest that the activity of NPC is affected by Al-induced changes in plasma membrane physical properties.

  15. Advanced Air Transportation Technologies (AATT) Project: Distributed Air-Ground Traffic Management

    NASA Technical Reports Server (NTRS)

    Mogford, Richard; Green, Steve; Ballin, Mark

    2002-01-01

    This viewgraph presentation provides an overview of active Distributed Air Ground Traffic Management (DAG-TM) work and reported on its overall progress to date. It does not include details on the concept elements (CEs).The DAG-TM research project is defined as a concept development and definition project and no tools will be delivered. Of the 14 CEs, three are being explored actively: CE-5, CE-6, and CE-11. Overviews of CE-5 (Free Maneuvering for User-Preferred Separation Assurance and Local TFM Conformance), CE-6 (En Route and Transition Trajectory Negotiation for User-Preferred Separation and Local TFM Conformance) and CE-11 (Self-Spacing for Merging and In-Trail Separation) are presented.

  16. Pleiotropic Alterations in Lipid Metabolism in Yeast sac1 Mutants: Relationship to “Bypass Sec14p” and Inositol Auxotrophy

    PubMed Central

    Rivas, Marcos P.; Kearns, Brian G.; Xie, Zhigang; Guo, Shuling; Sekar, M. Chandra; Hosaka, Kohei; Kagiwada, Satoshi; York, John D.; Bankaitis, Vytas A.

    1999-01-01

    SacIp dysfunction results in bypass of the requirement for phosphatidylinositol transfer protein (Sec14p) function in yeast Golgi processes. This effect is accompanied by alterations in inositol phospholipid metabolism and inositol auxotrophy. Elucidation of how sac1 mutants effect “bypass Sec14p” will provide insights into Sec14p function in vivo. We now report that, in addition to a dramatic accumulation of phosphatidylinositol-4-phosphate, sac1 mutants also exhibit a specific acceleration of phosphatidylcholine biosynthesis via the CDP-choline pathway. This phosphatidylcholine metabolic phenotype is sensitive to the two physiological challenges that abolish bypass Sec14p in sac1 strains; i.e. phospholipase D inactivation and expression of bacterial diacylglycerol (DAG) kinase. Moreover, we demonstrate that accumulation of phosphatidylinositol-4-phosphate in sac1 mutants is insufficient to effect bypass Sec14p. These data support a model in which phospholipase D activity contributes to generation of DAG that, in turn, effects bypass Sec14p. A significant fate for this DAG is consumption by the CDP-choline pathway. Finally, we determine that CDP-choline pathway activity contributes to the inositol auxotrophy of sac1 strains in a novel manner that does not involve obvious defects in transcriptional expression of the INO1 gene. PMID:10397762

  17. Physicochemical, textural and viscoelastic properties of palm diacylglycerol bakery shortening during storage.

    PubMed

    Cheong, Ling-Zhi; Tan, Chin-Ping; Long, Kamariah; Affandi Yusoff, Mohd Suria; Lai, Oi-Ming

    2010-10-01

    Diacylglycerol (DAG), which has health-enhancing properties, is sometimes added to bakery shortening to produce baked products with enhanced physical functionality. Nevertheless, the quantity present is often too little to exert any positive healthful effects. This research aimed to produce bakery shortenings containing significant amounts of palm diacyglycerol (PDG). Physicochemical, textural and viscoelastic properties of the PDG bakery shortenings during 3 months storage were evaluated and compared with those of commercial bakery shortening (CS). PDG bakery shortenings (DS55, DS64 and DS73) had less significant increments in slip melting point (SMP), solid fat content (SFC) and hardness during storage as compared to CS. Unlike CS, melting behaviour and viscoelastic properties of PDG bakery shortenings remained unchanged during storage. As for polymorphic transformation, CS contained only β crystals after 8 weeks of storage. PDG bakery shortenings managed to retard polymorphic transformation for up to 10 weeks of storage in DS55 and 12 weeks of storage in DS64 and DS73. PDG bakery shortenings had similar if not better storage stability as compared to CS. This is mainly due to the ability of DAG to retard polymorphic transformation from β' to β crystals. Thus, incorporation of DAG improved physical functionality of bakery shortening. Copyright © 2010 Society of Chemical Industry.

  18. Lipid droplets form from distinct regions of the cell in the fission yeast Schizosaccharomyces pombe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Meyers, Alex; del Rio, Zuania P.; Beaver, Rachael A.

    Eukaryotic cells store cholesterol/sterol esters (SEs) and triacylglycerols (TAGs) in lipid droplets, which form from the contiguous endoplasmic reticulum (ER) network. However, it is not known if droplets preferentially form from certain regions of the ER over others. Here, we used fission yeast Schizosaccharomyces pombe cells where the nuclear and cortical/peripheral ER domains are distinguishable by light microscopy to show that SE-enriched lipid droplets form away from the nucleus at the cell tips, whereas TAG-enriched lipid droplets form around the nucleus. Sterols localize to the regions of the cells where droplets enriched in SEs are observed. TAG droplet formation aroundmore » the nucleus appears to be a strong function of diacylglycerol (DAG) homeostasis with Cpt1p, which coverts DAG into phosphatidylcholine and phosphatidylethanolamine localized exclusively to the nuclear ER. Also, Dgk1p, which converts DAG into phosphatidic acid localized strongly to the nuclear ER over the cortical/peripheral ER. We also show that TAG more readily translocates from the ER to lipid droplets than do SEs. Lastly, the results augment the standard lipid droplet formation model, which has SEs and TAGs flowing into the same nascent lipid droplet regardless of its biogenesis point in the cell.« less

  19. Liposome-encapsulated diacyl glycerol and inositol triphosphate-induced delayed oocyte activation and poor development of parthenotes.

    PubMed

    Nair, Ramya; Manikkath, Jyothsna; Hegde, Aswathi R; Mutalik, Srinivas; Kalthur, Guruprasad; Adiga, Satish Kumar

    2017-09-01

    To explore the ability of diacyl glycerol (DAG) and inositol triphosphate (IP3), two major secondary messengers in the calcium signaling pathway, in activating oocytes. Oocyte cumulus complex obtained from superovulated Swiss albino mice were incubated in M16 medium with liposome-encapsulated 1,2-Dipalmitoyl-sn-glycerol (LEDAG) and/or IP3 for 3 h. Strontium chloride was used as positive control. The activation potential, ploidy status, and blastocyst rate was calculated. Both DAG and IP3, individually, induced activation in ~98% of oocytes, which was significantly higher (p<0.01) than activation induced by strontium chloride (60%). Delayed pronucleus formation and a higher percentage of diploid parthenotes was observed in oocytes activated with LEDAG and/or IP3. However, these embryos failed to progress beyond the 6-8-cell stage. Only when the medium was supplemented with LEDAG (5 μg/mL) and IP3 (10 μg/mL) could activated oocytes progress till the blastocyst stage (5.26%), which was lower than the blastocyst rate in the positive controls (13.91%). The results of the present study indicate that DAG and IP3 can induce delayed oocyte activation and poor development of parthenotes in vitro.

  20. Lipid droplets form from distinct regions of the cell in the fission yeast Schizosaccharomyces pombe

    DOE PAGES

    Meyers, Alex; del Rio, Zuania P.; Beaver, Rachael A.; ...

    2016-04-29

    Eukaryotic cells store cholesterol/sterol esters (SEs) and triacylglycerols (TAGs) in lipid droplets, which form from the contiguous endoplasmic reticulum (ER) network. However, it is not known if droplets preferentially form from certain regions of the ER over others. Here, we used fission yeast Schizosaccharomyces pombe cells where the nuclear and cortical/peripheral ER domains are distinguishable by light microscopy to show that SE-enriched lipid droplets form away from the nucleus at the cell tips, whereas TAG-enriched lipid droplets form around the nucleus. Sterols localize to the regions of the cells where droplets enriched in SEs are observed. TAG droplet formation aroundmore » the nucleus appears to be a strong function of diacylglycerol (DAG) homeostasis with Cpt1p, which coverts DAG into phosphatidylcholine and phosphatidylethanolamine localized exclusively to the nuclear ER. Also, Dgk1p, which converts DAG into phosphatidic acid localized strongly to the nuclear ER over the cortical/peripheral ER. We also show that TAG more readily translocates from the ER to lipid droplets than do SEs. Lastly, the results augment the standard lipid droplet formation model, which has SEs and TAGs flowing into the same nascent lipid droplet regardless of its biogenesis point in the cell.« less

  1. Among Metabolic Factors, Significance of Fasting and Postprandial Increases in Acyl and Desacyl Ghrelin and the Acyl/Desacyl Ratio in Obstructive Sleep Apnea before and after Treatment

    PubMed Central

    Chihara, Yuichi; Akamizu, Takashi; Azuma, Masanori; Murase, Kimihiko; Harada, Yuka; Tanizawa, Kiminobu; Handa, Tomohiro; Oga, Toru; Mishima, Michiaki; Chin, Kazuo

    2015-01-01

    Study Objectives: There are reports suggesting that obstructive sleep apnea (OSA) may itself cause weight gain. However, recent reports showed increases in body mass index (BMI) following continuous positive airway pressure (CPAP) treatments. When considering weight changes, changes in humoral factors that have significant effects on appetite such as acyl (AG) and desacyl ghrelin (DAG), leptin, insulin, and glucose and their interactions, examples of which are AG/DAG and AG/insulin, are important. The aim of this study was to test the hypothesis that some appetite-related factors had a specific profile before and after CPAP treatment. Methods: Metabolic parameters were measured cross-sectionally while fasting and 30, 60, 90, and 120 min following breakfast in no or mild OSA (apnea-hypopnea index < 15, n = 15) and moderate-to-severe OSA (apnea-hypopnea index ≥ 15, n = 39) participants in a single institute. There were no differences in age, sex, BMI, or visceral fat accumulation between the two groups. Twenty-one patients with moderate-to-severe OSA who received CPAP treatment also prospectively underwent the same testing following 3 months of CPAP treatment. Results: Although fasting and postprandial glucose, insulin, and leptin levels did not differ between no or mild OSA and moderate-to-severe OSA participants, AG and DAG, including AG/DAG and AG/insulin, under fasting and postprandial conditions were significantly increased in the moderate-to-severe OSA patients (p < 0.01). After 3 months of CPAP treatment in 21 of the moderate-to-severe OSA participants, AG/DAG did not change significantly, but other ghrelin-related parameters including AG/insulin significantly decreased compared with values before treatment but remained higher than in no or mild OSA. Conclusions: Among several important metabolic factors, ghrelin-related factors had the strongest associations with moderate-to-severe OSA. These results indicate that continuous changes in ghrelin secretion in

  2. BioJS DAGViewer: A reusable JavaScript component for displaying directed graphs

    PubMed Central

    Micklem, Gos

    2014-01-01

    Summary: The DAGViewer BioJS component is a reusable JavaScript component made available as part of the BioJS project and intended to be used to display graphs of structured data, with a particular emphasis on Directed Acyclic Graphs (DAGs). It enables users to embed representations of graphs of data, such as ontologies or phylogenetic trees, in hyper-text documents (HTML). This component is generic, since it is capable (given the appropriate configuration) of displaying any kind of data that is organised as a graph. The features of this component which are useful for examining and filtering large and complex graphs are described. Availability: http://github.com/alexkalderimis/dag-viewer-biojs; http://github.com/biojs/biojs; http://dx.doi.org/10.5281/zenodo.8303. PMID:24627804

  3. Time Evolution of the Wigner Operator as a Quasi-density Operator in Amplitude Dessipative Channel

    NASA Astrophysics Data System (ADS)

    Yu, Zhisong; Ren, Guihua; Yu, Ziyang; Wei, Chenhuinan; Fan, Hongyi

    2018-06-01

    For developing quantum mechanics theory in phase space, we explore how the Wigner operator {Δ } (α ,α ^{\\ast } )≡ {1}/{π } :e^{-2(α ^{\\ast } -α ^{\\dag })(α -α )}:, when viewed as a quasi-density operator correponding to the Wigner quasiprobability distribution, evolves in a damping channel. with the damping constant κ. We derive that it evolves into 1/T + 1:\\exp 2/T + 1[-(α^{\\ast} e^{-κ t}-a^{\\dag} )(α e^{-κ t}-a)]: where T ≡ 1 - e - 2 κ t . This in turn helps to directly obtain the final state ρ( t) out of the dessipative channel from the initial classical function corresponding to initial ρ(0). Throught the work, the method of integration within ordered product (IWOP) of operators is employed.

  4. Seven Modeling Perspectives on Teaching and Learning: Some Interrelations and Cognitive Effects

    ERIC Educational Resources Information Center

    Easley, J. A., Jr.

    1977-01-01

    The categories of models associated with the seven perspectives are designated as combinatorial models, sampling models, cybernetic models, game models, critical thinking models, ordinary language analysis models, and dynamic structural models. (DAG)

  5. Pertussis toxin treatment attenuates some effects of insulin in BC3H-1 murine myocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luttrell, L.M.; Hewlett, E.L.; Romero, G.

    1988-05-05

    The effects of pertussis toxin (PT) treatment on insulin-stimulated myristoyl-diacylglycerol (DAG) generation, hexose transport, and thymidine incorporation were studied in differentiated BC3H-1 mycocytes. Insulin treatment caused a biphasic increase in myristoyl-DAG production which was abolished in myocytes treated with PT. There was no effect of PT treatment on basal (nonstimulated) myristoyl-DAG production. Insulin-stimulated hydrolysis of a membrane phosphatidylinositol glycan was blocked by PT treatment. ADP-ribosylation of BC3H-1 plasma membranes with (/sup 32/P)NAD revealed a 40-kDa protein as the major PT substrate in vivo and in vitro. The time course and dose dependence of the effects of PT on diacylglycerol generationmore » correlated with the in vivo ADP-ribosylation of the 40-kDa substrate. Pertussis toxin treatment resulted in a 71% attenuation of insulin-stimulated hexose uptake without effect on either basal or phorbol ester-stimulated uptake. The stimulatory effects of insulin and fetal calf serum on (/sup 3/H)thymidine incorporation into quiescent myocytes were attenuated by 61 and 59%, respectively, when PT was added coincidently with the growth factors. Nonstimulated and EGF-stimulated (/sup 3/H)thymidine incorporation was unaffected by PT treatment. These data suggest that a PT-sensitive G protein is involved in the cellular signaling mechanisms of insulin.« less

  6. Novel LC/MS/MS and High-Throughput Mass Spectrometric Assays for Monoacylglycerol Acyltransferase Inhibitors.

    PubMed

    Qi, Jenson; Masucci, John A; Lang, Wensheng; Connelly, Margery A; Caldwell, Gary W; Petrounia, Ioanna; Kirkpatrick, Jennifer; Barnakov, Alexander N; Struble, Geoffrey; Miller, Robyn; Dzordzorine, Keli; Kuo, Gee-Hong; Gaul, Michael; Pocai, Alessandro; Lee, Seunghun

    2017-04-01

    Monoacylglycerol acyltransferase enzymes (MGAT1, MGAT2, and MGAT3) convert monoacylglycerol to diacylglycerol (DAG). MGAT1 and MGAT2 are both implicated in obesity-related metabolic diseases. Conventional MGAT enzyme assays use radioactive substrates, wherein the product of the MGAT-catalyzed reaction is usually resolved by time-consuming thin layer chromatography (TLC) analysis. Furthermore, microsomal membrane preparations typically contain endogenous diacylglycerol acyltransferase (DGAT) from the host cells, and these DGAT activities can further acylate DAG to form triglyceride (TG). Our mass spectrometry (liquid chromatography-tandem mass spectrometry, or LC/MS/MS) MGAT2 assay measures human recombinant MGAT2-catalyzed formation of didecanoyl-glycerol from 1-decanoyl-rac-glycerol and decanoyl-CoA, to produce predominantly 1,3-didecanoyl-glycerol. Unlike 1,2-DAG, 1,3-didecanoyl-glycerol is proved to be not susceptible to further acylation to TG. 1,3-Didecanoyl-glycerol product can be readily solubilized and directly subjected to high-throughput mass spectrometry (HTMS) without further extraction in a 384-well format. We also have established the LC/MS/MS MGAT activity assay in the intestinal microsomes from various species. Our assay is proved to be highly sensitive, and thus it allows measurement of endogenous MGAT activity in cell lysates and tissue preparations. The implementation of the HTMS MGAT activity assay has facilitated the robust screening and evaluation of MGAT inhibitors for the treatment of metabolic diseases.

  7. Activities of acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT) in microsomal preparations of developing sunflower and safflower seeds.

    PubMed

    Banaś, Walentyna; Sanchez Garcia, Alicia; Banaś, Antoni; Stymne, Sten

    2013-06-01

    The last step in triacylglycerols (TAG) biosynthesis in oil seeds, the acylation of diacylglycerols (DAG), is catalysed by two types of enzymes: the acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT). The relative contribution of these enzymes in the synthesis of TAG has not yet been defined in any plant tissue. In the presented work, microsomal preparations were obtained from sunflower and safflower seeds at different stages of development and used in DGAT and PDAT enzyme assays. The ratio between PDAT and DGAT activity differed dramatically between the two different species. DGAT activities were measured with two different acyl acceptors and assay methods using two different acyl-CoAs, and in all cases the ratio of PDAT to DGAT activity was significantly higher in safflower than sunflower. The sunflower DGAT, measured by both methods, showed significant higher activity with 18:2-CoA than with 18:1-CoA, whereas the opposite specificity was seen with the safflower enzyme. The specificities of PDAT on the other hand, were similar in both species with 18:2-phosphatidylcholine being a better acyl donor than 18:1-PC and with acyl groups at the sn-2 position utilised about fourfold the rate of the sn-1 position. No DAG:DAG transacylase activity could be detected in the microsomal preparations.

  8. Mitochondrial-Targeted Catalase Protects Against High-Fat Diet-Induced Muscle Insulin Resistance by Decreasing Intramuscular Lipid Accumulation.

    PubMed

    Lee, Hui-Young; Lee, Jae Sung; Alves, Tiago; Ladiges, Warren; Rabinovitch, Peter S; Jurczak, Michael J; Choi, Cheol Soo; Shulman, Gerald I; Samuel, Varman T

    2017-08-01

    We explored the role of reactive oxygen species (ROS) in the pathogenesis of muscle insulin resistance. We assessed insulin action in vivo with a hyperinsulinemic-euglycemic clamp in mice expressing a mitochondrial-targeted catalase (MCAT) that were fed regular chow (RC) or a high-fat diet (HFD) or underwent an acute infusion of a lipid emulsion. RC-fed MCAT mice were similar to littermate wild-type (WT) mice. However, HFD-fed MCAT mice were protected from diet-induced insulin resistance. In contrast, an acute lipid infusion caused muscle insulin resistance in both MCAT and WT mice. ROS production was decreased in both HFD-fed and lipid-infused MCAT mice and cannot explain the divergent response in insulin action. MCAT mice had subtly increased energy expenditure and muscle fat oxidation with decreased intramuscular diacylglycerol (DAG) accumulation, protein kinase C-θ (PKCθ) activation, and impaired insulin signaling with HFD. In contrast, the insulin resistance with the acute lipid infusion was associated with increased muscle DAG content in both WT and MCAT mice. These studies suggest that altering muscle mitochondrial ROS production does not directly alter the development of lipid-induced insulin resistance. However, the altered energy balance in HFD-fed MCAT mice protected them from DAG accumulation, PKCθ activation, and impaired muscle insulin signaling. © 2017 by the American Diabetes Association.

  9. Role of phosphatidylserine in the activation of Rho1-related Pkc1 signaling in Saccharomyces cerevisiae.

    PubMed

    Nomura, Wataru; Ito, Yusuke; Inoue, Yoshiharu

    2017-02-01

    Protein kinase C (PKC) belongs to a family of serine/threonine kinases and is evolutionary conserved among eukaryotes. It contains several functional domains, with the C1 domain being identified as a membrane-targeting module. Diacylglycerol (DAG) and phorbol esters bind to the C1 domain to enhance its kinase activity. The C1 domain is conserved in PKC (Pkc1) in the budding yeast Saccharomyces cerevisiae; however, its kinase activity does not respond to DAG. Although the C1 domain of Pkc1 physically interacts with the small GTPase Rho1, the interaction between C1 domain and lipids has not yet been characterized. We herein provide evidence to show the physical interaction between the C1 domain of Pkc1 and phosphatidylserine (PS), but not DAG. The stress-induced activation of Pkc1 signaling was abolished in a cho1 mutant, which was defective in PS synthase. The deletion of CHO1 perturbed the appropriate localization of Pkc1 at the bud tip, and impaired the physical interaction between Pkc1 and GTP-bound Rho1 in vivo. Our results suggest that PS is necessary for Pkc1 signaling due to its role in regulating the localization of Pkc1 as well as the physical interaction between Rho1 and Pkc1. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Effective diagnosis of genetic disease by computational phenotype analysis of the disease-associated genome

    PubMed Central

    Zemojtel, Tomasz; Köhler, Sebastian; Mackenroth, Luisa; Jäger, Marten; Hecht, Jochen; Krawitz, Peter; Graul-Neumann, Luitgard; Doelken, Sandra; Ehmke, Nadja; Spielmann, Malte; Øien, Nancy Christine; Schweiger, Michal R.; Krüger, Ulrike; Frommer, Götz; Fischer, Björn; Kornak, Uwe; Flöttmann, Ricarda; Ardeshirdavani, Amin; Moreau, Yves; Lewis, Suzanna E.; Haendel, Melissa; Smedley, Damian; Horn, Denise; Mundlos, Stefan; Robinson, Peter N.

    2015-01-01

    Less than half of patients with suspected genetic disease receive a molecular diagnosis. We have therefore integrated next-generation sequencing (NGS), bioinformatics, and clinical data into an effective diagnostic workflow. We used variants in the 2741 established Mendelian disease genes [the disease-associated genome (DAG)] to develop a targeted enrichment DAG panel (7.1 Mb), which achieves a coverage of 20-fold or better for 98% of bases. Furthermore, we established a computational method [Phenotypic Interpretation of eXomes (PhenIX)] that evaluated and ranked variants based on pathogenicity and semantic similarity of patients’ phenotype described by Human Phenotype Ontology (HPO) terms to those of 3991 Mendelian diseases. In computer simulations, ranking genes based on the variant score put the true gene in first place less than 5% of the time; PhenIX placed the correct gene in first place more than 86% of the time. In a retrospective test of PhenIX on 52 patients with previously identified mutations and known diagnoses, the correct gene achieved a mean rank of 2.1. In a prospective study on 40 individuals without a diagnosis, PhenIX analysis enabled a diagnosis in 11 cases (28%, at a mean rank of 2.4). Thus, the NGS of the DAG followed by phenotype-driven bioinformatic analysis allows quick and effective differential diagnostics in medical genetics. PMID:25186178

  11. Effective diagnosis of genetic disease by computational phenotype analysis of the disease-associated genome.

    PubMed

    Zemojtel, Tomasz; Köhler, Sebastian; Mackenroth, Luisa; Jäger, Marten; Hecht, Jochen; Krawitz, Peter; Graul-Neumann, Luitgard; Doelken, Sandra; Ehmke, Nadja; Spielmann, Malte; Oien, Nancy Christine; Schweiger, Michal R; Krüger, Ulrike; Frommer, Götz; Fischer, Björn; Kornak, Uwe; Flöttmann, Ricarda; Ardeshirdavani, Amin; Moreau, Yves; Lewis, Suzanna E; Haendel, Melissa; Smedley, Damian; Horn, Denise; Mundlos, Stefan; Robinson, Peter N

    2014-09-03

    Less than half of patients with suspected genetic disease receive a molecular diagnosis. We have therefore integrated next-generation sequencing (NGS), bioinformatics, and clinical data into an effective diagnostic workflow. We used variants in the 2741 established Mendelian disease genes [the disease-associated genome (DAG)] to develop a targeted enrichment DAG panel (7.1 Mb), which achieves a coverage of 20-fold or better for 98% of bases. Furthermore, we established a computational method [Phenotypic Interpretation of eXomes (PhenIX)] that evaluated and ranked variants based on pathogenicity and semantic similarity of patients' phenotype described by Human Phenotype Ontology (HPO) terms to those of 3991 Mendelian diseases. In computer simulations, ranking genes based on the variant score put the true gene in first place less than 5% of the time; PhenIX placed the correct gene in first place more than 86% of the time. In a retrospective test of PhenIX on 52 patients with previously identified mutations and known diagnoses, the correct gene achieved a mean rank of 2.1. In a prospective study on 40 individuals without a diagnosis, PhenIX analysis enabled a diagnosis in 11 cases (28%, at a mean rank of 2.4). Thus, the NGS of the DAG followed by phenotype-driven bioinformatic analysis allows quick and effective differential diagnostics in medical genetics. Copyright © 2014, American Association for the Advancement of Science.

  12. C1 Domain-Targeted Isophthalate Derivatives Induce Cell Elongation and Cell Cycle Arrest in HeLa Cells

    PubMed Central

    Talman, Virpi; Tuominen, Raimo K.; Gennäs, Gustav Boije af; Yli-Kauhaluoma, Jari; Ekokoski, Elina

    2011-01-01

    Diacylglycerol (DAG)-mediated signaling pathways, such as those mediated by protein kinase C (PKC), are central in regulating cell proliferation and apoptosis. DAG-responsive C1 domains are therefore considered attractive drug targets. Our group has designed a novel class of compounds targeted to the DAG binding site within the C1 domain of PKC. We have previously shown that these 5-(hydroxymethyl)isophthalates modulate PKC activation in living cells. In this study we investigated their effects on HeLa human cervical cancer cell viability and proliferation by using standard cytotoxicity tests and an automated imaging platform with machine vision technology. Cellular effects and their mechanisms were further characterized with the most potent compound, HMI-1a3. Isophthalate derivatives with high affinity to the PKC C1 domain exhibited antiproliferative and non-necrotic cytotoxic effects on HeLa cells. The anti-proliferative effect was irreversible and accompanied by cell elongation. HMI-1a3 induced down-regulation of retinoblastoma protein and cyclins A, B1, D1, and E. Effects of isophthalates on cell morphology, cell proliferation and expression of cell cycle-related proteins were different from those induced by phorbol 12-myristate-13-acetate (PMA) or bryostatin 1, but correlated closely to binding affinities. Therefore, the results strongly indicate that the effect is C1 domain-mediated. PMID:21629792

  13. Conflict Resolution Performance in an Experimental Study of En Route Free Maneuvering Operations

    NASA Technical Reports Server (NTRS)

    Doble, Nathan A.; Barhydt, Richard; Hitt, James M., II

    2005-01-01

    NASA has developed a far-term air traffic management concept, termed Distributed Air/Ground Traffic Management (DAG-TM). One component of DAG-TM, En Route Free Maneuvering, allows properly trained flight crews of equipped autonomous aircraft to assume responsibility for separation from other autonomous aircraft and from Instrument Flight Rules (IFR) aircraft. Ground-based air traffic controllers continue to separate IFR traffic and issue flow management constraints to all aircraft. To examine En Route Free Maneuvering operations, a joint human-in-the-loop experiment was conducted in summer 2004 at the NASA Ames and Langley Research Centers. Test subject pilots used desktop flight simulators to resolve traffic conflicts and adhere to air traffic flow constraints issued by subject controllers. The experimental airspace integrated both autonomous and IFR aircraft at varying traffic densities. This paper presents a subset of the En Route Free Maneuvering experimental results, focusing on airborne and ground-based conflict resolution, and the effects of increased traffic levels on the ability of pilots and air traffic controllers to perform this task. The results show that, in general, increases in autonomous traffic do not significantly impact conflict resolution performance. In addition, pilot acceptability of autonomous operations remains high throughout the range of traffic densities studied. Together with previously reported findings, these results continue to support the feasibility of the En Route Free Maneuvering component of DAG-TM.

  14. A Modal Model to Simulate Typical Structural Dynamic Nonlinearity [PowerPoint

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mayes, Randall L.; Pacini, Benjamin Robert; Roettgen, Dan

    2016-01-01

    Some initial investigations have been published which simulate nonlinear response with almost traditional modal models: instead of connecting the modal mass to ground through the traditional spring and damper, a nonlinear Iwan element was added. This assumes that the mode shapes do not change with amplitude and there are no interactions between modal degrees of freedom. This work expands on these previous studies. An impact experiment is performed on a structure which exhibits typical structural dynamic nonlinear response, i.e. weak frequency dependence and strong damping dependence on the amplitude of vibration. Use of low level modal test results in combinationmore » with high level impacts are processed using various combinations of modal filtering, the Hilbert Transform and band-pass filtering to develop response data that are then fit with various nonlinear elements to create a nonlinear pseudo-modal model. Simulations of forced response are compared with high level experimental data for various nonlinear element assumptions.« less

  15. A Modal Model to Simulate Typical Structural Dynamic Nonlinearity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pacini, Benjamin Robert; Mayes, Randall L.; Roettgen, Daniel R

    2015-10-01

    Some initial investigations have been published which simulate nonlinear response with almost traditional modal models: instead of connecting the modal mass to ground through the traditional spring and damper, a nonlinear Iwan element was added. This assumes that the mode shapes do not change with amplitude and there are no interactions between modal degrees of freedom. This work expands on these previous studies. An impact experiment is performed on a structure which exhibits typical structural dynamic nonlinear response, i.e. weak frequency dependence and strong damping dependence on the amplitude of vibration. Use of low level modal test results in combinationmore » with high level impacts are processed using various combinations of modal filtering, the Hilbert Transform and band-pass filtering to develop response data that are then fit with various nonlinear elements to create a nonlinear pseudo-modal model. Simulations of forced response are compared with high level experimental data for various nonlinear element assumptions.« less

  16. Integration of mouse and human genome-wide association data identifies KCNIP4 as an asthma gene.

    PubMed

    Himes, Blanca E; Sheppard, Keith; Berndt, Annerose; Leme, Adriana S; Myers, Rachel A; Gignoux, Christopher R; Levin, Albert M; Gauderman, W James; Yang, James J; Mathias, Rasika A; Romieu, Isabelle; Torgerson, Dara G; Roth, Lindsey A; Huntsman, Scott; Eng, Celeste; Klanderman, Barbara; Ziniti, John; Senter-Sylvia, Jody; Szefler, Stanley J; Lemanske, Robert F; Zeiger, Robert S; Strunk, Robert C; Martinez, Fernando D; Boushey, Homer; Chinchilli, Vernon M; Israel, Elliot; Mauger, David; Koppelman, Gerard H; Postma, Dirkje S; Nieuwenhuis, Maartje A E; Vonk, Judith M; Lima, John J; Irvin, Charles G; Peters, Stephen P; Kubo, Michiaki; Tamari, Mayumi; Nakamura, Yusuke; Litonjua, Augusto A; Tantisira, Kelan G; Raby, Benjamin A; Bleecker, Eugene R; Meyers, Deborah A; London, Stephanie J; Barnes, Kathleen C; Gilliland, Frank D; Williams, L Keoki; Burchard, Esteban G; Nicolae, Dan L; Ober, Carole; DeMeo, Dawn L; Silverman, Edwin K; Paigen, Beverly; Churchill, Gary; Shapiro, Steve D; Weiss, Scott T

    2013-01-01

    Asthma is a common chronic respiratory disease characterized by airway hyperresponsiveness (AHR). The genetics of asthma have been widely studied in mouse and human, and homologous genomic regions have been associated with mouse AHR and human asthma-related phenotypes. Our goal was to identify asthma-related genes by integrating AHR associations in mouse with human genome-wide association study (GWAS) data. We used Efficient Mixed Model Association (EMMA) analysis to conduct a GWAS of baseline AHR measures from males and females of 31 mouse strains. Genes near or containing SNPs with EMMA p-values <0.001 were selected for further study in human GWAS. The results of the previously reported EVE consortium asthma GWAS meta-analysis consisting of 12,958 diverse North American subjects from 9 study centers were used to select a subset of homologous genes with evidence of association with asthma in humans. Following validation attempts in three human asthma GWAS (i.e., Sepracor/LOCCS/LODO/Illumina, GABRIEL, DAG) and two human AHR GWAS (i.e., SHARP, DAG), the Kv channel interacting protein 4 (KCNIP4) gene was identified as nominally associated with both asthma and AHR at a gene- and SNP-level. In EVE, the smallest KCNIP4 association was at rs6833065 (P-value 2.9e-04), while the strongest associations for Sepracor/LOCCS/LODO/Illumina, GABRIEL, DAG were 1.5e-03, 1.0e-03, 3.1e-03 at rs7664617, rs4697177, rs4696975, respectively. At a SNP level, the strongest association across all asthma GWAS was at rs4697177 (P-value 1.1e-04). The smallest P-values for association with AHR were 2.3e-03 at rs11947661 in SHARP and 2.1e-03 at rs402802 in DAG. Functional studies are required to validate the potential involvement of KCNIP4 in modulating asthma susceptibility and/or AHR. Our results suggest that a useful approach to identify genes associated with human asthma is to leverage mouse AHR association data.

  17. Inhibitory effects of herbal constituents on P-glycoprotein in vitro and in vivo: herb-drug interactions mediated via P-gp.

    PubMed

    Li, Xue; Hu, Jinping; Wang, Baolian; Sheng, Li; Liu, Zhihao; Yang, Shuang; Li, Yan

    2014-03-01

    Modulation of drug transporters via herbal medicines which have been widely used in combination with conventional prescription drugs may result in herb-drug interactions in clinical practice. The present study was designed to investigate the inhibitory effects of 50 major herbal constituents on P-glycoprotein (P-gp) in vitro and in vivo as well as related inhibitory mechanisms. Among these herbal medicines, four constituents, including emodin, 18β-glycyrrhetic acid (18β-GA), dehydroandrographolide (DAG), and 20(S)-ginsenoside F₁ [20(S)-GF₁] exhibited significant inhibition (>50%) on P-gp in MDR1-MDCKII and Caco-2 cells. Emodin was the strongest inhibitor of P-gp (IC₅₀=9.42 μM), followed by 18β-GA (IC₅₀=21.78 μM), 20(S)-GF₁ (IC₅₀=76.08 μM) and DAG (IC₅₀=77.80 μM). P-gp ATPase activity, which was used to evaluate the affinity of substrates to P-gp, was stimulated by emodin and DAG with Km and Vmax values of 48.61, 29.09 μM and 71.29, 38.45 nmol/min/mg protein, respectively. However, 18β-GA and 20(S)-GF₁ exhibited significant inhibition on both basal and verapamil-stimulated P-gp ATPase activities at high concentration. Molecular docking analysis (CDOCKER) further elucidated the mechanism for structure-inhibition relationships of herbal constituents with P-gp. When digoxin was co-administered to male SD rats with emodin or 18β-GA, the AUC(₀₋t) and Cmax of digoxin were increased by approximately 51% and 58%, respectively. Furthermore, 18β-GA, DAG, 20(S)-GF₁ and Rh₁ at 10 μM significantly inhibited CYP3A4/5 activity, while emodin activated the metabolism of midazolam in human liver microsomes. In conclusion, four herbal constituents demonstrated inhibition of P-gp to specific extents in vitro and in vivo. Taken together, our findings provided the basis for the reliable assessment of the potential risks of herb-drug interactions in humans. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. ⁵³Mn-⁵³Cr and ²⁶Al-²⁶Mg ages of a feldspathic lithology in polymict ureilites

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goodrich, Cyrena Anne; Hutcheon, Ian D.; Kita, Noriko T.

    2010-07-01

    We report 53Mn– 53Cr and 26Al– 26Mg isotopic data, obtained by in-situ SIMS analysis, for feldspathic clasts in polymict ureilites DaG 319 and DaG 165. The analyzed clasts belong to the “albitic lithology,” the most abundant population of indigenous feldspathic materials in polymict ureilites, and are highly fractionated igneous assemblages of albitic plagioclase, Fe-rich pyroxenes, phosphates, ilmenite, silica, and Fe(Mn, K, P, Ti)-enriched glass. Glass in DaG 165 clast 19 has extremely high and variable 55Mn/ 52Cr ratios (500–58,000) and shows correlated 53Cr excesses up to ~ 1500‰, clearly indicating the presence of live 53Mn at the time of formation.more » The slope of the well-correlated isochron defined by glass and pyroxenes from this clast corresponds to ( 53Mn/ 55Mn) = (2.84 ± 0.10) × 10 -6 (2σ). Data for less 55Mn/ 52Cr-enriched glasses from DaG 319 clast B1, as well as phosphates from several other clasts, are consistent with this isochron. The 53Mn/ 55Mn ratio obtained from the isochron implies that these clasts are 0.70 ± 0.18 Ma younger than the D'Orbigny angrite, corresponding to the absolute age of 4563.72 ± 0.22 Ma. Plagioclase in DaG 319 clast B1 has a fairly constant 27Al/ 24Mg ratio of ~ 900 and shows resolvable 26Mg excesses of ~ 2‰. The slope of the isochron defined by pyroxene and plagioclase in this clast is (3.0 ± 1.1) × 10 -7 (2σ), corresponding to a time difference of 5.4 (-0.3/+0.5) Ma after CAI (assuming the canonical initial 26Al/ 27Al ratio of 5 × 10 -5) and an age 0.5 (-0.3/+0.5) Ma younger than D'Orbigny. Its absolute age (relative to D'Orbigny) is 4563.9 (+ 0.4/-0.5) Ma, in agreement with the 53Mn– 53Cr age from clast 19. These data provide the first high-precision age date, ~ 5.4 Ma after CAI, for ureilites, giving a minimum estimate for the age of differentiation of their parent asteroid. Interpretation of this age for the thermal and physical history of that asteroid depends on a number of currently

  19. ASTRONAUT CHARLE CONRAD - SKYLAB II (M-114)

    NASA Image and Video Library

    1973-06-05

    S73-27508 (6 June 1973) --- An artist's concept showing astronaut Charles Conrad Jr., Skylab 2 commander, attempting to free the solar array system wing on the Orbital Workshop during extravehicular activity at the Skylab 1 & 2 space station cluster in Earth orbit. The astronaut in the background is Joseph P. Kerwin, Skylab 2 science pilot. Here, Conrad is pushing up on the Beam Erection Tether (BET) to raise the stuck solar panel. The solar wing is only partially deployed; an aluminum strap is believed to be holding it down. Note the cut aluminum angle. Attach points for the BET are on the vent module of the solar array beam. The other end of the BET is attached to the "A" frame supporting the Apollo Telescope Mount (ATM) which is out of view. The aluminum strapping is to be out first, freeing the solar array beam. Then, if the beam does not automatically deploy, Conrad will attempt to help by pulling on the BET. The automatic openers may have become too cold to open without assistance. A deployed solar panel of the ATM is at upper left. The EVA is scheduled for Thursday, June 7th. This concept is by artist Paul Fjeld. Photo credit: NASA

  20. Semi-automated ontology generation within OBO-Edit.

    PubMed

    Wächter, Thomas; Schroeder, Michael

    2010-06-15

    Ontologies and taxonomies have proven highly beneficial for biocuration. The Open Biomedical Ontology (OBO) Foundry alone lists over 90 ontologies mainly built with OBO-Edit. Creating and maintaining such ontologies is a labour-intensive, difficult, manual process. Automating parts of it is of great importance for the further development of ontologies and for biocuration. We have developed the Dresden Ontology Generator for Directed Acyclic Graphs (DOG4DAG), a system which supports the creation and extension of OBO ontologies by semi-automatically generating terms, definitions and parent-child relations from text in PubMed, the web and PDF repositories. DOG4DAG is seamlessly integrated into OBO-Edit. It generates terms by identifying statistically significant noun phrases in text. For definitions and parent-child relations it employs pattern-based web searches. We systematically evaluate each generation step using manually validated benchmarks. The term generation leads to high-quality terms also found in manually created ontologies. Up to 78% of definitions are valid and up to 54% of child-ancestor relations can be retrieved. There is no other validated system that achieves comparable results. By combining the prediction of high-quality terms, definitions and parent-child relations with the ontology editor OBO-Edit we contribute a thoroughly validated tool for all OBO ontology engineers. DOG4DAG is available within OBO-Edit 2.1 at http://www.oboedit.org. Supplementary data are available at Bioinformatics online.

  1. Enzymatic properties and substrate specificity of a bacterial phosphatidylcholine synthase.

    PubMed

    Aktas, Meriyem; Köster, Stefan; Kizilirmak, Sarah; Casanova, Javier C; Betz, Heidi; Fritz, Christiane; Moser, Roman; Yildiz, Özkan; Narberhaus, Franz

    2014-08-01

    Phosphatidylcholine (PC) is a rare membrane lipid in bacteria, but is crucial for virulence of the plant pathogen Agrobacterium tumefaciens and various other pathogens. Agrobacterium tumefaciens uses two independent PC biosynthesis pathways. One is dependent on the integral membrane protein PC synthase (Pcs), which catalyzes the conversion of cytidine diphosphate-diacylglycerol (CDP-DAG) and choline to PC, thereby releasing a cytidine monophosphate (CMP). Here, we show that Pcs consists of eight transmembrane segments with its N- and C-termini located in the cytoplasm. A cytoplasmic loop between the second and third membrane helix contains the majority of the conserved amino acids of a CDP-alcohol phosphotransferase motif (DGX2 ARX12 GX3 DX3 D). Using point mutagenesis, we provide evidence for a crucial role of this motif in choline binding and enzyme activity. To study the catalytic features of the enzyme, we established a purification protocol for recombinant Pcs. The enzyme forms stable oligomers and exhibits broad substrate specificity towards choline derivatives. The presence of CDP-DAG and manganese is a prerequisite for cooperative binding of choline. PC formation by Pcs is reversible and proceeds via two successive reactions. In a first choline- and manganese-independent reaction, CDP-DAG is hydrolyzed releasing a CMP molecule. The resulting phosphatidyl intermediate reacts with choline in a second manganese-dependent step to form PC. Pcs and Pcs bind by molecular sieving (1, 2, 3). © 2014 FEBS.

  2. Disruption of the Arabidopsis Defense Regulator Genes SAG101, EDS1, and PAD4 Confers Enhanced Freezing Tolerance

    PubMed Central

    Chen, Qin-Fang; Xu, Le; Tan, Wei-Juan; Chen, Liang; Qi, Hua; Xie, Li-Juan; Chen, Mo-Xian; Liu, Bin-Yi; Yu, Lu-Jun; Yao, Nan; Zhang, Jian-Hua; Shu, Wensheng; Xiao, Shi

    2017-01-01

    In Arabidopsis, three lipase-like regulators, SAG101, EDS1, and PAD4, act downstream of resistance protein-associated defense signaling. Although the roles of SAG101, EDS1, and PAD4 in biotic stress have been extensively studied, little is known about their functions in plant responses to abiotic stresses. Here, we show that SAG101, EDS1, and PAD4 are involved in the regulation of freezing tolerance in Arabidopsis. With or without cold acclimation, the sag101, eds1, and pad4 single mutants, as well as their double mutants exhibited similarly enhanced tolerance to freezing temperatures. Upon cold exposure, the sag101, eds1, and pad4 mutants showed increased transcript levels of C-REPEAT/DRE BINDING FACTORs and their regulons, compared with wild type. Moreover, freezing-induced cell death and accumulation of hydrogen peroxide were ameliorated in sag101, eds1, and pad4 mutants. The sag101, eds1, and pad4 mutants had much lower salicylic acid (SA) and diacylglycerol (DAG) contents than wild type and exogenous application of SA and DAG compromised the freezing tolerance of the mutants. Furthermore, SA suppressed the cold-induced expression of DGATs and DGKs in wild-type leaves. These findings indicate that SAG101, EDS1, and PAD4 are involved in freezing response in Arabidopsis, at least in part, by modulating the homeostasis of SA and DAG. PMID:26149542

  3. Metabolism of sn-1(3)-Monoacylglycerol and sn-2-Monoacylglycerol in Caecal Enterocytes and Hepatocytes of Brown Trout (Salmo trutta).

    PubMed

    Li, Keshuai; Olsen, Rolf Erik

    2017-01-01

    sn-2-Monoacylglycerol (2-MAG) and sn-1(3)-monoacylglycerol [1(3)-MAG] are important but yet little studied intermediates in lipid metabolism. The current study compared the metabolic fate of 2-MAG and 1(3)-MAG in isolated caecal enterocytes and hepatocytes of brown trout (Salmo trutta). 1(3)-Oleoyl [9,10-3H(N)]-glycerol and 2-Oleoyl [9,10-3H(N)]-glycerol were prepared by pancreatic lipase digestion of triolein [9,10-3H(N)]. The 1(3)-MAG and 2-MAG were efficiently absorbed by enterocytes and hepatocytes at similar rates. The 2-MAG was quickly resynthesized into TAG through the monoacylglycerol acyltransferase (EC: 2.3.1.22, MGAT) pathway in both tissues, whereas 1(3)-MAG was processed into TAG and phospholipids at a much slower rate, suggesting 2-MAG was the preferred substrates for MGAT. Further analysis showed that 1(3)-MAG was synthesized into 1,3-DAG, but there were no accumulation of 1,3-DAG in either enterocytes or hepatocytes, which contrasts that of mammalian studies. Some of the 1(3)-MAG may be acylated to 1,2(2,3)-DAG and then utilized for TAG synthesis. Alternatively, 1(3)-MAG can be hydrolyzed to free fatty acid and glycerol, and re-synthesized into TAG through the glycerol-3-phosphate (Gro-3-P) pathway. The overall data suggested that the limiting step of the intracellular 1(3)-MAG metabolism is the conversion of 1(3)-MAG itself.

  4. Decreased diacylglycerol metabolism enhances ERK activation and augments CD8+ T cell functional responses.

    PubMed

    Riese, Matthew J; Grewal, Jashanpreet; Das, Jayajit; Zou, Tao; Patil, Vineet; Chakraborty, Arup K; Koretzky, Gary A

    2011-02-18

    Modulation of T cell receptor signal transduction in CD8(+) T cells represents a novel strategy toward enhancing the immune response to tumor. Recently, levels of guanine exchange factors, RasGRP and SOS, within T cells have been shown to represent a key determinant in the regulation of the analog to the digital activation threshold of Ras. One important for regulating activation levels of RasGRP is diacylglycerol (DAG), and its levels are influenced by diacylglycerol kinase-ζ (DGKζ), which metabolizes DAG into phosphatidic acid, terminating DAG-mediated Ras signaling. We sought to determine whether DGKζ-deficient CD8(+) T cells demonstrated enhanced in vitro responses in a manner predicted by the current model of Ras activation and to evaluate whether targeting this threshold confers enhanced CD8(+) T cell responsiveness to tumor. We observed that DGKζ-deficient CD8(+) T cells conform to most predictions of the current model of how RasGRP levels influence Ras activation. But our results differ in that the EC(50) value of stimulation is not altered for any T cell receptor stimulus, a finding that suggests a further degree of complexity to how DGKζ deficiency affects signals important for Ras and ERK activation. Additionally, we found that DGKζ-deficient CD8(+) T cells demonstrate enhanced responsiveness in a subcutaneous lymphoma model, implicating the analog to a digital conversion threshold as a novel target for potential therapeutic manipulation.

  5. An In-Situ Study of REE Abundances in Three Anorthositic Impact Melt Lunar Highland Meteorites

    NASA Astrophysics Data System (ADS)

    Consolmagno, G. J.; Russell, S. S.; Jeffries, T. E.

    2004-03-01

    REE measurements of the lunar highland meteorites DAG 400, Dhofar 081, and NWA 482, and models of the REE in melts in equilibrium with them, suggest that they may contain components more primitive than those found in Apollo FAN samples.

  6. Enzymatically interesterified fats based on mutton tallow and walnut oil suitable for cosmetic emulsions.

    PubMed

    Kowalska, M; Mendrycka, M; Zbikowska, A; Stawarz, S

    2015-02-01

    Formation of emulsion systems based on interesterified fats was the objective of the study. Enzymatic interesterification was carried out between enzymatic mutton tallow and walnut oil in the proportions 2 : 3 (w/w) to produce fats not available in nature. At the beginning of the interesterification process, the balance between the interesterification and fat hydrolysis was intentionally disturbed by adding more water to the catalyst (Lipozyme IR MR) of the reaction to produce more of the polar fraction monoacylglycerols [MAGs] and diacylglycerols [DAGs]. To obtain a greater quantity of MAGs and DAGs in the reaction environment via hydrolysis, water was added (11, 13, 14, 16 w-%) to the enzymatic preparation. The obtained fats were used to form emulsions. The emulsions were evaluated with respect to sensory and skin moisturizing properties by 83 respondents. Determination of emulsion stability using temperature and centrifugal tests was carried out. Morphology and the type of emulsions were determined. The respondents described the skin to which the emulsions in testing were applied as smooth, pleasant to touch and adequately moisturized. The work has demonstrated that interesterification of a mutton tallow and walnut oil blend resulted in new fats with very interesting characteristics of triacylglycerols that are not present in the environment. The results of the present work indicate the possibility of application of fats with the largest quantity of MAGs and DAGs as a fat base of emulsions in the cosmetic industries. The hypothesis assumed in this work of producing additional quantities of MAGs and DAGs (in the process of enzymatic interesterification) responsible for the stability of the system was confirmed. It should be pointed out that the emulsions based on interesterified fats exhibited a greater level of moisturization of the skin than the emulsions containing non-interesterified fat. Also, in the respondents' opinion, the emulsion containing fat, which

  7. Production of soy polyol oils: Results of microbial screening and identification of positive cultures

    USDA-ARS?s Scientific Manuscript database

    Triacylglycerols (TAG) containing hydroxy fatty acids have many industrial uses, such as the manufacture of aviation lubricants, plastics, paints, nylons and cosmetics, because of the hydroxyl groups on the fatty acid (FA) constituents. Diacylglycerols (DAG) containing hydroxy FA can also be used in...

  8. Quantification of the molecular species of diacylglycerols,triacylglycerols and tetraacylglycerols in lesquerella (Physaria fendleri) oil by HPLC and MS

    USDA-ARS?s Scientific Manuscript database

    Ten diacylglycerols (DAG), 74 triacylglycerols (TAG) and 13 tetraacylglycerols in the seed oil of Physaria fendleri were recently identified by HPLC and MS. These acylglycerols (AG) were quantified by HPLC with evaporative light scattering detector and electrospray ionization mass spectrometry of th...

  9. Crystallization kinetics of olivine-phyric shergottites

    NASA Astrophysics Data System (ADS)

    Ennis, Megan E.; McSween, Harry Y.

    2014-08-01

    Crystal size distribution (CSD) and spatial distribution pattern (SDP) analyses are applied to the early crystallizing phases, olivine and pyroxene, in olivine-phyric shergottites (Elephant moraine [EET] 79001A, Dar al Gani [DaG] 476, and dhofar [Dho] 019) from each sampling locality inferred from Mars ejection ages. Trace element zonation patterns (P and Cr) in olivine are also used to characterize the crystallization history of these Martian basalts. Previously reported 2-D CSDs for these meteorites are re-evaluated using a newer stereographically corrected methodology. Kinks in the olivine CSD plots suggest several populations that crystallized under different conditions. CSDs for pyroxene in DaG 476 and EET 79001A reveal single populations that grew under steady-state conditions; pyroxenes in Dho 019 were too intergrown for CSD analysis. Magma chamber residence times of several days for small grains to several months for olivine megacrysts are calculated using the CSD slopes and growth rates inferred from previous experimental data. Phosphorus imaging in olivines in DaG 476 and Dho 019 indicate rapid growth of skeletal, sector-zoned, or patchy cores, probably in response to delayed nucleation, followed by slow growth, and finally rapid dendritic growth with back-filling to form oscillatory zoning in rims. SPD analyses indicate that olivine and pyroxene crystals grew or accumulated in clusters rather than as randomly distributed grains. These data reveal complex solidification histories for Martian basalts, and are generally consistent with the formation at depth of olivine megacryst cores, which were entrained in ascending magmas that crystallized pyroxenes, small olivines, and oscillatory rims on megacrysts.

  10. Animal-Based Measures to Assess the Welfare of Extensively Managed Ewes

    PubMed Central

    Hemsworth, Paul; Doyle, Rebecca

    2017-01-01

    Simple Summary The aim of this study was to assess the reliability and practicality of 10 animal-based welfare measures for extensively managed ewes, which were derived from the scientific literature, previous welfare protocols and through consultation with veterinarians and animal welfare scientists. Measures were examined on 100 Merino ewes, which were individually identified and repeatedly examined at mid-pregnancy, mid-lactation and weaning. Body condition score, fleece condition, skin lesions, tail length, dag score and lameness are proposed for on-farm use in welfare assessments of extensive sheep production systems. These six welfare measures, which address the main welfare concerns for extensively managed ewes, can be reliably and feasibly measured in the field. Abstract The reliability and feasibility of 10 animal-based measures of ewe welfare were examined for use in extensive sheep production systems. Measures were: Body condition score (BCS), rumen fill, fleece cleanliness, fleece condition, skin lesions, tail length, dag score, foot-wall integrity, hoof overgrowth and lameness, and all were examined on 100 Merino ewes (aged 2–4 years) during mid-pregnancy, mid-lactation and weaning by a pool of nine trained observers. The measures of BCS, fleece condition, skin lesions, tail length, dag score and lameness were deemed to be reliable and feasible. All had good observer agreement, as determined by the percentage of agreement, Kendall’s coefficient of concordance (W) and Kappa (k) values. When combined, these nutritional and health measures provide a snapshot of the current welfare status of ewes, as well as evidencing previous or potential welfare issues. PMID:29295551

  11. Diacylglycerol kinase α inactivation is an integral component of the costimulatory pathway that amplifies TCR signals.

    PubMed

    Arranz-Nicolás, Javier; Ogando, Jesús; Soutar, Denise; Arcos-Pérez, Raquel; Meraviglia-Crivelli, Daniel; Mañes, Santos; Mérida, Isabel; Ávila-Flores, Antonia

    2018-06-01

    The arsenal of cancer therapies has evolved to target T lymphocytes and restore their capacity to destroy tumor cells. T cells rely on diacylglycerol (DAG) to carry out their functions. DAG availability and signaling are regulated by the enzymes diacylglycerol kinase (DGK) α and ζ, whose excess function drives T cells into hyporesponsive states. Targeting DGKα is a promising strategy for coping with cancer; its blockade could reinstate T-cell attack on tumors while limiting tumor growth, due to positive DGKα functions in several oncogenic pathways. Here, we made a side-by-side comparison of the effects of commercial pharmacological DGK inhibitors on T-cell responses with those promoted by DGKα and DGKζ genetic deletion or silencing. We show the specificity for DGKα of DGK inhibitors I and II and the structurally similar compound ritanserin. Inhibitor treatment promoted Ras/ERK (extracellular signal-regulated kinase) signaling and AP-1 (Activator protein-1) transcription, facilitated DGKα membrane localization, reduced the requirement for costimulation, and cooperated with enhanced activation following DGKζ silencing/deletion. DGKiII and ritanserin had similar effects on TCR proximal signaling, but ritanserin counteracted long-term T-cell activation, an effect that was potentiated in DGKα -/- cells. In contrast with enhanced activation triggered by pharmacological inhibition, DGKα silencing/genetic deletion led to impaired Lck (lymphocyte-specific protein tyrosine kinase) activation and limited costimulation responses. Our results demonstrate that pharmacological inhibition of DGKα downstream of the TCR provides a gain-of-function effect that amplifies the DAG-dependent signaling cascade, an ability that could be exploited therapeutically to reinvigorate T cells to attack tumors.

  12. Alcohol binding in the C1 (C1A + C1B) domain of protein kinase C epsilon

    PubMed Central

    Pany, Satyabrata; Das, Joydip

    2015-01-01

    Background Alcohol regulates the expression and function of protein kinase C epsilon (PKCε). In a previous study we identified an alcohol binding site in the C1B, one of the twin C1 subdomains of PKCε. Methods In this study, we investigated alcohol binding in the entire C1 domain (combined C1A and C1B) of PKCε. Fluorescent phorbol ester, SAPD and fluorescent diacylglycerol (DAG) analog, dansyl-DAG were used to study the effect of ethanol, butanol, and octanol on the ligand binding using fluorescence resonance energy transfer (FRET). To identify alcohol binding site(s), PKCεC1 was photolabeled with 3-azibutanol and 3-azioctanol, and analyzed by mass spectrometry. The effects of alcohols and the azialcohols on PKCε were studied in NG108-15 cells. Results In the presence of alcohol, SAPD and dansyl-DAG showed different extent of FRET, indicating differential effects of alcohol on the C1A and C1B subdomains. Effects of alcohols and azialcohols on PKCε in NG108-15 cells were comparable. Azialcohols labeled Tyr-176 of C1A and Tyr-250 of C1B. Inspection of the model structure of PKCεC1 reveals that these residues are 40 Å apart from each other indicating that these residues form two different alcohol binding sites. Conclusions The present results provide evidence for the presence of multiple alcohol-binding sites on PKCε and underscore the importance of targeting this PKC isoform in developing alcohol antagonists. PMID:26210390

  13. Optimum conditions for the production of soy polyol oils and diacylglycerol from soybean oil by Acinetobacter haemolyticus A01-35 NRRL B-59985

    USDA-ARS?s Scientific Manuscript database

    Triacylglycerols (TAG) containing hydroxy fatty acids have many industrial uses such as the manufacture of aviation lubricant, plastic, paint, nylons, and cosmetics, because of the hydroxyl groups on the fatty acid (FA) constituents. Diacylglycerols (DAG) containing hydroxy FA can also be used in th...

  14. Measuring phosphatidic acid phosphatase (EC 3.1.3.4) activity using two phosphomolybdate-based colorimetric methods

    USDA-ARS?s Scientific Manuscript database

    Phosphatidate phosphatase (3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4), which is also known as PAP, catalyzes the dephosphorylation of phosphatidate (PtdOH) to form diacylglycerol (DAG) and inorganic phosphate. In eukaryotes, PAP driven reaction is the committed step in the synthesis of triacyl...

  15. Mass spectrometry of the lithium adducts of diacylglycerols containing hydroxy FA in castor oil and two normal FA

    USDA-ARS?s Scientific Manuscript database

    Castor oil can be used in industry. The molecular species of triacylglycerols containing hydroxy fatty acids (FA) in castor oil have been identified. We report here the identification of twelve diacylglycerols (DAG) containing hydroxy FA in castor oil using positive ion electrospray ionization mass ...

  16. Quantification of the molecular species of acylglycerols containing hydroxy fatty acids in lesquerella oils using high-performance liquid chromatography and mass spectrometry

    USDA-ARS?s Scientific Manuscript database

    Ten molecular species of diacylglycerols (DAG), 54 of triacylglycerols (TAG) and 13 of tetraacylglycerols (tetraAG, triacylglycerol estolides) containing hydroxy fatty acids (FA) as well as 20 of TAG containing three normal FA (non-hydroxylated) in lesquerella oil were quantified by a newly improved...

  17. MIT CSAIL and Lincoln Laboratory Task Force Report

    DTIC Science & Technology

    2016-06-09

    Regina Barzilay • Tommi Jaakkola • Stephanie Jagelka • Tamara Broderick • Leslie Kaelbling • Olga Simek • Danelle Shah • Charlie Dagli • Develop...Jagelka • Tamara Broderick • Leslie Kaelbling • Arjun Majumdar • Mike Hurley • Ben Smith • Generalized object detection/ classification and

  18. Correlative and integrated light and electron microscopy of in-resin GFP fluorescence, used to localise diacylglycerol in mammalian cells

    PubMed Central

    Peddie, Christopher J.; Blight, Ken; Wilson, Emma; Melia, Charlotte; Marrison, Jo; Carzaniga, Raffaella; Domart, Marie-Charlotte; O׳Toole, Peter; Larijani, Banafshe; Collinson, Lucy M.

    2014-01-01

    Fluorescence microscopy of GFP-tagged proteins is a fundamental tool in cell biology, but without seeing the structure of the surrounding cellular space, functional information can be lost. Here we present a protocol that preserves GFP and mCherry fluorescence in mammalian cells embedded in resin with electron contrast to reveal cellular ultrastructure. Ultrathin in-resin fluorescence (IRF) sections were imaged simultaneously for fluorescence and electron signals in an integrated light and scanning electron microscope. We show, for the first time, that GFP is stable and active in resin sections in vacuo. We applied our protocol to study the subcellular localisation of diacylglycerol (DAG), a modulator of membrane morphology and membrane dynamics in nuclear envelope assembly. We show that DAG is localised to the nuclear envelope, nucleoplasmic reticulum and curved tips of the Golgi apparatus. With these developments, we demonstrate that integrated imaging is maturing into a powerful tool for accurate molecular localisation to structure. PMID:24637200

  19. Myxococcus CsgA, Drosophila Sniffer, and human HSD10 are cardiolipin phospholipases

    PubMed Central

    Boynton, Tye O'Hara; Shimkets, Lawrence Joseph

    2015-01-01

    Myxococcus xanthus development requires CsgA, a member of the short-chain alcohol dehydrogenase (SCAD) family of proteins. We show that CsgA and SocA, a protein that can replace CsgA function in vivo, oxidize the 2′-OH glycerol moiety on cardiolipin and phosphatidylglycerol to produce diacylglycerol (DAG), dihydroxyacetone, and orthophosphate. A lipid extract enriched in DAGs from wild-type cells initiates development and lipid body production in a csgA mutant to bypass the mutational block. This novel phospholipase C-like reaction is widespread. SCADs that prevent neurodegenerative disorders, such as Drosophila Sniffer and human HSD10, oxidize cardiolipin with similar kinetic parameters. HSD10 exhibits a strong preference for cardiolipin with oxidized fatty acids. This activity is inhibited in the presence of the amyloid β peptide. Three HSD10 variants associated with neurodegenerative disorders are inactive with cardiolipin. We suggest that HSD10 protects humans from reactive oxygen species by removing damaged cardiolipin before it induces apoptosis. PMID:26338420

  20. Rb-Sr and Sm-Nd Isotopic Studies of Martian Depleted Shergottes SaU 094/005

    NASA Technical Reports Server (NTRS)

    Shih, C.-Y.; Nyquist, L. E.; Reese, Y.

    2007-01-01

    Sayh al Uhaymir (SaU) 094 and SaU 005 are olivine-phyric shergottites from the Oman desert and are considered as pairs. [e.g., 1]. They are very similar to the Libyan desert shergottite Dar al Gani (DaG) 476 in petrology, chemistry and ejection age [2-6]. This group of shergottites, also recognized as depleted shergottites [e.g. 7] has been strongly shocked and contains very low abundances of light rare earth elements (REE). In addition, terrestrial contaminants are commonly present in meteorites found in desert environments. Age-dating these samples is very challenging, but lower calcite contents in the SaU meteorites suggest that they have been subjected to less severe desert weathering than their DaG counterparts [3-4]. In this report, we present Rb-Sr and Sm-Nd isotopic results for SaU 094 and SaU 005, discuss the correlation of their ages with those of other similar shergottites, and discuss their petrogenesis.

  1. Optimization of diacylglycerol production by glycerolysis of fish oil catalyzed by Lipozyme TL IM with Tween 65.

    PubMed

    Monte Blanco, S F M; Santos, J S; Feltes, M M C; Dors, G; Licodiedoff, S; Lerin, L A; de Oliveira, D; Ninow, J L; Furigo, A

    2015-12-01

    The diacylglycerols (DAG) are emulsifiers with high added value used as functional additives in food, medicine, and cosmetic industries. In glycerolysis of oils for the production of DAG, the immiscibility between the substrates (glycerol and oil phases) has to be overcome, for example, by the addition of a food grade surfactant like Tween 65. The main objective of this work was to optimize the process conditions for obtaining diacylglycerols rich in the omega-3 eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, through the enzymatic glycerolysis of fish oil, in systems with Tween 65 and without this surfactant, using Lipozyme TL(®) IM as biocatalyst. The experiments were performed according to predetermined conditions varying the temperature, enzyme load, the oil to glycerol molar ratio and, when added, the surfactant load. After 6 h of reaction, it was possible to produce up to 20.76 and 13.76% of diacylglycerols from fish oil in the reactions with and without Tween 65, respectively.

  2. Conformationally Constrained Analogues of Diacylglycerol. 29. Cells Sort Diacylglycerol-Lactone Chemical Zip Codes to Produce Diverse and Selective Biological Activities

    PubMed Central

    Duan, Dehui; Sigano, Dina M.; Kelley, James A.; Lai, Christopher C.; Lewin, Nancy E.; Kedei, Noemi; Peach, Megan L.; Lee, Jeewoo; Abeyweera, Thushara P.; Rotenberg, Susan A.; Kim, Hee; Kim, Young Ho; Kazzouli, Saïd El; Chung, Jae-Uk; Young, Howard A.; Young, Matthew R.; Baker, Alyson; Colburn, Nancy H.; Haimovitz-Friedman, Adriana; Truman, Jean-Philip; Parrish, Damon A.; Deschamps, Jeffrey R.; Perry, Nicholas A.; Surawski, Robert J.; Blumberg, Peter M.; Marquez, Victor E.

    2008-01-01

    Diacylglycerol-lactone (DAG-lactone) libraries generated by a solid-phase approach using IRORI technology produced a variety of unique biological activities. Subtle differences in chemical diversity in two areas of the molecule, the combination of which generates what we have termed “chemical zip codes”, are able to transform a relatively small chemical space into a larger universe of biological activities, as membrane-containing organelles within the cell appear to be able to decode these “chemical zip codes”. It is postulated that after binding to protein kinase C (PKC) isozymes or other non-kinase target proteins that contain diacylglycerol responsive, membrane interacting domains (C1 domains), the resulting complexes are directed to diverse intracellular sites where different sets of substrates are accessed. Multiple cellular bioassays show that DAG-lactones, which bind in vitro to PKCα to varying degrees, expand their biological repertoire into a larger domain, eliciting distinct cellular responses. PMID:18698758

  3. Learning directed acyclic graphs from large-scale genomics data.

    PubMed

    Nikolay, Fabio; Pesavento, Marius; Kritikos, George; Typas, Nassos

    2017-09-20

    In this paper, we consider the problem of learning the genetic interaction map, i.e., the topology of a directed acyclic graph (DAG) of genetic interactions from noisy double-knockout (DK) data. Based on a set of well-established biological interaction models, we detect and classify the interactions between genes. We propose a novel linear integer optimization program called the Genetic-Interactions-Detector (GENIE) to identify the complex biological dependencies among genes and to compute the DAG topology that matches the DK measurements best. Furthermore, we extend the GENIE program by incorporating genetic interaction profile (GI-profile) data to further enhance the detection performance. In addition, we propose a sequential scalability technique for large sets of genes under study, in order to provide statistically significant results for real measurement data. Finally, we show via numeric simulations that the GENIE program and the GI-profile data extended GENIE (GI-GENIE) program clearly outperform the conventional techniques and present real data results for our proposed sequential scalability technique.

  4. A chloroplast pathway for the de novo biosynthesis of triacylglycerol in Chlamydomonas reinhardtii

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fan, J.; Xu, C.; Andre, C.

    2011-06-23

    Neutral lipid metabolism has been extensively studied in yeast, plants and mammals. In contrast, little information is available regarding the biochemical pathway, enzymes and regulatory factors involved in the biosynthesis of triacylglycerol (TAG) in microalgae. In the conventional TAG biosynthetic pathway widely accepted for yeast, plants and mammals, TAG is assembled in the endoplasmic reticulum (ER) from its immediate precursor diacylglycerol (DAG) made by ER-specific acyltransferases, and is deposited exclusively in lipid droplets in the cytosol. Here, we demonstrated that the unicellular microalga Chlamydomonas reinhardtii employs a distinct pathway that uses DAG derived almost exclusively from the chloroplast to producemore » TAG. This unique TAG biosynthesis pathway is largely dependent on de novo fatty acid synthesis, and the TAG formed in this pathway is stored in lipid droplets in both the chloroplast and the cytosol. These findings have wide implications for understanding TAG biosynthesis and storage and other areas of lipid metabolism in microalgae and other organisms.« less

  5. Active Tectonics of the Iran Plateau and South Caspian Basin

    NASA Astrophysics Data System (ADS)

    Priestely, K.; Jackson, J.; Maggi, A.; Talebian, M.; Walker, R.

    2002-12-01

    We use observations of surface faulting, well-constrained earthquake focal mechanisms and centroid depths, and velocity structure to investigate the present-day deformation and kinematics of the region. Current deformation is primarily concentrated in three seismically active belts: the Zagros Mountains of southwest Iran,the Talesh-Alborz-Kopeh Dag Mountains of northern Iran, and the Apsheron-Balkhan Sill in the central Caspian Sea. These belts are separated by seismically inactive regions that act as semi-rigid blocks. The extent to which the active shortening is divided between the three belts is still uncertain. Earthquake locations in the region, particularly their focal depths which are determined from teleseismic arrival times, are poor, and reported subcrustal earthquakes have been cited as evidence for present-day subduction beneath the Zagros. A detailed analysis of earthquake focal depths in the Zagros and elsewhere in the region confirms that no substantial subcrustal earthquakes occur in this part of the Middle East except beneath the Makran subduction zone in the south and the Apsheron-Balkhan Sill in the north. The present-day N-S deformation across the Zagros is partitioned with right-lateral, strike-slip motion on the NW-SE striking Main Recent Fault, and NE-SW shortening across the Zagros. Shortening in the Zagros is accommodated by folding in the sediments (0-10 km depth), moderate earthquakes on high-angle reverse faults striking parallel to the surface folds (~10-20 km depth), and aseismic thickening of the lower crust (~20-45 km depth). The south Caspian basin is essentially free of earthquakes and acts as a rigid block which strongly influences the nature of the deformation in the surrounding active belts. No significant subcrustal earthquakes occur in the Talesh, Alborz, or Kopeh Dag Mountains which bound the northeast, south and west sides of the south Caspian basin, but substantial subcrustal seismicity occurs beneath the Apsheron

  6. Studying Intrapersonal Communication through Memoirs and Journals.

    ERIC Educational Resources Information Center

    Jensen, Marvin D.

    One theoretical approach to self-awareness is the study of introspective writing. Among the characteristics of intrapersonal communication that can be explored through memoirs and journals are selective memory and chronology revision. From the reflections of writers like Lillian Hellman, Dag Hammarskjold, and May Sarton comes confirmation that…

  7. The effect of big endothelin-1 in the proximal tubule of the rat kidney

    PubMed Central

    Beara-Lasić, Lada; Knotek, Mladen; Čejvan, Kenan; Jakšić, Ozren; Lasić, Zoran; Skorić, Boško; Brkljačić, Vera; Banfić, Hrvoje

    1997-01-01

    An obligatory step in the biosynthesis of endothelin-1 (ET-1) is the conversion of its inactive precursor, big ET-1, into the mature form by the action of specific, phosphoramidon-sensitive, endothelin converting enzyme(s) (ECE). Disparate effects of big ET-1 and ET-1 on renal tubule function suggest that big ET-1 might directly influence renal tubule function. Therefore, the role of the enzymatic conversion of big ET-1 into ET-1 in eliciting the functional response (generation of 1,2-diacylglycerol) to big ET-1 was studied in the rat proximal tubules.In renal cortical slices incubated with big ET-1, pretreatment with phosphoramidon (an ECE inhibitor) reduced tissue immunoreactive ET-1 to a level similar to that of cortical tissue not exposed to big ET-1. This confirms the presence and effectiveness of ECE inhibition by phosphoramidon.In freshly isolated proximal tubule cells, big ET-1 stimulated the generation of 1,2-diacylglycerol (DAG) in a time- and dose-dependent manner. Neither phosphoramidon nor chymostatin, a chymase inhibitor, influenced the generation of DAG evoked by big ET-1.Big ET-1-dependent synthesis of DAG was found in the brush-border membrane. It was unaffected by BQ123, an ETA receptor antagonist, but was blocked by bosentan, an ETA,B-nonselective endothelin receptor antagonist.These results suggest that the proximal tubule is a site for the direct effect of big ET-1 in the rat kidney. The effect of big ET-1 is confined to the brush-border membrane of the proximal tubule, which may be the site of big ET-1-sensitive receptors. PMID:9051300

  8. Rapid phosphatidic acid accumulation in response to low temperature stress in Arabidopsis is generated through diacylglycerol kinase.

    PubMed

    Arisz, Steven A; van Wijk, Ringo; Roels, Wendy; Zhu, Jian-Kang; Haring, Michel A; Munnik, Teun

    2013-01-01

    Phosphatidic acid (PtdOH) is emerging as an important signaling lipid in abiotic stress responses in plants. The effect of cold stress was monitored using (32)P-labeled seedlings and leaf discs of Arabidopsis thaliana. Low, non-freezing temperatures were found to trigger a very rapid (32)P-PtdOH increase, peaking within 2 and 5 min, respectively. In principle, PtdOH can be generated through three different pathways, i.e., (1) via de novo phospholipid biosynthesis (through acylation of lyso-PtdOH), (2) via phospholipase D hydrolysis of structural phospholipids, or (3) via phosphorylation of diacylglycerol (DAG) by DAG kinase (DGK). Using a differential (32)P-labeling protocol and a PLD-transphosphatidylation assay, evidence is provided that the rapid (32)P-PtdOH response was primarily generated through DGK. A simultaneous decrease in the levels of (32)P-PtdInsP, correlating in time, temperature dependency, and magnitude with the increase in (32)P-PtdOH, suggested that a PtdInsP-hydrolyzing PLC generated the DAG in this reaction. Testing T-DNA insertion lines available for the seven DGK genes, revealed no clear changes in (32)P-PtdOH responses, suggesting functional redundancy. Similarly, known cold-stress mutants were analyzed to investigate whether the PtdOH response acted downstream of the respective gene products. The hos1, los1, and fry1 mutants were found to exhibit normal PtdOH responses. Slight changes were found for ice1, snow1, and the overexpression line Super-ICE1, however, this was not cold-specific and likely due to pleiotropic effects. A tentative model illustrating direct cold effects on phospholipid metabolism is presented.

  9. Rapid phosphatidic acid accumulation in response to low temperature stress in Arabidopsis is generated through diacylglycerol kinase

    PubMed Central

    Arisz, Steven A.; van Wijk, Ringo; Roels, Wendy; Zhu, Jian-Kang; Haring, Michel A.; Munnik, Teun

    2013-01-01

    Phosphatidic acid (PtdOH) is emerging as an important signaling lipid in abiotic stress responses in plants. The effect of cold stress was monitored using 32P-labeled seedlings and leaf discs of Arabidopsis thaliana. Low, non-freezing temperatures were found to trigger a very rapid 32P-PtdOH increase, peaking within 2 and 5 min, respectively. In principle, PtdOH can be generated through three different pathways, i.e., (1) via de novo phospholipid biosynthesis (through acylation of lyso-PtdOH), (2) via phospholipase D hydrolysis of structural phospholipids, or (3) via phosphorylation of diacylglycerol (DAG) by DAG kinase (DGK). Using a differential 32P-labeling protocol and a PLD-transphosphatidylation assay, evidence is provided that the rapid 32P-PtdOH response was primarily generated through DGK. A simultaneous decrease in the levels of 32P-PtdInsP, correlating in time, temperature dependency, and magnitude with the increase in 32P-PtdOH, suggested that a PtdInsP-hydrolyzing PLC generated the DAG in this reaction. Testing T-DNA insertion lines available for the seven DGK genes, revealed no clear changes in 32P-PtdOH responses, suggesting functional redundancy. Similarly, known cold-stress mutants were analyzed to investigate whether the PtdOH response acted downstream of the respective gene products. The hos1, los1, and fry1 mutants were found to exhibit normal PtdOH responses. Slight changes were found for ice1, snow1, and the overexpression line Super-ICE1, however, this was not cold-specific and likely due to pleiotropic effects. A tentative model illustrating direct cold effects on phospholipid metabolism is presented. PMID:23346092

  10. PKCε plays a causal role in acute ethanol-induced steatosis

    PubMed Central

    Kaiser, J. Phillip; Beier, Juliane I.; Zhang, Jun; Hoetker, J. David; von Montfort, Claudia; Guo, Luping; Zheng, Yuting; Monia, Brett P.; Bhatnagar, Aruni; Arteel, Gavin E.

    2009-01-01

    Steatosis is a critical stage in the pathology of alcoholic liver disease (ALD), and preventing steatosis could protect against later stages of ALD. PKCε has been shown to contribute to hepatic steatosis in experimental non-alcoholic fatty liver disease (NAFLD); however, the role of PKCε in ethanol-induced steatosis has not been determined. The purpose of this study was to therefore test the hypothesis that PKCε contributes to ethanol-induced steatosis. Accordingly, the effect of acute ethanol on indices of hepatic steatosis and insulin signaling were determined in PKCε knockout mice and in wild-type mice that received an antisense oligonucleotide (ASO) to knockdown PKCε expression. Acute ethanol (6 g/kg i.g.) caused a robust increase in hepatic non-esterified free fatty acids (NEFA), which peaked 1 h after ethanol exposure. This increase in NEFA was followed by elevated diacylglycerols (DAG), as well as by the concomitant activation of PKCε. Acute ethanol also changed the expression of insulin-responsive genes (i.e. increased G6Pase, downregulated GK), in a pattern indicative of impaired insulin signaling. Acute ethanol exposure subsequently caused a robust increase in hepatic triglycerides. The accumulation of triglycerides caused by ethanol was blunted in ASO-treated or in PKCε−/− mice. Taken together, these data suggest that the increase in NEFA caused by hepatic ethanol metabolism leads to an increase in DAG production via the triacylglycerol pathway. DAG then subsequently activates PKCε, which then exacerbates hepatic lipid accumulation by inducing insulin resistance. These data also suggest that PKCε plays a causal role in at least the early phases of ethanol-induced liver injury. PMID:19022218

  11. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martinson, E.A.; Goldstein, D.; Brown, J.H.

    We examined the relationship between phosphatidylcholine (PC) hydrolysis, phosphoinositide hydrolysis, and diacylglycerol (DAG) formation in response to muscarinic acetylcholine receptor (mAChR) stimulation in 1321N1 astrocytoma cells. Carbachol increases the release of (3H)choline and (3H)phosphorylcholine ((3H)Pchol) from cells containing (3H)choline-labeled PC. The production of Pchol is rapid and transient, while choline production continues for at least 30 min. mAChR-stimulated release of Pchol is reduced in cells that have been depleted of intracellular Ca2+ stores by ionomycin pretreatment, whereas choline release is unaffected by this pretreatment. Phorbol 12-myristate 13-acetate (PMA) increases the release of choline, but not Pchol, from 1321N1 cells, andmore » down-regulation of protein kinase C blocks the ability of carbachol to stimulate choline production. Taken together, these results suggest that Ca2+ mobilization is involved in mAChR-mediated hydrolysis of PC by a phospholipase C, whereas protein kinase C activation is required for mAChR-stimulated hydrolysis of PC by a phospholipase D. Both carbachol and PMA rapidly increase the formation of (3H)phosphatidic acid ((3H)PA) in cells containing (3H)myristate-labeled PC. (3H)Diacylglycerol ((3H)DAG) levels increase more slowly, suggesting that the predominant pathway for PC hydrolysis is via phospholipase D. When cells are labeled with (3H)myristate and (14C)arachidonate such that there is a much greater 3H/14C ratio in PC compared with the phosphoinositides, the 3H/14C ratio in DAG and PA increases with PMA treatment but decreases in response to carbachol.« less

  12. Metabolomics analysis: Finding out metabolic building blocks

    PubMed Central

    2017-01-01

    In this paper we propose a new methodology for the analysis of metabolic networks. We use the notion of strongly connected components of a graph, called in this context metabolic building blocks. Every strongly connected component is contracted to a single node in such a way that the resulting graph is a directed acyclic graph, called a metabolic DAG, with a considerably reduced number of nodes. The property of being a directed acyclic graph brings out a background graph topology that reveals the connectivity of the metabolic network, as well as bridges, isolated nodes and cut nodes. Altogether, it becomes a key information for the discovery of functional metabolic relations. Our methodology has been applied to the glycolysis and the purine metabolic pathways for all organisms in the KEGG database, although it is general enough to work on any database. As expected, using the metabolic DAGs formalism, a considerable reduction on the size of the metabolic networks has been obtained, specially in the case of the purine pathway due to its relative larger size. As a proof of concept, from the information captured by a metabolic DAG and its corresponding metabolic building blocks, we obtain the core of the glycolysis pathway and the core of the purine metabolism pathway and detect some essential metabolic building blocks that reveal the key reactions in both pathways. Finally, the application of our methodology to the glycolysis pathway and the purine metabolism pathway reproduce the tree of life for the whole set of the organisms represented in the KEGG database which supports the utility of this research. PMID:28493998

  13. Allocating Tactical High-Performance Computer (HPC) Resources to Offloaded Computation in Battlefield Scenarios

    DTIC Science & Technology

    2013-12-01

    authors present a Computing on Dissemination with predictable contacts ( pCoD ) algorithm, since it is impossible to reserve task execution time in advance...Computing While Charging DAG Directed Acyclic Graph 18 TTL Time-to-live pCoD Predictable contacts CoD Computing on Dissemination upCoD Unpredictable

  14. 76 FR 4421 - Mercedes-Benz USA, LLC and Daimler AG, Receipt of Petition for Decision of Inconsequential...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ... company Daimler AG (DAG) has determined that certain 2002-2009 G-Class multipurpose vehicles, equipped... meet the requirements of paragraph S7.8.5 of Federal Motor Vehicle Safety Standard (FMVSS) No. 108... of the subject vehicles and Daimler AG is the manufacturer of the vehicles. Daimler AG is organized...

  15. Executable Architecture Modeling and Simulation Based on fUML

    DTIC Science & Technology

    2014-06-01

    SoS behaviors. Wang et al.[9] use SysML sequence diagram to model the behaviors and translate the models into Colored Petri Nets (CPN). Staines T.S...Renzhong and Dagli C H. An executable system architecture approach to discrete events system modeling using SysML in conjunction with colored Petri

  16. Purification, characterization, and bioinformatics studies of phosphatidic acid phosphohydrolase from Lagenaria siceraria

    USDA-ARS?s Scientific Manuscript database

    Phosphatidic acid phosphohydrolase (PAP), EC 3.1.3.4, is the penultimate step in the Kennedy pathway of triacyl glycerol (TAG) synthesis leading to the formation of diacyl glycerol (DAG), which is a key intermediate in TAG synthesis. We partially purified a soluble PAP from mid maturing seeds of bot...

  17. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Drug Enforcement Task Force Evaluation and Reporting System (JUSTICE/DAG-003). (2) General Files System... Files System apply only to the extent that information is subject to exemption pursuant to 5 U.S.C. 552a..., release of an accounting of disclosures from the General Files System may reveal information that is...

  18. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Drug Enforcement Task Force Evaluation and Reporting System (JUSTICE/DAG-003). (2) General Files System... Files System apply only to the extent that information is subject to exemption pursuant to 5 U.S.C. 552a..., release of an accounting of disclosures from the General Files System may reveal information that is...

  19. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Drug Enforcement Task Force Evaluation and Reporting System (JUSTICE/DAG-003). (2) General Files System... Files System apply only to the extent that information is subject to exemption pursuant to 5 U.S.C. 552a..., release of an accounting of disclosures from the General Files System may reveal information that is...

  20. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Drug Enforcement Task Force Evaluation and Reporting System (JUSTICE/DAG-003). (2) General Files System... Files System apply only to the extent that information is subject to exemption pursuant to 5 U.S.C. 552a..., release of an accounting of disclosures from the General Files System may reveal information that is...

  1. Collaborative Research: Ground Truth of African and Eastern Mediterranean Shallow Seismicity Using SAR Interferometry and Gibbs Sampling Inversion

    DTIC Science & Technology

    2006-10-05

    the likely existence of a small foreshock . 2. BACKGROUND 2.1. InSAR The most well-known examples of InSAR used as a geodetic tool involve...the event. We have used the seismic waveforms in the Sultan Dag event to identify a small foreshock preceding the main shock by about 3 seconds

  2. [The correlation between the concentrations of VEGF and PEDF and Ca2+-PKC signaling pathways in human retinal pigment epithelial cells cultured in vitro after exposuring to blue light].

    PubMed

    Wang, Limin; Cai, Shanjun; Wu, Zhipeng; Gong, Xin; Lyu, Jianping; Su, Gang; Wang, Lili

    2015-11-01

    To investigate the concentrations of vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), inositol triphosphate (IP3) and diacylglycerol (DAG) in human retinal pigment epithelium (RPE) cells after exposuring to blue light, and to explore the relationship with Ca2+-PKC signaling pathways, to evaluate the role of Ca2+-PKC signaling pathways of blue-light irradiation induced apoptosis in RPE cells. The fourth generation human RPE cells in vitro were exposured to blue light (2000±500 lux) for 6 hours, 24 hours prolongation of post-exposure culture. The concentrations of VEGF, PEDF, IP3 and DAG were assayed by enzyme linked immunosorbent assay (ELISA). Cells were randomly divided into 6 groups, group A (control), group B (exposure to blue light), group C (exposure to blue light+PMA), group D (exposure to blue light+Calphostin C), group E (exposure to blue light+Nifedipine), group F (exposure to blue light+Calphostin C+Nifedipine). Flow cytometry was used to detect the apoptosis rate of human RPE cells in A, B and F group. Comparing with group A (584.38±10.66), the concentration of VEGF in group B (700.70±5.88), group C (698.21±6.66) and group E (648.30±4.91) was higher, the difference was statistically significant (P=0.002, 0.002, 0.016). Comparing with group B (700.70±5.88), the concentration of VEGF in Group D (623.87±3.12) and E (648.30±4.91) was lower (P=0.001, 0.002). Comparing with group A (75.96±1.70), the concentration of PEDF in Group B (71.82±1.67) and C (72.43±0.58) was lower (P=0.004, 0.011), but the concentration of PEDF in Group D (86.31±1.35) and E (93.72±1.24) was higher (P=0.000, 0.000). Comparing with group B (71.82±1.67), the concentration of PEDF in Group D (86.31±1.35) and E (93.72±1.24) was higher (P=0.000, 0.000). Comparing with group A (7.70±0.29), the ratio of VEGF to PEDF in Group B (9.85±0.34) and Croup C (9.64±0.02) was higher (P=0.008, 0.027) Comparing with group B, The ratio of VEGF to PEDF

  3. Lipid accumulation and utilization by oocytes and eggs of Rhodnius prolixus.

    PubMed

    Santos, Rachel; Rosas-Oliveira, Rafael; Saraiva, Felipe B; Majerowicz, David; Gondim, Katia C

    2011-05-01

    Insect eggs must contain the necessary nutrients for embryonic growth. In this article, we investigated the accumulation of triacylglycerol (TAG) in growing oocytes and its utilization during embryonic development. TAG makes up about 60% of the neutral lipids in oocytes and accumulates as oocytes grow, from 2.2 ± 0.1 µg in follicles containing 1.0 mm length oocytes to 10.2 ± 0.8 µg in 2.0 mm length oocytes. Lipophorin (Lp), the hemolymphatic lipoprotein, radioactively labeled in free fatty acid (FFA) or diacylglycerol (DAG), was used to follow the transport of these lipids to the ovary. Radioactivity from both lipid classes accumulated in the oocytes, which was abolished at 4°C. The capacity of the ovary to receive FFA or DAG from Lp varied according to time after a blood meal and reached a maximum around the second day. (3) H-DAG supplied by Lp to the ovaries was used in the synthesis of TAG as, 48 hr after injection, most of the radioactivity was found in TAG (85.7% of labeling in neutral lipids). During embryogenesis, lipid stores were mobilized, and the TAG content decreased from 16.4 ± 2.1 µg/egg on the first day to 10.0 ± 1.3 µg on day 15, just before hatching. Of these, 7.4 ± 0.9 µg were found in the newly emerged nymphs. In unfertilized eggs, the TAG content did not change. Although the TAG content decreased during embryogenesis, the relative lipid composition of the egg did not change. The amount of TAG in the nymph slowly decreased during the days after hatching. © 2011 Wiley Periodicals, Inc.

  4. PC-PLC/sphingomyelin synthase activity plays a central role in the development of myogenic tone in murine resistance arteries

    PubMed Central

    Zacharia, Joseph; Fairfax, Seth; Wier, Withrow Gil

    2015-01-01

    Myogenic tone is an intrinsic property of the vasculature that contributes to blood pressure control and tissue perfusion. Earlier investigations assigned a key role in myogenic tone to phospholipase C (PLC) and its products, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). Here, we used the PLC inhibitor, U-73122, and two other, specific inhibitors of PLC subtypes (PI-PLC and PC-PLC) to delineate the role of PLC in myogenic tone of pressurized murine mesenteric arteries. U-73122 inhibited depolarization-induced contractions (high external K+ concentration), thus confirming reports of nonspecific actions of U-73122 and its limited utility for studies of myogenic tone. Edelfosine, a specific inhibitor of PI-PLC, did not affect depolarization-induced contractions but modulated myogenic tone. Because PI-PLC produces IP3, we investigated the effect of blocking IP3 receptor-mediated Ca2+ release on myogenic tone. Incubation of arteries with xestospongin C did not affect tone, consistent with the virtual absence of Ca2+ waves in arteries with myogenic tone. D-609, an inhibitor of PC-PLC and sphingomyelin synthase, strongly inhibited myogenic tone and had no effect on depolarization-induced contraction. D-609 appeared to act by lowering cytoplasmic Ca2+ concentration to levels below those that activate contraction. Importantly, incubation of pressurized arteries with a membrane-permeable analog of DAG induced vasoconstriction. The results therefore mandate a reexamination of the signaling pathways activated by the Bayliss mechanism. Our results suggest that PI-PLC and IP3 are not required in maintaining myogenic tone, but DAG, produced by PC-PLC and/or SM synthase, is likely through multiple mechanisms to increase Ca2+ entry and promote vasoconstriction. PMID:25888510

  5. Plant phosphatidylcholine-hydrolyzing phospholipases C NPC3 and NPC4 with roles in root development and brassinolide signaling in Arabidopsis thaliana.

    PubMed

    Wimalasekera, Rinukshi; Pejchar, Premysl; Holk, André; Martinec, Jan; Scherer, Günther F E

    2010-05-01

    Phosphatidylcholine-hydrolyzing phospholipase C (PC-PLC) catalyzes the hydrolysis of phosphatidylcholine (PC) to generate phosphocholine and diacylglycerol (DAG). PC-PLC has a long tradition in animal signal transduction to generate DAG as a second messenger besides the classical phosphatidylinositol splitting phospholipase C (PI-PLC). Based on amino acid sequence similarity to bacterial PC-PLC, six putative PC-PLC genes (NPC1 to NPC6) were identified in the Arabidopsis genome. RT-PCR analysis revealed overlapping expression pattern of NPC genes in root, stem, leaf, flower, and silique. In auxin-treated P(NPC3):GUS and P(NPC4):GUS seedlings, strong increase of GUS activity was visible in roots, leaves, and shoots and, to a weaker extent, in brassinolide-treated (BL) seedlings. P(NPC4):GUS seedlings also responded to cytokinin with increased GUS activity in young leaves. Compared to wild-type, T-DNA insertional knockouts npc3 and npc4 showed shorter primary roots and lower lateral root density at low BL concentrations but increased lateral root densities in response to exogenous 0.05-1.0 μM BL. BL-induced expression of TCH4 and LRX2, which are involved in cell expansion, was impaired but not impaired in repression of CPD, a BL biosynthesis gene, in BL-treated npc3 and npc4. These observations suggest NPC3 and NPC4 are important in BL-mediated signaling in root growth. When treated with 0.1 μM BL, DAG accumulation was observed in tobacco BY-2 cell cultures labeled with fluorescent PC as early as 15 min after application. We hypothesize that at least one PC-PLC is a plant signaling enzyme in BL signal transduction and, as shown earlier, in elicitor signal transduction.

  6. The impact of obesity in the cardiac lipidome and its consequences in the cardiac damage observed in obese rats.

    PubMed

    Marín-Royo, Gema; Martínez-Martínez, Ernesto; Gutiérrez, Beatriz; Jurado-López, Raquel; Gallardo, Isabel; Montero, Olimpio; Bartolomé, Mª Visitación; Román, José Alberto San; Salaices, Mercedes; Nieto, María Luisa; Cachofeiro, Victoria

    To explore the impact of obesity on the cardiac lipid profile in rats with diet-induced obesity, as well as to evaluate whether or not the specific changes in lipid species are associated with cardiac fibrosis. Male Wistar rats were fed either a high-fat diet (HFD, 35% fat) or standard diet (3.5% fat) for 6 weeks. Cardiac lipids were analyzed using by liquid chromatography-tandem mass spectrometry. HFD rats showed cardiac fibrosis and enhanced levels of cardiac superoxide anion (O 2 ), HOMA index, adiposity, and plasma leptin, as well as a reduction in those of cardiac glucose transporter (GLUT 4), compared with control animals. Cardiac lipid profile analysis showed a significant increase in triglycerides, especially those enriched with palmitic, stearic, and arachidonic acid. An increase in levels of diacylglycerol (DAG) was also observed. No changes in cardiac levels of diacyl phosphatidylcholine, or even a reduction in total levels of diacyl phosphatidylethanolamine, diacyl phosphatidylinositol, and sphingomyelins (SM) was observed in HFD, as compared with control animals. After adjustment for other variables (oxidative stress, HOMA, cardiac hypertrophy), total levels of DAG were independent predictors of cardiac fibrosis while the levels of total SM were independent predictors of the cardiac levels of GLUT 4. These data suggest that obesity has a significant impact on cardiac lipid composition, although it does not modulate the different species in a similar manner. Nonetheless, these changes are likely to participate in the cardiac damage in the context of obesity, since total DAG levels can facilitate the development of cardiac fibrosis, and SM levels predict GLUT4 levels. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Activation of peroxisome proliferator-activated receptor-{delta} by GW501516 prevents fatty acid-induced nuclear factor-{kappa}B activation and insulin resistance in skeletal muscle cells.

    PubMed

    Coll, Teresa; Alvarez-Guardia, David; Barroso, Emma; Gómez-Foix, Anna Maria; Palomer, Xavier; Laguna, Juan C; Vázquez-Carrera, Manuel

    2010-04-01

    Elevated plasma free fatty acids cause insulin resistance in skeletal muscle through the activation of a chronic inflammatory process. This process involves nuclear factor (NF)-kappaB activation as a result of diacylglycerol (DAG) accumulation and subsequent protein kinase Ctheta (PKCtheta) phosphorylation. At present, it is unknown whether peroxisome proliferator-activated receptor-delta (PPARdelta) activation prevents fatty acid-induced inflammation and insulin resistance in skeletal muscle cells. In C2C12 skeletal muscle cells, the PPARdelta agonist GW501516 prevented phosphorylation of insulin receptor substrate-1 at Ser(307) and the inhibition of insulin-stimulated Akt phosphorylation caused by exposure to the saturated fatty acid palmitate. This latter effect was reversed by the PPARdelta antagonist GSK0660. Treatment with the PPARdelta agonist enhanced the expression of two well known PPARdelta target genes involved in fatty acid oxidation, carnitine palmitoyltransferase-1 and pyruvate dehydrogenase kinase 4 and increased the phosphorylation of AMP-activated protein kinase, preventing the reduction in fatty acid oxidation caused by palmitate exposure. In agreement with these changes, GW501516 treatment reversed the increase in DAG and PKCtheta activation caused by palmitate. These effects were abolished in the presence of the carnitine palmitoyltransferase-1 inhibitor etomoxir, thereby indicating that increased fatty acid oxidation was involved in the changes observed. Consistent with these findings, PPARdelta activation by GW501516 blocked palmitate-induced NF-kappaB DNA-binding activity. Likewise, drug treatment inhibited the increase in IL-6 expression caused by palmitate in C2C12 and human skeletal muscle cells as well as the protein secretion of this cytokine. These findings indicate that PPARdelta attenuates fatty acid-induced NF-kappaB activation and the subsequent development of insulin resistance in skeletal muscle cells by reducing DAG accumulation

  8. Phospholipase C and D regulation of Src, calcium release and membrane fusion during Xenopus laevis development

    PubMed Central

    Stith, Bradley J.

    2015-01-01

    This review emphasizes how lipids regulate membrane fusion and the proteins involved in three developmental stages: oocyte maturation to the fertilizable egg, fertilization and during first cleavage. Decades of work show that phosphatidic acid (PA) releases intracellular calcium, and recent work shows that the lipid can activate Src tyrosine kinase or phospholipase C during Xenopus fertilization. Numerous reports are summarized to show three levels of increase in lipid second messengers inositol 1,4,5-trisphosphate and sn 1,2-diacylglycerol (DAG) during the three different developmental stages. In addition, possible roles for PA, ceramide, lysophosphatidylcholine, plasmalogens, phosphatidylinositol 4-phosphate, phosphatidylinositol 5-phosphate, phosphatidylinositol 4,5-bisphosphate, membrane microdomains (rafts) and phosphatidylinositol 3,4,5-trisphosphate in regulation of membrane fusion (acrosome reaction, sperm-egg fusion, cortical granule exocytosis), inositol 1,4,5-trisphosphate receptors, and calcium release are discussed. The role of six lipases involved in generating putative lipid second messengers during fertilization is also discussed: phospholipase D, autotaxin, lipin1, sphingomyelinase, phospholipase C, and phospholipase A2. More specifically, proteins involved in developmental events and their regulation through lipid binding to SH3, SH4, PH, PX, or C2 protein domains is emphasized. New models are presented for PA activation of Src (through SH3, SH4 and a unique domain), that this may be why the SH2 domain of PLCγ is not required for Xenopus fertilization, PA activation of phospholipase C, a role for PA during the calcium wave after fertilization, and that calcium/calmodulin may be responsible for the loss of Src from rafts after fertilization. Also discussed is that the large DAG increase during fertilization derives from phospholipase D production of PA and lipin dephosphorylation to DAG. PMID:25748412

  9. The Teacher, the Physician and the Person: Exploring Causal Connections between Teaching Performance and Role Model Types Using Directed Acyclic Graphs

    PubMed Central

    Boerebach, Benjamin C. M.; Lombarts, Kiki M. J. M. H.; Scherpbier, Albert J. J.; Arah, Onyebuchi A.

    2013-01-01

    Background In fledgling areas of research, evidence supporting causal assumptions is often scarce due to the small number of empirical studies conducted. In many studies it remains unclear what impact explicit and implicit causal assumptions have on the research findings; only the primary assumptions of the researchers are often presented. This is particularly true for research on the effect of faculty’s teaching performance on their role modeling. Therefore, there is a need for robust frameworks and methods for transparent formal presentation of the underlying causal assumptions used in assessing the causal effects of teaching performance on role modeling. This study explores the effects of different (plausible) causal assumptions on research outcomes. Methods This study revisits a previously published study about the influence of faculty’s teaching performance on their role modeling (as teacher-supervisor, physician and person). We drew eight directed acyclic graphs (DAGs) to visually represent different plausible causal relationships between the variables under study. These DAGs were subsequently translated into corresponding statistical models, and regression analyses were performed to estimate the associations between teaching performance and role modeling. Results The different causal models were compatible with major differences in the magnitude of the relationship between faculty’s teaching performance and their role modeling. Odds ratios for the associations between teaching performance and the three role model types ranged from 31.1 to 73.6 for the teacher-supervisor role, from 3.7 to 15.5 for the physician role, and from 2.8 to 13.8 for the person role. Conclusions Different sets of assumptions about causal relationships in role modeling research can be visually depicted using DAGs, which are then used to guide both statistical analysis and interpretation of results. Since study conclusions can be sensitive to different causal assumptions, results

  10. Troglitazone stimulates {beta}-arrestin-dependent cardiomyocyte contractility via the angiotensin II type 1{sub A} receptor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tilley, Douglas G., E-mail: douglas.tilley@jefferson.edu; Center for Translational Medicine, Thomas Jefferson University; Nguyen, Anny D.

    2010-06-11

    Peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) agonists are commonly used to treat cardiovascular diseases, and are reported to have several effects on cardiovascular function that may be due to PPAR{gamma}-independent signaling events. Select angiotensin receptor blockers (ARBs) interact with and modulate PPAR{gamma} activity, thus we hypothesized that a PPAR{gamma} agonist may exert physiologic effects via the angiotensin II type 1{sub A} receptor (AT1{sub A}R). In AT1{sub A}R-overexpressing HEK 293 cells, both angiotensin II (Ang II) and the PPAR{gamma} agonist troglitazone (Trog) enhanced AT1{sub A}R internalization and recruitment of endogenous {beta}-arrestin1/2 ({beta}arr1/2) to the AT1{sub A}R. A fluorescence assay to measure diacylglycerolmore » (DAG) accumulation showed that although Ang II induced AT1{sub A}R-G{sub q} protein-mediated DAG accumulation, Trog had no impact on DAG generation. Trog-mediated recruitment of {beta}arr1/2 was selective to AT1{sub A}R as the response was prevented by an ARB- and Trog-mediated {beta}arr1/2 recruitment to {beta}1-adrenergic receptor ({beta}1AR) was not observed. In isolated mouse cardiomyocytes, Trog increased both % and rate of cell shortening to a similar extent as Ang II, effects which were blocked with an ARB. Additionally, these effects were found to be {beta}arr2-dependent, as cardiomyocytes isolated from {beta}arr2-KO mice showed blunted contractile responses to Trog. These findings show for the first time that the PPAR{gamma} agonist Trog acts at the AT1{sub A}R to simultaneously block G{sub q} protein activation and induce the recruitment of {beta}arr1/2, which leads to an increase in cardiomyocyte contractility.« less

  11. MKR mice have increased dynamic glucose disposal despite metabolic inflexibility, and hepatic and peripheral insulin insensitivity.

    PubMed

    Vaitheesvaran, B; LeRoith, D; Kurland, I J

    2010-10-01

    Recent work has shown that there can be significant differences when glucose disposal is assessed for high-fat induced insulin resistance by static clamp methods vs dynamic assessment during a stable isotope i.p. glucose tolerance test. MKR mice, though lean, have severe insulin resistance and decreased muscle fatty acid oxidation. Our goal was to assess dynamic vs static glucose disposal in MKR mice, and to correlate glucose disposal and muscle-adipose-liver flux interactions with metabolic flexibility (indirect calorimetry) and muscle characteristics. Stable isotope flux phenotyping was performed using [6,6-(2)H(2)]glucose, [U-(13)C(6)]glucose and [2-(13)C]glycerol. Muscle triacylglycerol (TAG) and diacylglycerol (DAG) content was assessed by thin layer chromatography, and histological determination of fibre type and cytochrome c activity performed. Metabolic flexibility was assessed by indirect calorimetry. Indirect calorimetry showed that MKR mice used more glucose than FVB/N mice during fasting (respiratory exchange ratio [RER] 0.88 vs 0.77, respectively). Compared with FVB/N mice, MKR mice had faster dynamic glucose disposal, despite increased whole-muscle DAG and TAG, and similar hepatic glucose production with higher fasting insulin and unchanged basal glucose. Fed MKR muscle had more glycogen, and increased levels of GLUT1 and GLUT4 than FVB/N muscle. Histology indicated that MKR soleus had mildly decreased cytochrome c activity overall and more type II (glycolytic) fibres compared with that in FVB/N mice. MKR muscle adapts to using glucose, with more type II fibres present in red muscle. Fasting RER is elevated and glucose disposal during an i.p. glucose tolerance test is accelerated despite increased muscle DAG and TAG. Metabolic inflexibility may result from the compensatory use of fuel that can be best utilised for energy requirements; static vs dynamic glucose disposal assessments may measure complementary aspects of metabolic flexibility and insulin

  12. Diagnostic performance of body mass index to identify excess body fat in children with cerebral palsy.

    PubMed

    Duran, Ibrahim; Schulze, Josefa; Martakis, KyriakoS; Stark, Christina; Schoenau, Eckhard

    2018-03-07

    To assess the diagnostic performance of body mass index (BMI) cut-off values according to recommendations of the World Health Organization (WHO), the World Obesity Federation (WOF), and the German Society for Adiposity (DAG) to identify excess body fat in children with cerebral palsy (CP). The present study was a monocentric retrospective analysis of prospectively collected data among children and adolescents with CP participating in a rehabilitation programme. Excess body fat was defined as a body fat percentage above the 85th centile assessed by dual-energy X-ray absorptiometry. In total, 329 children (181 males, 148 females) with CP were eligible for analysis. The mean age was 12 years 4 months (standard deviation 2y 9mo). The BMI cut-off values for 'overweight' according to the WHO, WOF, and DAG showed the following sensitivities and specificities for the prediction of excess body fat in our population: WHO: sensitivity 0.768 (95% confidence interval [CI] 0.636-0.870), specificity 0.894 (95% CI 0.851-0.928); WOF: sensitivity 0.696 (95% CI 0.559-0.812), specificity 0.934 (95% CI 0.898-0.960); DAG: sensitivity 0.411 (95% CI 0.281-0.550), specificity 0.993 (95% CI 0.974-0.999). Body mass index showed high specificity, but low sensitivity in children with CP. Thus, 'normal-weight obese' children with CP were overlooked, when assessing excess body fat only using BMI. Excess body fat in children with cerebral palsy (CP) is less common than previously reported. Body mass index (BMI) had high specificity but low sensitivity in detecting excess body fat in children with CP. BMI evaluation criteria of the German Society for Adiposity could be improved in children with CP. © 2018 Mac Keith Press.

  13. The biopsychosocial benefits and shortfalls for armed forces veterans engaged in archaeological activities.

    PubMed

    Finnegan, Alan

    2016-12-01

    Organised outdoor activities are advocated as promoting multiple benefits for a veteran's wellbeing, of whom up to 50% have suffered either/both physical and mental health (MH) problems. This has resulted in significant investment in a growing number of outdoor events, one of which is the Defence Archaeology Group (DAG) which utilises the technical and social aspects of field archaeology in the recovery and skill development of injured veterans. To advance knowledge within veterans' MH and wellbeing through an understanding of the potential long term biopsychosocial benefits and shortfalls for veterans undertaking DAG activities. A constructivist grounded theory approach was used to enable identification of the issues from the participant veteran's perspective. DAG archaeological excavations in April and August 2015. Semi-structured interviews with 14 veterans. The qualitative coding resulted in the indication of 18 categories subsumed within four clusters: motivation and access; mental health; veteran and teamwork; therapeutic environment and leadership. The psychological benefits were improved self-esteem, confidence, a reduction in stigma and motivation to seek help. The reduction in situational stressors associated with difficult life conditions also appeared to improve mood, and there was a clear benefit in being in a caring environment where other people actively paid an interest. There were extended social benefits associated with being accepted as part of a team within a familiar military environment, which presented an opportunity to establish friendships and utilise military skill sets. Organised outdoor activities offer multi-factorial hope for veterans searching for ways to ease the transition to civilian life and recover from military stress and trauma. The relaxing and reflective environment within a military setting appears to construct a sense of personal safety and thereby offers therapeutic value. Copyright © 2016 Elsevier Ltd. All rights

  14. Tracking synthesis and turnover of triacylglycerol in leaves

    PubMed Central

    Tjellström, Henrik; Strawsine, Merissa; Ohlrogge, John B.

    2015-01-01

    Triacylglycerol (TAG), typically represents <1% of leaf glycerolipids but can accumulate under stress and other conditions or if leaves are supplied with fatty acids, or in plants transformed with regulators or enzymes of lipid metabolism. To better understand the metabolism of TAG in leaves, pulse–chase radiolabelling experiments were designed to probe its synthesis and turnover. When Arabidopsis leaves were incubated with [14C]lauric acid (12:0), a major initial product was [14C]TAG. Thus, despite low steady-state levels, leaves possess substantial TAG biosynthetic capacity. The contributions of diacylglycerol acyltransferase1 and phospholipid:diacylglycerol acyltransferase1 to leaf TAG synthesis were examined by labelling of dgat1 and pdat1 mutants. The dgat1 mutant displayed a major (76%) reduction in [14C]TAG accumulation whereas pdat1 TAG labelling was only slightly reduced. Thus, DGAT1 has a principal role in TAG biosynthesis in young leaves. During a 4h chase period, radioactivity in TAG declined 70%, whereas the turnover of [14C]acyl chains of phosphatidylcholine (PC) and other polar lipids was much lower. Sixty percent of [14C]12:0 was directly incorporated into glycerolipids without modification, whereas 40% was elongated and desaturated to 16:0 and 18:1 by plastids. The unmodified [14C]12:0 and the plastid products of [14C]12:0 metabolism entered different pathways. Although plastid-modified 14C-labelled products accumulated in monogalactosyldiacylglycerol, PC, phosphatidylethanolamine, and diacylglcerol (DAG), there was almost no accumulation of [14C]16:0 and [14C]18:1 in TAG. Because DAG and acyl-CoA are direct precursors of TAG, the differential labelling of polar glycerolipids and TAG by [14C]12:0 and its plastid-modified products provides evidence for multiple subcellular pools of both acyl-CoA and DAG. PMID:25609824

  15. Evidence for a role of MRCK in mediating HeLa cell elongation induced by the C1 domain ligand HMI-1a3.

    PubMed

    Talman, Virpi; Gateva, Gergana; Ahti, Marja; Ekokoski, Elina; Lappalainen, Pekka; Tuominen, Raimo K

    2014-05-13

    Diacylglycerol (DAG) is a central mediator of signaling pathways that regulate cell proliferation, survival and apoptosis. Therefore, C1 domain, the DAG binding site within protein kinase C (PKC) and other DAG effector proteins, is considered a potential cancer drug target. Derivatives of 5-(hydroxymethyl)isophthalic acid are a novel group of C1 domain ligands with antiproliferative and differentiation-inducing effects. Our previous work showed that these isophthalate derivatives exhibit antiproliferative and elongation-inducing effects in HeLa human cervical cancer cells. In this study we further characterized the effects of bis(3-trifluoromethylbenzyl) 5-(hydroxymethyl)isophthalate (HMI-1a3) on HeLa cell proliferation and morphology. HMI-1a3-induced cell elongation was accompanied with loss of focal adhesions and actin stress fibers, and exposure to HMI-1a3 induced a prominent relocation of cofilin-1 into the nucleus regardless of cell phenotype. The antiproliferative and morphological responses to HMI-1a3 were not modified by pharmacological inhibition or activation of PKC, or by RNAi knock-down of specific PKC isoforms, suggesting that the effects of HMI-1a3 were not mediated by PKC. Genome-wide gene expression microarray and gene set enrichment analysis suggested that, among others, HMI-1a3 induces changes in small GTPase-mediated signaling pathways. Our experiments revealed that the isophthalates bind also to the C1 domains of β2-chimaerin, protein kinase D (PKD) and myotonic dystrophy kinase-related Cdc42-binding kinase (MRCK), which are potential mediators of small GTPase signaling and cytoskeletal reorganization. Pharmacological inhibition of MRCK, but not that of PKD attenuated HMI-1a3-induced cell elongation, suggesting that MRCK participates in mediating the effects of HMI-1a3 on HeLa cell morphology. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Tracking synthesis and turnover of triacylglycerol in leaves

    DOE PAGES

    Tjellstrom, Henrik; Strawsine, Merissa; Ohlrogge, John B.

    2015-01-21

    Triacylglycerol (TAG), typically represents <1% of leaf glycerolipids but can accumulate under stress and other conditions or if leaves are supplied with fatty acids, or in plants transformed with regulators or enzymes of lipid metabolism. To better understand the metabolism of TAG in leaves, pulse-chase radiolabelling experiments were designed to probe its synthesis and turnover. When Arabidopsis leaves were incubated with [ 14C]lauric acid (12:0), a major initial product was [ 14C]TAG. Thus, despite low steady-state levels, leaves possess substantial TAG biosynthetic capacity. The contributions of diacylglycerol acyltransferase1 and phospholipid:diacylglycerol acyltransferase1 to leaf TAG synthesis were examined by labelling ofmore » dgat1 and pdat1 mutants. The dgat1 mutant displayed a major (76%) reduction in [ 14C]TAG accumulation whereas pdat1 TAG labelling was only slightly reduced. Thus, DGAT1 has a principal role in TAG biosynthesis in young leaves. During a 4h chase period, radioactivity in TAG declined 70%, whereas the turnover of [ 14C]acyl chains of phosphatidylcholine (PC) and other polar lipids was much lower. Sixty percent of [ 14C]12:0 was directly incorporated into glycerolipids without modification, whereas 40% was elongated and desaturated to 16:0 and 18:1 by plastids. The unmodified [ 14C]12:0 and the plastid products of [ 14C]12:0 metabolism entered different pathways. Although plastid-modified 14C-labelled products accumulated in monogalactosyldiacylglycerol, PC, phosphatidylethanolamine, and diacylglcerol (DAG), there was almost no accumulation of [ 14C]16:0 and [ 14C]18:1 in TAG. Lastly, because DAG and acyl-CoA are direct precursors of TAG, the differential labelling of polar glycerolipids and TAG by [ 14C]12:0 and its plastid-modified products provides evidence for multiple subcellular pools of both acyl-CoA and DAG.« less

  17. Dietary polyunsaturated fatty acids and adaptation to chronic hypoxia alter acyl composition of serum and heart lipids.

    PubMed

    Balková, Patricie; Jezková, Jana; Hlavácková, Markéta; Neckár, Jan; Stanková, Barbora; Kolár, Frantisek; Novák, Frantisek; Nováková, Olga

    2009-11-01

    The effects of dietary supplementation with fat of different fatty acid profile and chronic intermittent hypoxia (CIH) on the fatty acid composition of serum and heart lipids were analysed. Adult male Wistar rats were fed a standard non-fat diet enriched with 10 % of lard, fish oil (n-3 PUFA) or maize oil (n-6 PUFA) for 10 weeks. After 4 weeks on the diets, each group was divided in two subgroups, either exposed to CIH in a barochamber (7000 m, twenty-five exposures) or kept at normoxia. In normoxic rats, the fish oil diet increased the level of conjugated dienes. The n-6:n-3 PUFA ratio in serum TAG, phospholipids (PL), cholesteryl esters (CE) and heart TAG, PL and diacylglycerols (DAG) followed the ratio in the fed diet (in the sequence maize oil>lard>fish oil). In heart TAG, PL and DAG, 20 : 4n-6 and 18 : 2n-6 were replaced by 22 : 6n-3 in the fish oil group. The main fatty acid in CE was 20 : 4n-6 in the lard and maize oil groups whereas in the fish oil group, half of 20 : 4n-6 was replaced by 20 : 5n-3. CIH further increased 20 : 5n-3 in CE in the fish oil group. CIH decreased the n-6:n-3 PUFA ratio in serum CE, heart TAG, PL and DAG in all dietary groups and stimulated the activity of catalase in the maize and fish oil groups. In conclusion, PUFA diets and CIH, both interventions considered to be cardioprotective, distinctly modified the fatty acid profile in serum and heart lipids with specific effects on conjugated diene production and catalase activity.

  18. Computational Model of the Insect Pheromone Transduction Cascade

    PubMed Central

    Gu, Yuqiao; Lucas, Philippe; Rospars, Jean-Pierre

    2009-01-01

    A biophysical model of receptor potential generation in the male moth olfactory receptor neuron is presented. It takes into account all pre-effector processes—the translocation of pheromone molecules from air to sensillum lymph, their deactivation and interaction with the receptors, and the G-protein and effector enzyme activation—and focuses on the main post-effector processes. These processes involve the production and degradation of second messengers (IP3 and DAG), the opening and closing of a series of ionic channels (IP3-gated Ca2+ channel, DAG-gated cationic channel, Ca2+-gated Cl− channel, and Ca2+- and voltage-gated K+ channel), and Ca2+ extrusion mechanisms. The whole network is regulated by modulators (protein kinase C and Ca2+-calmodulin) that exert feedback inhibition on the effector and channels. The evolution in time of these linked chemical species and currents and the resulting membrane potentials in response to single pulse stimulation of various intensities were simulated. The unknown parameter values were fitted by comparison to the amplitude and temporal characteristics (rising and falling times) of the experimentally measured receptor potential at various pheromone doses. The model obtained captures the main features of the dose–response curves: the wide dynamic range of six decades with the same amplitudes as the experimental data, the short rising time, and the long falling time. It also reproduces the second messenger kinetics. It suggests that the two main types of depolarizing ionic channels play different roles at low and high pheromone concentrations; the DAG-gated cationic channel plays the major role for depolarization at low concentrations, and the Ca2+-gated Cl− channel plays the major role for depolarization at middle and high concentrations. Several testable predictions are proposed, and future developments are discussed. PMID:19300479

  19. Dominant Achievement Goals and Academic Outcomes across Tracks in High School

    ERIC Educational Resources Information Center

    Scheltinga, Peter A. M.; Timmermans, Anneke C.; van der Werf, Greetje P. C.

    2017-01-01

    The self-reported grades Dutch, English and Math of 13,970 students in the third grade of Dutch secondary education (US grade 9) were investigated with regard to educational track-level and dominant achievement goal (DAG). The performance approach goal group scored significantly higher on all three subjects than the performance avoidance group,…

  20. Lipid profiles of oil from trout (Oncorhynchus mykiss) heads, spines and viscera: trout by-products as a possible source of omega-3 lipids?

    PubMed

    Fiori, L; Solana, M; Tosi, P; Manfrini, M; Strim, C; Guella, G

    2012-09-15

    Lipid profiles of fish oil extracted from trout heads, spines and viscera using supercritical carbon dioxide and Randall extraction with hexane were measured. The amount of unsaturated fatty acids (as a percentage of total fatty acids) was within the range of 72.6-75.3% in all the substrates. A significant presence of the most important omega-3 fatty acids was detected. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content in oil from spines, heads and viscera resulted to be 8.7% and 7.3%, 7.9% and 6.3%, and 6.4% and 6.0%, respectively. A low (≈3%), but worth noting, presence of lipids with omega-1 polyunsaturated fatty chains was observed in all the oils. Finally, significant differences were noticed in the relative amounts of triacylglycerides (TAG), diacylglycerides (DAG) and free fatty acids (FFA). Whereas oil from heads and spines was essentially composed of TAG (≈98%), in viscera oil the molar distribution ratio became TAG:DAG:FFA=87:8:5. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Myxococcus CsgA, Drosophila Sniffer, and human HSD10 are cardiolipin phospholipases.

    PubMed

    Boynton, Tye O'Hara; Shimkets, Lawrence Joseph

    2015-09-15

    Myxococcus xanthus development requires CsgA, a member of the short-chain alcohol dehydrogenase (SCAD) family of proteins. We show that CsgA and SocA, a protein that can replace CsgA function in vivo, oxidize the 2'-OH glycerol moiety on cardiolipin and phosphatidylglycerol to produce diacylglycerol (DAG), dihydroxyacetone, and orthophosphate. A lipid extract enriched in DAGs from wild-type cells initiates development and lipid body production in a csgA mutant to bypass the mutational block. This novel phospholipase C-like reaction is widespread. SCADs that prevent neurodegenerative disorders, such as Drosophila Sniffer and human HSD10, oxidize cardiolipin with similar kinetic parameters. HSD10 exhibits a strong preference for cardiolipin with oxidized fatty acids. This activity is inhibited in the presence of the amyloid β peptide. Three HSD10 variants associated with neurodegenerative disorders are inactive with cardiolipin. We suggest that HSD10 protects humans from reactive oxygen species by removing damaged cardiolipin before it induces apoptosis. © 2015 Boynton and Shimkets; Published by Cold Spring Harbor Laboratory Press.

  2. PMCA activity and membrane tubulin affect deformability of erythrocytes from normal and hypertensive human subjects.

    PubMed

    Monesterolo, Noelia E; Nigra, Ayelen D; Campetelli, Alexis N; Santander, Verónica S; Rivelli, Juan F; Arce, Carlos A; Casale, Cesar H

    2015-11-01

    Our previous studies demonstrated formation of a complex between acetylated tubulin and brain plasma membrane Ca(2+)-ATPase (PMCA), and the effect of the lipid environment on structure of this complex and on PMCA activity. Deformability of erythrocytes from hypertensive human subjects was reduced by an increase in membrane tubulin content. In the present study, we examined the regulation of PMCA activity by tubulin in normotensive and hypertensive erythrocytes, and the effect of exogenously added diacylglycerol (DAG) and phosphatidic acid (PA) on erythrocyte deformability. Some of the key findings were that: (i) PMCA was associated with tubulin in normotensive and hypertensive erythrocytes, (ii) PMCA enzyme activity was directly correlated with erythrocyte deformability, and (iii) when tubulin was present in the erythrocyte membrane, treatment with DAG or PA led to increased deformability and associated PMCA activity. Taken together, our findings indicate that PMCA activity is involved in deformability of both normotensive and hypertensive erythrocytes. This rheological property of erythrocytes is affected by acetylated tubulin and its lipid environment because both regulate PMCA activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Antioxidants produced by Eurotium herbariorum of filamentous fungi used for the manufacture of karebushi, dried bonito (Katsuobushi).

    PubMed

    Miyake, Yoshiaki; Ito, Chihiro; Itoigawa, Masataka; Osawa, Toshihiko

    2009-06-01

    Extracts prepared by culturing ten filamentous fungi from Aspergillus and Eurotium species isolated from dried bonito (katsuobushi) were examined for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity. The extracts prepared by culturing E. herbariorum NE-1 and NE-4, which are used in the molding process for the manufacture of karebushi (a kind of katsuobushi), were shown to have higher activity than the others. Five antioxidants were isolated from the extracts and identified as isodihydroauroglaucin (IDAG), auroglaucin (AG), dihydroauroglaucin (DAG), tetrahydroauroglaucin (TAG), and flavoglaucin (FG) by (1)H-NMR, (13)C-NMR, and EI-MS analyses. Compared with alpha-tocopherol, the isolated antioxidants exhibited high antioxidative activity for the radical scavenging capacity of DPPH and superoxide, but low activity for inhibiting the autoxidation of docosahexaenoic acid (DHA). The isolated antioxidants were produced by the Eurotium species, but not by the Aspergillus species. DAG and TAG exhibited higher radical scavenging capacity than the other antioxidants and were abundantly contained in the extracts of E. herbariorum NE-1 and NE-4.

  4. A multiplexed fluorescent assay for independent second-messenger systems: decoding GPCR activation in living cells.

    PubMed

    Tewson, Paul H; Quinn, Anne Marie; Hughes, Thomas E

    2013-08-01

    There is a growing need in drug discovery and basic research to measure multiple second-messenger components of cell signaling pathways in real time and in relevant tissues and cell types. Many G-protein-coupled receptors activate the heterotrimeric protein, Gq, which in turn activates phospholipase C (PLC). PLC cleaves phosphatidylinositol 4,5-bisphosphate (PIP2) to produce two second messengers: diacylglycerol (DAG), which remains in the plasma membrane, and inositol triphosphate (IP3), which diffuses through the cytosol to release stores of intracellular calcium ions (Ca(2+)). Our goal was to create a series of multiplex sensors that would make it possible to simultaneously measure two different components of the Gq pathway in living cells. Here we describe new fluorescent sensors for DAG and PIP2 that produce robust changes in green or red fluorescence and can be combined with one another, or with existing Ca(2+) sensors, in a live-cell assay. These assays can detect multiple components of Gq signaling, simultaneously in real time, on standard fluorescent plate readers or live-cell imaging systems.

  5. An ER protein functionally couples neutral lipid metabolism on lipid droplets to membrane lipid synthesis in the ER.

    PubMed

    Markgraf, Daniel F; Klemm, Robin W; Junker, Mirco; Hannibal-Bach, Hans K; Ejsing, Christer S; Rapoport, Tom A

    2014-01-16

    Eukaryotic cells store neutral lipids such as triacylglycerol (TAG) in lipid droplets (LDs). Here, we have addressed how LDs are functionally linked to the endoplasmic reticulum (ER). We show that, in S. cerevisiae, LD growth is sustained by LD-localized enzymes. When LDs grow in early stationary phase, the diacylglycerol acyl-transferase Dga1p moves from the ER to LDs and is responsible for all TAG synthesis from diacylglycerol (DAG). During LD breakdown in early exponential phase, an ER membrane protein (Ice2p) facilitates TAG utilization for membrane-lipid synthesis. Ice2p has a cytosolic domain with affinity for LDs and is required for the efficient utilization of LD-derived DAG in the ER. Ice2p breaks a futile cycle on LDs between TAG degradation and synthesis, promoting the rapid relocalization of Dga1p to the ER. Our results show that Ice2p functionally links LDs with the ER and explain how cells switch neutral lipid metabolism from storage to consumption. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Role of protein kinase C alpha and mitogen-activated protein kinases in endothelin-1-stimulation of cytosolic phospholipase A2 in iris sphincter smooth muscle.

    PubMed

    Abdel-Latif, A A; Husain, S; Yousufzai, S Y

    2000-11-01

    We have investigated the roles of protein kinase C (PKC) and mitogen-activated protein kinases (MAPK) in the phosphorylation and activation of cytosolic phospholipase A2 (cPLA2) in endothelin-1- (ET-1) stimulated cat iris sphincter smooth muscle (CISM) cells. We found that in these cells both PKC and p38 MAP kinases play a critical role in ET-1-induced cPLA, phosphorylation and arachidonic acid (AA) release. Our findings indicate that stimulation of the endothelin-A- (ET(A)) receptor leads to: (1) activation of Gq protein which stimulates phospholipase C to hydrolyze the polyphosphoinositide PIP, into diacylglycerol (DAG) and inositol trisphosphate (IP3), the DAG may then activate PKC to phosphorylate and activate cPLA2; and (2) activation of Gi protein, which, through a series of kinases, leads to the stimulation of p38 MAPK and subsequently to phosphorylation and activation of cPLA2. The ability of the activated ET(A)-receptor, which is coupled to both Gq and Gi proteins, to recruit and activate this complex signal transduction mechanism remains to be clarified.

  7. An Analysis of the Root Causes of Delays and Deficiencies in the Development of Embedded Software for Air Force Weapon Systems

    DTIC Science & Technology

    1993-12-01

    the ability to pull up sharply to avoid hitting hills. To maintain the ability to pull up at the level desired by the Air Force (2.4 g’s, or...by whadmss. la& akon ?dmuenua;c Alniinal Fm’mmname. Small Rcducszms in Samlmlactima in Ssghcua DagUdam in as Taedaclm Goali Cum Impac Taclmncul

  8. Source Physics Experiment Phase II, Dry Alluvium Geology (DAG) Experiments Using Nitromethane

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Traeger, Scott R.

    Need to provide briefing to the State of Nevada as part of the Permitting process for the Nevada Chemical Accident Prevention Program (CAPP) for use of nitromethane at the NNSS. This document will be accessible to the public as part of the CAPP program.

  9. Canes Implementation: Analysis of Budgetary, Business, and Policy Challenges

    DTIC Science & Technology

    2014-12-01

    Concept of Operations COTS Commercial Off the Shelf DAG Defense Acquisitions Guidebook DAS Defense Acquisitions System DOD Department of Defense...and Integration NSS National Security Strategy OA Open Architecture OCO Overseas Contingency Operations OEF Operation Enduring Freedom OIF...and software and civilian-type open architecture ( OA ) presents a series of challenges. The purpose of this report is to provide the Navy with a

  10. A Bayesian network analysis of posttraumatic stress disorder symptoms in adults reporting childhood sexual abuse

    PubMed Central

    McNally, Richard J.; Heeren, Alexandre; Robinaugh, Donald J.

    2017-01-01

    ABSTRACT Background: The network approach to mental disorders offers a novel framework for conceptualizing posttraumatic stress disorder (PTSD) as a causal system of interacting symptoms. Objective: In this study, we extended this work by estimating the structure of relations among PTSD symptoms in adults reporting personal histories of childhood sexual abuse (CSA; N = 179).   Method: We employed two complementary methods. First, using the graphical LASSO, we computed a sparse, regularized partial correlation network revealing associations (edges) between pairs of PTSD symptoms (nodes). Next, using a Bayesian approach, we computed a directed acyclic graph (DAG) to estimate a directed, potentially causal model of the relations among symptoms. Results: For the first network, we found that physiological reactivity to reminders of trauma, dreams about the trauma, and lost of interest in previously enjoyed activities were highly central nodes. However, stability analyses suggest that these findings were unstable across subsets of our sample. The DAG suggests that becoming physiologically reactive and upset in response to reminders of the trauma may be key drivers of other symptoms in adult survivors of CSA. Conclusions: Our study illustrates the strengths and limitations of these network analytic approaches to PTSD. PMID:29038690

  11. Muscle ERRγ mitigates Duchenne muscular dystrophy via metabolic and angiogenic reprogramming.

    PubMed

    Matsakas, Antonios; Yadav, Vikas; Lorca, Sabina; Narkar, Vihang

    2013-10-01

    Treatment of Duchenne muscular dystrophy (DMD) by replacing mutant dystrophin or restoring dystrophin-associated glycoprotein complex (DAG) has been clinically challenging. Instead, identifying and targeting muscle pathways deregulated in DMD will provide new therapeutic avenues. We report that the expression of nuclear receptor estrogen-related receptor-γ (ERRγ), and its metabolic and angiogenic targets are down-regulated (50-85%) in skeletal muscles of mdx mice (DMD model) vs. wild-type mice. Corelatively, oxidative myofibers, muscle vasculature, and exercise tolerance (33%) are decreased in mdx vs. wild-type mice. Overexpressing ERRγ selectively in the dystrophic muscles of the mdx mice restored metabolic and angiogenic gene expression compared with control mdx mice. Further, ERRγ enhanced muscle oxidative myofibers, vasculature, and blood flow (by 33-66%) and improved exercise tolerance (by 75%) in the dystrophic mice. Restoring muscle ERRγ pathway ameliorated muscle damage and also prevented DMD hallmarks of postexercise muscle damage, hypoxia, and fatigue in mdx mice. Notably, ERRγ did not restore sarcolemmal DAG complex, which is thus dispensable for antidystrophic effects of ERRγ. In summary, ERRγ-dependent metabolic and angiogenic gene program is defective in DMD, and we demonstrate that its restoration is a potential strategy for treating muscular dystrophy.

  12. Vanilla mosaic virus isolates from French Polynesia and the Cook Islands are Dasheen mosaic virus strains that exclusively infect vanilla.

    PubMed

    Farreyrol, K; Pearson, M N; Grisoni, M; Cohen, D; Beck, D

    2006-05-01

    Sequence was determined for the coat protein (CP) gene and 3' non-translated region (3'NTR) of two vanilla mosaic virus (VanMV) isolates from Vanilla tahitensis, respectively from the Cook Islands (VanMV-CI) and French Polynesia (VanMV-FP). Both viruses displayed distinctive features in the N-terminal region of their CPs; for VanMV-CI, a 16-amino-acid deletion including the aphid transmission-related DAG motif, and for VanMV-FP, a stretch of GTN repeats that putatively belongs to the class of natively unfolded proteins. VanMV-FP CP also has a novel DVG motif in place of the DAG motif, and an uncommon Q//V protease cleavage site. The sequences were compared to a range of Dasheen mosaic virus (DsMV) strains and to potyviruses infecting orchids. Identity was low to DsMV strains across the entire CP coding region and across the 3'NTR, but high across the CP core and the CI-6K2-NIa region. In accordance with current ICTV criteria for species demarcation within the family Potyviridae, VanMV-CI and VanMV-FP are strains of DsMV that exclusively infect vanilla.

  13. A potential vector of domoic acid: the swimming crab Polybius henslowii Leach (Decapoda-brachyura).

    PubMed

    Costa, Pedro R; Rodrigues, Susana M; Botelho, Maria J; Sampayo, Maria Antónia de M

    2003-08-01

    The swimming crab Polybius henslowii may play an important role in the movement of the amnesic shellfish toxin, domoic acid (DA), through the marine food chain. High DA concentrations have been determined in crab samples harvested along the Portuguese coast during the summer of 2002, reaching a level of 323.1 microg DA/g crab tissue. Toxin distribution in the different crab organs showed levels as high as 571.6 microg DA/g in the visceral tissues. Levels of toxin 4-12 times lower were detected in the remaining tissues. This crab might be a prominent vector of the toxin to higher trophic levels, including fishes, sea birds and even humans. In Portugal P. henslowii is commercialised during the summer in some local markets. DA concentrations were found close to the legal limit of 20 microg/g in samples purchased at Figueira da Foz market. The crabs are boiled prior to reaching the consumers. The cooking process was evaluated. Determination of toxin losses during the cooking process showed a toxin reduction higher than 50%. DA was determined by HPLC-UV and confirmed by spectra acquired with diode-array detector.

  14. A soluble diacylglycerol acyltransferase is involved in triacylglycerol biosynthesis in the oleaginous yeast Rhodotorula glutinis.

    PubMed

    Rani, Sapa Hima; Saha, Saikat; Rajasekharan, Ram

    2013-01-01

    The biosynthesis of triacylglycerol (TAG) occurs in the microsomal membranes of eukaryotes. Here, we report the identification and functional characterization of diacylglycerol acyltransferase (DGAT), a member of the 10 S cytosolic TAG biosynthetic complex (TBC) in Rhodotorula glutinis. Both a full-length and an N-terminally truncated cDNA clone of a single gene were isolated from R. glutinis. The DGAT activity of the protein encoded by RgDGAT was confirmed in vivo by the heterologous expression of cDNA in a Saccharomyces cerevisiae quadruple mutant (H1246) that is defective in TAG synthesis. RgDGAT overexpression in yeast was found to be capable of acylating diacylglycerol (DAG) in an acyl-CoA-dependent manner. Quadruple mutant yeast cells exhibit growth defects in the presence of oleic acid, but wild-type yeast cells do not. In an in vivo fatty acid supplementation experiment, RgDGAT expression rescued quadruple mutant growth in an oleate-containing medium. We describe a soluble acyl-CoA-dependent DAG acyltransferase from R. glutinis that belongs to the DGAT3 class of enzymes. The study highlights the importance of an alternative TAG biosynthetic pathway in oleaginous yeasts.

  15. Sphingolipid-Mediated Apoptosis and Tumor Suppression in Breast Carcinoma.

    DTIC Science & Technology

    1996-10-01

    diacylglycerol and ceramide. The radioactive spots corresponding to phosphatidic acid and ceramide-phosphate, the phosphorylated products of diacylglycerol (DAG...threonine protein phosphatase (7). This phosphatase is inhibited by okadaic acid , and okadaic acid appears to inhibit the effects of ceramide on...Arg to Thr at amino acid 291 in the reactive site loop. In MCF-7 cells expressing this mutant, there was no significant inhibition of ceramide

  16. United Nations Peacekeeping Operations: Challenges and Opportunities

    DTIC Science & Technology

    2012-04-27

    close the gap between aspiration and performance…makes the difference between civilisation and chaos” AND OPPORTUNITIES - Dag Hammarskjöld...usual lists of their tasks range from electoral supervision, human rights monitoring, civilian protection, assisting the delivery of humanitarian relief...put a strain on the human and material resources available for the protection of civilians.22 in 2009 the New Horizons report commented: “[t]he

  17. Identification of the GnRH-(1-5) Receptor and Signaling Pathway

    DTIC Science & Technology

    2013-03-22

    Coimmunoprecipitation DAG Diacylglycerol DNA Deoxyribonucleic Acid DR Aspartic Acid/ Aspargine Motif ED Embryonic Day ELISA Enzyme -Linked...candidate GnRH-(1-5) receptors by using a high-throughput enzyme fragment complementation assay (DiscoveRx, Fremont, CA). The results from the assay...for an orphan GPCR is of paramount significance since there are greater than 100 orphan GPCRs considered potential targets for the development of

  18. New denture adhesive containing miconazole nitrate polymeric microparticles: Antifungal, adhesive force and toxicity properties.

    PubMed

    Cartagena, Andrés Felipe; Esmerino, Luís Antonio; Polak-Junior, Rogerio; Olivieri Parreiras, Sibelli; Domingos Michél, Milton; Farago, Paulo Vitor; Campanha, Nara Hellen

    2017-02-01

    The purpose of this study was to develop a new oral drug delivery system by incorporating polymeric miconazole nitrate (MN) microparticles on an experimental antifungal denture adhesive (DA). Spray drying Eudragit L-100 (E) and Gantrez MS-955 (G) MN-microparticles were incorporated in DA. DAE1, DAG1, DAEG1, DAE2, DAG2, DAEG2 groups were obtained from the combination of polymers used in MN-microparticles (E, G and EG) and concentration of MN into DA (1, for 1% and 2, for 2%). DA with 2% pure MN (DAM) and DA without microparticles or drug (DACT) were both control groups. All groups were evaluated to determine microbiological assay, adhesive force and toxicity. Minimum inhibitory concentration (MIC) against Candida albicans was performed by broth micro-dilution and agar dilution methods in extract of DAs and conventional gel form (Daktarin ® ). Adhesive load testing was made between acrylic resin samples on a universal testing machine after immersion in water. The toxicity of several dilutions of DAs was performed with Artemia salina bioassay after 24 and 48h. Data of adhesive force were evaluated with two-way ANOVA and Bonferroni tests (α=0.05). The concentration required to kill 50% (LC50) was determined using the Provit analysis. DA with polymeric microparticles and pure drug presented MIC between 1.25-5μg/mL similar to MIC values of DAM. DAEG2, DAEG1, DAG20 showed the most actives against C. albicans. The best adhesive properties were exhibited by DAEG2, consisting of high initial adhesive force which was maintained for up to 6h. The extracts of all DA presented low or not toxicity at 24 and 48h. DA containing 2% of MN loaded in microparticles made by Gantrez MS-955 alone or combined with Eudragit L-100 produce effective antifungal activity, good adhesive force, and no toxicity effect being a promising therapeutics for removable denture wearers affected by denture stomatitis. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All

  19. Identification and physiological characterization of phosphatidic acid phosphatase enzymes involved in triacylglycerol biosynthesis in Streptomyces coelicolor

    PubMed Central

    2013-01-01

    Background Phosphatidic acid phosphatase (PAP, EC 3.1.3.4) catalyzes the dephosphorylation of phosphatidate yielding diacylglycerol (DAG), the lipid precursor for triacylglycerol (TAG) biosynthesis. Despite the importance of PAP activity in TAG producing bacteria, studies to establish its role in lipid metabolism have been so far restricted only to eukaryotes. Considering the increasing interest of bacterial TAG as a potential source of raw material for biofuel production, we have focused our studies on the identification and physiological characterization of the putative PAP present in the TAG producing bacterium Streptomyces coelicolor. Results We have identified two S. coelicolor genes, named lppα (SCO1102) and lppβ (SCO1753), encoding for functional PAP proteins. Both enzymes mediate, at least in part, the formation of DAG for neutral lipid biosynthesis. Heterologous expression of lppα and lppβ genes in E. coli resulted in enhanced PAP activity in the membrane fractions of the recombinant strains and concomitantly in higher levels of DAG. In addition, the expression of these genes in yeast complemented the temperature-sensitive growth phenotype of the PAP deficient strain GHY58 (dpp1lpp1pah1). In S. coelicolor, disruption of either lppα or lppβ had no effect on TAG accumulation; however, the simultaneous mutation of both genes provoked a drastic reduction in de novo TAG biosynthesis as well as in total TAG content. Consistently, overexpression of Lppα and Lppβ in the wild type strain of S. coelicolor led to a significant increase in TAG production. Conclusions The present study describes the identification of PAP enzymes in bacteria and provides further insights on the genetic basis for prokaryotic oiliness. Furthermore, this finding completes the whole set of enzymes required for de novo TAG biosynthesis pathway in S. coelicolor. Remarkably, the overexpression of these PAPs in Streptomyces bacteria contributes to a higher productivity of this single

  20. Tracking synthesis and turnover of triacylglycerol in leaves.

    PubMed

    Tjellström, Henrik; Strawsine, Merissa; Ohlrogge, John B

    2015-03-01

    Triacylglycerol (TAG), typically represents <1% of leaf glycerolipids but can accumulate under stress and other conditions or if leaves are supplied with fatty acids, or in plants transformed with regulators or enzymes of lipid metabolism. To better understand the metabolism of TAG in leaves, pulse-chase radiolabelling experiments were designed to probe its synthesis and turnover. When Arabidopsis leaves were incubated with [(14)C]lauric acid (12:0), a major initial product was [(14)C]TAG. Thus, despite low steady-state levels, leaves possess substantial TAG biosynthetic capacity. The contributions of diacylglycerol acyltransferase1 and phospholipid:diacylglycerol acyltransferase1 to leaf TAG synthesis were examined by labelling of dgat1 and pdat1 mutants. The dgat1 mutant displayed a major (76%) reduction in [(14)C]TAG accumulation whereas pdat1 TAG labelling was only slightly reduced. Thus, DGAT1 has a principal role in TAG biosynthesis in young leaves. During a 4h chase period, radioactivity in TAG declined 70%, whereas the turnover of [(14)C]acyl chains of phosphatidylcholine (PC) and other polar lipids was much lower. Sixty percent of [(14)C]12:0 was directly incorporated into glycerolipids without modification, whereas 40% was elongated and desaturated to 16:0 and 18:1 by plastids. The unmodified [(14)C]12:0 and the plastid products of [(14)C]12:0 metabolism entered different pathways. Although plastid-modified (14)C-labelled products accumulated in monogalactosyldiacylglycerol, PC, phosphatidylethanolamine, and diacylglcerol (DAG), there was almost no accumulation of [(14)C]16:0 and [(14)C]18:1 in TAG. Because DAG and acyl-CoA are direct precursors of TAG, the differential labelling of polar glycerolipids and TAG by [(14)C]12:0 and its plastid-modified products provides evidence for multiple subcellular pools of both acyl-CoA and DAG. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  1. Fully Burdened Cost of Fuel Using Input-Output Analysis

    DTIC Science & Technology

    2011-12-01

    Distribution Model could be used to replace the current seven-step Fully Burdened Cost of Fuel process with a single step, allowing for less complex and...wide extension of the Bulk Fuels Distribution Model could be used to replace the current seven-step Fully Burdened Cost of Fuel process with a single...ABBREVIATIONS AEM Atlantic, Europe, and the Mediterranean AOAs Analysis of Alternatives DAG Defense Acquisition Guidebook DAU Defense Acquisition University

  2. A Recommended Framework for the Network-Centric Acquisition Process

    DTIC Science & Technology

    2009-09-01

    ISO /IEC 12207 , Systems and Software Engineering-Software Life-Cycle Processes  ANSI/EIA 632, Processes for Engineering a System. There are...engineering [46]. Some of the process models presented in the DAG are:  ISO /IEC 15288, Systems and Software Engineering-System Life-Cycle Processes...e.g., ISO , IA, Security, etc.). Vetting developers helps ensure that they are using industry best industry practices and maximize the IA compliance

  3. Molecular Basis of Autophagic Cell Death in Prostate Cancer

    DTIC Science & Technology

    2009-03-01

    lipid-binding proteinwith high affinity for phosphatidic acid (PA) and cardiolipin (CL). Previously, it has been shown that PA directly interacted...lyceride), PI (phosphatidylinositol), DAG (diacylglycerol), PI4P (PtdIns(4)P), PA ( phosphatidic acid ), PI4,5P2 (PtdIns(4,5)P2), PS (phosphatidylserine...with high affinity for phosphatidic acid and cardiolipin and less affinity for various phosphoinositides. Functional genomics analysis identified 5

  4. Data management and processing plan, Department of Applied Geodesy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1992-08-01

    This plan outlines Data Management and Data Processing requirements of the Department of Applied Geodesy (DAG) and presents the plan to meet these requirements (These requirements are derived from the functional needs of the Department to meet the SSCL alignment tolerances and schedules). In addition, this document presents a schedule for the implementation of this plan. This document is an integral part of the Alignment Plan of the SSCL.

  5. Comparative study on nutrient depletion-induced lipidome adaptations in Staphylococcus haemolyticus and Staphylococcus epidermidis.

    PubMed

    Luo, Yu; Javed, Muhammad Afzal; Deneer, Harry

    2018-02-05

    Staphylococcus species are emerging opportunistic pathogens that cause outbreaks of hospital and community-acquired infections. Some of these bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are difficult to treat due to their resistance to multiple antibiotics. We carried out a comparative study on the lipidome adaptations in response to starvation in the two most common coagulase-negative Staphylococcus species: a S. epidermidis strain sensitive to ampicillin and erythromycin and a S. haemolyticus strain resistant to both. The predominant fatty acid composition in glycerolipids was (17:0-15:0) in both bacteria. During the exponential phase, the two bacterial lipidomes were similar. Both were dominated by diacylglycerol (DAG), phosphatidylglycerol (PG), lysyl-phosphatidylglycerol (Lysyl-PG) and Diglucosyl-diacylglycerol (DGDG). Alanyl-PG was detected in small amounts in both bacterial lipids. N-succinyl-lysyl-PG was detected only in S. haemolyticus, while lysyl-DAG only in S. epidermidis. As the two bacteria entered stationary phase, both lipidomes became essentially nitrogen-free. Both bacteria accumulated large amounts of free fatty acids. Strikingly, the lipidome of S. epidermidis became dominated by cardiolipin (CL), while that of S. haemolyticus was simplified to DGDG and PG. The S. epidermidis strain also produced acyl-phosphatidylglycerol (APG) in the stationary phase.

  6. Ethanol-Induced Changes in PKCε: From Cell to Behavior.

    PubMed

    Pakri Mohamed, Rashidi M; Mokhtar, Mohd H; Yap, Ernie; Hanim, Athirah; Abdul Wahab, Norhazlina; Jaffar, Farah H F; Kumar, Jaya

    2018-01-01

    The long-term binge intake of ethanol causes neuroadaptive changes that lead to drinkers requiring higher amounts of ethanol to experience its effects. This neuroadaptation can be partly attributed to the modulation of numerous neurotransmitter receptors by the various protein kinases C (PKCs). PKCs are enzymes that control cellular activities by regulating other proteins via phosphorylation. Among the various isoforms of PKC, PKCε is the most implicated in ethanol-induced biochemical and behavioral changes. Ethanol exposure causes changes to PKCε expression and localization in various brain regions that mediate addiction-favoring plasticity. Ethanol works in conjunction with numerous upstream kinases and second messenger activators to affect cellular PKCε expression. Chauffeur proteins, such as receptors for activated C kinase (RACKs), cause the translocation of PKCε to aberrant sites and mediate ethanol-induced changes. In this article, we aim to review the following: the general structure and function of PKCε, ethanol-induced changes in PKCε expression, the regulation of ethanol-induced PKCε activities in DAG-dependent and DAG-independent environments, the mechanisms underlying PKCε-RACKε translocation in the presence of ethanol, and the existing literature on the role of PKCε in ethanol-induced neurobehavioral changes, with the goal of creating a working model upon which further research can build.

  7. Blood plasma lipidomic signature of epicardial fat in healthy obese women.

    PubMed

    Scherer, Max; Montoliu, Ivan; Qanadli, Salah D; Collino, Sebastiano; Rezzi, Serge; Kussmann, Martin; Giusti, Vittorio; Martin, François-Pierre J

    2015-01-01

    A lipidomic approach was employed in a clinically well-defined cohort of healthy obese women to explore blood lipidome phenotype ascribed to body fat deposition, with emphasis on epicardial adipose tissue (EAT). The present investigation delivered a lipidomics signature of epicardial adiposity under healthy clinical conditions using a cohort of 40 obese females (age: 25-45 years, BMI: 28-40 kg/m(2) ) not showing any metabolic disease traits. Lipidomics analysis of blood plasma was employed in combination with in vivo quantitation of mediastinal fat depots by computerized tomography. All cardiac fat depots correlated to indicators of hepatic dysfunctions (ALAT and ASAT), which describe physiological connections between hepatic and cardiac steatosis. Plasma lipidomics encompassed overall levels of lipid classes, fatty acid profiles, and individual lipid species. EAT and visceral fat associated with diacylglycerols (DAG), triglycerides, and distinct phospholipid and sphingolipid species. A pattern of DAG and phosphoglycerols was specific to EAT. Human blood plasma lipidomics appears to be a promising clinical and potentially diagnostic readout for patient stratification and monitoring. Association of blood lipidomics signature to regio-specific mediastinal and visceral adiposity under healthy clinical conditions may help provide more biological insights into obese patient stratification for cardiovascular disease risks. © 2014 The Obesity Society.

  8. Dynamic Uncertain Causality Graph for Knowledge Representation and Probabilistic Reasoning: Directed Cyclic Graph and Joint Probability Distribution.

    PubMed

    Zhang, Qin

    2015-07-01

    Probabilistic graphical models (PGMs) such as Bayesian network (BN) have been widely applied in uncertain causality representation and probabilistic reasoning. Dynamic uncertain causality graph (DUCG) is a newly presented model of PGMs, which can be applied to fault diagnosis of large and complex industrial systems, disease diagnosis, and so on. The basic methodology of DUCG has been previously presented, in which only the directed acyclic graph (DAG) was addressed. However, the mathematical meaning of DUCG was not discussed. In this paper, the DUCG with directed cyclic graphs (DCGs) is addressed. In contrast, BN does not allow DCGs, as otherwise the conditional independence will not be satisfied. The inference algorithm for the DUCG with DCGs is presented, which not only extends the capabilities of DUCG from DAGs to DCGs but also enables users to decompose a large and complex DUCG into a set of small, simple sub-DUCGs, so that a large and complex knowledge base can be easily constructed, understood, and maintained. The basic mathematical definition of a complete DUCG with or without DCGs is proved to be a joint probability distribution (JPD) over a set of random variables. The incomplete DUCG as a part of a complete DUCG may represent a part of JPD. Examples are provided to illustrate the methodology.

  9. Other factors to consider in the formation of chloropropandiol fatty esters in oil processes.

    PubMed

    Ramli, Muhamad Roddy; Siew, Wai Lin; Ibrahim, Nuzul Amri; Kuntom, Ainie; Abd Razak, Raznim Arni

    2015-01-01

    This paper examines the processing steps of extracting palm oil from fresh fruit bunches in a way that may impact on the formation of chloropropandiol fatty esters (3-MCPD esters), particularly during refining. Diacylglycerols (DAGs) do not appear to be a critical factor when crude palm oils are extracted from various qualities of fruit bunches. Highly hydrolysed oils, in spite of the high free fatty acid (FFA) contents, did not show exceptionally high DAGs, and the oils did not display a higher formation of 3-MCPD esters upon heat treatment. However, acidity measured in terms of pH appears to have a strong impact on 3-MCPD ester formation in the crude oil when heated at high temperatures. The differences in the extraction process of crude palm oil from current commercial processes and that from a modified experimental process showed clearly the effect of acidity of the oil on the formation of 3-MCPD esters. This paper concludes that the washing or dilution step in palm oil mills removes the acidity of the vegetative materials and that a well-optimised dilution/washing step in the extraction process will play an important role in reducing formation of 3-MCPD esters in crude palm oil upon further heat processing.

  10. Ethanol-Induced Changes in PKCε: From Cell to Behavior

    PubMed Central

    Pakri Mohamed, Rashidi M.; Mokhtar, Mohd H.; Yap, Ernie; Hanim, Athirah; Abdul Wahab, Norhazlina; Jaffar, Farah H. F.; Kumar, Jaya

    2018-01-01

    The long-term binge intake of ethanol causes neuroadaptive changes that lead to drinkers requiring higher amounts of ethanol to experience its effects. This neuroadaptation can be partly attributed to the modulation of numerous neurotransmitter receptors by the various protein kinases C (PKCs). PKCs are enzymes that control cellular activities by regulating other proteins via phosphorylation. Among the various isoforms of PKC, PKCε is the most implicated in ethanol-induced biochemical and behavioral changes. Ethanol exposure causes changes to PKCε expression and localization in various brain regions that mediate addiction-favoring plasticity. Ethanol works in conjunction with numerous upstream kinases and second messenger activators to affect cellular PKCε expression. Chauffeur proteins, such as receptors for activated C kinase (RACKs), cause the translocation of PKCε to aberrant sites and mediate ethanol-induced changes. In this article, we aim to review the following: the general structure and function of PKCε, ethanol-induced changes in PKCε expression, the regulation of ethanol-induced PKCε activities in DAG-dependent and DAG-independent environments, the mechanisms underlying PKCε-RACKε translocation in the presence of ethanol, and the existing literature on the role of PKCε in ethanol-induced neurobehavioral changes, with the goal of creating a working model upon which further research can build. PMID:29706864

  11. Evaluation of treadmill exercise effect on muscular lipid profiles of diabetic fatty rats by nanoflow liquid chromatography-tandem mass spectrometry

    NASA Astrophysics Data System (ADS)

    Lee, Jong Cheol; Kim, Il Yong; Son, Yeri; Byeon, Seul Kee; Yoon, Dong Hyun; Son, Jun Seok; Song, Han Sol; Song, Wook; Seong, Je Kyung; Moon, Myeong Hee

    2016-07-01

    We compare comprehensive quantitative profiling of lipids at the molecular level from skeletal muscle tissues (gastrocnemius and soleus) of Zucker diabetic fatty rats and Zucker lean control rats during treadmill exercise by nanoflow liquid chromatography-tandem mass spectrometry. Because type II diabetes is caused by decreased insulin sensitivity due to excess lipids accumulated in skeletal muscle tissue, lipidomic analysis of muscle tissues under treadmill exercise can help unveil the mechanism of lipid-associated insulin resistance. In total, 314 lipid species, including phospholipids, sphingolipids, ceramides, diacylglycerols (DAGs), and triacylglycerols (TAGs), were analyzed to examine diabetes-related lipid species and responses to treadmill exercise. Most lysophospholipid levels increased with diabetes. While DAG levels (10 from the gastrocnemius and 13 from the soleus) were >3-fold higher in diabetic rats, levels of most of these decreased after exercise in soleus but not in gastrocnemius. Levels of 5 highly abundant TAGs (52:1 and 54:3 in the gastrocnemius and 48:2, 50:2, and 52:4 in the soleus) displaying 2-fold increases in diabetic rats decreased after exercise in the soleus but not in the gastrocnemius in most cases. Thus, aerobic exercise has a stronger influence on lipid levels in the soleus than in the gastrocnemius in type 2 diabetic rats.

  12. Yadage and Packtivity - analysis preservation using parametrized workflows

    NASA Astrophysics Data System (ADS)

    Cranmer, Kyle; Heinrich, Lukas

    2017-10-01

    Preserving data analyses produced by the collaborations at LHC in a parametrized fashion is crucial in order to maintain reproducibility and re-usability. We argue for a declarative description in terms of individual processing steps - “packtivities” - linked through a dynamic directed acyclic graph (DAG) and present an initial set of JSON schemas for such a description and an implementation - “yadage” - capable of executing workflows of analysis preserved via Linux containers.

  13. Job Oriented Training: Handleiding Serious Gaming (Job Oriented Training: Handleiding (Handbook) Serious Gaming)

    DTIC Science & Technology

    2008-09-01

    bijvoorbeeld de toekomstige uitzendgebieden in zich heeft. De praktijk gaat hierbij vooraf aan de theorie , de benodigde theoretische kennis wordt niet vooraf...rapportnummer TNO-DV 2008 A340 Opdrachtnummer Datum September 2008 Auteur (s) dr. A.H. van der Hulst ir. T.J. Muller maj C.L. Roos Rubricering rapport...Oriented Training toegepast. Dit betekent in essentie dat de leerlingen vanaf dag een, integrale missies uitvoeren en niet eerst de theorie wordt

  14. How Deep Neural Networks Can Improve Emotion Recognition on Video Data

    DTIC Science & Technology

    2016-09-25

    HOW DEEP NEURAL NETWORKS CAN IMPROVE EMOTION RECOGNITION ON VIDEO DATA Pooya Khorrami1 , Tom Le Paine1, Kevin Brady2, Charlie Dagli2, Thomas S...this work, we present a system that per- forms emotion recognition on video data using both con- volutional neural networks (CNNs) and recurrent...neural net- works (RNNs). We present our findings on videos from the Audio/Visual+Emotion Challenge (AV+EC2015). In our experiments, we analyze the effects

  15. Intracellular postsynaptic cannabinoid receptors link thyrotropin-releasing hormone receptors to TRPC-like channels in thalamic paraventricular nucleus neurons.

    PubMed

    Zhang, L; Kolaj, M; Renaud, L P

    2015-12-17

    In rat thalamic paraventricular nucleus of thalamus (PVT) neurons, activation of thyrotropin-releasing hormone (TRH) receptors enhances excitability via concurrent decrease in G protein-coupled inwardly-rectifying potassium (GIRK)-like and activation of transient receptor potential cation (TRPC)4/5-like cationic conductances. An exploration of intracellular signaling pathways revealed the TRH-induced current to be insensitive to phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitors, but reduced by D609, an inhibitor of phosphatidylcholine-specific PLC (PC-PLC). A corresponding change in the I-V relationship implied suppression of the cationic component of the TRH-induced current. Diacylglycerol (DAG) is a product of the hydrolysis of PC. Studies focused on the isolated cationic component of the TRH-induced response revealed a reduction by RHC80267, an inhibitor of DAG lipase, the enzyme involved in the hydrolysis of DAG to the endocannabinoid 2-arachidonoylglycerol (2-AG). Further investigation revealed enhancement of the cationic component in the presence of either JZL184 or WWL70, inhibitors of enzymes involved in the hydrolysis of 2-AG. A decrease in the TRH-induced response was noted in the presence of rimonabant or SR144528, membrane permeable CB1 and CB2 receptor antagonists, respectively. A decrease in the TRH-induced current by intracellular, but not by bath application of the membrane impermeable peptide hemopressin, selective for CB1 receptors, suggests a postsynaptic intracellular localization of these receptors. The TRH-induced current was increased in the presence of arachidonyl-2'-chloroethylamide (ACEA) or JWH133, CB1 and CB2 receptor agonists, respectively. The PI3-kinase inhibitor LY294002, known to inhibit TRPC translocation, decreased the response to TRH. In addition, a TRH-induced enhancement of the low-threshold spike was prevented by both rimonabant, and SR144528. TRH had no influence on excitatory or inhibitory miniature

  16. s-Ordered Exponential of Quadratic Forms Gained via IWSOP Technique

    NASA Astrophysics Data System (ADS)

    Bazrafkan, M. R.; Shähandeh, F.; Nahvifard, E.

    2012-11-01

    Using the generalized bar{s}-ordered Wigner operator, in which bar{s} is a vector over the field of complex numbers, the technique of integration within an s-ordered product of operators (IWSOP) has been extended to multimode case. We derive the bar{s}-ordered form of the widely applicable multimode exponential of quadratic form exp\\{sum_{i,j = 1}n ai^{dag}\\varLambda_{ij}{aj}\\} , each mode being in some particular order s i , applying this method.

  17. Preventive Detention in the War on Terror: A Plan for a More Moderate and Sustainable Solution

    DTIC Science & Technology

    2008-12-01

    speeches /2004/dag6104.htm (accessed November 10, 2007). 25 Ron Suskind, The One Percent Doctrine (New York: Simon and Schuster, 2006), 95-100. 26 The 9...suspected terrorists for purposes of interrogation and/or incapacitation but also for ultimately trying them for various war crimes or violations of...conflict should be thought of as a “war” as opposed to “ crime .” This chapter serves to better define the problems with the enemy-combatant policy and

  18. The Post-Cold War Force-Sizing Debate: Paradigms, Metaphors, and Disconnects

    DTIC Science & Technology

    1992-01-01

    Lynn D . Pullen, John Y. Schrader, and Michael D . Swaine, A New Strategy and Fewer Forces: The Pacifu: Dimension. RAND, R -4089/2- USDP, 1992. 80...and Forces, Vol. II. RAND, N-3098/2-DAG, October 1990. Wohlstetter, Roberta, Pearl Harbor: Warning and Decision. Stan- ford: Stanford University Press, 1962. RAN D / R -4243-JS ...The Post-Cold War Force-Sizing Debate Paradigms, Metaphors, and Disconnects James A. Winnefeld RAN D I NATIONAL DEFENSE RESEARCH INSTITUTE

  19. A causal framework for understanding the effect of losses to follow-up on epidemiologic analyses in clinic-based cohorts: the case of HIV-infected patients on antiretroviral therapy in Africa.

    PubMed

    Geng, Elvin H; Glidden, David V; Bangsberg, David R; Bwana, Mwebesa Bosco; Musinguzi, Nicholas; Nash, Denis; Metcalfe, John Z; Yiannoutsos, Constantin T; Martin, Jeffrey N; Petersen, Maya L

    2012-05-15

    Although clinic-based cohorts are most representative of the "real world," they are susceptible to loss to follow-up. Strategies for managing the impact of loss to follow-up are therefore needed to maximize the value of studies conducted in these cohorts. The authors evaluated adult patients starting antiretroviral therapy at an HIV/AIDS clinic in Uganda, where 29% of patients were lost to follow-up after 2 years (January 1, 2004-September 30, 2007). Unweighted, inverse probability of censoring weighted (IPCW), and sampling-based approaches (using supplemental data from a sample of lost patients subsequently tracked in the community) were used to identify the predictive value of sex on mortality. Directed acyclic graphs (DAGs) were used to explore the structural basis for bias in each approach. Among 3,628 patients, unweighted and IPCW analyses found men to have higher mortality than women, whereas the sampling-based approach did not. DAGs encoding knowledge about the data-generating process, including the fact that death is a cause of being classified as lost to follow-up in this setting, revealed "collider" bias in the unweighted and IPCW approaches. In a clinic-based cohort in Africa, unweighted and IPCW approaches-which rely on the "missing at random" assumption-yielded biased estimates. A sampling-based approach can in general strengthen epidemiologic analyses conducted in many clinic-based cohorts, including those examining other diseases.

  20. Activation of Phospholipase C Increases Intramembrane Electric Fields in N1E-115 Neuroblastoma Cells

    PubMed Central

    Xu, Chang; Loew, Leslie M.

    2003-01-01

    We imaged the intramembrane potential (a combination of transmembrane, surface, and dipole potential) on N1E-115 neuroblastoma cells with a voltage-sensitive dye. After activation of the B2 bradykinin receptor, the electric field sensed by the dye increased by an amount equivalent to a depolarization of 83 mV. The increase in intramembrane potential was blocked by the phospholipase C (PLC) inhibitors U-73122 and neomycin, and was invariably accompanied by a transient rise of [Ca2+]i. A depolarized inner surface potential, as the membrane loses negative charges via phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis, and an increase in the dipole potential, as PIP2 is hydrolyzed to 1,2-diacylglycerol (DAG), can each account for a small portion of the change in intramembrane potential. The primary contribution to the measured change in intramembrane potential may arise from an increased dipole potential, as DAG molecules are generated from hydrolysis of other phospholipids. We found bradykinin produced an inhibition of a M-type voltage-dependent K+ current (IK(M)). This inhibition was also blocked by the PLC inhibitors and had similar kinetics as the bradykinin-induced modulation of intramembrane potential. Our results suggest that the change in the local intramembrane potential induced by bradykinin may play a role in mediating the IK(M) inhibition. PMID:12770917

  1. Bruton's Tyrosine Kinase (BTK) and Vav1 Contribute to Dectin1-Dependent Phagocytosis of Candida albicans in Macrophages

    PubMed Central

    Strijbis, Karin; Tafesse, Fikadu G.; Fairn, Gregory D.; Witte, Martin D.; Dougan, Stephanie K.; Watson, Nicki; Spooner, Eric; Esteban, Alexandre; Vyas, Valmik K.; Fink, Gerald R.; Grinstein, Sergio; Ploegh, Hidde L.

    2013-01-01

    Phagocytosis of the opportunistic fungal pathogen Candida albicans by cells of the innate immune system is vital to prevent infection. Dectin-1 is the major phagocytic receptor involved in anti-fungal immunity. We identify two new interacting proteins of Dectin-1 in macrophages, Bruton's Tyrosine Kinase (BTK) and Vav1. BTK and Vav1 are recruited to phagocytic cups containing C. albicans yeasts or hyphae but are absent from mature phagosomes. BTK and Vav1 localize to cuff regions surrounding the hyphae, while Dectin-1 lines the full length of the phagosome. BTK and Vav1 colocalize with the lipid PI(3,4,5)P3 and F-actin at the phagocytic cup, but not with diacylglycerol (DAG) which marks more mature phagosomal membranes. Using a selective BTK inhibitor, we show that BTK contributes to DAG synthesis at the phagocytic cup and the subsequent recruitment of PKCε. BTK- or Vav1-deficient peritoneal macrophages display a defect in both zymosan and C. albicans phagocytosis. Bone marrow-derived macrophages that lack BTK or Vav1 show reduced uptake of C. albicans, comparable to Dectin1-deficient cells. BTK- or Vav1-deficient mice are more susceptible to systemic C. albicans infection than wild type mice. This work identifies an important role for BTK and Vav1 in immune responses against C. albicans. PMID:23825946

  2. Bruton's Tyrosine Kinase (BTK) and Vav1 contribute to Dectin1-dependent phagocytosis of Candida albicans in macrophages.

    PubMed

    Strijbis, Karin; Tafesse, Fikadu G; Fairn, Gregory D; Witte, Martin D; Dougan, Stephanie K; Watson, Nicki; Spooner, Eric; Esteban, Alexandre; Vyas, Valmik K; Fink, Gerald R; Grinstein, Sergio; Ploegh, Hidde L

    2013-01-01

    Phagocytosis of the opportunistic fungal pathogen Candida albicans by cells of the innate immune system is vital to prevent infection. Dectin-1 is the major phagocytic receptor involved in anti-fungal immunity. We identify two new interacting proteins of Dectin-1 in macrophages, Bruton's Tyrosine Kinase (BTK) and Vav1. BTK and Vav1 are recruited to phagocytic cups containing C. albicans yeasts or hyphae but are absent from mature phagosomes. BTK and Vav1 localize to cuff regions surrounding the hyphae, while Dectin-1 lines the full length of the phagosome. BTK and Vav1 colocalize with the lipid PI(3,4,5)P3 and F-actin at the phagocytic cup, but not with diacylglycerol (DAG) which marks more mature phagosomal membranes. Using a selective BTK inhibitor, we show that BTK contributes to DAG synthesis at the phagocytic cup and the subsequent recruitment of PKCε. BTK- or Vav1-deficient peritoneal macrophages display a defect in both zymosan and C. albicans phagocytosis. Bone marrow-derived macrophages that lack BTK or Vav1 show reduced uptake of C. albicans, comparable to Dectin1-deficient cells. BTK- or Vav1-deficient mice are more susceptible to systemic C. albicans infection than wild type mice. This work identifies an important role for BTK and Vav1 in immune responses against C. albicans.

  3. RasGRP3 regulates the migration of glioma cells via interaction with Arp3

    PubMed Central

    Lee, Hae Kyung; Finniss, Susan; Cazacu, Simona; Xiang, Cunli; Poisson, Laila M.; Blumberg, Peter M.; Brodie, Chaya

    2015-01-01

    Glioblastoma (GBM), the most aggressive primary brain tumors, are highly infiltrative. Although GBM express high Ras activity and Ras proteins have been implicated in gliomagenesis, Ras-activating mutations are not frequent in these tumors. RasGRP3, an important signaling protein responsive to diacylglycerol (DAG), increases Ras activation. Here, we examined the expression and functions of RasGRP3 in GBM and glioma cells. RasGRP3 expression was upregulated in GBM specimens and glioma stem cells compared with normal brains and neural stem cells, respectively. RasGRP3 activated Ras and Rap1 in glioma cells and increased cell migration and invasion partially via Ras activation. Using pull-down assay and mass spectroscopy we identified the actin-related protein, Arp3, as a novel interacting protein of RasGRP3. The interaction of RasGRP3 and Arp3 was validated by immunofluorescence staining and co-immunoprecipitation, and PMA, which activates RasGRP3 and induces its translocation to the peri-nuclear region, increased the association of Arp3 and RasGRP3. Arp3 was upregulated in GBM, regulated cell spreading and migration and its silencing partially decreased these effects of RasGRP3 in glioma cells. In summary, RasGRP3 acts as an important integrating signaling protein of the DAG and Ras signaling pathways and actin polymerization and represents an important therapeutic target in GBM. PMID:25682201

  4. Embryonic stem cells in scaffold-free three-dimensional cell culture: osteogenic differentiation and bone generation.

    PubMed

    Handschel, Jörg; Naujoks, Christian; Depprich, Rita; Lammers, Lydia; Kübler, Norbert; Meyer, Ulrich; Wiesmann, Hans-Peter

    2011-07-14

    Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells (ESCs) in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone, ascorbic acid, and ß-glycerolphosphate (DAG). After three days of cultivation microspheres were formed. These spherical three-dimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin. © 2011 Handschel et al; licensee BioMed Central Ltd.

  5. Neutral sphingomyelinase (SMPD3) deficiency disrupts the Golgi secretory pathway and causes growth inhibition

    PubMed Central

    Stoffel, Wilhelm; Hammels, Ina; Jenke, Bitta; Binczek, Erika; Schmidt-Soltau, Inga; Brodesser, Susanne; Schauss, Astrid; Etich, Julia; Heilig, Juliane; Zaucke, Frank

    2016-01-01

    Systemic loss of neutral sphingomyelinase (SMPD3) in mice leads to a novel form of systemic, juvenile hypoplasia (dwarfism). SMPD3 deficiency in mainly two growth regulating cell types contributes to the phenotype, in chondrocytes of skeletal growth zones to skeletal malformation and chondrodysplasia, and in hypothalamic neurosecretory neurons to systemic hypothalamus–pituitary–somatotropic hypoplasia. The unbiased smpd3−/− mouse mutant and derived smpd3−/− primary chondrocytes were instrumental in defining the enigmatic role underlying the systemic and cell autonomous role of SMPD3 in the Golgi compartment. Here we describe the unprecedented role of SMPD3. SMPD3 deficiency disrupts homeostasis of sphingomyelin (SM), ceramide (Cer) and diacylglycerol (DAG) in the Golgi SMPD3-SMS1 (SM-synthase1) cycle. Cer and DAG, two fusogenic intermediates, modify the membrane lipid bilayer for the initiation of vesicle formation and transport. Dysproteostasis, unfolded protein response, endoplasmic reticulum stress and apoptosis perturb the Golgi secretory pathway in the smpd3−/− mouse. Secretion of extracellular matrix proteins is arrested in chondrocytes and causes skeletal malformation and chondrodysplasia. Similarly, retarded secretion of proteo-hormones in hypothalamic neurosecretory neurons leads to hypothalamus induced combined pituitary hormone deficiency. SMPD3 in the regulation of the protein vesicular secretory pathway may become a diagnostic target in the etiology of unknown forms of juvenile growth and developmental inhibition. PMID:27882938

  6. Methods for the Quality Control of Inactivated Poliovirus Vaccines.

    PubMed

    Wilton, Thomas

    2016-01-01

    Inactivated poliovirus vaccine (IPV) plays an instrumental role in the Global Poliovirus Eradication Initiative (GPEI). The quality of IPV is controlled by assessment of the potency of vaccine batches. The potency of IPV can be assessed by both in vivo and in vitro methods. In vitro potency assessment is based upon the assessment of the quantity of the D-Antigen (D-Ag) units in an IPV. The D-Ag unit is used as a measure of potency as it is largely expressed on native infectious virions and is the protective immunogen. The most commonly used in vitro test is the indirect ELISA which is used to ensure consistency throughout production.A range of in vivo assays have been developed in monkeys, chicks, guinea pigs, mice, and rats to assess the potency of IPV. All are based on assessment of the neutralizing antibody titer within the sera of the respective animal model. The rat potency test has become the favored in vivo potency test as it shows minimal variation between laboratories and the antibody patterns of rats and humans are similar. With the development of transgenic mice expressing the human poliovirus receptor, immunization-challenge tests have been developed to assess the potency of IPVs. This chapter describes in detail the methodology of these three laboratory tests to assess the quality of IPVs.

  7. Neutral sphingomyelinase (SMPD3) deficiency disrupts the Golgi secretory pathway and causes growth inhibition.

    PubMed

    Stoffel, Wilhelm; Hammels, Ina; Jenke, Bitta; Binczek, Erika; Schmidt-Soltau, Inga; Brodesser, Susanne; Schauss, Astrid; Etich, Julia; Heilig, Juliane; Zaucke, Frank

    2016-11-24

    Systemic loss of neutral sphingomyelinase (SMPD3) in mice leads to a novel form of systemic, juvenile hypoplasia (dwarfism). SMPD3 deficiency in mainly two growth regulating cell types contributes to the phenotype, in chondrocytes of skeletal growth zones to skeletal malformation and chondrodysplasia, and in hypothalamic neurosecretory neurons to systemic hypothalamus-pituitary-somatotropic hypoplasia. The unbiased smpd3-/- mouse mutant and derived smpd3-/- primary chondrocytes were instrumental in defining the enigmatic role underlying the systemic and cell autonomous role of SMPD3 in the Golgi compartment. Here we describe the unprecedented role of SMPD3. SMPD3 deficiency disrupts homeostasis of sphingomyelin (SM), ceramide (Cer) and diacylglycerol (DAG) in the Golgi SMPD3-SMS1 (SM-synthase1) cycle. Cer and DAG, two fusogenic intermediates, modify the membrane lipid bilayer for the initiation of vesicle formation and transport. Dysproteostasis, unfolded protein response, endoplasmic reticulum stress and apoptosis perturb the Golgi secretory pathway in the smpd3-/- mouse. Secretion of extracellular matrix proteins is arrested in chondrocytes and causes skeletal malformation and chondrodysplasia. Similarly, retarded secretion of proteo-hormones in hypothalamic neurosecretory neurons leads to hypothalamus induced combined pituitary hormone deficiency. SMPD3 in the regulation of the protein vesicular secretory pathway may become a diagnostic target in the etiology of unknown forms of juvenile growth and developmental inhibition.

  8. QDR Analysis: Lessons Learned and Future Directions Mini- Symposium

    DTIC Science & Technology

    1999-07-02

    Bob Sheldon, Mr. Ted Smyth, COL BJ. Thornburg, LTC Mark Youngren, Mr. Clayton Thomas , FS and Dr. Jerry Kotchka. 23 OVERVIEW * Working Group Insights...DAG, "Air Force QDR Analysis" "* CAPT T. J. Gregory, The Joint Staff, J8, "The Baseline Engagement Force Study" Working Group 6, Littoral Warfare...FAX: (703)-751-8171 Email: None Email: morsvpa@aol.com COL Thomas L. Allen MAJ Steven M Aviles AFSAA/CC US Army Concepts Analysis Agency 1570 Air

  9. Regulation of 2-5A Dependent RNase at the Level of its Phosphorylation

    DTIC Science & Technology

    1991-06-26

    extract as follows: 25 ul wheat germ extract 10 ul H2O 1 ul RNasin ribonuclease inhibitor (40 u/ml) 7 ul ImM amino acid mixture 1 ul IM...diacylglycerol (DAG) 2. TPA 3. Indolactam Figure 6. Chemical structure of: 1. H-7 (A kinase inhibitor) 2. okadaic acid (A phosphatase inhibitor) Figure 7...elevating agents: Forskolin and Cholera toxin Figure 17. Down-regulation of 2-5A-depRNase by Okadaic 77 acid : A phosphatase inhibitor Figure 18

  10. Massive Ca-induced Membrane Fusion and Phospholipid Changes Triggered by Reverse Na/Ca Exchange in BHK Fibroblasts

    PubMed Central

    Yaradanakul, Alp; Wang, Tzu-Ming; Lariccia, Vincenzo; Lin, Mei-Jung; Shen, Chengcheng; Liu, Xinran; Hilgemann, Donald W.

    2008-01-01

    Baby hamster kidney (BHK) fibroblasts increase their cell capacitance by 25–100% within 5 s upon activating maximal Ca influx via constitutively expressed cardiac Na/Ca exchangers (NCX1). Free Ca, measured with fluo-5N, transiently exceeds 0.2 mM with total Ca influx amounting to ∼5 mmol/liter cell volume. Capacitance responses are half-maximal when NCX1 promotes a free cytoplasmic Ca of 0.12 mM (Hill coefficient ≈ 2). Capacitance can return to baseline in 1–3 min, and responses can be repeated several times. The membrane tracer, FM 4-64, is taken up during recovery and can be released at a subsequent Ca influx episode. Given recent interest in signaling lipids in membrane fusion, we used green fluorescent protein (GFP) fusions with phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and diacylglycerol (DAG) binding domains to analyze phospholipid changes in relation to these responses. PI(4,5)P2 is rapidly cleaved upon activating Ca influx and recovers within 2 min. However, PI(4,5)P2 depletion by activation of overexpressed hM1 muscarinic receptors causes only little membrane fusion, and subsequent fusion in response to Ca influx remains massive. Two results suggest that DAG may be generated from sources other than PI(4,5)P in these protocols. First, acylglycerols are generated in response to elevated Ca, even when PI(4,5)P2 is metabolically depleted. Second, DAG-binding C1A-GFP domains, which are brought to the cell surface by exogenous ligands, translocate rapidly back to the cytoplasm in response to Ca influx. Nevertheless, inhibitors of PLCs and cPLA2, PI(4,5)P2-binding peptides, and PLD modification by butanol do not block membrane fusion. The cationic agents, FM 4-64 and heptalysine, bind profusely to the extracellular cell surface during membrane fusion. While this binding might reflect phosphatidylserine (PS) “scrambling” between monolayers, it is unaffected by a PS-binding protein, lactadherin, and by polylysine from the cytoplasmic side

  11. Formation of Glycidyl Fatty Acid Esters Both in Real Edible Oils during Laboratory-Scale Refining and in Chemical Model during High Temperature Exposure.

    PubMed

    Cheng, Weiwei; Liu, Guoqin; Liu, Xinqi

    2016-07-27

    In the present study, the formation mechanisms of glycidyl fatty acid esters (GEs) were investigated both in real edible oils (soybean oil, camellia oil, and palm oil) during laboratory-scale preparation and refining and in chemical model (1,2-dipalmitin (DPG) and 1-monopalmitin (MPG)) during high temperature exposure (160-260 °C under nitrogen). The formation process of GEs in the chemical model was monitored using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The results showed that the roasting and pressing process could produce certain amounts of GEs that were much lower than that produced in the deodorization process. GE contents in edible oils increased continuously and significantly with increasing deodorization time below 200 °C. However, when the temperature exceeded 200 °C, GE contents sharply increased in 1-2 h followed by a gradual decrease, which could verify a simultaneous formation and degradation of GEs at high temperature. In addition, it was also found that the presence of acylglycerol (DAGs and MAGs) could significantly increase the formation yield of GEs both in real edible oils and in chemical model. Compared with DAGs, moreover, MAGs displayed a higher formation capacity but substantially lower contribution to GE formation due to their low contents in edible oils. In situ ATR-FTIR spectroscopic evidence showed that cyclic acyloxonium ion intermediate was formed during GE formation derived from DPG and MPG in chemical model heated at 200 °C.

  12. Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand Alters Mitochondrial Membrane Lipids

    PubMed Central

    Sandra, Ferry; Esposti, Mauro Degli; Ndebele, Kenneth; Gona, Philimon; Knight, David; Rosenquist, Magnus; Khosravi-Far, Roya

    2010-01-01

    Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) has been shown to have selective antitumor activity. TRAIL induces ubiquitous pathways of cell death in which caspase activation is mediated either directly or via the release of apoptogenic factors from mitochondria; however, the precise components of the mitochondrial signaling pathway have not been well defined. Notably, mitochondria constitute an important target in overcoming resistance to TRAIL in many types of tumors. Bid is considered to be fundamental in engaging mitochondria during death receptor–mediated apoptosis, but this action is dependent on mitochondrial lipids. Here, we report that TRAIL signaling induces an alteration in mitochondrial membrane lipids, particularly cardiolipin. This occurs independently of caspase activation and primes mitochondrial membranes to the proapoptotic action of Bid. We unveil a link between TRAIL signaling and alteration of membrane lipid homeostasis that occurs in parallel to apical caspase activation but does not take over the mode of cell death because of the concurrent activation of caspase-8. In particular, TRAIL-induced alteration of mitochondrial lipids follows an imbalance in the cellular homeostasis of phosphatidylcholine, which results in an elevation in diacylglycerol (DAG). Elevated DAG in turn activates the δ isoform of phospholipid-dependent serine/threonine protein kinase C, which then accelerates the cleavage of caspase-8. We also show that preservation of phosphatidylcholine homeostasis by inhibition of lipid-degrading enzymes almost completely impedes the activation of pro-caspase-9 while scarcely changing the activation of caspase-8. PMID:16166305

  13. A Parallel Fast Sweeping Method for the Eikonal Equation

    NASA Astrophysics Data System (ADS)

    Baker, B.

    2017-12-01

    Recently, there has been an exciting emergence of probabilistic methods for travel time tomography. Unlike gradient-based optimization strategies, probabilistic tomographic methods are resistant to becoming trapped in a local minimum and provide a much better quantification of parameter resolution than, say, appealing to ray density or performing checkerboard reconstruction tests. The benefits associated with random sampling methods however are only realized by successive computation of predicted travel times in, potentially, strongly heterogeneous media. To this end this abstract is concerned with expediting the solution of the Eikonal equation. While many Eikonal solvers use a fast marching method, the proposed solver will use the iterative fast sweeping method because the eight fixed sweep orderings in each iteration are natural targets for parallelization. To reduce the number of iterations and grid points required the high-accuracy finite difference stencil of Nobel et al., 2014 is implemented. A directed acyclic graph (DAG) is created with a priori knowledge of the sweep ordering and finite different stencil. By performing a topological sort of the DAG sets of independent nodes are identified as candidates for concurrent updating. Additionally, the proposed solver will also address scalability during earthquake relocation, a necessary step in local and regional earthquake tomography and a barrier to extending probabilistic methods from active source to passive source applications, by introducing an asynchronous parallel forward solve phase for all receivers in the network. Synthetic examples using the SEG over-thrust model will be presented.

  14. Acid sphingomyelinase activity is regulated by membrane lipids and facilitates cholesterol transfer by NPC2[S

    PubMed Central

    Oninla, Vincent O.; Breiden, Bernadette; Babalola, Jonathan O.; Sandhoff, Konrad

    2014-01-01

    During endocytosis, membrane components move to intraluminal vesicles of the endolysosomal compartment for digestion. At the late endosomes, cholesterol is sorted out mainly by two sterol-binding proteins, Niemann-Pick protein type C (NPC)1 and NPC2. To study the NPC2-mediated intervesicular cholesterol transfer, we developed a liposomal assay system. (Abdul-Hammed, M., B. Breiden, M. A. Adebayo, J. O. Babalola, G. Schwarzmann, and K. Sandhoff. 2010. Role of endosomal membrane lipids and NPC2 in cholesterol transfer and membrane fusion. J. Lipid Res. 51: 1747–1760.) Anionic lipids stimulate cholesterol transfer between liposomes while SM inhibits it, even in the presence of anionic bis(monoacylglycero)phosphate (BMP). Preincubation of vesicles containing SM with acid sphingomyelinase (ASM) (SM phosphodiesterase, EC 3.1.4.12) results in hydrolysis of SM to ceramide (Cer), which enhances cholesterol transfer. Besides SM, ASM also cleaves liposomal phosphatidylcholine. Anionic phospholipids derived from the plasma membrane (phosphatidylglycerol and phosphatidic acid) stimulate SM and phosphatidylcholine hydrolysis by ASM more effectively than BMP, which is generated during endocytosis. ASM-mediated hydrolysis of liposomal SM was also stimulated by incorporation of diacylglycerol (DAG), Cer, and free fatty acids into the liposomal membranes. Conversely, phosphatidylcholine hydrolysis was inhibited by incorporation of cholesterol, Cer, DAG, monoacylglycerol, and fatty acids. Our data suggest that SM degradation by ASM is required for physiological secretion of cholesterol from the late endosomal compartment, and is a key regulator of endolysosomal lipid digestion. PMID:25339683

  15. Handling Trajectory Uncertainties for Airborne Conflict Management

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Doble, Nathan A.; Karr, David; Palmer, Michael T.

    2005-01-01

    Airborne conflict management is an enabling capability for NASA's Distributed Air-Ground Traffic Management (DAG-TM) concept. DAGTM has the goal of significantly increasing capacity within the National Airspace System, while maintaining or improving safety. Under DAG-TM, autonomous aircraft maintain separation from each other and from managed aircraft unequipped for autonomous flight. NASA Langley Research Center has developed the Autonomous Operations Planner (AOP), an onboard decision support system that provides airborne conflict management (ACM) and strategic flight planning support for autonomous aircraft pilots. The AOP performs conflict detection, prevention, and resolution from nearby traffic aircraft and area hazards. Traffic trajectory information is assumed to be provided by Automatic Dependent Surveillance Broadcast (ADS-B). Reliable trajectory prediction is a key capability for providing effective ACM functions. Trajectory uncertainties due to environmental effects, differences in aircraft systems and performance, and unknown intent information lead to prediction errors that can adversely affect AOP performance. To accommodate these uncertainties, the AOP has been enhanced to create cross-track, vertical, and along-track buffers along the predicted trajectories of both ownship and traffic aircraft. These buffers will be structured based on prediction errors noted from previous simulations such as a recent Joint Experiment between NASA Ames and Langley Research Centers and from other outside studies. Currently defined ADS-B parameters related to navigation capability, trajectory type, and path conformance will be used to support the algorithms that generate the buffers.

  16. Chang'E-3 data pre-processing system based on scientific workflow

    NASA Astrophysics Data System (ADS)

    tan, xu; liu, jianjun; wang, yuanyuan; yan, wei; zhang, xiaoxia; li, chunlai

    2016-04-01

    The Chang'E-3(CE3) mission have obtained a huge amount of lunar scientific data. Data pre-processing is an important segment of CE3 ground research and application system. With a dramatic increase in the demand of data research and application, Chang'E-3 data pre-processing system(CEDPS) based on scientific workflow is proposed for the purpose of making scientists more flexible and productive by automating data-driven. The system should allow the planning, conduct and control of the data processing procedure with the following possibilities: • describe a data processing task, include:1)define input data/output data, 2)define the data relationship, 3)define the sequence of tasks,4)define the communication between tasks,5)define mathematical formula, 6)define the relationship between task and data. • automatic processing of tasks. Accordingly, Describing a task is the key point whether the system is flexible. We design a workflow designer which is a visual environment for capturing processes as workflows, the three-level model for the workflow designer is discussed:1) The data relationship is established through product tree.2)The process model is constructed based on directed acyclic graph(DAG). Especially, a set of process workflow constructs, including Sequence, Loop, Merge, Fork are compositional one with another.3)To reduce the modeling complexity of the mathematical formulas using DAG, semantic modeling based on MathML is approached. On top of that, we will present how processed the CE3 data with CEDPS.

  17. TLR4 activation of TRPC6-dependent calcium signaling mediates endotoxin-induced lung vascular permeability and inflammation

    PubMed Central

    Tauseef, Mohammad; Knezevic, Nebojsa; Chava, Koteswara R.; Smith, Monica; Sukriti, Sukriti; Gianaris, Nicholas; Obukhov, Alexander G.; Vogel, Stephen M.; Schraufnagel, Dean E.; Dietrich, Alexander; Birnbaumer, Lutz; Malik, Asrar B.

    2012-01-01

    Lung vascular endothelial barrier disruption and the accompanying inflammation are primary pathogenic features of acute lung injury (ALI); however, the basis for the development of both remains unclear. Studies have shown that activation of transient receptor potential canonical (TRPC) channels induces Ca2+ entry, which is essential for increased endothelial permeability. Here, we addressed the role of Toll-like receptor 4 (TLR4) intersection with TRPC6-dependent Ca2+ signaling in endothelial cells (ECs) in mediating lung vascular leakage and inflammation. We find that the endotoxin (lipopolysaccharide; LPS) induces Ca2+ entry in ECs in a TLR4-dependent manner. Moreover, deletion of TRPC6 renders mice resistant to endotoxin-induced barrier dysfunction and inflammation, and protects against sepsis-induced lethality. TRPC6 induces Ca2+ entry in ECs, which is secondary to the generation of diacylglycerol (DAG) induced by LPS. Ca2+ entry mediated by TRPC6, in turn, activates the nonmuscle myosin light chain kinase (MYLK), which not only increases lung vascular permeability but also serves as a scaffold to promote the interaction of myeloid differentiation factor 88 and IL-1R–associated kinase 4, which are required for NF-κB activation and lung inflammation. Our findings suggest that TRPC6-dependent Ca2+ entry into ECs, secondary to TLR4-induced DAG generation, participates in mediating both lung vascular barrier disruption and inflammation induced by endotoxin. PMID:23045603

  18. Automatic Rotational Sky Quality Meter (R-SQM) Design and Software for Astronomical Observatories

    NASA Astrophysics Data System (ADS)

    Dogan, E.; Ozbaldan, E. E.; Shameoni, Niaei M.; Yesilyaprak, C.

    2016-12-01

    We have presented the new design of Sky Quality Meter (SQM) device that is an automatic rotational model of sky quality meter (R-SQM) carried out by DAG (Eastern Anatolia Observatory) Technical Team. R-SQM is required for determining the long-term changes of sky quality of an astronomical observatory and consists of four SQM devices mounted on a rotating shaft with different angles for scanning all sky. This system is controlled by a Raspberry Pi control card and a step motor with its driver and a special software.

  19. Glycerol-3-Phosphate Acyltransferase 1 Deficiency in ob/ob Mice Diminishes Hepatic Steatosis but Does Not Protect Against Insulin Resistance or Obesity

    PubMed Central

    Wendel, Angela A.; Li, Lei O.; Li, Yue; Cline, Gary W.; Shulman, Gerald I.; Coleman, Rosalind A.

    2010-01-01

    OBJECTIVE Hepatic steatosis is strongly associated with insulin resistance, but a causal role has not been established. In ob/ob mice, sterol regulatory element binding protein 1 (SREBP1) mediates the induction of steatosis by upregulating target genes, including glycerol-3-phosphate acyltransferase-1 (Gpat1), which catalyzes the first and committed step in the pathway of glycerolipid synthesis. We asked whether ob/ob mice lacking Gpat1 would have reduced hepatic steatosis and improved insulin sensitivity. RESEARCH DESIGN AND METHODS Hepatic lipids, insulin sensitivity, and hepatic insulin signaling were compared in lean (Lep+/?), lean-Gpat1−/−, ob/ob (Lepob/ob), and ob/ob-Gpat1−/− mice. RESULTS Compared with ob/ob mice, the lack of Gpat1 in ob/ob mice reduced hepatic triacylglycerol (TAG) and diacylglycerol (DAG) content 59 and 74%, respectively, but increased acyl-CoA levels. Despite the reduction in hepatic lipids, fasting glucose and insulin concentrations did not improve, and insulin tolerance remained impaired. In both ob/ob and ob/ob-Gpat1−/− mice, insulin resistance was accompanied by elevated hepatic protein kinase C-ε activation and blunted insulin-stimulated Akt activation. CONCLUSIONS These results suggest that decreasing hepatic steatosis alone does not improve insulin resistance, and that factors other than increased hepatic DAG and TAG contribute to hepatic insulin resistance in this genetically obese model. They also show that the SREBP1-mediated induction of hepatic steatosis in ob/ob mice requires Gpat1. PMID:20200319

  20. Regulation of Drosophila transient receptor potential-like (TrpL) channels by phospholipase C-dependent mechanisms.

    PubMed

    Estacion, M; Sinkins, W G; Schilling, W P

    2001-01-01

    Patch clamp and fura-2 fluorescence were employed to characterize receptor-mediated activation of recombinant Drosophila TrpL channels expressed in Sf9 insect cells. TrpL was activated by receptor stimulation and by exogenous application of diacylglycerol (DAG) or poly-unsaturated fatty acids (PUFAs). Activation of TrpL was blocked more than 70% by U73122, suggesting that the effect of these agents was dependent upon phospholipase C (PLC). In fura-2 assays, extracellular application of bacterial phosphatidylinositol (PI)-PLC or phosphatidylcholine (PC)-PLC caused a transient increase in TrpL channel activity, the magnitude of which was significantly less than that observed following receptor stimulation. TrpL channels were also activated in excised inside-out patches by cytoplasmic application of mammalian PLC-b2, bacterial PI-PLC and PC-PLC, but not by phospholipase D (PLD). The phospholipases had little or no effect when examined in either whole-cell or cell-attached configurations.TrpL activity was inhibited by addition of phosphatidylinositol-4,5-bisphosphate (PIP2) to excised inside-out membrane patches exhibiting spontaneous channel activity or to patches pre-activated by treatment with PLC. The effect was reversible, specific for PIP2, and was not observed with phosphatidylethanolamine (PE), PI, PC or phosphatidylserine (PS). However, antibodies against PIP2 consistently failed to activate TrpL in inside-out patches. It is concluded that both the hydrolysis of PIP2 and the generation of DAG are required to rapidly activate TrpL following receptor stimulation, or that some other PLC-dependent mechanism plays a crucial role in the activation process.

  1. Increased bioactive lipids content in human subcutaneous and epicardial fat tissue correlates with insulin resistance.

    PubMed

    Błachnio-Zabielska, Agnieszka U; Baranowski, Marcin; Hirnle, Tomasz; Zabielski, Piotr; Lewczuk, Anna; Dmitruk, Iwona; Górski, Jan

    2012-12-01

    Obesity is a risk factor for metabolic diseases. Intramuscular lipid accumulation of ceramides, diacylglycerols, and long chain acyl-CoA is responsible for the induction of insulin resistance. These lipids are probably implicated in obesity-associated insulin resistance not only in skeletal muscle but also in fat tissue. Only few data are available about ceramide content in human subcutaneous adipose tissue. However, there are no data on DAG and LCACoA content in adipose tissue. The aim of our study was to measure the lipids content in human SAT and epicardial adipose tissue we sought to determine the bioactive lipids content by LC/MS/MS in fat tissue from lean non-diabetic, obese non-diabetic, and obese diabetic subjects and test whether the lipids correlate with HOMA-IR. We found, that total content of measured lipids was markedly higher in OND and OD subjects in both types of fat tissue (for all p < 0.001) as compared to LND group. In SAT we found positive correlation between HOMA-IR and C16:0-Cer (r = 0.79, p < 0.001) and between HOMA-IR and C16:0/18:2 DAG (r = 0.56, p < 0.001). In EAT we found a strong correlation between C16:0-CoA content and HOMA-IR (r = 0.73, p < 0.001). The study showed that in obese and obese diabetic patients, bioactive lipids content is greater in subcutaneous and epicardial fat tissue and the particular lipids content positively correlates with HOMA-IR.

  2. Congenital Muscle Disease Study of Patient and Family Reported Medical Information

    ClinicalTrials.gov

    2017-05-05

    Congenital Muscular Dystrophy (Including Unspecified/Undiagnosed); Dystroglycanopathy; Congenital Fiber Type Disproportion; Rigid Spine Muscular Dystrophy; Congenital Myopathy (Including Unspecified/Undiagnosed); Collagen VI CMD (Ullrich CMD, Intermediate, Bethlem Myopathy); Laminin Alpha 2 Related Congenital Muscular Dystrophy; LAMA2-CMD/Merosin Deficient/MDC1A; Walker-Warburg Syndrome; Muscle-Eye-Brain Disease; Fukuyama/Fukutin Related Muscular Dystrophy; Integrin Alpha 7 Deficiency; Integrin Alpha 9 Deficiency; LMNA-CMD/Lamin A/C/Laminopathy; SEPN1-Related Myopathy; Bethlem Myopathy; Actin Aggregation Myopathy; Cap Disease; Central Core Disease; Centronuclear Myopathy; Core Rod Myopathy; Hyaline Body Myopathy; Multiminicore Myopathy; Myotubular Myopathy; Nemaline Myopathy; Tubular Aggregate Myopathy; Zebra Body Myopathy; Reducing Body Myopathy; Spheroid Body Myopathy; LGMD1B (LMNA); LGMD1E (DES); LGMD2G (TCAP); LGMD2H (TRIM32); LGMD2I (FKRP); LGMD2J (TTN); LGMD2K (POMT1); LGMD2M (FKTN); LGMD2N (POMT2); LGMD2O (POMGnT1); LGMD2P (DAG1); LGMD2Q (PLEC1); LGMD2R (DES); LGMD2S (TRAPPC11); LGMD2T (GMPPB); LGMD2U (ISPD); LGMD2V (GAA); Ullrich Congenital Muscular Dystrophy; Titinopathy; Choline Kinase B Receptor; Emery-Dreifuss Muscular Dystrophy; RYR1 Related Myopathy; SYNE1/Nesprin Related Muscular Dystrophy; Telethonin Related Muscular Dystrophy (TCAP/Titin-Cap); Congenital Myasthenic Syndrome; Escobar Syndrome; Myofibrillar Myopathy; Malignant Hyperthermia; Alpha-Dystroglycan Related Muscular Dystrophy (DAG1, DPM1, DPM2, DPM3, FKRP, FKTN); Alpha-Dystroglycan Related Muscular Dystrophy (GAA, ISPD, LARGE, POMT1, POMT2, POMGnT1); Alpha-Dystroglycan Related Muscular Dystrophy (Unspecified/Undiagnosed/Other)

  3. Repeated homotypic stress elevates 2-arachidonoylglycerol levels and enhances short-term endocannabinoid signaling at inhibitory synapses in basolateral amygdala.

    PubMed

    Patel, Sachin; Kingsley, Philip J; Mackie, Ken; Marnett, Lawrence J; Winder, Danny G

    2009-12-01

    Psychosocial stress is a risk factor for development and exacerbation of neuropsychiatric illness. Repeated stress causes biochemical adaptations in endocannabinoid (eCB) signaling that contribute to stress-response habituation, however, the synaptic correlates of these adaptations have not been examined. Here, we show that the synthetic enzyme for the eCB 2-arachidonoylglycerol (2-AG), diacylglycerol (DAG) lipase alpha, is heterogeneously expressed in the amygdala, and that levels of 2-AG and precursor DAGs are increased in the basolateral amygdala (BLA) after 10 days, but not 1 day, of restraint stress. In contrast, arachidonic acid was decreased after both 1 and 10 days of restraint stress. To examine the synaptic correlates of these alterations in 2-AG metabolism, we used whole-cell electrophysiology to determine the effects of restraint stress on depolarization-induced suppression of inhibition (DSI) in the BLA. A single restraint stress exposure did not alter DSI compared with control mice. However, after 10 days of restraint stress, DSI duration, but not magnitude, was significantly prolonged. Inhibition of 2-AG degradation with MAFP also prolonged DSI duration; the effects of repeated restraint stress and MAFP were mutually occlusive. These data indicate that exposure to repeated, but not acute, stress produces neuroadaptations that confer BLA neurons with an enhanced capacity to elevate 2-AG content and engage in 2-AG-mediated short-term retrograde synaptic signaling. We suggest stress-induced enhancement of eCB-mediated suppression of inhibitory transmission in the BLA could contribute to affective dysregulation associated with chronic stress.

  4. Acid sphingomyelinase activity is regulated by membrane lipids and facilitates cholesterol transfer by NPC2.

    PubMed

    Oninla, Vincent O; Breiden, Bernadette; Babalola, Jonathan O; Sandhoff, Konrad

    2014-12-01

    During endocytosis, membrane components move to intraluminal vesicles of the endolysosomal compartment for digestion. At the late endosomes, cholesterol is sorted out mainly by two sterol-binding proteins, Niemann-Pick protein type C (NPC)1 and NPC2. To study the NPC2-mediated intervesicular cholesterol transfer, we developed a liposomal assay system. (Abdul-Hammed, M., B. Breiden, M. A. Adebayo, J. O. Babalola, G. Schwarzmann, and K. Sandhoff. 2010. Role of endosomal membrane lipids and NPC2 in cholesterol transfer and membrane fusion. J. Lipid Res. 51: 1747-1760.) Anionic lipids stimulate cholesterol transfer between liposomes while SM inhibits it, even in the presence of anionic bis(monoacylglycero)phosphate (BMP). Preincubation of vesicles containing SM with acid sphingomyelinase (ASM) (SM phosphodiesterase, EC 3.1.4.12) results in hydrolysis of SM to ceramide (Cer), which enhances cholesterol transfer. Besides SM, ASM also cleaves liposomal phosphatidylcholine. Anionic phospholipids derived from the plasma membrane (phosphatidylglycerol and phosphatidic acid) stimulate SM and phosphatidylcholine hydrolysis by ASM more effectively than BMP, which is generated during endocytosis. ASM-mediated hydrolysis of liposomal SM was also stimulated by incorporation of diacylglycerol (DAG), Cer, and free fatty acids into the liposomal membranes. Conversely, phosphatidylcholine hydrolysis was inhibited by incorporation of cholesterol, Cer, DAG, monoacylglycerol, and fatty acids. Our data suggest that SM degradation by ASM is required for physiological secretion of cholesterol from the late endosomal compartment, and is a key regulator of endolysosomal lipid digestion. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  5. Computational design of d-peptide inhibitors of hepatitis delta antigen dimerization

    NASA Astrophysics Data System (ADS)

    Elkin, Carl D.; Zuccola, Harmon J.; Hogle, James M.; Joseph-McCarthy, Diane

    2000-11-01

    Hepatitis delta virus (HDV) encodes a single polypeptide called hepatitis delta antigen (DAg). Dimerization of DAg is required for viral replication. The structure of the dimerization region, residues 12 to 60, consists of an anti-parallel coiled coil [Zuccola et al., Structure, 6 (1998) 821]. Multiple Copy Simultaneous Searches (MCSS) of the hydrophobic core region formed by the bend in the helix of one monomer of this structure were carried out for many diverse functional groups. Six critical interaction sites were identified. The Protein Data Bank was searched for backbone templates to use in the subsequent design process by matching to these sites. A 14 residue helix expected to bind to the d-isomer of the target structure was selected as the template. Over 200 000 mutant sequences of this peptide were generated based on the MCSS results. A secondary structure prediction algorithm was used to screen all sequences, and in general only those that were predicted to be highly helical were retained. Approximately 100 of these 14-mers were model built as d-peptides and docked with the l-isomer of the target monomer. Based on calculated interaction energies, predicted helicity, and intrahelical salt bridge patterns, a small number of peptides were selected as the most promising candidates. The ligand design approach presented here is the computational analogue of mirror image phage display. The results have been used to characterize the interactions responsible for formation of this model anti-parallel coiled coil and to suggest potential ligands to disrupt it.

  6. An Enriched Unified Medical Language System Semantic Network with a Multiple Subsumption Hierarchy

    PubMed Central

    Zhang, Li; Perl, Yehoshua; Halper, Michael; Geller, James; Cimino, James J.

    2004-01-01

    Objective: The Unified Medical Language System's (UMLS's) Semantic Network's (SN's) two-tree structure is restrictive because it does not allow a semantic type to be a specialization of several other semantic types. In this article, the SN is expanded into a multiple subsumption structure with a directed acyclic graph (DAG) IS-A hierarchy, allowing a semantic type to have multiple parents. New viable IS-A links are added as warranted. Design: Two methodologies are presented to identify and add new viable IS-A links. The first methodology is based on imposing the characteristic of connectivity on a previously presented partition of the SN. Four transformations are provided to find viable IS-A links in the process of converting the partition's disconnected groups into connected ones. The second methodology identifies new IS-A links through a string matching process involving names and definitions of various semantic types in the SN. A domain expert is needed to review all the results to determine the validity of the new IS-A links. Results: Nineteen new IS-A links are added to the SN, and four new semantic types are also created to support the multiple subsumption framework. The resulting network, called the Enriched Semantic Network (ESN), exhibits a DAG-structured hierarchy. A partition of the ESN containing 19 connected groups is also derived. Conclusion: The ESN is an expanded abstraction of the UMLS compared with the original SN. Its multiple subsumption hierarchy can accommodate semantic types with multiple parents. Its representation thus provides direct access to a broader range of subsumption knowledge. PMID:14764611

  7. [Progress in the study on diacylgycerol acyltransferase (DGAT)-related genes].

    PubMed

    Ma, Hai-Ming; Shi, Qi-Shun; Liu, Xiao-Chun

    2005-12-01

    Diacylgycerol Acyltransferase (DGAT) plays an important role in the formation of lipid in different tissues of biological body. DGAT catalyzes the final step in triacylglycerol (TAG) biosynthesis by converting diacylgycerol (DAG) and fatty acyl-coenzyme A (CoA) into triacylglycerol. This enzyme is coded by both DGAT1 and DGAT2. DGAT1 belongs to the gene family of cholesterol acyltransferase (ACAT). DGAT2 belongs to the gene family of monoacylgycerol acyltransferases (MGAT1). This paper reviewed the structure, location on chromosome and biological effect of DGAT-related genes. The relationship between polymorphism and performance of animal was also discussed.

  8. Particle Dynamics in Linear Resonance Accelerators,

    DTIC Science & Technology

    1982-11-08

    function, which describes the defocusing action of accelerating field eS ’ dE1 Q. (,) _ as, -. .(). (2.57) Before passing to the analysis of equations (2.53...no focusing fields; therefore, according to expressions (2.55), (2.57), DOC - 82105202 PAGE|I eS dE, Q (T) 2 0y- * -N (T). Let us replace derivative of...d2.vS OU Y,-- 1 + Q X (T) X + g0- - -j = 0; d2u _ 2_d_a~g , eS ’ aU’ Let us assume that there is such-stationary distribution of phase density

  9. Pilot Preference, Compliance, and Performance With an Airborne Conflict Management Toolset

    NASA Technical Reports Server (NTRS)

    Doble, Nathan A.; Barhydt, Richard; Krishnamurthy, Karthik

    2005-01-01

    A human-in-the-loop experiment was conducted at the NASA Ames and Langley Research Centers, investigating the En Route Free Maneuvering component of a future air traffic management concept termed Distributed Air/Ground Traffic Management (DAG-TM). NASA Langley test subject pilots used the Autonomous Operations Planner (AOP) airborne toolset to detect and resolve traffic conflicts, interacting with subject pilots and air traffic controllers at NASA Ames. Experimental results are presented, focusing on conflict resolution maneuver choices, AOP resolution guidance acceptability, and performance metrics. Based on these results, suggestions are made to further improve the AOP interface and functionality.

  10. Mutational Analysis of Lassa Virus Glycoprotein Highlights Regions Required for Alpha-Dystroglycan Utilization.

    PubMed

    Acciani, Marissa; Alston, Jacob T; Zhao, Guohui; Reynolds, Hayley; Ali, Afroze M; Xu, Brian; Brindley, Melinda A

    2017-09-15

    Lassa virus (LASV) is an enveloped RNA virus endemic to West Africa and responsible for severe cases of hemorrhagic fever. Virus entry is mediated by the glycoprotein complex consisting of a stable-signal peptide, a receptor-binding subunit, GP1, and a viral-host membrane fusion subunit, GP2. Several cellular receptors can interact with the GP1 subunit and mediate viral entry, including alpha-dystroglycan (αDG) and lysosome-associated membrane protein 1 (LAMP1). In order to define the regions within GP1 that interact with the cellular receptors, we implemented insertional mutagenesis, carbohydrate shielding, and alanine scanning mutagenesis. Eighty GP constructs were engineered and evaluated for GP1-GP2 processing, surface expression, and the ability to mediate cell-to-cell fusion after low-pH exposure. To examine virus-to-cell entry, 49 constructs were incorporated onto vesicular stomatitis virus (VSV) pseudoparticles and transduction efficiencies were monitored in HAP1 and HAP1-ΔDAG1 cells that differentially produce the αDG cell surface receptor. Seven constructs retained efficient transduction in HAP1-ΔDAG1 cells yet poorly transduced HAP1 cells, suggesting that they are involved in αDG utilization. Residues H141, N146, F147, and Y150 cluster at the predicted central core of the trimeric interface and are important for GP-αDG interaction. Additionally, H92A-H93A, 150HA, 172HA, and 230HA displayed reduced transduction in both HAP1 and HAP1-ΔDAG1 cells, despite efficient cell-to-cell fusion activity. These mutations may interfere with interactions with the endosomal receptor LAMP1 or interfere at another stage in entry that is common to both cell lines. Insight gained from these data can aid in the development of more-effective entry inhibitors by blocking receptor interactions. IMPORTANCE Countries in which Lassa virus is endemic, such as Nigeria, Sierra Leone, Guinea, and Liberia, usually experience a seasonal outbreak of the virus from December to March

  11. Regulation of triacylglycerol biosynthesis in embryos and microsomal preparations from the developing seeds of Cuphea lanceolata.

    PubMed

    Bafor, M; Jonsson, L; Stobart, A K; Stymne, S

    1990-11-15

    Embryos of Cuphea lanceolata have more than 80 mol% of decanoic acid ('capric acid') in their triacylglycerols, while this fatty acid is virtually absent in phosphatidylcholine (PtdCho). Seed development was complete 25-27 days after pollination, with rapid triacylglycerol deposition occurring between 9 and 24 days. PtdCho amounts increased until day 15 after pollination. Analysis of embryo lipids showed that the diacylglycerol (DAG) pool consisted of mainly long-chain molecular species, with a very small amount of mixed medium-chain/long-chain glycerols. Almost 100% of the fatty acid at position sn-2 in triacylglycerols (TAG) was decanoic acid. When equimolar mixtures of [14C]decanoic and [14C]oleic acid were fed to whole detached embryos, over half of the radioactivity in the DAG resided in [14C]oleate, whereas [14C]decanoic acid accounted for 93% of the label in the TAG. Microsomal preparations from developing embryos at the mid-stage of TAG accumulation catalysed the acylation of [14C]glycerol 3-phosphate with either decanoyl-CoA or oleoyl-CoA, resulting in the formation of phosphatidic acid (PtdOH), DAG and TAG. Very little [14C]glycerol entered PtdCho. In combined incubations, with an equimolar supply of [14C]oleoyl-CoA and [14C]decanoyl-CoA in the presence of glycerol 3-phosphate, the synthesized PtdCho species consisted to 95% of didecanoic and dioleic species. The didecanoyl-glycerols were very selectively utilized over the dioleoylglycerols in the production of TAG. Substantial amounts of [14C]oleate, but not [14C]decanoate, entered PtdCho. The microsomal preparations of developing embryos were used to assess the acyl specificities of the acyl-CoA:sn-glycerol-3-phosphate acyltransferase (GPAT, EC 2.3.1.15) and the acyl-CoA:sn-1-acyl-glycerol-3-phosphate acyltransferase (LPAAT, EC 2.3.1.51) in Cuphea lanceolata embryos. The efficiency of acyl-CoA utilization by the GPAT was in the order decanoyl = dodecanoyl greater than linoleoyl greater than myristoyl

  12. Regulation of triacylglycerol biosynthesis in embryos and microsomal preparations from the developing seeds of Cuphea lanceolata.

    PubMed Central

    Bafor, M; Jonsson, L; Stobart, A K; Stymne, S

    1990-01-01

    Embryos of Cuphea lanceolata have more than 80 mol% of decanoic acid ('capric acid') in their triacylglycerols, while this fatty acid is virtually absent in phosphatidylcholine (PtdCho). Seed development was complete 25-27 days after pollination, with rapid triacylglycerol deposition occurring between 9 and 24 days. PtdCho amounts increased until day 15 after pollination. Analysis of embryo lipids showed that the diacylglycerol (DAG) pool consisted of mainly long-chain molecular species, with a very small amount of mixed medium-chain/long-chain glycerols. Almost 100% of the fatty acid at position sn-2 in triacylglycerols (TAG) was decanoic acid. When equimolar mixtures of [14C]decanoic and [14C]oleic acid were fed to whole detached embryos, over half of the radioactivity in the DAG resided in [14C]oleate, whereas [14C]decanoic acid accounted for 93% of the label in the TAG. Microsomal preparations from developing embryos at the mid-stage of TAG accumulation catalysed the acylation of [14C]glycerol 3-phosphate with either decanoyl-CoA or oleoyl-CoA, resulting in the formation of phosphatidic acid (PtdOH), DAG and TAG. Very little [14C]glycerol entered PtdCho. In combined incubations, with an equimolar supply of [14C]oleoyl-CoA and [14C]decanoyl-CoA in the presence of glycerol 3-phosphate, the synthesized PtdCho species consisted to 95% of didecanoic and dioleic species. The didecanoyl-glycerols were very selectively utilized over the dioleoylglycerols in the production of TAG. Substantial amounts of [14C]oleate, but not [14C]decanoate, entered PtdCho. The microsomal preparations of developing embryos were used to assess the acyl specificities of the acyl-CoA:sn-glycerol-3-phosphate acyltransferase (GPAT, EC 2.3.1.15) and the acyl-CoA:sn-1-acyl-glycerol-3-phosphate acyltransferase (LPAAT, EC 2.3.1.51) in Cuphea lanceolata embryos. The efficiency of acyl-CoA utilization by the GPAT was in the order decanoyl = dodecanoyl greater than linoleoyl greater than myristoyl

  13. Nonlinear characterization of a bolted, industrial structure using a modal framework

    NASA Astrophysics Data System (ADS)

    Roettgen, Daniel R.; Allen, Matthew S.

    2017-02-01

    This article presents measurements from a sub assembly of an off-the-shelf automotive exhaust system containing a bolted-flange connection and uses a recently proposed modal framework to develop a nonlinear dynamic model for the structure. The nonlinear identification and characterization methods used are reviewed to highlight the strengths of the current approach and the areas where further development is needed. This marks the first use of these new testing and nonlinear identification tools, and the associated modal framework, on production hardware with a realistic joint and realistic torque levels. To screen the measurements for nonlinearities, we make use of a time frequency analysis routine designed for transient responses called the zeroed early-time fast Fourier transform (ZEFFT). This tool typically reveals the small frequency shifts and distortions that tend to occur near each mode that is affected by the nonlinearity. The damping in this structure is found to be significantly nonlinear and a Hilbert transform is used to characterize the damping versus amplitude behavior. A model is presented that captures these effects for each mode individually (e.g. assuming negligible nonlinear coupling between modes), treating each mode as a single degree-of-freedom oscillator with a spring and viscous damping element in parallel with a four parameter Iwan model. The parameters of this model are identified for each of the structure's modes that exhibited nonlinearity and the resulting nonlinear model is shown to capture the stiffness and damping accurately over a large range of response amplitudes.

  14. Joint NASA Ames/Langley Experimental Evaluation of Integrated Air/Ground Operations for En Route Free Maneuvering

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Kopardekar, Parimal; Battiste, Vernol; Doble, Nathan; Johnson, Walter; Lee, Paul; Prevot, Thomas; Smith, Nancy

    2005-01-01

    In order to meet the anticipated future demand for air travel, the National Aeronautics and Space Administration (NASA) is investigating a new concept of operations known as Distributed Air-Ground Traffic Management (DAG-TM). Under the En Route Free Maneuvering component of DAG-TM, appropriately equipped autonomous aircraft self separate from other autonomous aircraft and from managed aircraft that continue to fly under today s Instrument Flight Rules (IFR). Controllers provide separation services between IFR aircraft and assign traffic flow management constraints to all aircraft. To address concept feasibility issues pertaining to integrated air/ground operations at various traffic levels, NASA Ames and Langley Research Centers conducted a joint human-in-the-loop experiment. Professional airline pilots and air traffic controllers flew a total of 16 scenarios under four conditions: mixed autonomous/managed operations at three traffic levels and a baseline all-managed condition at the lowest traffic level. These scenarios included en route flights and descents to a terminal area meter fix in airspace modeled after the Dallas Ft. Worth area. Pilots of autonomous aircraft met controller assigned meter fix constraints with high success. Separation violations by subject pilots did not appear to vary with traffic level and were mainly attributable to software errors and procedural lapses. Controller workload was lower for mixed flight conditions, even at higher traffic levels. Pilot workload was deemed acceptable under all conditions. Controllers raised several safety concerns, most of which pertained to the occurrence of near-term conflicts between autonomous and managed aircraft. These issues are being addressed through better compatibility between air and ground systems and refinements to air and ground procedures.

  15. Bayesian Estimation and Inference Using Stochastic Electronics

    PubMed Central

    Thakur, Chetan Singh; Afshar, Saeed; Wang, Runchun M.; Hamilton, Tara J.; Tapson, Jonathan; van Schaik, André

    2016-01-01

    In this paper, we present the implementation of two types of Bayesian inference problems to demonstrate the potential of building probabilistic algorithms in hardware using single set of building blocks with the ability to perform these computations in real time. The first implementation, referred to as the BEAST (Bayesian Estimation and Stochastic Tracker), demonstrates a simple problem where an observer uses an underlying Hidden Markov Model (HMM) to track a target in one dimension. In this implementation, sensors make noisy observations of the target position at discrete time steps. The tracker learns the transition model for target movement, and the observation model for the noisy sensors, and uses these to estimate the target position by solving the Bayesian recursive equation online. We show the tracking performance of the system and demonstrate how it can learn the observation model, the transition model, and the external distractor (noise) probability interfering with the observations. In the second implementation, referred to as the Bayesian INference in DAG (BIND), we show how inference can be performed in a Directed Acyclic Graph (DAG) using stochastic circuits. We show how these building blocks can be easily implemented using simple digital logic gates. An advantage of the stochastic electronic implementation is that it is robust to certain types of noise, which may become an issue in integrated circuit (IC) technology with feature sizes in the order of tens of nanometers due to their low noise margin, the effect of high-energy cosmic rays and the low supply voltage. In our framework, the flipping of random individual bits would not affect the system performance because information is encoded in a bit stream. PMID:27047326

  16. Quantitative properties and receptor reserve of the IP3 and calcium branch of Gq-coupled receptor signaling

    PubMed Central

    Dickson, Eamonn J.; Falkenburger, Björn H.

    2013-01-01

    Gq-coupled plasma membrane receptors activate phospholipase C (PLC), which hydrolyzes membrane phosphatidylinositol 4,5-bisphosphate (PIP2) into the second messengers inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). This leads to calcium release, protein kinase C (PKC) activation, and sometimes PIP2 depletion. To understand mechanisms governing these diverging signals and to determine which of these signals is responsible for the inhibition of KCNQ2/3 (KV7.2/7.3) potassium channels, we monitored levels of PIP2, IP3, and calcium in single living cells. DAG and PKC are monitored in our companion paper (Falkenburger et al. 2013. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.201210887). The results extend our previous kinetic model of Gq-coupled receptor signaling to IP3 and calcium. We find that activation of low-abundance endogenous P2Y2 receptors by a saturating concentration of uridine 5′-triphosphate (UTP; 100 µM) leads to calcium release but not to PIP2 depletion. Activation of overexpressed M1 muscarinic receptors by 10 µM Oxo-M leads to a similar calcium release but also depletes PIP2. KCNQ2/3 channels are inhibited by Oxo-M (by 85%), but not by UTP (<1%). These differences can be attributed purely to differences in receptor abundance. Full amplitude calcium responses can be elicited even after PIP2 was partially depleted by overexpressed inducible phosphatidylinositol 5-phosphatases, suggesting that very low amounts of IP3 suffice to elicit a full calcium release. Hence, weak PLC activation can elicit robust calcium signals without net PIP2 depletion or KCNQ2/3 channel inhibition. PMID:23630337

  17. Role of Patatin-Like Phospholipase Domain-Containing 3 on Lipid-Induced Hepatic Steatosis and Insulin Resistance in Rats

    PubMed Central

    Kumashiro, Naoki; Yoshimura, Toru; Cantley, Jennifer L; Majumdar, Sachin K; Guebre-Egziabher, Fitsum; Kursawe, Romy; Vatner, Daniel F; Fat, Ioana; Kahn, Mario; Erion, Derek M; Zhang, Xian-Man; Zhang, Dongyan; Manchem, Vara Prasad; Bhanot, Sanjay; Gerhard, Glenn S; Petersen, Kitt F; Cline, Gary W; Samuel, Varman T; Shulman, Gerald I

    2013-01-01

    Genome-wide array studies have associated the patatin-like phospholipase domain-containing 3 (PNPLA3) gene polymorphisms with hepatic steatosis. However, it is unclear whether PNPLA3 functions as a lipase or a lipogenic enzyme and whether PNPLA3 is involved in the pathogenesis of hepatic insulin resistance. To address these questions we treated high-fat-fed rats with specific antisense oligonucleotides to decrease hepatic and adipose pnpla3 expression. Reducing pnpla3 expression prevented hepatic steatosis, which could be attributed to decreased fatty acid esterification measured by the incorporation of [U-13C]-palmitate into hepatic triglyceride. While the precursors for phosphatidic acid (PA) (long-chain fatty acyl-CoAs and lysophosphatidic acid [LPA]) were not decreased, we did observe an ∼20% reduction in the hepatic PA content, ∼35% reduction in the PA/LPA ratio, and ∼60%-70% reduction in transacylation activity at the level of acyl-CoA:1-acylglycerol-sn-3-phosphate acyltransferase. These changes were associated with an ∼50% reduction in hepatic diacylglycerol (DAG) content, an ∼80% reduction in hepatic protein kinase Cε activation, and increased hepatic insulin sensitivity, as reflected by a 2-fold greater suppression of endogenous glucose production during the hyperinsulinemic-euglycemic clamp. Finally, in humans, hepatic PNPLA3 messenger RNA (mRNA) expression was strongly correlated with hepatic triglyceride and DAG content, supporting a potential lipogenic role of PNPLA3 in humans. Conclusion: PNPLA3 may function primarily in a lipogenic capacity and inhibition of PNPLA3 may be a novel therapeutic approach for treatment of nonalcoholic fatty liver disease-associated hepatic insulin resistance. ((Hepatology 2013;57:1763-1772)) PMID:23175050

  18. The current deconstruction of paradoxes: one sign of the ongoing methodological "revolution".

    PubMed

    Porta, Miquel; Vineis, Paolo; Bolúmar, Francisco

    2015-10-01

    The current deconstruction of paradoxes is one among several signs that a profound renewal of methods for clinical and epidemiological research is taking place; perhaps for some basic life sciences as well. The new methodological approaches have already deconstructed and explained long puzzling apparent paradoxes, including the (non-existent) benefits of obesity in diabetics, or of smoking in low birth weight. Achievements of the new methods also comprise the elucidation of the causal structure of long-disputed and highly complex questions, as Berkson's bias and Simpson's paradox, and clarifying reasons for deep controversies, as those on estrogens and endometrial cancer, or on adverse effects of hormone replacement therapy. These are signs that the new methods can go deeper and beyond the methods in current use. A major example of a highly relevant idea is: when we condition on a common effect of a pair of variables, then a spurious association between such pair is likely. The implications of these ideas are potentially vast. A substantial number of apparent paradoxes may simply be the result of collider biases, a source of selection bias that is common not just in epidemiologic research, but in many types of research in the health, life, and social sciences. The new approaches develop a new framework of concepts and methods, as collider, instrumental variables, d-separation, backdoor path and, notably, Directed Acyclic Graphs (DAGs). The current theoretical and methodological renewal-or, perhaps, "revolution"-may be changing deeply how clinical and epidemiological research is conceived and performed, how we assess the validity and relevance of findings, and how causal inferences are made. Clinical and basic researchers, among others, should get acquainted with DAGs and related concepts.

  19. Different phospholipase-C-coupled receptors differentially regulate capacitative and non-capacitative Ca2+ entry in A7r5 cells

    PubMed Central

    Moneer, Zahid; Pino, Irene; Taylor, Emily J. A.; Broad, Lisa M.; Liu, Yingjie; Tovey, Stephen C.; Staali, Leila; Taylor, Colin W.

    2005-01-01

    Several receptors, including those for AVP (Arg8-vasopressin) and 5-HT (5-hydroxytryptamine), share an ability to stimulate PLC (phospholipase C) and so production of IP3 (inositol 1,4,5-trisphosphate) and DAG (diacylglycerol) in A7r5 vascular smooth muscle cells. Our previous analysis of the effects of AVP on Ca2+ entry [Moneer, Dyer and Taylor (2003) Biochem. J. 370, 439–448] showed that arachidonic acid released from DAG stimulated NO synthase. NO then stimulated an NCCE (non-capacitative Ca2+ entry) pathway, and, via cGMP and protein kinase G, it inhibited CCE (capacitative Ca2+ entry). This reciprocal regulation ensured that, in the presence of AVP, all Ca2+ entry occurred via NCCE to be followed by a transient activation of CCE only when AVP was removed [Moneer and Taylor (2002) Biochem. J. 362, 13–21]. We confirm that, in the presence of AVP, all Ca2+ entry occurs via NCCE, but 5-HT, despite activating PLC and evoking release of Ca2+ from intracellular stores, stimulates Ca2+ entry only via CCE. We conclude that two PLC-coupled receptors differentially regulate CCE and NCCE. We also address evidence that, in some A7r5 cells lines, AVP fails either to stimulate NCCE or inhibit CCE [Brueggemann, Markun, Barakat, Chen and Byron (2005) Biochem. J. 388, 237–244]. Quantitative PCR analysis suggests that these cells predominantly express TRPC1 (transient receptor potential canonical 1), whereas cells in which AVP reciprocally regulates CCE and NCCE express a greater variety of TRPC subtypes (TRPC1=6>2>3). PMID:15918794

  20. The role of diacylglycerol kinase ζ and phosphatidic acid in the mechanical activation of mammalian target of rapamycin (mTOR) signaling and skeletal muscle hypertrophy.

    PubMed

    You, Jae-Sung; Lincoln, Hannah C; Kim, Chan-Ran; Frey, John W; Goodman, Craig A; Zhong, Xiao-Ping; Hornberger, Troy A

    2014-01-17

    The activation of mTOR signaling is essential for mechanically induced changes in skeletal muscle mass, and previous studies have suggested that mechanical stimuli activate mTOR (mammalian target of rapamycin) signaling through a phospholipase D (PLD)-dependent increase in the concentration of phosphatidic acid (PA). Consistent with this conclusion, we obtained evidence which further suggests that mechanical stimuli utilize PA as a direct upstream activator of mTOR signaling. Unexpectedly though, we found that the activation of PLD is not necessary for the mechanically induced increases in PA or mTOR signaling. Motivated by this observation, we performed experiments that were aimed at identifying the enzyme(s) that promotes the increase in PA. These experiments revealed that mechanical stimulation increases the concentration of diacylglycerol (DAG) and the activity of DAG kinases (DGKs) in membranous structures. Furthermore, using knock-out mice, we determined that the ζ isoform of DGK (DGKζ) is necessary for the mechanically induced increase in PA. We also determined that DGKζ significantly contributes to the mechanical activation of mTOR signaling, and this is likely driven by an enhanced binding of PA to mTOR. Last, we found that the overexpression of DGKζ is sufficient to induce muscle fiber hypertrophy through an mTOR-dependent mechanism, and this event requires DGKζ kinase activity (i.e. the synthesis of PA). Combined, these results indicate that DGKζ, but not PLD, plays an important role in mechanically induced increases in PA and mTOR signaling. Furthermore, this study suggests that DGKζ could be a fundamental component of the mechanism(s) through which mechanical stimuli regulate skeletal muscle mass.

  1. Quantitative properties and receptor reserve of the IP(3) and calcium branch of G(q)-coupled receptor signaling.

    PubMed

    Dickson, Eamonn J; Falkenburger, Björn H; Hille, Bertil

    2013-05-01

    Gq-coupled plasma membrane receptors activate phospholipase C (PLC), which hydrolyzes membrane phosphatidylinositol 4,5-bisphosphate (PIP2) into the second messengers inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). This leads to calcium release, protein kinase C (PKC) activation, and sometimes PIP2 depletion. To understand mechanisms governing these diverging signals and to determine which of these signals is responsible for the inhibition of KCNQ2/3 (KV7.2/7.3) potassium channels, we monitored levels of PIP2, IP3, and calcium in single living cells. DAG and PKC are monitored in our companion paper (Falkenburger et al. 2013. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.201210887). The results extend our previous kinetic model of Gq-coupled receptor signaling to IP3 and calcium. We find that activation of low-abundance endogenous P2Y2 receptors by a saturating concentration of uridine 5'-triphosphate (UTP; 100 µM) leads to calcium release but not to PIP2 depletion. Activation of overexpressed M1 muscarinic receptors by 10 µM Oxo-M leads to a similar calcium release but also depletes PIP2. KCNQ2/3 channels are inhibited by Oxo-M (by 85%), but not by UTP (<1%). These differences can be attributed purely to differences in receptor abundance. Full amplitude calcium responses can be elicited even after PIP2 was partially depleted by overexpressed inducible phosphatidylinositol 5-phosphatases, suggesting that very low amounts of IP3 suffice to elicit a full calcium release. Hence, weak PLC activation can elicit robust calcium signals without net PIP2 depletion or KCNQ2/3 channel inhibition.

  2. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Simpson, Jeffrey P.; Thrower, Nicholas; Ohlrogge, John B.

    Bayberry (Myrica pensylvanica) fruits are covered with a remarkably thick layer of crystalline wax consisting of triacylglycerol (TAG) and diacylglycerol (DAG) esterified exclusively with saturated fatty acids. As the only plant known to accumulate soluble glycerolipids as a major component of surface waxes, Bayberry represents a novel system to investigate neutral lipid biosynthesis and lipid secretion by vegetative plant cells. The assembly of Bayberry wax is distinct from conventional TAG and other surface waxes, and instead proceeds through a pathway related to cutin synthesis (Simpson and Ohlrogge, 2016). In this study, microscopic examination revealed that the fruit tissue that producesmore » and secretes wax (Bayberry knobs) is fully developed before wax accumulates and that wax is secreted to the surface without cell disruption. Comparison of transcript expression to genetically related tissues (Bayberry leaves, M. rubra fruits), cutin-rich tomato and cherry fruit epidermis, and to oil-rich mesocarp and seeds, revealed exceptionally high expression of 13 transcripts for acyl-lipid metabolism together with down-regulation of fatty acid oxidases and desaturases. The predicted protein sequences of the most highly expressed lipid-related enzyme-encoding transcripts in Bayberry knobs are 100% identical to the sequences from Bayberry leaves,which do not produce surface DAG or TAG. Together, these results indicate that TAG biosynthesis and secretion in Bayberry is achieved by both up and down-regulation of a small subset of genes related to the biosynthesis of cutin and saturated fatty acids, and also implies that modifications in gene expression, rather than evolution of new gene functions, was the major mechanism by which Bayberry evolved its specialized lipid metabolism.« less

  3. How did nature engineer the highest surface lipid accumulation among plants? Exceptional expression of acyl-lipid-associated genes for the assembly of extracellular triacylglycerol by Bayberry ( Myrica pensylvanica ) fruits

    DOE PAGES

    Simpson, Jeffrey P.; Thrower, Nicholas; Ohlrogge, John B.

    2016-02-09

    Bayberry (Myrica pensylvanica) fruits are covered with a remarkably thick layer of crystalline wax consisting of triacylglycerol (TAG) and diacylglycerol (DAG) esterified exclusively with saturated fatty acids. As the only plant known to accumulate soluble glycerolipids as a major component of surface waxes, Bayberry represents a novel system to investigate neutral lipid biosynthesis and lipid secretion by vegetative plant cells. The assembly of Bayberry wax is distinct from conventional TAG and other surface waxes, and instead proceeds through a pathway related to cutin synthesis (Simpson and Ohlrogge, 2016). In this study, microscopic examination revealed that the fruit tissue that producesmore » and secretes wax (Bayberry knobs) is fully developed before wax accumulates and that wax is secreted to the surface without cell disruption. Comparison of transcript expression to genetically related tissues (Bayberry leaves, M. rubra fruits), cutin-rich tomato and cherry fruit epidermis, and to oil-rich mesocarp and seeds, revealed exceptionally high expression of 13 transcripts for acyl-lipid metabolism together with down-regulation of fatty acid oxidases and desaturases. The predicted protein sequences of the most highly expressed lipid-related enzyme-encoding transcripts in Bayberry knobs are 100% identical to the sequences from Bayberry leaves,which do not produce surface DAG or TAG. Together, these results indicate that TAG biosynthesis and secretion in Bayberry is achieved by both up and down-regulation of a small subset of genes related to the biosynthesis of cutin and saturated fatty acids, and also implies that modifications in gene expression, rather than evolution of new gene functions, was the major mechanism by which Bayberry evolved its specialized lipid metabolism.« less

  4. Bayesian Estimation and Inference Using Stochastic Electronics.

    PubMed

    Thakur, Chetan Singh; Afshar, Saeed; Wang, Runchun M; Hamilton, Tara J; Tapson, Jonathan; van Schaik, André

    2016-01-01

    In this paper, we present the implementation of two types of Bayesian inference problems to demonstrate the potential of building probabilistic algorithms in hardware using single set of building blocks with the ability to perform these computations in real time. The first implementation, referred to as the BEAST (Bayesian Estimation and Stochastic Tracker), demonstrates a simple problem where an observer uses an underlying Hidden Markov Model (HMM) to track a target in one dimension. In this implementation, sensors make noisy observations of the target position at discrete time steps. The tracker learns the transition model for target movement, and the observation model for the noisy sensors, and uses these to estimate the target position by solving the Bayesian recursive equation online. We show the tracking performance of the system and demonstrate how it can learn the observation model, the transition model, and the external distractor (noise) probability interfering with the observations. In the second implementation, referred to as the Bayesian INference in DAG (BIND), we show how inference can be performed in a Directed Acyclic Graph (DAG) using stochastic circuits. We show how these building blocks can be easily implemented using simple digital logic gates. An advantage of the stochastic electronic implementation is that it is robust to certain types of noise, which may become an issue in integrated circuit (IC) technology with feature sizes in the order of tens of nanometers due to their low noise margin, the effect of high-energy cosmic rays and the low supply voltage. In our framework, the flipping of random individual bits would not affect the system performance because information is encoded in a bit stream.

  5. The One-On-One Stochastic Duel. Part III

    DTIC Science & Technology

    1980-11-15

    bl; P(I a )mca~ P(T a 4) a, a-,,. and cZ.+ %i 1 -0 P(Ji -J) - p P(J j a~. 3ini2,..., and Aa+ 7, p u J1-0~ P(A) qi A- + 3- [na/a 3+ pVpB - - 1 qVa - 1 imO...AUTHORIED DOCUMENTS$ SECURITY CLASSIFICATION OF THIS PAGE (%ohmn Data Efntined_"’_ REPORT DOCUMENTATION PAGE REFoRE CIPNS.,UTIJG FONS 1 . REPORT NUMBER R2...DUEL: PART III O TECHNICAL REPORT S. PERFORMING ORG. REPORT NUMBER r" t’ /)1r ISE R 80- 1 " 7. AUTHOR(s) --- M---CfO RN UBRs ,,. J. Ancker, Jr. DAG

  6. [Progress in the study on mammalian diacylgycerol acyltransgerase (DGAT) gene and its biological function].

    PubMed

    Wang, Yan; Xu, Heng-Yong; Zhu, Qing

    2007-10-01

    Diacylglycerol acyltransferase (DGAT; EC 2.3.1.20) is a microsomal enzyme that plays a central role in the metabolism of cellular glycerolipids. DGAT catalyzes the final step in triacylglycerol (TAG) biosynthesis by converting diacylgycerol (DAG) and fatty acyl-coenzyme A (CoA) into triacylglycero1. DGAT plays a fundamental role in the metabolism of cellular diacylglycerol and is important in higher eukaryotes for physiologic processes involving triacylglycerol metabolism such as intestinal fat absorption, lipoprotein assembly, adipose tissue formation, and lactation. Therefore, DGAT is not only an key factor for control triglycerides and fatty acids, but also may play a key modulatory role in animal fat deposition.

  7. An Interface Tracking Algorithm for the Porous Medium Equation.

    DTIC Science & Technology

    1983-03-01

    equation (1.11). N [v n n 2(2) = n . AV k + wk---IY" 2] +l~ x A t K Ax E E 2+ VeTA i;- 2k1 n- o (nr+l) <k-<.(n+l) N [Av] [ n+l <Ax Z m(v ) I~+lIAxAt...RD-R127 685 AN INTERFACE TRACKING ALGORITHM FOR THE POROUS MEDIUM / EQURTION(U) WISCONSIN UNIV-MRDISON MATHEMATICS RESEARCH CENTER E DIBENEDETTO ET...RL. MAR 83 NRC-TSR-249 UNCLASSIFIED DAG29-88-C-8041 F/G 12/1i N E -EEonshhhhI EhhhMhhhhhhhhE mhhhhhhhhhhhhE mhhhhhhhhhhhhI IMhhhhhhhMhhhE

  8. Avocado fruit maturation and ripening: dynamics of aliphatic acetogenins and lipidomic profiles from mesocarp, idioblasts and seed.

    PubMed

    Rodríguez-López, Carlos Eduardo; Hernández-Brenes, Carmen; Treviño, Víctor; Díaz de la Garza, Rocío I

    2017-09-29

    Avocado fruit contains aliphatic acetogenins (oft-acetylated, odd-chain fatty alcohols) with promising bioactivities for both medical and food industries. However, we have scarce knowledge about their metabolism. The present work aimed to study changes in acetogenin profiles from mesocarp, lipid-containing idioblasts, and seeds from 'Hass' cultivar during fruit development, germination, and three harvesting years. An untargeted LC-MS based lipidomic analysis was also conducted to profile the lipidome of avocado fruit in each tissue. The targeted analysis showed that acetogenin profiles and contents remained unchanged in avocado mesocarp during maturation and postharvest ripening, germination, and different harvesting years. However, a shift in the acetogenin profile distribution, accompanied with a sharp increase in concentration, was observed in seed during early maturation. Untargeted lipidomics showed that this shift was accompanied with remodeling of glycerolipids: TAGs and DAGs decreased during fruit growing in seed. Remarkably, the majority of the lipidome in mature seed was composed by acetogenins; we suggest that this tissue is able to synthesize them independently from mesocarp. On the other hand, lipid-containing idioblasts accumulated almost the entire acetogenin pool measured in the whole mesocarp, while only having 4% of the total fatty acids. The lipidome of this cell type changed the most when the fruit was ripening after harvesting, TAGs decreased while odd-chain DAGs increased. Notably, idioblast lipidome was more diverse than that from mesocarp. Evidence shown here suggests that idioblasts are the main site of acetogenin biosynthesis in avocado mesocarp. This work unveiled the prevalence of aliphatic acetogenins in the avocado fruit lipidome and evidenced TAGs as initial donors of the acetogenin backbones in its biosynthesis. It also sets evidence for acetogenins being included in future works aimed at characterizing the avocado seed, as they are

  9. A green analytical chemistry approach for lipid extraction: computation methods in the selection of green solvents as alternative to hexane.

    PubMed

    Cascant, Mari Merce; Breil, Cassandra; Garrigues, Salvador; de la Guardia, Miguel; Fabiano-Tixier, Anne Silvie; Chemat, Farid

    2017-05-01

    There is a great interest in finding alternatives and green solvents in extraction processes to replace petroleum based solvents. In order to investigate these possibilities, computational methods, as Hansen solubility parameters (HSP) and conductor-like screening model for real solvent (COSMO-RS), were used in this work to predict the solvation power of a series of solvents in salmon fish lipids. Additionally, experimental studies were used to evaluate the performance in lipids extraction using 2-methyltetrahydrofurane, cyclopentyl methyl ether, dimethyl carbonate, isopropanol, ethanol, ethyl acetate, p-cymene and d-limonene compared with hexane. Lipid classes of extracts were obtained by using high performance thin-layer chromatography (HPTLC), whereas gas chromatography with a flame ionization detector (GC/FID) technique was employed to obtain fatty acid profiles. Some differences between theoretical and experimental results were observed, especially regarding the behavior of p-cymene and d-limonene, which separate from the predicted capability. Results obtained from HPTLC indicated that p-cymene and d-limonene extract triglycerides (TAGs) and diglycerides (DAGs) at levels of 73 and 19%, respectively, whereas the other studied extracts contain between 75 and 76% of TAGs and between 16 and 17% of DAGs. Fatty acid profiles, obtained by using GC-FID, indicated that saturated fatty acids (SFAs) between 19.5 and 19.9% of extracted oil, monounsaturated fatty acids (MUFAs) in the range between 43.5 and 44.9%, and PUFAs between 31.2 and 34.6% were extracted. p-Cymene and limonene extracts contained lower percentages than the other studied solvents of some PUFAs due probably to the fact that these unsaturated fatty acids are more susceptible to oxidative degradation than MUFAs. Ethyl acetate has been found to be the best alternative solvent to hexane for the extraction of salmon oil lipids. Graphical Abstract ᅟ.

  10. Effect of a sustained reduction in plasma free fatty acid concentration on insulin signalling and inflammation in skeletal muscle from human subjects

    PubMed Central

    Liang, Hanyu; Tantiwong, Puntip; Sriwijitkamol, Apiradee; Shanmugasundaram, Karthigayan; Mohan, Sumathy; Espinoza, Sara; DeFronzo, Ralph A; Dubé, John J; Musi, Nicolas

    2013-01-01

    Free fatty acids (FFAs) have been implicated in the pathogenesis of insulin resistance. Reducing plasma FFA concentration in obese and type 2 diabetic (T2DM) subjects improves insulin sensitivity. However, the molecular mechanism by which FFA reduction improves insulin sensitivity in human subjects is not fully understood. In the present study, we tested the hypothesis that pharmacological FFA reduction enhances insulin action by reducing local (muscle) inflammation, leading to improved insulin signalling. Insulin-stimulated total glucose disposal (TGD), plasma FFA species, muscle insulin signalling, IκBα protein, c-Jun phosphorylation, inflammatory gene (toll-like receptor 4 and monocyte chemotactic protein 1) expression, and ceramide and diacylglycerol (DAG) content were measured in muscle from a group of obese and T2DM subjects before and after administration of the antilipolytic drug acipimox for 7 days, and the results were compared to lean individuals. We found that obese and T2DM subjects had elevated saturated and unsaturated FFAs in plasma, and acipimox reduced all FFA species. Acipimox-induced reductions in plasma FFAs improved TGD and insulin signalling in obese and T2DM subjects. Acipimox increased IκBα protein (an indication of decreased IκB kinase–nuclear factor κB signalling) in both obese and T2DM subjects, but did not affect c-Jun phosphorylation in any group. Acipimox also decreased inflammatory gene expression, although this reduction only occurred in T2DM subjects. Ceramide and DAG content did not change. To summarize, pharmacological FFA reduction improves insulin signalling in muscle from insulin-resistant subjects. This beneficial effect on insulin action could be related to a decrease in local inflammation. Notably, the improvements in insulin action were more pronounced in T2DM, indicating that these subjects are more susceptible to the toxic effect of FFAs. PMID:23529132

  11. Effect of a sustained reduction in plasma free fatty acid concentration on insulin signalling and inflammation in skeletal muscle from human subjects.

    PubMed

    Liang, Hanyu; Tantiwong, Puntip; Sriwijitkamol, Apiradee; Shanmugasundaram, Karthigayan; Mohan, Sumathy; Espinoza, Sara; Defronzo, Ralph A; Dubé, John J; Musi, Nicolas

    2013-06-01

    Free fatty acids (FFAs) have been implicated in the pathogenesis of insulin resistance. Reducing plasma FFA concentration in obese and type 2 diabetic (T2DM) subjects improves insulin sensitivity. However, the molecular mechanism by which FFA reduction improves insulin sensitivity in human subjects is not fully understood. In the present study, we tested the hypothesis that pharmacological FFA reduction enhances insulin action by reducing local (muscle) inflammation, leading to improved insulin signalling. Insulin-stimulated total glucose disposal (TGD), plasma FFA species, muscle insulin signalling, IBα protein, c-Jun phosphorylation, inflammatory gene (toll-like receptor 4 and monocyte chemotactic protein 1) expression, and ceramide and diacylglycerol (DAG) content were measured in muscle from a group of obese and T2DM subjects before and after administration of the antilipolytic drug acipimox for 7 days, and the results were compared to lean individuals. We found that obese and T2DM subjects had elevated saturated and unsaturated FFAs in plasma, and acipimox reduced all FFA species. Acipimox-induced reductions in plasma FFAs improved TGD and insulin signalling in obese and T2DM subjects. Acipimox increased IBα protein (an indication of decreased IB kinase-nuclear factor B signalling) in both obese and T2DM subjects, but did not affect c-Jun phosphorylation in any group. Acipimox also decreased inflammatory gene expression, although this reduction only occurred in T2DM subjects. Ceramide and DAG content did not change. To summarize, pharmacological FFA reduction improves insulin signalling in muscle from insulin-resistant subjects. This beneficial effect on insulin action could be related to a decrease in local inflammation. Notably, the improvements in insulin action were more pronounced in T2DM, indicating that these subjects are more susceptible to the toxic effect of FFAs.

  12. Positive Effects of Voluntary Running on Metabolic Syndrome-Related Disorders in Non-Obese Hereditary Hypertriacylglycerolemic Rats

    PubMed Central

    Škop, Vojtěch; Malínská, Hana; Trnovská, Jaroslava; Hüttl, Martina; Cahová, Monika; Blachnio-Zabielska, Agnieszka; Baranowski, Marcin; Burian, Martin; Oliyarnyk, Olena; Kazdová, Ludmila

    2015-01-01

    While metabolic syndrome is often associated with obesity, 25% of humans suffering from it are not obese and the effect of physical activity remains unclear in such cases. Therefore, we used hereditary hypertriaclyglycerolemic (HHTg) rats as a unique model for studying the effect of spontaneous physical activity [voluntary running (VR)] on metabolic syndrome-related disorders, such as dyslipidemia, in non-obese subjects. Adult HHTg males were fed standard (CD) or high-sucrose (HSD) diets ad libitum for four weeks. Within both dietary groups, some of the rats had free access to a running wheel (CD+VR, HSD+VR), whereas the controls (CD, HSD) had no possibility of extra physical activity. At the end of the four weeks, we measured the effects of VR on various metabolic syndrome-associated parameters: (i) biochemical parameters, (ii) the content and composition of triacylglycerols (TAG), diacylglycerols (DAG), ceramides and membrane phospholipids, and (iii) substrate utilization in brown adipose tissue. In both dietary groups, VR led to various positive effects: reduced epididymal and perirenal fat depots; increased epididymal adipose tissue lipolysis; decreased amounts of serum TAG, non-esterified fatty acids and insulin; a higher insulin sensitivity index. While tissue ceramide content was not affected, decreased TAG accumulation resulted in reduced and modified liver, heart and skeletal muscle DAG. VR also had a beneficial effect on muscle membrane phospholipid composition. In addition, compared with the CD group, the CD+VR rats exhibited increased fatty acid oxidation and protein content in brown adipose tissue. Our results confirm that physical activity in a non-obese model of severe dyslipidemia has many beneficial effects and can even counteract the negative effects of sucrose consumption. Furthermore, they suggest that the mechanism by which these effects are modulated involves a combination of several positive changes in lipid metabolism. PMID:25830228

  13. Positive effects of voluntary running on metabolic syndrome-related disorders in non-obese hereditary hypertriacylglycerolemic rats.

    PubMed

    Škop, Vojt ch; Malínská, Hana; Trnovská, Jaroslava; Hüttl, Martina; Cahová, Monika; Blachnio-Zabielska, Agnieszka; Baranowski, Marcin; Burian, Martin; Oliyarnyk, Olena; Kazdová, Ludmila

    2015-01-01

    While metabolic syndrome is often associated with obesity, 25% of humans suffering from it are not obese and the effect of physical activity remains unclear in such cases. Therefore, we used hereditary hypertriaclyglycerolemic (HHTg) rats as a unique model for studying the effect of spontaneous physical activity [voluntary running (VR)] on metabolic syndrome-related disorders, such as dyslipidemia, in non-obese subjects. Adult HHTg males were fed standard (CD) or high-sucrose (HSD) diets ad libitum for four weeks. Within both dietary groups, some of the rats had free access to a running wheel (CD+VR, HSD+VR), whereas the controls (CD, HSD) had no possibility of extra physical activity. At the end of the four weeks, we measured the effects of VR on various metabolic syndrome-associated parameters: (i) biochemical parameters, (ii) the content and composition of triacylglycerols (TAG), diacylglycerols (DAG), ceramides and membrane phospholipids, and (iii) substrate utilization in brown adipose tissue. In both dietary groups, VR led to various positive effects: reduced epididymal and perirenal fat depots; increased epididymal adipose tissue lipolysis; decreased amounts of serum TAG, non-esterified fatty acids and insulin; a higher insulin sensitivity index. While tissue ceramide content was not affected, decreased TAG accumulation resulted in reduced and modified liver, heart and skeletal muscle DAG. VR also had a beneficial effect on muscle membrane phospholipid composition. In addition, compared with the CD group, the CD+VR rats exhibited increased fatty acid oxidation and protein content in brown adipose tissue. Our results confirm that physical activity in a non-obese model of severe dyslipidemia has many beneficial effects and can even counteract the negative effects of sucrose consumption. Furthermore, they suggest that the mechanism by which these effects are modulated involves a combination of several positive changes in lipid metabolism.

  14. Investigation of Coatings for Langmuir Probes in an Oxygen-Rich Space Environment

    NASA Astrophysics Data System (ADS)

    Samaniego, J. I.; Wang, X.; Andersson, L.; Malaspina, D.; Ergun, R.; Horanyi, M.

    2017-12-01

    The surface properties of the Langmuir probes, such as the one on the MAVEN mission, will change after exposure to upper planetary atmospheres where high concentrations of atomic oxygen and other oxidizing compounds are present. TiN (Titanium Nitride) or DAG (a resin based graphite dispersion) are the most common coatings for current Langmuir probes, yet both of these coatings pose issues when exposed to oxygen-rich space environment. TiN showed reduced surface conductivity while the DAG layers erode with exposure to oxygen. It is known that Iridium (Ir) and Rhenium (Rh) are difficult to oxidize and maintain high conductivity even in their oxidized forms, suggesting them to be good candidates for probe coatings. Oxidation of most metals creates a resistive layer on the surface of the probe that will affect the amount of current being collected at a given voltage during the probe sweep and therefore affect the accuracy of plasma parameters determined by the Langmuir probe (e.g. density, temperature). We present the results of the oxidation effect on the current-voltage curves (I-V curves) and therefore the resulting measured plasma parameters of Ir and Rh wire probes compared with other control metals and coatings (Cu, Ni, TiN) in controlled plasma environments. The oxidation process is performed in an oxygen plasma chamber in which both O+ and O2+ are created and accelerated toward the probes with energies < 10 eV. An argon plasma chamber is used to compare the probe's I-V curves before and after the oxidation process. Our preliminary results indicate that iridium shows the least effect of oxidation on the probe measurements. The second objective of this study is to identify methods that can be used in orbit to clean the surface of Langmuir probes to minimize the effect of exposure to oxidizing compounds.

  15. Comparison of normalization methods for the analysis of metagenomic gene abundance data.

    PubMed

    Pereira, Mariana Buongermino; Wallroth, Mikael; Jonsson, Viktor; Kristiansson, Erik

    2018-04-20

    In shotgun metagenomics, microbial communities are studied through direct sequencing of DNA without any prior cultivation. By comparing gene abundances estimated from the generated sequencing reads, functional differences between the communities can be identified. However, gene abundance data is affected by high levels of systematic variability, which can greatly reduce the statistical power and introduce false positives. Normalization, which is the process where systematic variability is identified and removed, is therefore a vital part of the data analysis. A wide range of normalization methods for high-dimensional count data has been proposed but their performance on the analysis of shotgun metagenomic data has not been evaluated. Here, we present a systematic evaluation of nine normalization methods for gene abundance data. The methods were evaluated through resampling of three comprehensive datasets, creating a realistic setting that preserved the unique characteristics of metagenomic data. Performance was measured in terms of the methods ability to identify differentially abundant genes (DAGs), correctly calculate unbiased p-values and control the false discovery rate (FDR). Our results showed that the choice of normalization method has a large impact on the end results. When the DAGs were asymmetrically present between the experimental conditions, many normalization methods had a reduced true positive rate (TPR) and a high false positive rate (FPR). The methods trimmed mean of M-values (TMM) and relative log expression (RLE) had the overall highest performance and are therefore recommended for the analysis of gene abundance data. For larger sample sizes, CSS also showed satisfactory performance. This study emphasizes the importance of selecting a suitable normalization methods in the analysis of data from shotgun metagenomics. Our results also demonstrate that improper methods may result in unacceptably high levels of false positives, which in turn may lead

  16. MS/MS analysis and imaging of lipids across Drosophila brain using secondary ion mass spectrometry.

    PubMed

    Phan, Nhu T N; Munem, Marwa; Ewing, Andrew G; Fletcher, John S

    2017-06-01

    Lipids are abundant biomolecules performing central roles to maintain proper functioning of cells and biological bodies. Due to their highly complex composition, it is critical to obtain information of lipid structures in order to identify particular lipids which are relevant for a biological process or metabolic pathway under study. Among currently available molecular identification techniques, MS/MS in secondary ion mass spectrometry (SIMS) imaging has been of high interest in the bioanalytical community as it allows visualization of intact molecules in biological samples as well as elucidation of their chemical structures. However, there have been few applications using SIMS and MS/MS owing to instrumental challenges for this capability. We performed MS and MS/MS imaging to study the lipid structures of Drosophila brain using the J105 and 40-keV Ar 4000 + gas cluster ion source, with the novelty being the use of MS/MS SIMS analysis of intact lipids in the fly brain. Glycerophospholipids were identified by MS/MS profiling. MS/MS was also used to characterize diglyceride fragment ions and to identify them as triacylglyceride fragments. Moreover, MS/MS imaging offers a unique possibility for detailed elucidation of biomolecular distribution with high accuracy based on the ion images of its fragments. This is particularly useful in the presence of interferences which disturb the interpretation of biomolecular localization. Graphical abstract MS/MS was performed during time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of Drosophila melongaster (fruit fly) to elucidate the structure and origin of different chemical species in the brain including a range of different phospholipid classes (PC, PI, PE) and di- and triacylglycerides (DAG & TAG) species where reference MS/MS spectra provided a potential means of discriminating between the isobaric [M-OH] + ion of DAGs and the [M-RCO] + ion of TAGs.

  17. On the structure of Bayesian network for Indonesian text document paraphrase identification

    NASA Astrophysics Data System (ADS)

    Prayogo, Ario Harry; Syahrul Mubarok, Mohamad; Adiwijaya

    2018-03-01

    Paraphrase identification is an important process within natural language processing. The idea is to automatically recognize phrases that have different forms but contain same meanings. For examples if we input query “causing fire hazard”, then the computer has to recognize this query that this query has same meaning as “the cause of fire hazard. Paraphrasing is an activity that reveals the meaning of an expression, writing, or speech using different words or forms, especially to achieve greater clarity. In this research we will focus on classifying two Indonesian sentences whether it is a paraphrase to each other or not. There are four steps in this research, first is preprocessing, second is feature extraction, third is classifier building, and the last is performance evaluation. Preprocessing consists of tokenization, non-alphanumerical removal, and stemming. After preprocessing we will conduct feature extraction in order to build new features from given dataset. There are two kinds of features in the research, syntactic features and semantic features. Syntactic features consist of normalized levenshtein distance feature, term-frequency based cosine similarity feature, and LCS (Longest Common Subsequence) feature. Semantic features consist of Wu and Palmer feature and Shortest Path Feature. We use Bayesian Networks as the method of training the classifier. Parameter estimation that we use is called MAP (Maximum A Posteriori). For structure learning of Bayesian Networks DAG (Directed Acyclic Graph), we use BDeu (Bayesian Dirichlet equivalent uniform) scoring function and for finding DAG with the best BDeu score, we use K2 algorithm. In evaluation step we perform cross-validation. The average result that we get from testing the classifier as follows: Precision 75.2%, Recall 76.5%, F1-Measure 75.8% and Accuracy 75.6%.

  18. [Population health surveillance of the general population living near Turin (Northern Italy) incinerator (SPoTT): methodology of the study].

    PubMed

    Bena, Antonella; Chiusolo, Monica; Orengia, Manuela; Cadum, Ennio; Farina, Elena; Musmeci, Loredana; Procopio, Enrico; Salamina, Giuseppe

    2016-01-01

    Si intende qui descrivere il sistema di sorveglianza sugli effetti sulla salute (SpoTT) dell'inquinamento ambientale nelle aree circostanti l'inceneritore di Torino. SPoTT ha 3 linee di attività: 1. monitoraggio epidemiologico degli effetti a breve termine attraverso analisi temporali e misura della correlazione tra livelli giornalieri di emissioni dell'impianto e andamento degli eventi individuati dagli archivi dei dimessi (SDO), di pronto soccorso e di mortalità; sono coinvolti coloro che nel 2013-2018 risiedevano nell'area di ricaduta delle emissioni; 2. sorveglianza epidemiologica degli effetti a lungo termine, stimando tassi standardizzati di mortalità e morbosità; a ogni soggetto è attribuito il valore stimato di esposizione cumulato nel tempo caratteristico della residenza anagrafica; le informazioni sulla salute sono reperite dagli archivi SDO, di mortalità e dai certificati di assistenza al parto; sono studiati due decenni pre-post l'avvio dell'impianto: 2003-2012 e 2013-2022; 3. monitoraggio biologico con misurazione pre-post di metalli, PCDD/F, PCB, OH-IPA; sono coinvolti 196 residenti esposti e 196 di controllo di 35-69 anni, campionati a caso dalle anagrafi comunali; sono effettuate misure di funzionalità endocrina e respiratoria, pressione arteriosa, rischio cardiovascolare; l'esposizione cumulativa sarà stimata per ciascuna persona campionata integrando l'indirizzo di residenza, il tempo di permanenza in ciascun indirizzo e i dati ricavati dai modelli di ricaduta; sarà costituita una biobanca per future indagini di laboratorio; sono coinvolti anche 20 allevatori e i lavoratori dell'impianto. Una quarta linea di attività, non descritta in questo articolo, riguarda il monitoraggio della salute dei lavoratori addetti all'impianto. SPoTT è il primo studio in Italia su inceneritori e salute che adotta un disegno di studio longitudinale di adeguata potenza sia per i residenti sia per i lavoratori. I primi risultati sono attesi nel corso del 2016.

  19. How did nature engineer the highest surface lipid accumulation among plants? Exceptional expression of acyl-lipid-associated genes for the assembly of extracellular triacylglycerol by Bayberry (Myrica pensylvanica) fruits.

    PubMed

    Simpson, Jeffrey P; Thrower, Nicholas; Ohlrogge, John B

    2016-09-01

    Bayberry (Myrica pensylvanica) fruits are covered with a remarkably thick layer of crystalline wax consisting of triacylglycerol (TAG) and diacylglycerol (DAG) esterified exclusively with saturated fatty acids. As the only plant known to accumulate soluble glycerolipids as a major component of surface waxes, Bayberry represents a novel system to investigate neutral lipid biosynthesis and lipid secretion by vegetative plant cells. The assembly of Bayberry wax is distinct from conventional TAG and other surface waxes, and instead proceeds through a pathway related to cutin synthesis (Simpson and Ohlrogge, 2016). In this study, microscopic examination revealed that the fruit tissue that produces and secretes wax (Bayberry knobs) is fully developed before wax accumulates and that wax is secreted to the surface without cell disruption. Comparison of transcript expression to genetically related tissues (Bayberry leaves, M. rubra fruits), cutin-rich tomato and cherry fruit epidermis, and to oil-rich mesocarp and seeds, revealed exceptionally high expression of 13 transcripts for acyl-lipid metabolism together with down-regulation of fatty acid oxidases and desaturases. The predicted protein sequences of the most highly expressed lipid-related enzyme-encoding transcripts in Bayberry knobs are 100% identical to the sequences from Bayberry leaves, which do not produce surface DAG or TAG. Together, these results indicate that TAG biosynthesis and secretion in Bayberry is achieved by both up and down-regulation of a small subset of genes related to the biosynthesis of cutin and saturated fatty acids, and also implies that modifications in gene expression, rather than evolution of new gene functions, was the major mechanism by which Bayberry evolved its specialized lipid metabolism. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Calcium ion as intracellular messenger and cellular toxin.

    PubMed

    Rasmussen, H; Barrett, P; Smallwood, J; Bollag, W; Isales, C

    1990-03-01

    Ca2+ serves a nearly universal intracellular messenger function in cell activation, but excess Ca2+ is also a cellular toxin. The possibility of Ca2+ intoxication is minimized by an elaborate autoregulatory system in which changes in Ca2+ influx rate across the plasma membrane are rapidly compensated for by parallel changes in Ca2+ efflux rate. By this mean, cellular Ca2+ homestasis is maintained so that minimal changes in total cell calcium and cytosolic Ca2+ concentration occur during sustained Ca2(+)-mediated responses. Rather than a sustained increase in cytosolic Ca2+ concentration, it is the localized cycling of Ca2+ across the plasma membrane that is the critically important Ca2+ messenger during the sustained phase of cellular responses mediated via surface receptors linked to the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2). PIP2 hydrolysis gives rise to inositol(1,4,5)trisphosphate (IP3) and diacylglycerol (DAG). The IP3 acts to release Ca2+ from an intracellular pool, thereby causing a transient rise in cytosolic Ca2+ concentration. This transient Ca2+ signal activates calmodulin-dependent protein kinases transiently, and hence, causes the transient phosphorylation of a subset of cellular proteins that mediate the initial phase of the response. The DAG brings about the association of protein kinase C (PKC) with the plasma membrane where a receptor-mediated increase in Ca2+ cycling across the membrane regulates PKC activity. The sustained phosphorylation of a second subset of proteins by PKC mediates the sustained phase of the response. Hence, Ca2+ serves as a messenger during both phases of the cellular response, but its cellular sites of action, its mechanisms of generation, and its molecular targets differ during the initial and sustained phases of the response.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Calcium ion as intracellular messenger and cellular toxin.

    PubMed Central

    Rasmussen, H; Barrett, P; Smallwood, J; Bollag, W; Isales, C

    1990-01-01

    Ca2+ serves a nearly universal intracellular messenger function in cell activation, but excess Ca2+ is also a cellular toxin. The possibility of Ca2+ intoxication is minimized by an elaborate autoregulatory system in which changes in Ca2+ influx rate across the plasma membrane are rapidly compensated for by parallel changes in Ca2+ efflux rate. By this mean, cellular Ca2+ homestasis is maintained so that minimal changes in total cell calcium and cytosolic Ca2+ concentration occur during sustained Ca2(+)-mediated responses. Rather than a sustained increase in cytosolic Ca2+ concentration, it is the localized cycling of Ca2+ across the plasma membrane that is the critically important Ca2+ messenger during the sustained phase of cellular responses mediated via surface receptors linked to the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2). PIP2 hydrolysis gives rise to inositol(1,4,5)trisphosphate (IP3) and diacylglycerol (DAG). The IP3 acts to release Ca2+ from an intracellular pool, thereby causing a transient rise in cytosolic Ca2+ concentration. This transient Ca2+ signal activates calmodulin-dependent protein kinases transiently, and hence, causes the transient phosphorylation of a subset of cellular proteins that mediate the initial phase of the response. The DAG brings about the association of protein kinase C (PKC) with the plasma membrane where a receptor-mediated increase in Ca2+ cycling across the membrane regulates PKC activity. The sustained phosphorylation of a second subset of proteins by PKC mediates the sustained phase of the response. Hence, Ca2+ serves as a messenger during both phases of the cellular response, but its cellular sites of action, its mechanisms of generation, and its molecular targets differ during the initial and sustained phases of the response.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2190811

  2. Crude palm oil from interspecific hybrid Elaeis oleifera×Elaeis guineensis: fatty acid regiodistribution and molecular species of glycerides.

    PubMed

    Mozzon, Massimo; Pacetti, Deborah; Lucci, Paolo; Balzano, Michele; Frega, Natale Giuseppe

    2013-11-01

    The composition and structure of triacylglycerols (TAGs) and partial glycerides of crude palm oil obtained from interspecific hybrid Elaeis oleifera×Elaeis guineensis, grown in Colombia, were fully characterised and compared to data obtained by analysing crude African palm oil. Hybridisation appears to substantially modify the biosynthesis of fatty acids (FAs) rather than their assembly in TAGs. In fact, total FAs analysis showed significant differences between these two types of oil, with hybrid palm oil having a higher percentage of oleic acid (54.6 ± 1.0 vs 41.4 ± 0.3), together with a lower saturated fatty acid content (33.5 ± 0.5 vs 47.3 ± 0.1), while the percentage of essential fatty acid, linoleic acid, does not undergo significant changes. Furthermore, 34 TAG types were identified, with no qualitative differences between African and E. guineensis×E. oleifera hybrid palm oil samples. Short and medium chain FAs (8:0, 10:0, 12:0, 14:0) were utilised, together, to build a restricted number of TAG molecular species. Oil samples from the E. guineensis×E. oleifera hybrid showed higher contents of monosaturated TAGs (47.5-51.0% vs 36.7-37.1%) and triunsaturated TAGs (15.5-15.6% vs 5.2-5.4%). The sn-2 position of TAGs in hybrid palm oil was shown to be predominantly esterified with oleic acid (64.7-66.0 mol% vs 55.1-58.2 mol% in African palm oil) with only 10-15% of total palmitic acid and 6-20% of stearic acid acylated in the secondary position. The total amount of diacylglycerols (DAGs) was in agreement with the values of free acidity; DAG types found were in agreement with the representativeness of different TAG species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Effects of Pfaffia paniculata (Brazilian ginseng) extract on macrophage activity.

    PubMed

    Pinello, Kátia Cristina; Fonseca, Evelise de S M; Akisue, Gokithi; Silva, Ana Paula; Salgado Oloris, Silvia Catarina; Sakai, Mônica; Matsuzaki, Patrícia; Nagamine, Márcia Kazumi; Palermo Neto, João; Dagli, Maria Lúcia Zaidan

    2006-02-16

    The roots of Pfaffia paniculata (Brazilian ginseng) have been indicated for the treatment of several diseases and as an analgesic and antiinflamatory drug. Treatment of mice with 200 mg/kg of the powdered root of P. paniculata reduced the Ehrlich ascitic volume [Matsuzaki, P., Akisue, G., Salgado Oloris, S.C., Gorniak, S.L., Zaidan Dagli, M.L., 2003. Effect of Pffafia paniculata (Brazilian ginseng) on the Ehrlich tumor on its ascitic form. Life Sciences, Dec 19; 74 (5), 573-579.]. One of the putative means to control the Ehrlich tumor growth is by increasing macrophage activity [Kleeb, S.R., Xavier, J.G., Frussa-Filho, R., Dagli, M.L.Z., 1997. Effect of haloperidol on the development of the solid Ehrlich tumor in mice. Life Sciences, 60 (4/5), 69-742.]. The aim of this study was to investigate experimentally the effects of the methanolic extract of P. paniculata roots on macrophage activity. Male mice received, by gavage, once a day, different doses (100, 250, or 500 mg/kg) of the methanolic extract of P. paniculata or filtered water, as control, for 10 days. Macrophage activity was evaluated through the phagocytosis index (PI), spreading index (SI), production of peroxide oxigen and nitric oxide. The peritoneal cells were activated with ip inoculation of Ehrlich ascitic cells, 24 h before the macrophage harvesting. The methanolic extract raised significantly the SI of mice from group of 500 mg/kg in comparison with the control group and group of 100 mg/kg. This raise of SI possibly induced the higher phagocytic activity observed in the experimental situation. Increased macrophage activity may be one of the effects contributing to inhibition of the Ehrlich ascitic tumor growth in mice.

  4. Wasatch: An architecture-proof multiphysics development environment using a Domain Specific Language and graph theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saad, Tony; Sutherland, James C.

    To address the coding and software challenges of modern hybrid architectures, we propose an approach to multiphysics code development for high-performance computing. This approach is based on using a Domain Specific Language (DSL) in tandem with a directed acyclic graph (DAG) representation of the problem to be solved that allows runtime algorithm generation. When coupled with a large-scale parallel framework, the result is a portable development framework capable of executing on hybrid platforms and handling the challenges of multiphysics applications. In addition, we share our experience developing a code in such an environment – an effort that spans an interdisciplinarymore » team of engineers and computer scientists.« less

  5. Wasatch: An architecture-proof multiphysics development environment using a Domain Specific Language and graph theory

    DOE PAGES

    Saad, Tony; Sutherland, James C.

    2016-05-04

    To address the coding and software challenges of modern hybrid architectures, we propose an approach to multiphysics code development for high-performance computing. This approach is based on using a Domain Specific Language (DSL) in tandem with a directed acyclic graph (DAG) representation of the problem to be solved that allows runtime algorithm generation. When coupled with a large-scale parallel framework, the result is a portable development framework capable of executing on hybrid platforms and handling the challenges of multiphysics applications. In addition, we share our experience developing a code in such an environment – an effort that spans an interdisciplinarymore » team of engineers and computer scientists.« less

  6. 77 FR 38391 - Mercedes-Benz USA, LLC, and Daimler AG (DAG), Receipt of Petition for Decision of Inconsequential...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... platform) passenger cars do not fully comply with paragraph S4.4 TPMS Malfunction of Federal Motor Vehicle... the issue is (``Wheel Sensor(s) Missing''), the vehicle depicts an aerial view of a car with the...). \\1\\ Mercedes-Benz USA, LLC, and Daimler AG are motor vehicle manufacturers and importers. Mercedes...

  7. Comittees

    NASA Astrophysics Data System (ADS)

    2004-10-01

    Fritz Caspers (CERN, Switzerland), Michel Chanel (CERN, Switzerland), Håkan Danared (MSL, Sweden), Bernhard Franzke (GSI, Germany), Manfred Grieser (MPI für Kernphysik, Germany), Dieter Habs (LMU München, Germany), Jeffrey Hangst (University of Aarhus, Denmark), Takeshi Katayama (RIKEN/Univ. Tokyo, Japan), H.-Jürgen Kluge (GSI, Germany), Shyh-Yuan Lee (Indiana University, USA), Rudolf Maier (FZ Jülich, Germany), John Marriner (FNAL, USA), Igor Meshkov (JINR, Russia), Dieter Möhl (CERN, Switzerland), Vasily Parkhomchuk (BINP, Russia), Robert Pollock (Indiana University), Dieter Prasuhn (FZ Jülich, Germany), Dag Reistad (TSL, Sweden), John Schiffer (ANL, USA), Andrew Sessler (LBNL, USA), Alexander Skrinsky (BINP, Russia), Markus Steck (GSI, Germany), Jie Wei (BNL, USA), Andreas Wolf (MPI für Kernphysik, Germany), Hongwei Zhao (IMP, People's Rep. of China).

  8. Use of DAGMan in CRAB3 to improve the splitting of CMS user jobs

    NASA Astrophysics Data System (ADS)

    Wolf, M.; Mascheroni, M.; Woodard, A.; Belforte, S.; Bockelman, B.; Hernandez, J. M.; Vaandering, E.

    2017-10-01

    CRAB3 is a workload management tool used by CMS physicists to analyze data acquired by the Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider (LHC). Research in high energy physics often requires the analysis of large collections of files, referred to as datasets. The task is divided into jobs that are distributed among a large collection of worker nodes throughout the Worldwide LHC Computing Grid (WLCG). Splitting a large analysis task into optimally sized jobs is critical to efficient use of distributed computing resources. Jobs that are too big will have excessive runtimes and will not distribute the work across all of the available nodes. However, splitting the project into a large number of very small jobs is also inefficient, as each job creates additional overhead which increases load on infrastructure resources. Currently this splitting is done manually, using parameters provided by the user. However the resources needed for each job are difficult to predict because of frequent variations in the performance of the user code and the content of the input dataset. As a result, dividing a task into jobs by hand is difficult and often suboptimal. In this work we present a new feature called “automatic splitting” which removes the need for users to manually specify job splitting parameters. We discuss how HTCondor DAGMan can be used to build dynamic Directed Acyclic Graphs (DAGs) to optimize the performance of large CMS analysis jobs on the Grid. We use DAGMan to dynamically generate interconnected DAGs that estimate the processing time the user code will require to analyze each event. This is used to calculate an estimate of the total processing time per job, and a set of analysis jobs are run using this estimate as a specified time limit. Some jobs may not finish within the alloted time; they are terminated at the time limit, and the unfinished data is regrouped into smaller jobs and resubmitted.

  9. Use of DAGMan in CRAB3 to Improve the Splitting of CMS User Jobs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wolf, M.; Mascheroni, M.; Woodard, A.

    CRAB3 is a workload management tool used by CMS physicists to analyze data acquired by the Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider (LHC). Research in high energy physics often requires the analysis of large collections of files, referred to as datasets. The task is divided into jobs that are distributed among a large collection of worker nodes throughout the Worldwide LHC Computing Grid (WLCG). Splitting a large analysis task into optimally sized jobs is critical to efficient use of distributed computing resources. Jobs that are too big will have excessive runtimes and will not distributemore » the work across all of the available nodes. However, splitting the project into a large number of very small jobs is also inefficient, as each job creates additional overhead which increases load on infrastructure resources. Currently this splitting is done manually, using parameters provided by the user. However the resources needed for each job are difficult to predict because of frequent variations in the performance of the user code and the content of the input dataset. As a result, dividing a task into jobs by hand is difficult and often suboptimal. In this work we present a new feature called “automatic splitting” which removes the need for users to manually specify job splitting parameters. We discuss how HTCondor DAGMan can be used to build dynamic Directed Acyclic Graphs (DAGs) to optimize the performance of large CMS analysis jobs on the Grid. We use DAGMan to dynamically generate interconnected DAGs that estimate the processing time the user code will require to analyze each event. This is used to calculate an estimate of the total processing time per job, and a set of analysis jobs are run using this estimate as a specified time limit. Some jobs may not finish within the alloted time; they are terminated at the time limit, and the unfinished data is regrouped into smaller jobs and resubmitted.« less

  10. FIFE-Jobsub: a grid submission system for intensity frontier experiments at Fermilab

    NASA Astrophysics Data System (ADS)

    Box, Dennis

    2014-06-01

    The Fermilab Intensity Frontier Experiments use an integrated submission system known as FIFE-jobsub, part of the FIFE (Fabric for Frontier Experiments) initiative, to submit batch jobs to the Open Science Grid. FIFE-jobsub eases the burden on experimenters by integrating data transfer and site selection details in an easy to use and well-documented format. FIFE-jobsub automates tedious details of maintaining grid proxies for the lifetime of the grid job. Data transfer is handled using the Intensity Frontier Data Handling Client (IFDHC) [1] tool suite, which facilitates selecting the appropriate data transfer method from many possibilities while protecting shared resources from overload. Chaining of job dependencies into Directed Acyclic Graphs (Condor DAGS) is well supported and made easier through the use of input flags and parameters.

  11. A Fast-Time Simulation Environment for Airborne Merging and Spacing Research

    NASA Technical Reports Server (NTRS)

    Bussink, Frank J. L.; Doble, Nathan A.; Barmore, Bryan E.; Singer, Sharon

    2005-01-01

    As part of NASA's Distributed Air/Ground Traffic Management (DAG-TM) effort, NASA Langley Research Center is developing concepts and algorithms for merging multiple aircraft arrival streams and precisely spacing aircraft over the runway threshold. An airborne tool has been created for this purpose, called Airborne Merging and Spacing for Terminal Arrivals (AMSTAR). To evaluate the performance of AMSTAR and complement human-in-the-loop experiments, a simulation environment has been developed that enables fast-time studies of AMSTAR operations. The environment is based on TMX, a multiple aircraft desktop simulation program created by the Netherlands National Aerospace Laboratory (NLR). This paper reviews the AMSTAR concept, discusses the integration of the AMSTAR algorithm into TMX and the enhancements added to TMX to support fast-time AMSTAR studies, and presents initial simulation results.

  12. FIFE-Jobsub: a grid submission system for intensity frontier experiments at Fermilab

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Box, Dennis

    2014-01-01

    The Fermilab Intensity Frontier Experiments use an integrated submission system known as FIFE-jobsub, part of the FIFE (Fabric for Frontier Experiments) initiative, to submit batch jobs to the Open Science Grid. FIFE-jobsub eases the burden on experimenters by integrating data transfer and site selection details in an easy to use and well-documented format. FIFE-jobsub automates tedious details of maintaining grid proxies for the lifetime of the grid job. Data transfer is handled using the Intensity Frontier Data Handling Client (IFDHC) [1] tool suite, which facilitates selecting the appropriate data transfer method from many possibilities while protecting shared resources from overload.more » Chaining of job dependencies into Directed Acyclic Graphs (Condor DAGS) is well supported and made easier through the use of input flags and parameters.« less

  13. Instantaneous characterization of vegetable oils via TAG and FFA profiles by easy ambient sonic-spray ionization mass spectrometry.

    PubMed

    Simas, Rosineide C; Catharino, Rodrigo R; Cunha, Ildenize B S; Cabral, Elaine C; Barrera-Arellano, Daniel; Eberlin, Marcos N; Alberici, Rosana M

    2010-04-01

    A fast and reliable method is presented for the analysis of vegetable oils. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to efficiently desorb and ionize the main oil constituents from an inert surface under ambient conditions and to provide comprehensive triacylglyceride (TAG) and free fatty acid (FFA) profiles detected mainly as either [TAG + Na](+) or [FFA-H](-) ions. EASI(+/-)-MS analysis is simple, easily implemented, requires just a tiny droplet of the oil and is performed without any pre-separation or chemical manipulation. It also causes no fragmentation of TAG ions hence diacylglyceride (DAG) and monoacylglyceride (MAG) profiles and contents can also be measured. The EASI(+/-)-MS profiles of TAG and FFA permit authentication and quality control and can be used, for instance, to access levels of adulteration, acidity, oxidation or hydrolysis of vegetable oils in general.

  14. L'effet Hall Quantique

    NASA Astrophysics Data System (ADS)

    Samson, Thomas

    Nous proposons une methode permettant d'obtenir une expression pour la conductivite de Hall de structures electroniques bidimensionnelles et nous examinons celle -ci a la limite d'une temperature nulle dans le but de verifier l'effet Hall quantique. Nous allons nous interesser essentiellement a l'effet Hall quantique entier et aux effets fractionnaires inferieurs a un. Le systeme considere est forme d'un gaz d'electrons en interaction faible avec les impuretes de l'echantillon. Le modele du gaz d'electrons consiste en un gaz bidimensionnel d'electrons sans spin expose perpendiculairement a un champ magnetique uniforme. Ce dernier est decrit par le potentiel vecteur vec{rm A} defini dans la jauge de Dingle ou jauge symetrique. Conformement au formalisme de la seconde quantification, l'hamiltonien de ce gaz est represente dans la base des etats a un-corps de Dingle |n,m> et exprime ainsi en terme des operateurs de creation et d'annihilation correspondants a_sp{ rm n m}{dag} et a _{rm n m}. Nous supposons de plus que les electrons du niveau fondamental de Dingle interagissent entre eux via le potentiel coulombien. La methode utilisee fait appel a une equation mai tresse a N-corps, de nature quantique et statistique, et verifiant le second principe de la thermodynamique. A partir de celle-ci, nous obtenons un systeme d'equations differentielles appele hierarchie d'equations quantique dont la resolution nous permet de determiner une equation a un-corps, dite de Boltzmann quantique, et dictant l'evolution de la moyenne statistique de l'operateur non-diagonal a _sp{rm n m}{dag } a_{rm n}, _{rm m}, sous l'action du champ electrique applique vec{rm E}(t). C'est sa solution Tr(p(t) a _sp{rm n m}{dag} a_{rm n},_ {rm m}), qui definit la relation de convolution entre la densite courant de Hall vec{rm J}_{rm H }(t) et le champ electrique vec {rm E}(t) dont la transformee de Laplace-Fourier du noyau nous fournit l'expression de la conductivite de Hall desiree. Pour une valeur de

  15. Regaining Lost Separation in a Piloted Simulation of Autonomous Aircraft Operations

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Eischeid, Todd M.; Palmer, Michael T.; Wing, David J.

    2002-01-01

    NASA is currently investigating a new concept of operations for the National Airspace System, designed to improve capacity while maintaining or improving current levels of safety. This concept, known as Distributed Air/Ground Traffic Management (DAG-TM), allows appropriately equipped autonomous aircraft to maneuver freely for flight optimization while resolving conflicts with other traffic and staying out of special use airspace and hazardous weather. While Airborne Separation Assurance System (ASAS) tools would normally allow pilots to resolve conflicts before they become hazardous, evaluation of system performance in sudden, near-term conflicts is needed in order to determine concept feasibility. If an acceptable safety level can be demonstrated in these situations, then operations may be conducted with lower separation minimums. An experiment was conducted in NASA Langley s Air Traffic Operations Lab to address issues associated with resolving near-term conflicts and the potential use of lower separation minimums. Sixteen commercial airline pilots flew a total of 32 traffic scenarios that required them to use prototype ASAS tools to resolve close range pop-up conflicts. Required separation standards were set at either 3 or 5 NM lateral spacing, with 1000 ft vertical separation being used for both cases. Reducing the lateral separation from 5 to 3 NM did not appear to increase operational risk, as indicated by the proximity to the intruder aircraft. Pilots performed better when they followed tactical guidance cues provided by ASAS than when they didn't follow the guidance. As air-air separation concepts are evolved, further studies will consider integration issues between ASAS and existing Airborne Collision Avoidance Systems (ACAS).These types of non-normal events will require the ASAS to provide effective alerts and resolutions prior to the time that an Airborne Collision Avoidance System (ACAS) would give a Resolution Advisory (RA). When an RA is issued, a

  16. Using Longitudinal Assessment on Extensively Managed Ewes to Quantify Welfare Compromise and Risks

    PubMed Central

    Barber, Stuart; Hemsworth, Paul; Doyle, Rebecca

    2018-01-01

    Simple Summary Sheep managed extensively can be exposed to several welfare challenges during the year, and the risk of some diseases can increase in warmer and wetter seasons. In this study, the welfare of Merino ewes was examined over a calendar year. The welfare of these animals, kept on a single farm with consistent management, varied substantially. Overall, the largest number of ewes experienced compromise and risk to welfare at weaning, indicating that this was the most vulnerable time. The main welfare issues identified were under and over feeding, ewe mortality, lameness, ecto-parasites (flystrike) and mastitis, all of which could be improved by modifying management practices, such as improved nutritional management and monitoring and better tail docking procedures. Future research must consider that significant variation in the on-farm welfare of ewes occurs during a calendar year, which needs to be accounted for when conducting on-farm assessments. Abstract This study examined variation in the welfare of extensively managed ewes and potential welfare risks. A total of 100 Merino ewes (aged 2–4 years) were individually identified and examined at three key stages: pregnancy, lactation and weaning. Eight animal-based welfare measures were used to assess welfare: flight distance, body condition score (BCS), fleece condition, skin lesions, tail length, dag score, lameness and mastitis. Data were analysed by ANOVA and McNemar’s statistics. Overall, the average BCS of the group was in agreement with industry recommendations. However, a number of animals were classified with inadequate condition (either too thin or too fat) across the three observation periods. The presence of heavy dags was greatest at mid-lactation (87%, P < 0.0001), lameness was greatest at weaning (14%, P = 0.01), clinical mastitis was 1% annually, and five ewes were lost from the study. Ewes had better health at mid-pregnancy compared to mid-lactation and weaning. The main welfare issues

  17. Frequency Upconversion and Parametric Surface Instabilities in Microwave Plasma Interactions.

    NASA Astrophysics Data System (ADS)

    Rappaport, Harold Lee

    In this thesis the interaction of radiation with plasmas whose density profiles are nearly step functions of space and/or time are studied. The wavelengths of radiation discussed are large compared with plasma density gradient scale lengths. The frequency spectra are evaluated and the energy balance investigated for the transmitted and reflected transient electromagnetic waves that are generated when a monochromatic source drives a finite width plasma in which a temporal step increase in density occurs. Transmission resonances associated with the abrupt boundaries manifest themselves as previously unreported multiple frequency peaks in the transmitted electromagnetic spectrum. A tunneling effect is described in which a burst of energy is transmitted from the plasma immediately following a temporal density transition. Stability of an abruptly bounded plasma, one for which the incident radiation wavelength is large compared with the plasma density gradient scale length, is investigated for both s and p polarized radiation types. For s-polarized radiation a new formalism is introduced in which pump induced perturbations are expressed as an explicit superposition of linear and non-linear plasma half-space modes. Results for a particular regime and a summary of relevant literature is presented. We conclude that when s-polarized radiation acts alone on an abrupt diffusely bounded underdense plasma stimulated excitation of electron surface modes is suppressed. For p-polarized radiation the recently proposed Lagrangian Frame Two-Plasmon Decay mode (LFTPD) ^dag is investigated in the regime in which the instability is not resonantly coupled to surface waves propagating along the boundary region. In this case, spatially dependent growth rate profiles and spatially dependent transit layer magnetic fields are reported. The regime is of interest because we have found that when the perturbation wavenumber parallel to the boundary is less than the pump frequency divided by twice

  18. Simulation of Local Seismic Ground Motions from the FLASK Underground Nuclear Explosion near the Source Physics Experiment Dry Alluvium Geology Site

    NASA Astrophysics Data System (ADS)

    Rodgers, A. J.; Pitarka, A.; Wagoner, J. L.; Helmberger, D. V.

    2017-12-01

    The FLASK underground nuclear explosion (UNE) was conducted in Area 2 of Yucca Flat at the Nevada Test Site on May 26, 1970. The yield was 105 kilotons (DOE/NV-209-Rev 16) and the working point was 529 m below the surface. This test was detonated in faulted Tertiary volcanic rocks of Yucca Flat. Coincidently, the FLASK UNE ground zero (GZ) is close (< 600 m) to the U2ez hole where the Source Physics Experiment will be conducting Phase II of its chemical high explosives test series in the so-called Dry Alluvium Geology (DAG) site. Ground motions from FLASK were recorded by twelve (12) three-component seismic stations in the near-field at ranges 3-4 km. We digitized the paper records and used available metadata on peak particle velocity measurements made at the time to adjust the amplitudes. These waveforms show great variability in amplitudes and waveform complexity with azimuth from the shot, likely due to along propagation path structure such as the geometry of the hard-rock/alluvium contact above the working point. Peak particle velocities at stations in the deeper alluvium to the north, east and south of GZ have larger amplitudes than those to the west where the basement rock is much shallower. Interestingly, the transverse components show a similar trend with azimuth. In fact, the transverse component amplitudes are similar to the other components for many stations overlying deeper basement. In this study, we simulated the seismic response at the available near-field stations using the SW4 three-dimensional (3D) finite difference code. SW4 can simulate seismic wave propagation in 3D inelastic earth structure, including surface topography. SW4 includes vertical mesh refinement which greatly reduces the computational resources needed to run a specific problem. Simulations are performed on high-performance computers with grid spacing as small as 10 meters and resolution to 6 Hz. We are testing various subsurface models to identify the role of 3D structure on path

  19. Analyzed immunogenicity of fractional doses of Sabin-inactivated poliovirus vaccine (sIPV) with intradermal delivery in rats.

    PubMed

    Ma, Lei; Cai, Wei; Sun, Mingbo; Cun, Yina; Zhou, Jian; Liu, Jing; Hu, Wenzhu; Zhang, Xinwen; Song, Shaohui; Jiang, Shude; Liao, Guoyang

    2016-12-01

    The live-attenuated oral polio vaccine (OPV) will be no longer used when wild poliovirus (WPV) eliminating in worldwide, according to GPEI (the Global Polio Eradication Initiative) Reports. It is planning to replace OPV by Sabin-based inactivated poliovirus vaccine (sIPV) in developing countries, with purpose of reducing of the economic burden and maintaining of the appropriate antibody levels in population. It studied serial fractional doses immunized by intradermal injection (ID) in rats, to reduce consume of antigen and financial burden, maintaining sufficient immunogenicity; Methods: Study groups were divided in 4 groups of dose gradient, which were one-tenth (1/10), one-fifth (1/5), one-third (1/3) and one-full dose (1/1), according to the volume of distribution taken from the same batch of vaccine (sIPV). Wistar rats were injected intradermally with the needle and syringe sing the mantoux technique taken once month for 3 times. It was used as positive control that intramuscular inoculation (IM) was injected with one-full dose (1/1) with same batch of sIPV. PBS was used as negative control. Blood samples were collected via tail vein. After 30 d with 3 round of immunization, it analyzed the changes of neutralization antibody titers in the each group by each immunization program end; Results: The results of seroconversion had positive correlation with different doses in ID groups. The higher concentration of D-antigen (D-Ag) could conduct higher seroconversion. Furthermore, different types of viruses had different seroconversion trend. It showed that the geometric mean titers (GMTs) of each fractional-dose ID groups increased by higher concentration of D-Ag, and it got significant lower than the full-dose IM group. At 90 th days of immunization, the GMTs for each poliovirus subtypes of fractional doses were almost higher than 1:8, implied that it could be meaning positive seroprotection titer for polio vaccine types, according to WHO suggestion; Conclusions

  20. Coupled Hydrodynamic and Wave Propagation Modeling for the Source Physics Experiment: Study of Rg Wave Sources for SPE and DAG series.

    NASA Astrophysics Data System (ADS)

    Larmat, C. S.; Delorey, A.; Rougier, E.; Knight, E. E.; Steedman, D. W.; Bradley, C. R.

    2017-12-01

    This presentation reports numerical modeling efforts to improve knowledge of the processes that affect seismic wave generation and propagation from underground explosions, with a focus on Rg waves. The numerical model is based on the coupling of hydrodynamic simulation codes (Abaqus, CASH and HOSS), with a 3D full waveform propagation code, SPECFEM3D. Validation datasets are provided by the Source Physics Experiment (SPE) which is a series of highly instrumented chemical explosions at the Nevada National Security Site with yields from 100kg to 5000kg. A first series of explosions in a granite emplacement has just been completed and a second series in alluvium emplacement is planned for 2018. The long-term goal of this research is to review and improve current existing seismic sources models (e.g. Mueller & Murphy, 1971; Denny & Johnson, 1991) by providing first principles calculations provided by the coupled codes capability. The hydrodynamic codes, Abaqus, CASH and HOSS, model the shocked, hydrodynamic region via equations of state for the explosive, borehole stemming and jointed/weathered granite. A new material model for unconsolidated alluvium materials has been developed and validated with past nuclear explosions, including the 10 kT 1965 Merlin event (Perret, 1971) ; Perret and Bass, 1975). We use the efficient Spectral Element Method code, SPECFEM3D (e.g. Komatitsch, 1998; 2002), and Geologic Framework Models to model the evolution of wavefield as it propagates across 3D complex structures. The coupling interface is a series of grid points of the SEM mesh situated at the edge of the hydrodynamic code domain. We will present validation tests and waveforms modeled for several SPE tests which provide evidence that the damage processes happening in the vicinity of the explosions create secondary seismic sources. These sources interfere with the original explosion moment and reduces the apparent seismic moment at the origin of Rg waves up to 20%.

  1. IceProd 2: A Next Generation Data Analysis Framework for the IceCube Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Schultz, D.

    2015-12-01

    We describe the overall structure and new features of the second generation of IceProd, a data processing and management framework. IceProd was developed by the IceCube Neutrino Observatory for processing of Monte Carlo simulations, detector data, and analysis levels. It runs as a separate layer on top of grid and batch systems. This is accomplished by a set of daemons which process job workflow, maintaining configuration and status information on the job before, during, and after processing. IceProd can also manage complex workflow DAGs across distributed computing grids in order to optimize usage of resources. IceProd is designed to be very light-weight; it runs as a python application fully in user space and can be set up easily. For the initial completion of this second version of IceProd, improvements have been made to increase security, reliability, scalability, and ease of use.

  2. Tackling pollution by organic farming is capable of increasing fortified foods.

    PubMed

    Navarro-Aviñó, J P; Navarro, J J Fernández; Castro, V Vargas; Ripoll, I Ilzarbe; Sahuquillo, M J Márquez

    2016-01-01

    The global pollution stage is poisoning the biosphere and causing global temperatures to rise, necessitating a drastic change in the way man is dealing with nature. One change that may produce many beneficial effects on the biosphere and human health is the use of specific organic farming to produce food in a more integrated way in nature and to increase the capacity of man's own response. Despite many experts' opinion another way to deal with environmental contamination is possible: organic farming, which can increase man's ability to fortify foods. After more than 20 years working under this discipline, Bodegas Dagon is able to achieve the highest stilbenes concentrations (as resveratrol). Versus 14.3 mg/l, "Bodegas Dagón" wines contain resveratrol (HPLC and UV-spectroscopy) up to 1611.73 ± 72.66 mg/l, standing as world's potentially healthiest wine reported to date.

  3. Design of a Multi-mode Flight Deck Decision Support System for Airborne Conflict Management

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Krishnamurthy, Karthik

    2004-01-01

    NASA Langley has developed a multi-mode decision support system for pilots operating in a Distributed Air-Ground Traffic Management (DAG-TM) environment. An Autonomous Operations Planner (AOP) assists pilots in performing separation assurance functions, including conflict detection, prevention, and resolution. Ongoing AOP design has been based on a comprehensive human factors analysis and evaluation results from previous human-in-the-loop experiments with airline pilot test subjects. AOP considers complex flight mode interactions and provides flight guidance to pilots consistent with the current aircraft control state. Pilots communicate goals to AOP by setting system preferences and actively probing potential trajectories for conflicts. To minimize training requirements and improve operational use, AOP design leverages existing alerting philosophies, displays, and crew interfaces common on commercial aircraft. Future work will consider trajectory prediction uncertainties, integration with the TCAS collision avoidance system, and will incorporate enhancements based on an upcoming air-ground coordination experiment.

  4. IceProd 2 Usage Experience

    NASA Astrophysics Data System (ADS)

    Delventhal, D.; Schultz, D.; Diaz Velez, J. C.

    2017-10-01

    IceProd is a data processing and management framework developed by the IceCube Neutrino Observatory for processing of Monte Carlo simulations, detector data, and data driven analysis. It runs as a separate layer on top of grid and batch systems. This is accomplished by a set of daemons which process job workflow, maintaining configuration and status information on the job before, during, and after processing. IceProd can also manage complex workflow DAGs across distributed computing grids in order to optimize usage of resources. IceProd has recently been rewritten to increase its scaling capabilities, handle user analysis workflows together with simulation production, and facilitate the integration with 3rd party scheduling tools. IceProd 2, the second generation of IceProd, has been running in production for several months now. We share our experience setting up the system and things we’ve learned along the way.

  5. Dual Functions of Lip6 and Its Regulation of Lipid Metabolism in the Oleaginous Fungus Mucor circinelloides.

    PubMed

    Zan, Xinyi; Tang, Xin; Chu, Linfang; Song, Yuanda

    2018-03-21

    Although multiple roles of lipases have been reported in yeasts and microalgae, the functions of lipases have not been studied in oleaginous filamentous fungi. Lipase Lip6 has been reported in the oleaginous filamentous fungus Mucor circinelloides with the consensus lipase motif GXSXG and the typical acyltransferase motif of H-(X) 4 -D. To demonstrate that Lip6 might play dual roles as a lipase and an acyltransferase, we performed site-directed mutagenesis in the lipase motif and the acyltransferase motif of Lip6. Mutation in the lipase motif increased cell biomass by 12%-18% and promoted lipid accumulation by 9%-24%, while mutation in the acyltransferase motif induced lipid degradation. In vitro, purified Lip6 had a slight lipase activity but had a stronger phospholipid:DAG acyltransferase activity. Enzyme activity assays in vivo and phospholipid synthesis pathway analysis suggested that phosphatidyl serine and phosphatidyl ethanolamine can be the supplier of a fatty acyl moiety to form TAG in M. circinelloides.

  6. A uniform approach for programming distributed heterogeneous computing systems

    PubMed Central

    Grasso, Ivan; Pellegrini, Simone; Cosenza, Biagio; Fahringer, Thomas

    2014-01-01

    Large-scale compute clusters of heterogeneous nodes equipped with multi-core CPUs and GPUs are getting increasingly popular in the scientific community. However, such systems require a combination of different programming paradigms making application development very challenging. In this article we introduce libWater, a library-based extension of the OpenCL programming model that simplifies the development of heterogeneous distributed applications. libWater consists of a simple interface, which is a transparent abstraction of the underlying distributed architecture, offering advanced features such as inter-context and inter-node device synchronization. It provides a runtime system which tracks dependency information enforced by event synchronization to dynamically build a DAG of commands, on which we automatically apply two optimizations: collective communication pattern detection and device-host-device copy removal. We assess libWater’s performance in three compute clusters available from the Vienna Scientific Cluster, the Barcelona Supercomputing Center and the University of Innsbruck, demonstrating improved performance and scaling with different test applications and configurations. PMID:25844015

  7. Beyond triglyceride synthesis: the dynamic functional roles of MGAT and DGAT enzymes in energy metabolism.

    PubMed

    Shi, Yuguang; Cheng, Dong

    2009-07-01

    Monoacyglycerol acyltransferases (MGATs) and diacylglycerol acyltransferases (DGATs) catalyze two consecutive steps of enzyme reactions in the synthesis of triacylglycerols (TAGs). The metabolic complexity of TAG synthesis is reflected by the presence of multiple isoforms of MGAT and DGAT enzymes that differ in catalytic properties, subcellular localization, tissue distribution, and physiological functions. MGAT and DGAT enzymes play fundamental roles in the metabolism of monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) that are involved in many aspects of physiological functions, such as intestinal fat absorption, lipoprotein assembly, adipose tissue formation, signal transduction, satiety, and lactation. The recent progress in the phenotypic characterization of mice deficient in MGAT and DGAT enzymes and the development of chemical inhibitors have revealed important roles of these enzymes in the regulation of energy homeostasis and insulin sensitivity. Consequently, selective inhibition of MGAT or DGAT enzymes by synthetic compounds may provide novel treatment for obesity and its related metabolic complications.

  8. Beyond triglyceride synthesis: the dynamic functional roles of MGAT and DGAT enzymes in energy metabolism

    PubMed Central

    Shi, Yuguang; Cheng, Dong

    2009-01-01

    Monoacyglycerol acyltransferases (MGATs) and diacylglycerol acyltransferases (DGATs) catalyze two consecutive steps of enzyme reactions in the synthesis of triacylglycerols (TAGs). The metabolic complexity of TAG synthesis is reflected by the presence of multiple isoforms of MGAT and DGAT enzymes that differ in catalytic properties, subcellular localization, tissue distribution, and physiological functions. MGAT and DGAT enzymes play fundamental roles in the metabolism of monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) that are involved in many aspects of physiological functions, such as intestinal fat absorption, lipoprotein assembly, adipose tissue formation, signal transduction, satiety, and lactation. The recent progress in the phenotypic characterization of mice deficient in MGAT and DGAT enzymes and the development of chemical inhibitors have revealed important roles of these enzymes in the regulation of energy homeostasis and insulin sensitivity. Consequently, selective inhibition of MGAT or DGAT enzymes by synthetic compounds may provide novel treatment for obesity and its related metabolic complications. PMID:19116371

  9. And then I saw her race: Race-based expectations affect infants' word processing.

    PubMed

    Weatherhead, Drew; White, Katherine S

    2018-08-01

    How do our expectations about speakers shape speech perception? Adults' speech perception is influenced by social properties of the speaker (e.g., race). When in development do these influences begin? In the current study, 16-month-olds heard familiar words produced in their native accent (e.g., "dog") and in an unfamiliar accent involving a vowel shift (e.g., "dag"), in the context of an image of either a same-race speaker or an other-race speaker. Infants' interpretation of the words depended on the speaker's race. For the same-race speaker, infants only recognized words produced in the familiar accent; for the other-race speaker, infants recognized both versions of the words. Two additional experiments showed that infants only recognized an other-race speaker's atypical pronunciations when they differed systematically from the native accent. These results provide the first evidence that expectations driven by unspoken properties of speakers, such as race, influence infants' speech processing. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Development of a Free-Flight Simulation Infrastructure

    NASA Technical Reports Server (NTRS)

    Miles, Eric S.; Wing, David J.; Davis, Paul C.

    1999-01-01

    In anticipation of a projected rise in demand for air transportation, NASA and the FAA are researching new air-traffic-management (ATM) concepts that fall under the paradigm known broadly as ":free flight". This paper documents the software development and engineering efforts in progress by Seagull Technology, to develop a free-flight simulation (FFSIM) that is intended to help NASA researchers test mature-state concepts for free flight, otherwise referred to in this paper as distributed air / ground traffic management (DAG TM). Under development is a distributed, human-in-the-loop simulation tool that is comprehensive in its consideration of current and envisioned communication, navigation and surveillance (CNS) components, and will allow evaluation of critical air and ground traffic management technologies from an overall systems perspective. The FFSIM infrastructure is designed to incorporate all three major components of the ATM triad: aircraft flight decks, air traffic control (ATC), and (eventually) airline operational control (AOC) centers.

  11. Canonical multi-valued input Reed-Muller trees and forms

    NASA Technical Reports Server (NTRS)

    Perkowski, M. A.; Johnson, P. D.

    1991-01-01

    There is recently an increased interest in logic synthesis using EXOR gates. The paper introduces the fundamental concept of Orthogonal Expansion, which generalizes the ring form of the Shannon expansion to the logic with multiple-valued (mv) inputs. Based on this concept we are able to define a family of canonical tree circuits. Such circuits can be considered for binary and multiple-valued input cases. They can be multi-level (trees and DAG's) or flattened to two-level AND-EXOR circuits. Input decoders similar to those used in Sum of Products (SOP) PLA's are used in realizations of multiple-valued input functions. In the case of the binary logic the family of flattened AND-EXOR circuits includes several forms discussed by Davio and Green. For the case of the logic with multiple-valued inputs, the family of the flattened mv AND-EXOR circuits includes three expansions known from literature and two new expansions.

  12. Compression of Probabilistic XML Documents

    NASA Astrophysics Data System (ADS)

    Veldman, Irma; de Keijzer, Ander; van Keulen, Maurice

    Database techniques to store, query and manipulate data that contains uncertainty receives increasing research interest. Such UDBMSs can be classified according to their underlying data model: relational, XML, or RDF. We focus on uncertain XML DBMS with as representative example the Probabilistic XML model (PXML) of [10,9]. The size of a PXML document is obviously a factor in performance. There are PXML-specific techniques to reduce the size, such as a push down mechanism, that produces equivalent but more compact PXML documents. It can only be applied, however, where possibilities are dependent. For normal XML documents there also exist several techniques for compressing a document. Since Probabilistic XML is (a special form of) normal XML, it might benefit from these methods even more. In this paper, we show that existing compression mechanisms can be combined with PXML-specific compression techniques. We also show that best compression rates are obtained with a combination of PXML-specific technique with a rather simple generic DAG-compression technique.

  13. A uniform approach for programming distributed heterogeneous computing systems.

    PubMed

    Grasso, Ivan; Pellegrini, Simone; Cosenza, Biagio; Fahringer, Thomas

    2014-12-01

    Large-scale compute clusters of heterogeneous nodes equipped with multi-core CPUs and GPUs are getting increasingly popular in the scientific community. However, such systems require a combination of different programming paradigms making application development very challenging. In this article we introduce libWater, a library-based extension of the OpenCL programming model that simplifies the development of heterogeneous distributed applications. libWater consists of a simple interface, which is a transparent abstraction of the underlying distributed architecture, offering advanced features such as inter-context and inter-node device synchronization. It provides a runtime system which tracks dependency information enforced by event synchronization to dynamically build a DAG of commands, on which we automatically apply two optimizations: collective communication pattern detection and device-host-device copy removal. We assess libWater's performance in three compute clusters available from the Vienna Scientific Cluster, the Barcelona Supercomputing Center and the University of Innsbruck, demonstrating improved performance and scaling with different test applications and configurations.

  14. Lipase catalyzed synthesis of neutral glycerides rich in micronutrients from rice bran oil fatty acid distillate.

    PubMed

    Nandi, Sumit; Gangopadhyay, Sarbani; Ghosh, Santinath

    2008-01-01

    Neutral glycerides with micronutrients like sterols, tocopherols and squalene may be prepared from cheap raw material like rice bran oil fatty acid distillate (RBO FAD). RBO FAD is an important byproduct of vegetable oil refining industries in the physical refining process. Glycerides like triacylglycerols (TAG), diacylglycerols (DAG) and monoacylglycerols (MAG) containing significant amounts of unsaponifiable matter like sterols, tocopherols and hydrocarbons (mainly squalene) may certainly be considered as novel functional food ingredients. Fatty acids present in RBO FAD were esterified with glycerol of varying amount (1:0.33, 1:0.5, 1:1 and 1:1.5 of FAD : glycerol ratio) for 8 h using non-specific enzyme NS 40013 (Candida antartica). After esterification the product mixture containing mono, di- and triglycerides was purified by molecular distillation to remove excess free fatty acids and also other volatile undesirable components. The purified product containing sterols, tocopherols and squalene can be utilized in various food formulations.

  15. Changes in fatty acid composition and lipid profile during koji fermentation and their relationships with soy sauce flavour.

    PubMed

    Feng, Yunzi; Chen, Zhiyao; Liu, Ning; Zhao, Haifeng; Cui, Chun; Zhao, Mouming

    2014-09-01

    Evolution of lipids during koji fermentation and the effect of lipase supplementation on the sensory properties of soy sauce were investigated. Results showed that total lipids of the koji samples were in the range of 16-21%. The extracted lipid of initial koji consisted mainly of triacylglycerols (TAGs, >98%), followed by phospholipids (PLs), diglycerides (DAGs), monoacylglycerols (MAGs) and free fatty acids (FFAs). As the fermentation proceeded, peroxide value of the lipids decreased while carbonyl value increased (p<0.05). Linoleic acid was utilised fastest according to the fatty acid composition of total lipids, and preferential degradation of PLs to liberate FFAs was also observed. Moreover, phospholipase supplementation had significant influence on the sensory characteristics of soy sauce, especially enhanced (p<0.05) scores for the umami and kokumi taste attributes. All these results indicated that the control of PLs utilisation during fermentation was a potential method to improve soy sauce's characteristic taste. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A Sparse Structure Learning Algorithm for Gaussian Bayesian Network Identification from High-Dimensional Data

    PubMed Central

    Huang, Shuai; Li, Jing; Ye, Jieping; Fleisher, Adam; Chen, Kewei; Wu, Teresa; Reiman, Eric

    2014-01-01

    Structure learning of Bayesian Networks (BNs) is an important topic in machine learning. Driven by modern applications in genetics and brain sciences, accurate and efficient learning of large-scale BN structures from high-dimensional data becomes a challenging problem. To tackle this challenge, we propose a Sparse Bayesian Network (SBN) structure learning algorithm that employs a novel formulation involving one L1-norm penalty term to impose sparsity and another penalty term to ensure that the learned BN is a Directed Acyclic Graph (DAG)—a required property of BNs. Through both theoretical analysis and extensive experiments on 11 moderate and large benchmark networks with various sample sizes, we show that SBN leads to improved learning accuracy, scalability, and efficiency as compared with 10 existing popular BN learning algorithms. We apply SBN to a real-world application of brain connectivity modeling for Alzheimer’s disease (AD) and reveal findings that could lead to advancements in AD research. PMID:22665720

  17. Analysis of Aircraft Clusters to Measure Sector-Independent Airspace Congestion

    NASA Technical Reports Server (NTRS)

    Bilimoria, Karl D.; Lee, Hilda Q.

    2005-01-01

    The Distributed Air/Ground Traffic Management (DAG-TM) concept of operations* permits appropriately equipped aircraft to conduct Free Maneuvering operations. These independent aircraft have the freedom to optimize their trajectories in real time according to user preferences; however, they also take on the responsibility to separate themselves from other aircraft while conforming to any local Traffic Flow Management (TFM) constraints imposed by the air traffic service provider (ATSP). Examples of local-TFM constraints include temporal constraints such as a required time of arrival (RTA), as well as spatial constraints such as regions of convective weather, special use airspace, and congested airspace. Under current operations, congested airspace typically refers to a sector(s) that cannot accept additional aircraft due to controller workload limitations; hence Dynamic Density (a metric that is indicative of controller workload) can be used to quantify airspace congestion. However, for Free Maneuvering operations under DAG-TM, an additional metric is needed to quantify the airspace congestion problem from the perspective of independent aircraft. Such a metric would enable the ATSP to prevent independent aircraft from entering any local areas of congestion in which the flight deck based systems and procedures may not be able to ensure separation. This new metric, called Gaggle Density, offers the ATSP a mode of control to regulate normal operations and to ensure safety and stability during rare-normal or off-normal situations (e.g., system failures). It may be difficult to certify Free Maneuvering systems for unrestricted operations, but it may be easier to certify systems and procedures for specified levels of Gaggle Density that could be monitored by the ATSP, and maintained through relatively minor flow-rate (RTA type) restrictions. Since flight deck based separation assurance is airspace independent, the challenge is to measure congestion independent of sector

  18. A cost-benefit analysis of pre- and post-lambing anthelmintic treatments to twin-bearing ewes on commercial farms in the southern North Island of New Zealand.

    PubMed

    Garland, C B; Leathwick, D M

    2015-07-01

    To conduct a cost-benefit analysis of the administration of anthelmintics to adult ewes around lambing. Production data from comparisons of different anthelmintic treatments with no treatment were used in a cost-benefit analysis. The data were from 14 trials (part of an experiment carried out on one farm in 1 year) conducted on sheep and beef farms (eight in 2011 and six in 2012) in the Wairarapa region of New Zealand. The cost structure involved the purchase price of products and the labour cost of administration. The four key benefits identified for the calculation of economic returns, relative to untreated ewes, were: increased value of ewes sold (culled) at weaning, additional lambs weaned related to ewe liveweight at mating, increased total weight of lamb weaned per ewe, and reduced number of ewes requiring removal of soiled wool at weaning due to a lower dag score. Commercial values for these variables as at December 2013 were used, with the measured production data, to calculate a net (NZ$) benefit for every treatment-trial combination. The economic return on treating ewes around lambing with anthelmintics was highly variable and across all trials treatment resulted in a financial loss in 18/38 (47%) groups of ewes. The mean net benefit from pre-lambing administration of a controlled release capsule (CRC) containing albendazole and abamectin was 5.36 (95% CI=-2.64 to 13.35) $/ewe, but overall was not different from zero (p=0.171). A breakdown of the overall gross benefit into its various components showed that weight of lamb weaned per ewe had the largest influence (a mean benefit of $5.68/ewe), followed by ewe liveweight pre-mating ($2.45/ewe), ewe liveweight at weaning ($0.66/ewe) and reduced dag score ($0.15/ewe). Other anthelmintic treatments all showed highly variable responses amongst trials, with some negative cost-benefits. There was no significant difference between any of the treatments except a short-acting oral treatment at tail-docking had a

  19. Skeletal muscle ceramide species in men with abdominal obesity.

    PubMed

    de la Maza, M P; Rodriguez, J M; Hirsch, S; Leiva, L; Barrera, G; Bunout, D

    2015-04-01

    Obesity is a risk factor for diabetes and its consequences, including accelerated ageing and mortality. The underlying factor could be accumulation of certain lipid moieties, such as ceramides (CER) and diacylgycerol (DAG) within muscle tissue, which are known to promote insulin resistance (IR), induce inflammation and oxidative injury, ultimately altering muscle function. First, to study the relationship between body composition and age (independent variables) with skeletal muscle accumulation of lipid species, oxidative injury and strength. Second, to analyze the relationship between muscle tissue metabolites and insulin resistance, inflammation and lymphocyte telomere length, the latter as an indicator of ageing. The sample included 56 healthy sedentary males, scheduled for inguinal hernia surgery, aged 27 to 80 y. Each individual was subject to anthropometric measurements, body composition assessment through radiologic densitometry (DEXA), measurement of handgrip and quadriceps strength, serum biochemical parameters (lipoproteins, creatinine, high sensitivity C reactive protein [hsCRP], fasting and post glucose insulin and glucose concentrations for calculation of IR through the Matsuda and HOMA-IR indexes), and extraction of peripheral leukocytes for measurement of telomere length. During the surgical procedure, a sample of muscle tissue was obtained (anterior abdominal oblique) in order to measure CER and DAG (and sub species according to chain length and saturation) by mass spectrometry, 4 hydroxy-2-nonenal adducts (4-HNE) using electron microscopy immunohistochemistry, and carboxymethyl-lisine (CML) by immunohistochemistry, the latter as indicators of oxidative stress (OS). Body mass index (BMI) of twenty six individuals was > 25 k/m2, while BMI of 7 was > 30 k/m2. Overweight/obese individuals, did not exhibit differences in skeletal muscle lipid metabolites, however total CER and specific long chain CER sub-species (20 and 22 carbon) increased

  20. Ag Isotopic Evolution of the Mantle During Accretion: New Constraints from Pd and Ag Metal-Silicate Partitioning

    NASA Technical Reports Server (NTRS)

    Righter, K.; Schonbachler, M.

    2018-01-01

    Decay of (sup 107) Pd to (sup 107) Ag has a half-life of 6.5 times 10 (sup 6) mega-annums. Because these elements are siderophile but also volatile, they offer potential constraints on the timing of core formation as well as volatile addition. Initial modelling has shown that the Ag isotopic composition of the bulk silicate Earth (BSE) can be explained if accretion occurs with late volatile addition. These arguments were tested for sensitivity for pre-cursor Pd/Ag contents, and for a fixed Pd/Ag ratio of the BSE of 0.1. New Ag and Pd partitioning data has allowed a better understanding of the partitioning behavior of Pd and Ag during core formation. The effects of S, C and Si, and the effect of high temperature and pressure has been evaluated. We can now calculate D(Ag) and D(Pd) over the wide range of PT conditions and variable metallic liquid compositions that are known during accretion. We then use this new partitioning information to revisit the Ag isotopic composition of the BSE during accretion.

  1. A network perspective on comorbid depression in adolescents with obsessive-compulsive disorder.

    PubMed

    Jones, Payton J; Mair, Patrick; Riemann, Bradley C; Mugno, Beth L; McNally, Richard J

    2018-01-01

    People with obsessive-compulsive disorder [OCD] frequently suffer from depression, a comorbidity associated with greater symptom severity and suicide risk. We examined the associations between OCD and depression symptoms in 87 adolescents with primary OCD. We computed an association network, a graphical LASSO, and a directed acyclic graph (DAG) to model symptom interactions. Models showed OCD and depression as separate syndromes linked by bridge symptoms. Bridges between the two disorders emerged between obsessional problems in the OCD syndrome, and guilt, concentration problems, and sadness in the depression syndrome. A directed network indicated that OCD symptoms directionally precede depression symptoms. Concentration impairment emerged as a highly central node that may be distinctive to adolescents. We conclude that the network approach to mental disorders provides a new way to understand the etiology and maintenance of comorbid OCD-depression. Network analysis can improve research and treatment of mental disorder comorbidities by generating hypotheses concerning potential causal symptom structures and by identifying symptoms that may bridge disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A central role for phosphatidic acid as a lipid mediator of regulated exocytosis in apicomplexa.

    PubMed

    Bullen, Hayley E; Soldati-Favre, Dominique

    2016-08-01

    Lipids are commonly known for the structural roles they play, however, the specific contribution of different lipid classes to wide-ranging signalling pathways is progressively being unravelled. Signalling lipids and their associated effector proteins are emerging as significant contributors to a vast array of effector functions within cells, including essential processes such as membrane fusion and vesicle exocytosis. Many phospholipids have signalling capacity, however, this review will focus on phosphatidic acid (PA) and the enzymes implicated in its production from diacylglycerol (DAG) and phosphatidylcholine (PC): DGK and PLD respectively. PA is a negatively charged, cone-shaped lipid identified as a key mediator in specific membrane fusion and vesicle exocytosis events in a variety of mammalian cells, and has recently been implicated in specialised secretory organelle exocytosis in apicomplexan parasites. This review summarises the recent work implicating a role for PA regulation in exocytosis in various cell types. We will discuss how these signalling events are linked to pathogenesis in the phylum Apicomplexa. © 2016 Federation of European Biochemical Societies.

  3. Mitochondrial lipids in Bufo arenarum full-grown oocytes.

    PubMed

    Gili, Valeria; Alonso, Telma S

    2004-05-01

    Both the content and composition of polar and neutral lipids from the mitochondrial fraction of ovarian full-grown Bufo arenarum oocytes were analysed in the present study. Triacylglycerols (TAG) represent 33% of the total lipids, followed by phosphatidylcholine (PC), free fatty acids (FFA) and phosphatidylethanolamine (PE). Diphosphatidylglycerol (DPG) or cardiolipin, a specific component of the inner mitochondrial membrane, represents about 4% of the total lipid content. Palmitic (16:0) and arachidonic (20:4n6) acids are the most abundant fatty acids in PC and PE, respectively. DPG is enriched in fatty acids with carbon chain lengths of 18, the principal component being linoleic acid. In phosphatidylinositol (PI), 20:4n6 and stearic acid (18:0) represent about 72 mol% of the total acyl group level. The main fatty acids in TAG are linoleic (18:2), oleic (18:1), and palmitic acids. The fatty acid composition of FFA and diacylglycerols (DAG) is similar, 16:0 being the most abundant acyl group. PE is the most unsaturated lipid and sphingomyelin (SM) has the lowest unsaturation index.

  4. UPC++ Specification v1.0, Draft 6

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bachan, J.; Baden, Scott; Bonachea, Dan

    UPC++ is a C++11 library providing classes and functions that support Partitioned Global Address Space (PGAS) programming. We are revising the library under the auspices of the DOE’s Exascale Computing Project, to meet the needs of applications requiring PGAS support. UPC++ is intended for implementing elaborate distributed data structures where communication is irregular or fine-grained. The UPC++ interfaces for moving non-contiguous data and handling memories with different optimal access methods are composable and similar to those used in conventional C++. The UPC++ programmer can expect communication to run at close to hardware speeds. The key facilities in UPC++ are globalmore » pointers, that enable the programmer to express ownership information for improving locality, one-sided communication, both put/get and RPC, futures and continuations. Futures capture data readiness state, which is useful in making scheduling decisions, and continuations provide for completion handling via callbacks. Together, these enable the programmer to chain together a DAG of operations to execute asynchronously as high-latency dependencies become satisfied.« less

  5. UPC++ Specification v1.0, Draft 4

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bachan, J.; Baden, S.; Bonachea, Dan

    UPC++ is a C++11 library providing classes and functions that support Asynchronous Partitioned Global Address Space (APGAS) programming. We are revising the library under the auspices of the DOE’s Exascale Computing Project, to meet the needs of applications requiring PGAS support. UPC++ is intended for implementing elaborate distributed data structures where communication is irregular or fine-grained. The UPC++ interfaces for moving non-contiguous data and handling memories with different optimal access methods are composable and similar to those used in conventional C++. The UPC++ programmer can expect communication to run at close to hardware speeds. The key facilities in UPC++ aremore » global pointers, that enable the programmer to express ownership information for improving locality, one-sided communication, both put/get and RPC, futures and continuations. Futures capture data readiness state, which is useful in making scheduling decisions, and continuations provide for completion handling via callbacks. Together, these enable the programmer to chain together a DAG of operations to execute asynchronously as high-latency dependencies become satisfied.« less

  6. The Role of Ambient Ozone in Epidemiologic Studies of Heat-Related Mortality

    PubMed Central

    Snowden, Jonathan M.; Kontgis, Caitlin; Tager, Ira B.

    2012-01-01

    Background: A large and growing literature investigating the role of extreme heat on mortality has conceptualized the role of ambient ozone in various ways, sometimes treating it as a confounder, sometimes as an effect modifier, and sometimes as a co-exposure. Thus, there is a lack of consensus about the roles that temperature and ozone together play in causing mortality. Objectives: We applied directed acyclic graphs (DAGs) to the topic of heat-related mortality to graphically represent the subject matter behind the research questions and to provide insight on the analytical options available. Discussion: On the basis of the subject matter encoded in the graphs, we assert that the role of ozone in studies of temperature and mortality is a causal intermediate that is affected by temperature and that can also affect mortality, rather than a confounder. Conclusions: We discuss possible questions of interest implied by this causal structure and propose areas of future work to further clarify the role of air pollutants in epidemiologic studies of extreme temperature. PMID:22899622

  7. Regulation of Hepatic Triacylglycerol Metabolism by CGI-58 Does Not Require ATGL Co-activation.

    PubMed

    Lord, Caleb C; Ferguson, Daniel; Thomas, Gwynneth; Brown, Amanda L; Schugar, Rebecca C; Burrows, Amy; Gromovsky, Anthony D; Betters, Jenna; Neumann, Chase; Sacks, Jessica; Marshall, Stephanie; Watts, Russell; Schweiger, Martina; Lee, Richard G; Crooke, Rosanne M; Graham, Mark J; Lathia, Justin D; Sakaguchi, Takuya F; Lehner, Richard; Haemmerle, Guenter; Zechner, Rudolf; Brown, J Mark

    2016-07-26

    Adipose triglyceride lipase (ATGL) and comparative gene identification 58 (CGI-58) are critical regulators of triacylglycerol (TAG) turnover. CGI-58 is thought to regulate TAG mobilization by stimulating the enzymatic activity of ATGL. However, it is not known whether this coactivation function of CGI-58 occurs in vivo. Moreover, the phenotype of human CGI-58 mutations suggests ATGL-independent functions. Through direct comparison of mice with single or double deficiency of CGI-58 and ATGL, we show here that CGI-58 knockdown causes hepatic steatosis in both the presence and absence of ATGL. CGI-58 also regulates hepatic diacylglycerol (DAG) and inflammation in an ATGL-independent manner. Interestingly, ATGL deficiency, but not CGI-58 deficiency, results in suppression of the hepatic and adipose de novo lipogenic program. Collectively, these findings show that CGI-58 regulates hepatic neutral lipid storage and inflammation in the genetic absence of ATGL, demonstrating that mechanisms driving TAG lipolysis in hepatocytes differ significantly from those in adipocytes. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. agriGO v2.0: a GO analysis toolkit for the agricultural community, 2017 update.

    PubMed

    Tian, Tian; Liu, Yue; Yan, Hengyu; You, Qi; Yi, Xin; Du, Zhou; Xu, Wenying; Su, Zhen

    2017-07-03

    The agriGO platform, which has been serving the scientific community for >10 years, specifically focuses on gene ontology (GO) enrichment analyses of plant and agricultural species. We continuously maintain and update the databases and accommodate the various requests of our global users. Here, we present our updated agriGO that has a largely expanded number of supporting species (394) and datatypes (865). In addition, a larger number of species have been classified into groups covering crops, vegetables, fish, birds and insects closely related to the agricultural community. We further improved the computational efficiency, including the batch analysis and P-value distribution (PVD), and the user-friendliness of the web pages. More visualization features were added to the platform, including SEACOMPARE (cross comparison of singular enrichment analysis), direct acyclic graph (DAG) and Scatter Plots, which can be merged by choosing any significant GO term. The updated platform agriGO v2.0 is now publicly accessible at http://systemsbiology.cau.edu.cn/agriGOv2/. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  9. agriGO v2.0: a GO analysis toolkit for the agricultural community, 2017 update

    PubMed Central

    Tian, Tian; Liu, Yue; Yan, Hengyu; You, Qi; Yi, Xin; Du, Zhou

    2017-01-01

    Abstract The agriGO platform, which has been serving the scientific community for >10 years, specifically focuses on gene ontology (GO) enrichment analyses of plant and agricultural species. We continuously maintain and update the databases and accommodate the various requests of our global users. Here, we present our updated agriGO that has a largely expanded number of supporting species (394) and datatypes (865). In addition, a larger number of species have been classified into groups covering crops, vegetables, fish, birds and insects closely related to the agricultural community. We further improved the computational efficiency, including the batch analysis and P-value distribution (PVD), and the user-friendliness of the web pages. More visualization features were added to the platform, including SEACOMPARE (cross comparison of singular enrichment analysis), direct acyclic graph (DAG) and Scatter Plots, which can be merged by choosing any significant GO term. The updated platform agriGO v2.0 is now publicly accessible at http://systemsbiology.cau.edu.cn/agriGOv2/. PMID:28472432

  10. Evaluation of a Terminal Area In-Trail Approach Spacing, Project and Study

    NASA Technical Reports Server (NTRS)

    Shelden, Stephen; Johnson, Walter (Editor)

    2001-01-01

    Reported here are the results of work completed as a precursor to Distributed Air Ground (DAG), Concept Element 11 (CE11) research. CE11 is a NASA, Advanced Air Transportation Technologies (AATT) concept initiated to promote research on in-trail merging and spacing during approach in the terminal area environment, such that improvements to the National Air Space (NAS) may be realized. A description of the project concept, results of a preliminary study, and a literature review are presented. In terms of conclusions, study results, and reference material respectively: 1) the concept is supported as being significant to NAS capacity improvement, 2) the preliminary study indicated that having more than one downstream, in-trail aircraft present on a CDTI during approach may be advantageous, and that flying traditional Standard Terminal Arrival Routes (STAR) utilizing advanced decision support tools (DST) may be complicated by wake turbulence considerations, a lack of vertical awareness on the part of the flight crew, and the 'step-down' nature of many terminal area approaches, and 3) the results of a literature review are presented for future reference.

  11. Itk tyrosine kinase substrate docking is mediated by a nonclassical SH2 domain surface of PLCgamma1.

    PubMed

    Min, Lie; Joseph, Raji E; Fulton, D Bruce; Andreotti, Amy H

    2009-12-15

    Interleukin-2 tyrosine kinase (Itk) is a Tec family tyrosine kinase that mediates signaling processes after T cell receptor engagement. Activation of Itk requires recruitment to the membrane via its pleckstrin homology domain, phosphorylation of Itk by the Src kinase, Lck, and binding of Itk to the SLP-76/LAT adapter complex. After activation, Itk phosphorylates and activates phospholipase C-gamma1 (PLC-gamma1), leading to production of two second messengers, DAG and IP(3). We have previously shown that phosphorylation of PLC-gamma1 by Itk requires a direct, phosphotyrosine-independent interaction between the Src homology 2 (SH2) domain of PLC-gamma1 and the kinase domain of Itk. We now define this docking interface using a combination of mutagenesis and NMR spectroscopy and show that disruption of the Itk/PLCgamma1 docking interaction attenuates T cell signaling. The binding surface on PLCgamma1 that mediates recognition by Itk highlights a nonclassical binding activity of the well-studied SH2 domain providing further evidence that SH2 domains participate in important signaling interactions beyond recognition of phosphotyrosine.

  12. SU-E-J-142: Performance Study of Automatic Image-Segmentation Algorithms in Motion Tracking Via MR-IGRT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feng, Y; Olsen, J.; Parikh, P.

    2014-06-01

    /organ-specific information, different filtering methods and their influences on the segmentation results. Parag Parikh receives research grant from ViewRay. Sasa Mutic has consulting and research agreements with ViewRay. Yanle Hu receives travel reimbursement from ViewRay. Iwan Kawrakow and James Dempsey are ViewRay employees.« less

  13. Terrestrial and Martian weathering signatures of xenon components in shergottite mineral separates

    NASA Astrophysics Data System (ADS)

    Cartwright, J. A.; Ocker, K. D.; Crowther, S. A.; Burgess, R.; Gilmour, J. D.

    2010-08-01

    Xenon-isotopic ratios, step-heating release patterns, and gas concentrations of mineral separates from Martian shergottites Roberts Massif (RBT) 04262, Dar al Gani (DaG) 489, Shergotty, and Elephant Moraine (EET) 79001 lithology B are reported. Concentrations of Martian atmospheric xenon are similar in mineral separates from all meteorites, but more weathered samples contain more terrestrial atmospheric xenon. The distributions of xenon from the Martian and terrestrial atmospheres among minerals in any one sample are similar, suggesting similarities in the processes by which they were acquired. However, in opaque and maskelynite fractions, Martian atmospheric xenon is released at higher temperatures than terrestrial atmospheric xenon. It is suggested that both Martian and terrestrial atmospheric xenon were initially introduced by weathering (low temperature alteration processes). However, the Martian component was redistributed by shock, accounting for its current residence in more retentive sites. The presence or absence of detectable 129Xe from the Martian atmosphere in mafic minerals may correspond to the extent of crustal contamination of the rock's parent melt. Variable contents of excess 129Xe contrast with previously reported consistent concentrations of excess 40Ar, suggesting distinct sources contributed these gases to the parent magma.

  14. Development and Evaluation of an Airborne Separation Assurance System for Autonomous Aircraft Operations

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Palmer, Michael T.; Eischeid, Todd M.

    2004-01-01

    NASA Langley Research Center is developing an Autonomous Operations Planner (AOP) that functions as an Airborne Separation Assurance System for autonomous flight operations. This development effort supports NASA s Distributed Air-Ground Traffic Management (DAG-TM) operational concept, designed to significantly increase capacity of the national airspace system, while maintaining safety. Autonomous aircraft pilots use the AOP to maintain traffic separation from other autonomous aircraft and managed aircraft flying under today's Instrument Flight Rules, while maintaining traffic flow management constraints assigned by Air Traffic Service Providers. AOP is designed to facilitate eventual implementation through careful modeling of its operational environment, interfaces with other aircraft systems and data links, and conformance with established flight deck conventions and human factors guidelines. AOP uses currently available or anticipated data exchanged over modeled Arinc 429 data buses and an Automatic Dependent Surveillance Broadcast 1090 MHz link. It provides pilots with conflict detection, prevention, and resolution functions and works with the Flight Management System to maintain assigned traffic flow management constraints. The AOP design has been enhanced over the course of several experiments conducted at NASA Langley and is being prepared for an upcoming Joint Air/Ground Simulation with NASA Ames Research Center.

  15. Non-triglyceride components modulate the fat crystal network of palm kernel oil and coconut oil.

    PubMed

    Chai, Xiuhang; Meng, Zong; Jiang, Jiang; Cao, Peirang; Liang, Xinyu; Piatko, Michael; Campbell, Shawn; Lo, Seong Koon; Liu, Yuanfa

    2018-03-01

    PKO and CNO are composed of 97-98% triacylglycerols and 2-3% minor non-triglyceride components (FFA, DAG and MAG). Triglycerides were separated from minor components by chromatographic method. The lipid composition, thermal properties, polymorphism, isothermal crystallization behavior, nanostructure and microstructure of PKO, PKO-TAG, CNO and CNO-TAG were evaluated. Removal of minor components had no effect on lipid composition and equilibrium solid fat contents. However, presence of minor components did increase the slip melting point and promoted the onset of crystallization from DSC crystallization profiles. The thickness of the nanoscale crystals increased with no polymorphic transformation after removing the minor components. Crystallization kinetics revealed that minor components decreased crystal growth rate with higher t 1/2 . Sharp changes in the values of the Avrami constant k and exponent n were observed for all fats around 10°C. Increases in n around 10°C indicated a change from one-dimensional to multi-dimensional growth . From the results of polarized light micrographs, the transformation from the coarser crystal structure to tiny crystal structure occurred in microstructure networks at the action of minor components. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Traffic Behavior Recognition Using the Pachinko Allocation Model

    PubMed Central

    Huynh-The, Thien; Banos, Oresti; Le, Ba-Vui; Bui, Dinh-Mao; Yoon, Yongik; Lee, Sungyoung

    2015-01-01

    CCTV-based behavior recognition systems have gained considerable attention in recent years in the transportation surveillance domain for identifying unusual patterns, such as traffic jams, accidents, dangerous driving and other abnormal behaviors. In this paper, a novel approach for traffic behavior modeling is presented for video-based road surveillance. The proposed system combines the pachinko allocation model (PAM) and support vector machine (SVM) for a hierarchical representation and identification of traffic behavior. A background subtraction technique using Gaussian mixture models (GMMs) and an object tracking mechanism based on Kalman filters are utilized to firstly construct the object trajectories. Then, the sparse features comprising the locations and directions of the moving objects are modeled by PAM into traffic topics, namely activities and behaviors. As a key innovation, PAM captures not only the correlation among the activities, but also among the behaviors based on the arbitrary directed acyclic graph (DAG). The SVM classifier is then utilized on top to train and recognize the traffic activity and behavior. The proposed model shows more flexibility and greater expressive power than the commonly-used latent Dirichlet allocation (LDA) approach, leading to a higher recognition accuracy in the behavior classification. PMID:26151213

  17. CDP-Diacylglycerol Synthetase Coordinates Cell Growth and Fat Storage through Phosphatidylinositol Metabolism and the Insulin Pathway

    PubMed Central

    Liu, Yuan; Wang, Wei; Shui, Guanghou; Huang, Xun

    2014-01-01

    During development, animals usually undergo a rapid growth phase followed by a homeostatic stage when growth has ceased. The increase in cell size and number during the growth phase requires a large amount of lipids; while in the static state, excess lipids are usually stored in adipose tissues in preparation for nutrient-limited conditions. How cells coordinate growth and fat storage is not fully understood. Through a genetic screen we identified Drosophila melanogaster CDP-diacylglycerol synthetase (CDS/CdsA), which diverts phosphatidic acid from triacylglycerol synthesis to phosphatidylinositol (PI) synthesis and coordinates cell growth and fat storage. Loss of CdsA function causes significant accumulation of neutral lipids in many tissues along with reduced cell/organ size. These phenotypes can be traced back to reduced PI levels and, subsequently, low insulin pathway activity. Overexpressing CdsA rescues the fat storage and cell growth phenotypes of insulin pathway mutants, suggesting that CdsA coordinates cell/tissue growth and lipid storage through the insulin pathway. We also revealed that a DAG-to-PE route mediated by the choline/ethanolamine phosphotransferase Bbc may contribute to the growth of fat cells in CdsA RNAi. PMID:24603715

  18. Highlights of X-Stack ExM Deliverable Swift/T

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wozniak, Justin M.

    Swift/T is a key success from the ExM: System support for extreme-scale, many-task applications1 X-Stack project, which proposed to use concurrent dataflow as an innovative programming model to exploit extreme parallelism in exascale computers. The Swift/T component of the project reimplemented the Swift language from scratch to allow applications that compose scientific modules together to be build and run on available petascale computers (Blue Gene, Cray). Swift/T does this via a new compiler and runtime that generates and executes the application as an MPI program. We assume that mission-critical emerging exascale applications will be composed as scalable applications using existingmore » software components, connected by data dependencies. Developers wrap native code fragments using a higherlevel language, then build composite applications to form a computational experiment. This exemplifies hierarchical concurrency: lower-level messaging libraries are used for fine-grained parallelism; highlevel control is used for inter-task coordination. These patterns are best expressed with dataflow, but static DAGs (i.e., other workflow languages) limit the applications that can be built; they do not provide the expressiveness of Swift, such as conditional execution, iteration, and recursive functions.« less

  19. Gene expression profiling gut microbiota in different races of humans

    PubMed Central

    Chen, Lei; Zhang, Yu-Hang; Huang, Tao; Cai, Yu-Dong

    2016-01-01

    The gut microbiome is shaped and modified by the polymorphisms of microorganisms in the intestinal tract. Its composition shows strong individual specificity and may play a crucial role in the human digestive system and metabolism. Several factors can affect the composition of the gut microbiome, such as eating habits, living environment, and antibiotic usage. Thus, various races are characterized by different gut microbiome characteristics. In this present study, we studied the gut microbiomes of three different races, including individuals of Asian, European and American races. The gut microbiome and the expression levels of gut microbiome genes were analyzed in these individuals. Advanced feature selection methods (minimum redundancy maximum relevance and incremental feature selection) and four machine-learning algorithms (random forest, nearest neighbor algorithm, sequential minimal optimization, Dagging) were employed to capture key differentially expressed genes. As a result, sequential minimal optimization was found to yield the best performance using the 454 genes, which could effectively distinguish the gut microbiomes of different races. Our analyses of extracted genes support the widely accepted hypotheses that eating habits, living environments and metabolic levels in different races can influence the characteristics of the gut microbiome. PMID:26975620

  20. Scheduling Multilevel Deadline-Constrained Scientific Workflows on Clouds Based on Cost Optimization

    DOE PAGES

    Malawski, Maciej; Figiela, Kamil; Bubak, Marian; ...

    2015-01-01

    This paper presents a cost optimization model for scheduling scientific workflows on IaaS clouds such as Amazon EC2 or RackSpace. We assume multiple IaaS clouds with heterogeneous virtual machine instances, with limited number of instances per cloud and hourly billing. Input and output data are stored on a cloud object store such as Amazon S3. Applications are scientific workflows modeled as DAGs as in the Pegasus Workflow Management System. We assume that tasks in the workflows are grouped into levels of identical tasks. Our model is specified using mathematical programming languages (AMPL and CMPL) and allows us to minimize themore » cost of workflow execution under deadline constraints. We present results obtained using our model and the benchmark workflows representing real scientific applications in a variety of domains. The data used for evaluation come from the synthetic workflows and from general purpose cloud benchmarks, as well as from the data measured in our own experiments with Montage, an astronomical application, executed on Amazon EC2 cloud. We indicate how this model can be used for scenarios that require resource planning for scientific workflows and their ensembles.« less

  1. Gene expression profiling gut microbiota in different races of humans

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Zhang, Yu-Hang; Huang, Tao; Cai, Yu-Dong

    2016-03-01

    The gut microbiome is shaped and modified by the polymorphisms of microorganisms in the intestinal tract. Its composition shows strong individual specificity and may play a crucial role in the human digestive system and metabolism. Several factors can affect the composition of the gut microbiome, such as eating habits, living environment, and antibiotic usage. Thus, various races are characterized by different gut microbiome characteristics. In this present study, we studied the gut microbiomes of three different races, including individuals of Asian, European and American races. The gut microbiome and the expression levels of gut microbiome genes were analyzed in these individuals. Advanced feature selection methods (minimum redundancy maximum relevance and incremental feature selection) and four machine-learning algorithms (random forest, nearest neighbor algorithm, sequential minimal optimization, Dagging) were employed to capture key differentially expressed genes. As a result, sequential minimal optimization was found to yield the best performance using the 454 genes, which could effectively distinguish the gut microbiomes of different races. Our analyses of extracted genes support the widely accepted hypotheses that eating habits, living environments and metabolic levels in different races can influence the characteristics of the gut microbiome.

  2. Quantitative shock stage assessment in olivine and pyroxene bearing meteorites via in situ micro-XRD

    NASA Astrophysics Data System (ADS)

    McCausland, P. J.; Flemming, R. L.; Izawa, M. R.

    2010-12-01

    Shock metamorphism is observed in most meteorites and impact structures [1]. Qualitative petrographic observations underpin a shock classification system [1-3] based on the deformation features in common silicates and on textural relations such as the development of maskelynite from feldspars, mobility of sulphides and metal in veins and local Fe-reduction in silicates. Shock deformation of minerals produces streaks (mosaicity) rather than discrete spots in 2D X-ray diffraction patterns, representing the progressive disruption of the crystal lattice into a mosaic of rotated domains [4,5]. Here we use in situ micro-XRD [5,6] to measure the mosaicity of olivine and pyroxene in ordinary chondrites of increasing shock stages S1 to S5 and then apply the method to achondrites with qualitatively low to high shock. X-ray diffraction data were collected in situ on polished thin sections and slab cut surfaces using a Bruker D8 Discover micro X-ray diffractometer [5], operated using CuKα radiation generated at 40 kV and 40 mA with a beam diameter of 500 μm. Diffracted X-rays were recorded with a 2D detector, giving images with information in both the 2-theta and chi dimensions, in which each lattice plane (hkl) will have a diffraction spot or streak lying along an arc in chi of radius 2-theta (hkl). Individual reflections can be indexed and then integrated as a function of chi angle, allowing examination of the peak shape and quantitative analysis of the mosaic peak FWHM along chi. We find that both forsterite and enstatite exhibit greater mosaicity in chi with increasing shock stage: Forsterite chi ranges from <1° for S1 to >6° for S5. Enstatite chi values from the same meteorites show a more subdued growth of streak length with shock state, from ~1° to ~4°. A slab of the olivine shergottite DaG 476 exhibits forsterite mosaicity of 6.9°+/-1.1°, indicating that it has experienced shock stage S5, with shock pressures 30-45 GPa [1,4], consistent with the 40-45 GPa shock

  3. Modelling strong seismic ground motion: three-dimensional loading path versus wavefield polarization

    NASA Astrophysics Data System (ADS)

    Santisi d'Avila, Maria Paola; Lenti, Luca; Semblat, Jean-François

    2012-09-01

    Seismic waves due to strong earthquakes propagating in surficial soil layers may both reduce soil stiffness and increase the energy dissipation into the soil. To investigate seismic wave amplification in such cases, past studies have been devoted to one-directional shear wave propagation in a soil column (1D-propagation) considering one motion component only (1C-polarization). Three independent purely 1C computations may be performed ('1D-1C' approach) and directly superimposed in the case of weak motions (linear behaviour). This research aims at studying local site effects by considering seismic wave propagation in a 1-D soil profile accounting for the influence of the 3-D loading path and non-linear hysteretic behaviour of the soil. In the proposed '1D-3C' approach, the three components (3C-polarization) of the incident wave are simultaneously propagated into a horizontal multilayered soil. A 3-D non-linear constitutive relation for the soil is implemented in the framework of the Finite Element Method in the time domain. The complex rheology of soils is modelled by mean of a multisurface cyclic plasticity model of the Masing-Prandtl-Ishlinskii-Iwan type. The great advantage of this choice is that the only data needed to describe the model is the modulus reduction curve. A parametric study is carried out to characterize the changes in the seismic motion of the surficial layers due to both incident wavefield properties and soil non-linearities. The numerical simulations show a seismic response depending on several parameters such as polarization of seismic waves, material elastic and dynamic properties, as well as on the impedance contrast between layers and frequency content and oscillatory character of the input motion. The 3-D loading path due to the 3C-polarization leads to multi-axial stress interaction that reduces soil strength and increases non-linear effects. The non-linear behaviour of the soil may have beneficial or detrimental effects on the seismic

  4. Plant phospholipase C family: Regulation and functional role in lipid signaling.

    PubMed

    Singh, Amarjeet; Bhatnagar, Nikita; Pandey, Amita; Pandey, Girdhar K

    2015-08-01

    Phospholipase C (PLC), a major membrane phospholipid hydrolyzing enzyme generates signaling messengers such as diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) in animals, and their phosphorylated forms such as phosphatidic acid (PA) and inositol hexakisphosphate (IP6) are thought to regulate various cellular processes in plants. Based on substrate specificity, plant PLC family is sub-divided into phosphatidylinositol-PLC (PI-PLC) and phosphatidylcholine-PLC (PC-PLC) groups. The activity of plant PLCs is regulated by various factors and the major ones include, Ca(2+) concentration, phospholipid substrate, post-translational modifications and interacting proteins. Most of the PLC members have been localized at the plasma membrane, suited for their function of membrane lipid hydrolysis. Several PLC members have been implicated in various cellular processes and signaling networks, triggered in response to a number of environmental cues and developmental events in different plant species, which makes them potential candidates for genetically engineering the crop plants for stress tolerance and enhancing the crop productivity. In this review article, we are focusing mainly on the plant PLC signaling and regulation, potential cellular and physiological role in different abiotic and biotic stresses, nutrient deficiency, growth and development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Electromagnetic unification of matter and force fields

    NASA Astrophysics Data System (ADS)

    John, Sarah

    2004-05-01

    Special relativity and quantum mechanics are descriptive of electromagnetic propagation in waveguides, with mass analogous to the cutoff frequency of a waveguide mode [S.John, Bull.Am.Phys.Soc. vol.39,no.2,1254 (1994)]. It is further postulated herein that all spin 1/2 matter (necessarily massive) and spin 1 force fields have their origin in the electromagnetic fields E and B. This concept is not new. Majorana, among others have obtained electromagnetic representations of Dirac-like equations valid for the zero-mass case. Here, the spinor representation of the Maxwell equations, as given by Sallhofer, is extended to oscillatory fields with propagation constant m to obtain, in the absence of charge and current densities, the coupled equation (M. hatp + β E)ψ = 0 , where M = diag[ M σ, M^* σ ] , β = offdiag[I,I] , ψ ^ = i ^dag ( σ. B0 ( p), σ. E_0(p)), and M=m+ip, with the energy-mass relation given by E^2 = M M . Further, it is shown that the interaction term of QED is a direct consequence of including the sources and currents of Maxwell equations. Qualitative field patterns for spin 1/2 and spin 1 states, such as the electron, neutrino, magnetic monopole, quarks, photon, and massive gauge bosons are suggested.

  6. A Novel Pathway for Triacylglycerol Biosynthesis Is Responsible for the Accumulation of Massive Quantities of Glycerolipids in the Surface Wax of Bayberry (Myrica pensylvanica) Fruit[OPEN

    PubMed Central

    Ohlrogge, John B.

    2016-01-01

    Bayberry (Myrica pensylvanica) fruits synthesize an extremely thick and unusual layer of crystalline surface wax that accumulates to 32% of fruit dry weight, the highest reported surface lipid accumulation in plants. The composition is also striking, consisting of completely saturated triacylglycerol, diacylglycerol, and monoacylglycerol with palmitate and myristate acyl chains. To gain insight into the unique properties of Bayberry wax synthesis, we examined the chemical and morphological development of the wax layer, monitored wax biosynthesis through [14C]-radiolabeling, and sequenced the transcriptome. Radiolabeling identified sn-2 monoacylglycerol as an initial glycerolipid intermediate. The kinetics of [14C]-DAG and [14C]-TAG accumulation and the regiospecificity of their [14C]-acyl chains indicated distinct pools of acyl donors and that final TAG assembly occurs outside of cells. The most highly expressed lipid-related genes were associated with production of cutin, whereas transcripts for conventional TAG synthesis were >50-fold less abundant. The biochemical and expression data together indicate that Bayberry surface glycerolipids are synthesized by a pathway for TAG synthesis that is related to cutin biosynthesis. The combination of a unique surface wax and massive accumulation may aid understanding of how plants produce and secrete non-membrane glycerolipids and also how to engineer alternative pathways for lipid production in non-seeds. PMID:26744217

  7. Alkyd paints in art: characterization using integrated mass spectrometry.

    PubMed

    La Nasa, Jacopo; Degano, Ilaria; Modugno, Francesca; Colombini, Maria Perla

    2013-10-03

    Alkyd resins have been commonly used as binders in artist paints since the 1940s. The characterization of alkyds in samples from artworks can help to solve attribution and dating issues, investigate decay processes, and contribute to the planning of conservation strategies. Being able to assess the components of industrially formulated paint materials and to differentiate between different trademarks and producers is extremely interesting and requires multi-analytical approaches. In this paper we describe the characterization of commercial alkyd paint materials using a multi-analytical approach based on the integration of three different mass spectrometric techniques: gas chromatography-mass spectrometry (GC/MS), high performance liquid chromatography coupled with electrospray ionization mass spectrometry with a tandem quadrupole-time of flight mass spectrometer (HPLC-ESI-Q-ToF), and flow injection analysis (FIA) in the ESI-Q-ToF mass spectrometer. GC/MS was successful in determining the fatty acid and aromatic fractions of the resins after hydrolysis; HPLC-ESI-Q-ToF analysis enabled us to identify the triglycerides (TAGs) and diglycerides (DAGs) profile of each resin, and FIA analysis was used as a rapid method to evaluate the presence of possible additives such as synthetic polymers. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Identification of novel phosphatidic acid binding domain on sphingosine kinase 1 of Arabidopsis thaliana.

    PubMed

    Pandit, Shatakshi; Dalal, Vikram; Mishra, Girish

    2018-07-01

    Phosphatidic acid (PA) is an important lipid signaling molecule which interacts with Arabidopsis thaliana Sphingosine kinase1 (AtSPHK1) during several abiotic stresses particularly drought stress as a result of Abscisic acid (ABA) signaling in guard cells. PA molecules respond by generating lipid signal and/or by binding and translocating target proteins to membrane. However, site of interaction and role of PA binding to AtSPHK1 is not clear yet. Owing to the importance of AtSPHK1 during stress signaling it is imperative to decipher the site of PA interaction with AtSPHK1. To identify the PA binding region of AtSPHK1, various deletion fragments from N-terminal and C-terminal region were prepared. Results from protein lipid overlay assay using various truncated proteins of AtSPHK1 suggested the involvement of N-terminal region, between 110 and 205 amino acids, in binding with PA. In-silico analyses performed to build homologous structure of AtSPHK1 revealed that PA docking occurs in the hydrophobic cavity of DAG-Kinase domain. Deletion of amino acids 182 VSGDGI 187 perturbed PA-AtSPHK1 binding, indicating an essential role of these six amino acids in PA-AtSPHK1 binding. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  9. Phosphatidic acid and neurotransmission

    PubMed Central

    Raben, Daniel M.; Barber, Casey N.

    2016-01-01

    Lipids play a vital role in the health and functioning of neurons and interest in the physiological role of neuronal lipids is certainly increasing. One neuronal function in which neuronal lipids appears to play key roles in neurotransmission. Our understanding of the role of lipids in the synaptic vesicle cycle and neurotransmitter release is becoming increasingly more important. Much of the initial research in this area has highlighted the major roles played by the phosphoinositides (PtdIns), diacylglycerol (DAG), and phosphatidic acid (PtdOH). Of these, PtdOH has not received as much attention as the other lipids although its role and metabolism appears to be extremely important. This lipid has been shown to play a role in modulating both exocytosis and endocytosis although its precise role in either process is not well defined. The currently evidence suggest this lipid likely participates in key processes by altering membrane architecture necessary for membrane fusion, mediating the penetration of membrane proteins, serving as a precursor for other important SV cycling lipids, or activating essential enzymes. In this review, we address the sources of PtdOH, the enzymes involved in its production, the regulation of these enzymes, and its potential roles in neurotransmission in the central nervous system. PMID:27671966

  10. Phosphatidic acid and neurotransmission.

    PubMed

    Raben, Daniel M; Barber, Casey N

    2017-01-01

    Lipids play a vital role in the health and functioning of neurons and interest in the physiological role of neuronal lipids is certainly increasing. One neuronal function in which neuronal lipids appears to play key roles in neurotransmission. Our understanding of the role of lipids in the synaptic vesicle cycle and neurotransmitter release is becoming increasingly more important. Much of the initial research in this area has highlighted the major roles played by the phosphoinositides (PtdIns), diacylglycerol (DAG), and phosphatidic acid (PtdOH). Of these, PtdOH has not received as much attention as the other lipids although its role and metabolism appears to be extremely important. This lipid has been shown to play a role in modulating both exocytosis and endocytosis although its precise role in either process is not well defined. The currently evidence suggest this lipid likely participates in key processes by altering membrane architecture necessary for membrane fusion, mediating the penetration of membrane proteins, serving as a precursor for other important SV cycling lipids, or activating essential enzymes. In this review, we address the sources of PtdOH, the enzymes involved in its production, the regulation of these enzymes, and its potential roles in neurotransmission in the central nervous system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Voyages of the Zodiac, an Impenitent Traveller across Lands and Ages

    NASA Astrophysics Data System (ADS)

    Belmonte, Juan Antonio

    2015-05-01

    The zodiac is one of humankind's oldest astronomical heritages. Indeed, it has a long history and had an impressive cultural influence in the past that could be traced from the steppes of Mesopotamia to the wilderness of the Roman frontiers in Great Britain. In the present essay, we will discuss the origin of the zodiacal constellations in ancient Mesopotamia from their possible prehistoric ancestors in the pre-ceramic context of the 10,000-year-old site of Göbleki Tepe. Later on, we will discuss the role that the zodiac played in the development of the new cult established by King Antiochos I of Commagene in his hierothesion at Nemrud Dag, where a planetary conjunction in Leo has played a role in the clues to understand the enigmas of such an impressive monument. This will be followed by the analysis of its southwards travel to the Valley of the Nile, where we will study the famous Zodiac of Dendera. Then we will travel westwards to discuss the astronomical aspects of a new religion where astronomical eras and the zodiac ought to play a most relevant role, Mithraism. Finally, new ideas for future research in this most interesting topic will briefly be sketched.

  12. Comprehensive genomic analysis and expression profiling of diacylglycerol kinase gene family in Malus prunifolia (Willd.) Borkh.

    PubMed

    Li, Yali; Tan, Yanxiao; Shao, Yun; Li, Mingjun; Ma, Fengwang

    2015-05-01

    Diacylglycerol kinase (DGK) is a pivotal enzyme that phosphorylates diacylglycerol (DAG) to form phosphatidic acid (PA). The production of PA from phospholipase D (PLD) and the coupled phospholipase C (PLC)/DGK route is a critical signaling process in animal and plant cells. Next to PLD, DGK is the second most important generator of PA in biotic and abiotic stress responses. We identified 8 DGK members within the apple genome and all of their putative proteins contain one DGK catalytic domain and one DGK accessory domain. Four coding sequences were confirmed by cloning from Malus prunifolia. Phylogenetic and gene structure analyses showed that the apple DGK genes could be assigned to Clusters I, II, or III. Expression analysis of 6 of them revealed that their transcript levels were highest in stems. Some apple DGK genes were also significantly up-regulated in response to salt and drought stresses. This suggested their possible roles in plant defenses against environmental challenges. As a first step toward genome-wide analyses of the DGK genes in woody plants, our results imply that apple DGK genes are involved in the signaling of stress responses. These findings will contribute to further functional dissection of this gene family. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. NIP/DuoxA is essential for Drosophila embryonic development and regulates oxidative stress response.

    PubMed

    Xie, Xiaojun; Hu, Jack; Liu, Xiping; Qin, Hanjuan; Percival-Smith, Anthony; Rao, Yong; Li, Shawn S C

    2010-05-11

    NIP/DuoxA, originally cloned as a protein capable of binding to the cell fate determinant Numb in Drosophila, was recently identified as a modulator of reactive oxygen species (ROS) production in mammalian systems. Despite biochemical and cellular studies that link NIP/DuoxA to the generation of ROS through the dual oxidase (Duox) enzyme, the in vivo function of NIP/DuoxA has not been characterized to date. Here we report a genetic and functional characterization of nip in Drosophila melanogaster. We show that nip is essential for Drosophila development as nip null mutants die at the 1(st) larval instar. Expression of UAS-nip, but not UAS-Duox, rescued the lethality. To understand the function of nip beyond the early larval stage, we generated GAL4 inducible UAS-RNAi transgenes. da(G32)-GAL4 driven, ubiquitous RNAi-mediated silencing of nip led to profound abnormality in pre-adult development, crinkled wing and markedly reduced lifespan at 29 degrees C. Compared to wild type flies, da-GAL4 induced nip-RNAi transgenic flies exhibited significantly reduced ability to survive under oxidative stress and displayed impaired mitochondrial aconitase function. Our work provides in vivo evidence for a critical role for nip in the development and oxidative stress response in Drosophila.

  14. Magnesium and chromium isotope evidence for initial melting by radioactive decay of 26Al and late stage impact-melting of the ureilite parent body

    NASA Astrophysics Data System (ADS)

    van Kooten, Elishevah M. M. E.; Schiller, Martin; Bizzarro, Martin

    2017-07-01

    Polymict ureilites are meteoritic breccias that provide insights into the differentiation history of the ureilite parent body. We have sampled a total of 24 clasts from the polymict ureilite Dar al Gani 319, representing a variety of lithologies such as mantle residues, cumulates and crustal fragments that are genetically related to monomict ureilites. In addition, we sampled four non-indigenous dark clasts and two chondrule-containing clasts from the same meteorite. We report on the petrology and the bulk mass-dependent and mass-independent magnesium and chromium isotope systematics of these clasts. The DaG 319 polymict ureilite consists predominantly of clasts related to Main Group ureilite residues (MG clasts) with varying Mg#s (0.74-0.91), as well as a significant fraction of olivine-orthopyroxene clasts related to Hughes Type ureilites (HT clasts) with consistently high Mg#s (∼0.89). In addition, DaG 319 contains less abundant feldspathic clasts that are thought to represent melts derived from the ureilite mantle. A significant mass-dependent Mg-isotope fractionation totaling Δμ25 Mg = ∼450 ppm was found between isotopically light feldspathic clasts (μ25 Mg = -305 ± 25 to 15 ± 12 ppm), MG clasts (μ25 Mg = -23 ± 51 ppm) and HT clasts (μ25 Mg = 157 ± 21 ppm). We suggest that this isotopic offset is the result of equilibrium isotope fractionation during melting in the presence of an isotopically light magnesite component. We propose Mg-carbonates to be stable in the upper ureilite mantle, and pure carbon phases such as graphite to be stable at higher pressures. This is consistent with HT clasts lacking carbon-related phases, whereas MG clasts contain abundant carbon. The timing of differentiation events for the ureilitic clasts are constrained by high precision 53Mn-53Cr systematics and 26Al-26Mg model ages. We show that a dichotomy of ages exist between the differentiation of main group ureilite residues and HT cumulates rapidly after CAI formation

  15. Treadmill exercise alleviates diabetic cardiomyopathy by suppressing plasminogen activator inhibitor expression and enhancing eNOS in streptozotocin-induced male diabetic rats.

    PubMed

    Chengji, Wang; Xianjin, Fan

    2018-04-01

    To investigate the biological mechanism of the effect of different intensity exercises on diabetic cardiomyopathy. 87 raise specific pathogen SPF healthy 6-week-old male Sprague-Dawley rats, fed 6 weeks with high-fat diet for rats were used, and a diabetic model was established by intraperitoneal injection of streptozotocin - randomly selected 43 rats were divided into Diabetic control group (DCG, n  = 10), Diabetic exercise group 1 (DEG1, n  = 11), Diabetic exercise group 2 (DEG2, n  = 11) and Diabetic exercise group 3 (DEG3, n  = 11). The rats in DEG1 were forced to run on a motorized treadmill, the exercise load consisted of running at a speed of 10 m/min, the exercise load of the rats in DEG2 were running at a speed of 15 m/min, the exercise load of the rats in DEG3 were running at a speed of 20 m/min, for one hour once a day for 6 weeks. After 6 weeks of exercise intervention, glucose metabolism-related indexes in rats such as blood glucose (FBG), glycosylated serum protein (GSP) and insulin (FINS); cardiac fibrinolytic system parameters such as PAI-1 (plasminogen activator inhibitor 1), Von Willebrand factor (vWF), protein kinase C (PKC) and diacylglycerol (DAG); and serum level of NO, eNOS and T-NOS were measured. Compared with DCG, fasting blood glucose and GSP were decreased, while insulin sensitivity index and insulin level were increased in all rats of the three exercise groups. FBG decrease was statistically significant ( P  < 0.01), only GSP decrease was statistically significant ( P  < 0.05) in DEG1 and DEG2, PAI-1 in three exercise groups were significantly reduced ( P  < 0.05), plasma vWF levels in the three exercise groups were significantly lower than those in the DCG group ( P  < 0.01); PKC levels decreased dramatically in the three exercise groups and DAG levels decrease slightly ( P  < 0.05), but with no significant difference. Compared with DCG, the serum level of NO was significantly higher ( P

  16. Spontaneous and LH-induced maturation in Bufo arenarum oocytes: importance of gap junctions.

    PubMed

    Toranzo, G Sánchez; Oterino, J; Zelarayán, L; Bonilla, F; Bühler, M I

    2007-02-01

    It has been demonstrated in Bufo arenarum that fully grown oocytes are capable of meiotic resumption in the absence of a hormonal stimulus if they are deprived of their follicular envelopes. This event, called spontaneous maturation, only takes place in oocytes collected during the reproductive period, which have a metabolically mature cytoplasm. In Bufo arenarum, progesterone acts on the oocyte surface and causes modifications in the activities of important enzymes, such as a decrease in the activity of adenylate cyclase (AC) and the activation of phospholipase C (PLC). PLC activation leads to the formation of diacylglycerol (DAG) and inositol triphosphate (IP(3)), second messengers that activate protein kinase C (PKC) and cause an increase in intracellular Ca(2+). Recent data obtained from Bufo arenarum show that progesterone-induced maturation causes significant modifications in the level and composition of neutral lipids and phospholipids of whole fully grown ovarian oocytes and of enriched fractions in the plasma membrane. In amphibians, the luteinizing hormone (LH) is responsible for meiosis resumption through the induction of progesterone production by follicular cells. The aim of this work was to study the importance of gap junctions in the spontaneous and LH-induced maturation in Bufo arenarum oocytes. During the reproductive period, Bufo arenarum oocytes are capable of undergoing spontaneous maturation in a similar way to mammalian oocytes while, during the non-reproductive period, they exhibit the behaviour that is characteristic of amphibian oocytes, requiring progesterone stimulation for meiotic resumption (incapable oocytes). This different ability to mature spontaneously is coincident with differences in the amount and composition of the phospholipids in the oocyte membranes. Capable oocytes exhibit in their membranes higher quantities of phospholipids than incapable oocytes, especially of PC and PI, which are precursors of second messengers such as

  17. Identification of Yju3p as functional orthologue of mammalian monoglyceride lipase in the yeast Saccharomycescerevisiae.

    PubMed

    Heier, Christoph; Taschler, Ulrike; Rengachari, Srinivasan; Oberer, Monika; Wolinski, Heimo; Natter, Klaus; Kohlwein, Sepp D; Leber, Regina; Zimmermann, Robert

    2010-09-01

    Monoacylglycerols (MAGs) are short-lived intermediates of glycerolipid metabolism. Specific molecular species, such as 2-arachidonoylglycerol, which is a potent activator of cannabinoid receptors, may also function as lipid signaling molecules. In mammals, enzymes hydrolyzing MAG to glycerol and fatty acids, resembling the final step in lipolysis, or esterifying MAG to diacylglycerol, are well known; however, despite the high level of conservation of lipolysis, the corresponding activities in yeast have not been characterized yet. Here we provide evidence that the protein Yju3p functions as a potent MAG hydrolase in yeast. Cellular MAG hydrolase activity was decreased by more than 90% in extracts of Yju3p-deficient cells, indicating that Yju3p accounts for the vast majority of this activity in yeast. Loss of this activity was restored by heterologous expression of murine monoglyceride lipase (MGL). Since yju3Delta mutants accumulated MAG in vivo only at very low concentrations, we considered the possibility that MAGs are re-esterified into DAG by acyltransferases. Indeed, cellular MAG levels were further increased in mutant cells lacking Yju3p and Dga1p or Lro1p acyltransferase activities. In conclusion, our studies suggest that catabolic and anabolic reactions affect cellular MAG levels. Yju3p is the functional orthologue of mammalian MGL and is required for efficient degradation of MAG in yeast. 2010 Elsevier B.V. All rights reserved.

  18. Identification of Yju3p as functional orthologue of mammalian monoglyceride lipase in the yeast Saccharomycescerevisiae

    PubMed Central

    Heier, Christoph; Taschler, Ulrike; Rengachari, Srinivasan; Oberer, Monika; Wolinski, Heimo; Natter, Klaus; Kohlwein, Sepp D.; Leber, Regina; Zimmermann, Robert

    2010-01-01

    Monoacylglycerols (MAGs) are short-lived intermediates of glycerolipid metabolism. Specific molecular species, such as 2-arachidonoylglycerol, which is a potent activator of cannabinoid receptors, may also function as lipid signaling molecules. In mammals, enzymes hydrolyzing MAG to glycerol and fatty acids, resembling the final step in lipolysis, or esterifying MAG to diacylglycerol, are well known; however, despite the high level of conservation of lipolysis, the corresponding activities in yeast have not been characterized yet. Here we provide evidence that the protein Yju3p functions as a potent MAG hydrolase in yeast. Cellular MAG hydrolase activity was decreased by more than 90% in extracts of Yju3p-deficient cells, indicating that Yju3p accounts for the vast majority of this activity in yeast. Loss of this activity was restored by heterologous expression of murine monoglyceride lipase (MGL). Since yju3Δ mutants accumulated MAG in vivo only at very low concentrations, we considered the possibility that MAGs are re-esterified into DAG by acyltransferases. Indeed, cellular MAG levels were further increased in mutant cells lacking Yju3p and Dga1p or Lro1p acyltransferase activities. In conclusion, our studies suggest that catabolic and anabolic reactions affect cellular MAG levels. Yju3p is the functional orthologue of mammalian MGL and is required for efficient degradation of MAG in yeast. PMID:20554061

  19. Tailoring the Synergistic Bronsted-Lewis acidic effects in Heteropolyacid catalysts: Applied in Esterification and Transesterification Reactions.

    PubMed

    Tao, Meilin; Xue, Lifang; Sun, Zhong; Wang, Shengtian; Wang, Xiaohong; Shi, Junyou

    2015-09-16

    In order to investigate the influences of Lewis metals on acidic properties and catalytic activities, a series of Keggin heteropolyacid (HPA) catalysts, HnPW11MO39 (M = Ti(IV), Cu(II), Al(III), Sn(IV), Fe(III), Cr(III), Zr(IV) and Zn(II); for Ti and Zr, the number of oxygen is 40), were prepared and applied in the esterification and transesterification reactions. Only those cations with moderate Lewis acidity had a higher impact. Ti Substituted HPA, H5PW11TiO40, posse lower acid content compared with Ti(x)H(3-4x)PW12O40 (Ti partial exchanged protons in saturated H3PW12O40), which demonstrated that the Lewis metal as an addenda atom (H5PW11TiO40) was less efficient than those as counter cations (Ti(x)H(3-4x)PW12O40). On the other hand, the highest conversion reached 92.2% in transesterification and 97.4% in esterification. Meanwhile, a good result was achieved by H5PW11TiO40 in which the total selectivity of DAG and TGA was 96.7%. In addition, calcination treatment to H5PW11TiO40 make it insoluble in water which resulted in a heterogeneous catalyst feasible for reuse.

  20. Mild hypoxia-induced cardiomyocyte hypertrophy via up-regulation of HIF-1α-mediated TRPC signalling

    PubMed Central

    Chu, Wenfeng; Wan, Lin; Zhao, Dan; Qu, Xuefeng; Cai, Fulai; Huo, Rong; Wang, Ning; Zhu, Jiuxin; Zhang, Chun; Zheng, Fangfang; Cai, Ruijun; Dong, Deli; Lu, Yanjie; Yang, Baofeng

    2012-01-01

    Hypoxia-inducible factor-1 alpha (HIF-1α) is a central transcriptional regulator of hypoxic response. The present study was designed to investigate the role of HIF-1α in mild hypoxia-induced cardiomyocytes hypertrophy and its underlying mechanism. Mild hypoxia (MH, 10% O2) caused hypertrophy in cultured neonatal rat cardiac myocytes, which was accompanied with increase of HIF-1α mRNA and accumulation of HIF-1α protein in nuclei. Transient receptor potential canonical (TRPC) channels including TRPC3 and TRPC6, except for TRPC1, were increased, and Ca2+-calcineurin signals were also enhanced in a time-dependent manner under MH condition. MH-induced cardiomyocytes hypertrophy, TRPC up-regulation and enhanced Ca2+-calcineurin signals were inhibited by an HIF-1α specific blocker, SC205346 (30 μM), whereas promoted by HIF-1α overexpression. Electrophysiological voltage-clamp demonstrated that DAG analogue, OAG (30 μM), induced TRPC current by as much as 170% in neonatal rat cardiomyocytes overexpressing HIF-1α compared to negative control. These results implicate that HIF-1α plays a key role in development of cardiac hypertrophy in responses to hypoxic stress. Its mechanism is associated with up-regulating TRPC3, TRPC6 expression, activating TRPC current and subsequently leading to enhanced Ca2+-calcineurin signals. PMID:22129453

  1. Modulation of HepG2 cell net apolipoprotein B secretion by the citrus polymethoxyflavone, tangeretin.

    PubMed

    Kurowska, Elzbieta M; Manthey, John A; Casaschi, Adele; Theriault, Andre G

    2004-02-01

    The purpose of the present study was to examine the role of tangeretin, a polymethoxylated flavone from citrus fruits, on the regulation of apolipoprotein B (apoB) and lipid metabolism in the human hepatoma cell-line HepG2. The marked reduction in apoB secretion observed in cells incubated with 72.8 microM tangeretin was rapid, apoB-specific, and partly reversible. The reduction also was observed under lipid-rich conditions and found to be insensitive to proteasomal degradation of nascent apoB. We followed our study by examining lipid synthesis and mass. A 24-h exposure of cells to 72.8 microM tangeretin decreased intracellular synthesis of cholesteryl esters, free cholesterol, and TAG by 82, 45, and 64%, respectively; tangeretin also reduced the mass of cellular TAG by 37%. The tangeretin-induced suppression of TAG synthesis and mass were associated with decreased activities of DAG acyltransferase (up to -39.0 +/- 3.0% vs. control) and microsomal triglyceride transfer protein (up to -35.5 +/- 2.5% vs. control). Tangeretin was also found to activate the peroxisome proliferator-activated receptor, a transcription factor with a positive regulatory impact on FA oxidation and TAG availability (up to 36% increase vs. control). The data suggest that tangeretin modulates apoB-containing lipoprotein metabolism through multiple mechanisms.

  2. Advillin acts upstream of phospholipase C ϵ1 in steroid-resistant nephrotic syndrome

    PubMed Central

    Rao, Jia; Ashraf, Shazia; Tan, Weizhen; van der Ven, Amelie T.; Braun, Daniela A.; Fehér, Krisztina; George, Sudeep P.; Esmaeilniakooshkghazi, Amin; Choi, Won-Il; Schneider, Ronen; Schmidt, Johanna Magdalena; Warejko, Jillian K.; Schapiro, David; Lovric, Svjetlana; Shril, Shirlee; Daga, Ankana; Nayir, Ahmet; Shenoy, Mohan; Tse, Yincent; Bald, Martin; Helmchen, Udo; Mir, Sevgi; Kari, Jameela A.; El Desoky, Sherif; Bagga, Arvind; Mane, Shrikant; Jairajpuri, Mohamad A.; Lifton, Richard P.; Khurana, Seema; Martins, Jose C.

    2017-01-01

    Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of chronic kidney disease. Here, we identified recessive mutations in the gene encoding the actin-binding protein advillin (AVIL) in 3 unrelated families with SRNS. While all AVIL mutations resulted in a marked loss of its actin-bundling ability, truncation of AVIL also disrupted colocalization with F-actin, thereby leading to impaired actin binding and severing. Additionally, AVIL colocalized and interacted with the phospholipase enzyme PLCE1 and with the ARP2/3 actin-modulating complex. Knockdown of AVIL in human podocytes reduced actin stress fibers at the cell periphery, prevented recruitment of PLCE1 to the ARP3-rich lamellipodia, blocked EGF-induced generation of diacylglycerol (DAG) by PLCE1, and attenuated the podocyte migration rate (PMR). These effects were reversed by overexpression of WT AVIL but not by overexpression of any of the 3 patient-derived AVIL mutants. The PMR was increased by overexpression of WT Avil or PLCE1, or by EGF stimulation; however, this increased PMR was ameliorated by inhibition of the ARP2/3 complex, indicating that ARP-dependent lamellipodia formation occurs downstream of AVIL and PLCE1 function. Together, these results delineate a comprehensive pathogenic axis of SRNS that integrates loss of AVIL function with alterations in the action of PLCE1, an established SRNS protein. PMID:29058690

  3. Influence of fenofibrate treatment on triacylglycerides, diacylglycerides and fatty acids in fructose fed rats.

    PubMed

    Kopf, Thomas; Schaefer, Hans-Ludwig; Troetzmueller, Martin; Koefeler, Harald; Broenstrup, Mark; Konovalova, Tatiana; Schmitz, Gerd

    2014-01-01

    Fenofibrate (FF) lowers plasma triglycerides via PPARα activation. Here, we analyzed lipidomic changes upon FF treatment of fructose fed rats. Three groups with 6 animals each were defined as control, fructose-fed and fructose-fed/FF treated. Male Wistar Unilever Rats were subjected to 10% fructose-feeding for 20 days. On day 14, fenofibrate treatment (100 mg/kg p.o.) was initiated and maintained for 7 days. Lipid species in serum were analyzed using mass spectrometry (ESI-MS/MS; LC-FT-MS, GC-MS) on days 0, 14 and 20 in all three groups. In addition, lipid levels in liver and intestine were determined. Short-chain TAGs increased in serum and liver upon fructose-feeding, while almost all TAG-species decreased under FF treatment. Long-chain unsaturated DAG-levels (36:1, 36:2, 36:4, 38:3, 38:4, 38:5) increased upon FF treatment in rat liver and decreased in rat serum. FAs, especially short-chain FAs (12:0, 14:0, 16:0) increased during fructose-challenge. VLDL secretion increased upon fructose-feeding and together with FA-levels decreased to control levels during FF treatment. Fructose challenge of de novo fatty acid synthesis through fatty acid synthase (FAS) may enhance the release of FAs ≤ 16:0 chain length, a process reversed by FF-mediated PPARα-activation.

  4. Move over protein kinase C, you've got company: alternative cellular effectors of diacylglycerol and phorbol esters.

    PubMed

    Brose, Nils; Rosenmund, Christian

    2002-12-01

    Diacylglycerol is an essential second messenger in mammalian cells. The most prominent intracellular targets of diacylglycerol and of the functionally analogous phorbol esters belong to the protein kinase C (PKC) family. However, at least five alternative types of high-affinity diacylglycerol/phorbol-ester receptor are known: chimaerins, protein kinase D, RasGRPs, Munc13s and DAG kinase gamma. Recent evidence indicates that these have functional roles in diacylglycerol second messenger signalling in vivo and that several cellular processes depend on these targets rather than protein kinase C isozymes. These findings contradict the still prevalent view according to which all diacylglycerol/phorbol-ester effects are caused by the activation of protein kinase C isozymes. RasGRP1 (in Ras/Raf/MEK/ERK signalling) and Munc13-1 (in neurotransmitter secretion) are examples of non-PKC diacylglycerol/phorbol-ester receptors that mediate diacylglycerol and phorbol-ester effects originally thought to be caused by PKC isozymes. In the future, pharmacological studies on PKC must be complemented with alternative experimental approaches to allow the separation of PKC-mediated effects from those caused by alternative targets of the diacylglycerol second messenger pathway. The examples of RasGRP1 and Munc13-1 show that detailed genetic analyses of C(1)-domain-containing non-PKC diacylglycerol/phorbol-ester receptors in mammals are ideally suited to achieve this goal.

  5. Tailoring the Synergistic Bronsted-Lewis acidic effects in Heteropolyacid catalysts: Applied in Esterification and Transesterification Reactions

    PubMed Central

    Tao, Meilin; Xue, Lifang; Sun, Zhong; Wang, Shengtian; Wang, Xiaohong; Shi, Junyou

    2015-01-01

    In order to investigate the influences of Lewis metals on acidic properties and catalytic activities, a series of Keggin heteropolyacid (HPA) catalysts, HnPW11MO39 (M = TiIV, CuII, AlIII, SnIV, FeIII, CrIII, ZrIV and ZnII; for Ti and Zr, the number of oxygen is 40), were prepared and applied in the esterification and transesterification reactions. Only those cations with moderate Lewis acidity had a higher impact. Ti Substituted HPA, H5PW11TiO40, posse lower acid content compared with TixH3−4xPW12O40 (Ti partial exchanged protons in saturated H3PW12O40), which demonstrated that the Lewis metal as an addenda atom (H5PW11TiO40) was less efficient than those as counter cations (TixH3−4xPW12O40). On the other hand, the highest conversion reached 92.2% in transesterification and 97.4% in esterification. Meanwhile, a good result was achieved by H5PW11TiO40 in which the total selectivity of DAG and TGA was 96.7%. In addition, calcination treatment to H5PW11TiO40 make it insoluble in water which resulted in a heterogeneous catalyst feasible for reuse. PMID:26374393

  6. Dual activities of ritanserin and R59022 as DGKα inhibitors and serotonin receptor antagonists.

    PubMed

    Boroda, Salome; Niccum, Maria; Raje, Vidisha; Purow, Benjamin W; Harris, Thurl E

    2017-01-01

    Diacylglycerol kinase alpha (DGKα) catalyzes the conversion of diacylglycerol (DAG) to phosphatidic acid (PA). Recently, DGKα was identified as a therapeutic target in various cancers, as well as in immunotherapy. Application of small-molecule DGK inhibitors, R59022 and R59949, induces cancer cell death in vitro and in vivo. The pharmacokinetics of these compounds in mice, however, are poor. Thus, there is a need to discover additional DGK inhibitors not only to validate these enzymes as targets in oncology, but also to achieve a better understanding of their biology. In the present study, we investigate the activity of ritanserin, a compound structurally similar to R59022, against DGKα. Ritanserin, originally characterized as a serotonin (5-HT) receptor (5-HTR) antagonist, underwent clinical trials as a potential medicine for the treatment of schizophrenia and substance dependence. We document herein that ritanserin attenuates DGKα kinase activity while increasing the enzyme's affinity for ATP in vitro. In addition, R59022 and ritanserin function as DGKα inhibitors in cultured cells and activate protein kinase C (PKC). While recognizing that ritanserin attenuates DGK activity, we also find that R59022 and R59949 are 5-HTR antagonists. In conclusion, ritanserin, R59022 and R59949 are combined pharmacological inhibitors of DGKα and 5-HTRs in vitro. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. A dystroglycan mutation (p.Cys667Phe) associated to muscle-eye-brain disease with multicystic leucodystrophy results in ER-retention of the mutant protein.

    PubMed

    Signorino, Giulia; Covaceuszach, Sonia; Bozzi, Manuela; Hübner, Wolfgang; Mönkemöller, Viola; Konarev, Petr V; Cassetta, Alberto; Brancaccio, Andrea; Sciandra, Francesca

    2018-02-01

    Dystroglycan (DG) is a cell adhesion complex composed by two subunits, the highly glycosylated α-DG and the transmembrane β-DG. In skeletal muscle, DG is involved in dystroglycanopathies, a group of heterogeneous muscular dystrophies characterized by a reduced glycosylation of α-DG. The genes mutated in secondary dystroglycanopathies are involved in the synthesis of O-mannosyl glycans and in the O-mannosylation pathway of α-DG. Mutations in the DG gene (DAG1), causing primary dystroglycanopathies, destabilize the α-DG core protein influencing its binding to modifying enzymes. Recently, a homozygous mutation (p.Cys699Phe) hitting the β-DG ectodomain has been identified in a patient affected by muscle-eye-brain disease with multicystic leucodystrophy, suggesting that other mechanisms than hypoglycosylation of α-DG could be implicated in dystroglycanopathies. Herein, we have characterized the DG murine mutant counterpart by transfection in cellular systems and high-resolution microscopy. We observed that the mutation alters the DG processing leading to retention of its uncleaved precursor in the endoplasmic reticulum. Accordingly, small-angle X-ray scattering data, corroborated by biochemical and biophysical experiments, revealed that the mutation provokes an alteration in the β-DG ectodomain overall folding, resulting in disulfide-associated oligomerization. Our data provide the first evidence of a novel intracellular mechanism, featuring an anomalous endoplasmic reticulum-retention, underlying dystroglycanopathy. © 2017 Wiley Periodicals, Inc.

  8. Fragrance material review on 16-hydroxy-7-hexadecenoic acid lactone.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2011-12-01

    A toxicologic and dermatologic review of 16-hydroxy-7-hexadecenoic acid lactone when used as a fragrance ingredient is presented. 16-Hydroxy-7-hexadecenoic acid lactone is a member of the fragrance structural group macrocyclic lactone and lactide derivatives. The fragrance ingredient described herein is one of 12 structurally diverse C14, C15 and C16 compounds that include (1) saturated mono-and (2) saturated di-ester lactones and (3) unsaturated lactones. For the latter, the double bond is not adjacent to (in conjugation with) the ester group. This review contains a detailed summary of all available toxicology and dermatology papers that are related to 16-hydroxy-7-hexadecenoic acid lactone and is not intended as a stand-alone document. Available data were evaluated, then summarized, and include physical properties data. A safety assessment of the entire macrocyclic lactone and lactide derivatives will be published simultaneously with this document. Please refer to Belsito et al., 2011 for an overall assessment of the safe use of this material and all macrocyclic lactone and lactide derivatives in fragrances. Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Hanifin, J.H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2011. A toxicologic and dermatologic assessment of macrocylic lactones and lactide derivatives when used as fragrance ingredients. Copyright © 2011. Published by Elsevier Ltd.

  9. Étude de la structure des alliages vitreux Ag-As2S3 par diffraction de rayons X

    NASA Astrophysics Data System (ADS)

    Popescu, M.; Sava, F.; Cornet, A.; Broll, N.

    2002-07-01

    The structure of several silver alloyed arsenic chalocgenide has been determined by X-ray diffraction. For low silver doping the disordered layer structure, characteristic to the glassy AS2S3 is retained as demonstrated by the well developed first sharp diffraction peak in the X-ray diffraction pattern. For high amount of silver introduced in the As2S3 matrix, the disoredered layer configurations disappear, as shown by the diminishing and even disappearance of the first sharp diffraction peak in the X-ray patterns. A three-dimensional structure based on Ag2S -type configuration is formed. La structure de quelques alliages sulfure d'arsenic - argent a été determinée par diffraction de rayons X. Pour de faibles dopages à l'argent on conserve la structure desordonnées caractéristique des couches atomique d'As2S3 vitreux ; ceci est prouvé par la forte intensité du premier pic étroit de diffraction. Pour des plus grandes proportions d'argent la structure de l'alliage vitreux fait apparaître des unités structurales caractéristiques du cristal d'Ag2S et la configuration atomique avec des couches desordonnées disparaît (le premier pic étroit de diffraction s'évanouit) en faisant place à une structure tridimensionelle.

  10. Tailoring the Synergistic Bronsted-Lewis acidic effects in Heteropolyacid catalysts: Applied in Esterification and Transesterification Reactions

    NASA Astrophysics Data System (ADS)

    Tao, Meilin; Xue, Lifang; Sun, Zhong; Wang, Shengtian; Wang, Xiaohong; Shi, Junyou

    2015-09-01

    In order to investigate the influences of Lewis metals on acidic properties and catalytic activities, a series of Keggin heteropolyacid (HPA) catalysts, HnPW11MO39 (M = TiIV, CuII, AlIII, SnIV, FeIII, CrIII, ZrIV and ZnII; for Ti and Zr, the number of oxygen is 40), were prepared and applied in the esterification and transesterification reactions. Only those cations with moderate Lewis acidity had a higher impact. Ti Substituted HPA, H5PW11TiO40, posse lower acid content compared with TixH3-4xPW12O40 (Ti partial exchanged protons in saturated H3PW12O40), which demonstrated that the Lewis metal as an addenda atom (H5PW11TiO40) was less efficient than those as counter cations (TixH3-4xPW12O40). On the other hand, the highest conversion reached 92.2% in transesterification and 97.4% in esterification. Meanwhile, a good result was achieved by H5PW11TiO40 in which the total selectivity of DAG and TGA was 96.7%. In addition, calcination treatment to H5PW11TiO40 make it insoluble in water which resulted in a heterogeneous catalyst feasible for reuse.

  11. Failure probability analysis of optical grid

    NASA Astrophysics Data System (ADS)

    Zhong, Yaoquan; Guo, Wei; Sun, Weiqiang; Jin, Yaohui; Hu, Weisheng

    2008-11-01

    Optical grid, the integrated computing environment based on optical network, is expected to be an efficient infrastructure to support advanced data-intensive grid applications. In optical grid, the faults of both computational and network resources are inevitable due to the large scale and high complexity of the system. With the optical network based distributed computing systems extensive applied in the processing of data, the requirement of the application failure probability have been an important indicator of the quality of application and an important aspect the operators consider. This paper will present a task-based analysis method of the application failure probability in optical grid. Then the failure probability of the entire application can be quantified, and the performance of reducing application failure probability in different backup strategies can be compared, so that the different requirements of different clients can be satisfied according to the application failure probability respectively. In optical grid, when the application based DAG (directed acyclic graph) is executed in different backup strategies, the application failure probability and the application complete time is different. This paper will propose new multi-objective differentiated services algorithm (MDSA). New application scheduling algorithm can guarantee the requirement of the failure probability and improve the network resource utilization, realize a compromise between the network operator and the application submission. Then differentiated services can be achieved in optical grid.

  12. Computational Prediction of Protein Epsilon Lysine Acetylation Sites Based on a Feature Selection Method.

    PubMed

    Gao, JianZhao; Tao, Xue-Wen; Zhao, Jia; Feng, Yuan-Ming; Cai, Yu-Dong; Zhang, Ning

    2017-01-01

    Lysine acetylation, as one type of post-translational modifications (PTM), plays key roles in cellular regulations and can be involved in a variety of human diseases. However, it is often high-cost and time-consuming to use traditional experimental approaches to identify the lysine acetylation sites. Therefore, effective computational methods should be developed to predict the acetylation sites. In this study, we developed a position-specific method for epsilon lysine acetylation site prediction. Sequences of acetylated proteins were retrieved from the UniProt database. Various kinds of features such as position specific scoring matrix (PSSM), amino acid factors (AAF), and disorders were incorporated. A feature selection method based on mRMR (Maximum Relevance Minimum Redundancy) and IFS (Incremental Feature Selection) was employed. Finally, 319 optimal features were selected from total 541 features. Using the 319 optimal features to encode peptides, a predictor was constructed based on dagging. As a result, an accuracy of 69.56% with MCC of 0.2792 was achieved. We analyzed the optimal features, which suggested some important factors determining the lysine acetylation sites. We developed a position-specific method for epsilon lysine acetylation site prediction. A set of optimal features was selected. Analysis of the optimal features provided insights into the mechanism of lysine acetylation sites, providing guidance of experimental validation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. A double-cusp type electrostatic analyzer for high-cadence ring current ion measurements

    NASA Astrophysics Data System (ADS)

    Ogasawara, K.; Allegrini, F.; Burch, J. L.; Desai, M. I.; Ebert, R. W.; Goldstein, J.; John, J. M.; Livi, S. A.; McComas, D. J.

    2015-12-01

    Detailed observations of a variety of ion species at a sufficiently high temporal resolution are essential to understanding the loss and acceleration processes of ring current ions. For example, CRESS/MICS observations indicated that the energy density of suprathermal O+ exceeds that of H+ in large magnetic storms (Daglis et al., 1997), while the H+ energy density dominates under quiet conditions. However, the primary ion loss processes during the storm recovery phase are still incompletely understood. The mechanisms to accelerate upflowing ions, regularly observed with energies of a few keV at ~1000 km altitude, up to the 100s-keV range in the geospace are also not fully understood. Our novel electrostatic analyzer (ESA) employs a toroidal double-shell structure to cover the entire ring current ion range of ~3-250 keV/Q with high temporal resolution (<1 minute with a necessary counting statistics for the quiet time), while saving significant resources in mass and size. In this presentation, we discuss the operation principle and the proof of concept study of the ESA in terms of numerical calculations and ion beam calibration activities. This presentation comprehensively covers the expected sensor performance important for the in-flight capabilities, such as sensor parameters (G-factor, K-factor, and energy resolution), cross-shell contaminations, and UV background counts.

  14. Sericea lespdeza as an aid in the control of Emeria spp. in lambs.

    PubMed

    Burke, J M; Miller, J E; Terrill, T H; Orlik, S T; Acharya, M; Garza, J J; Mosjidis, J A

    2013-03-31

    The objective was to examine the effects of feeding sericea lespedeza leaf meal (SL) on control of coccidiosis in lambs. In Exp. 1, naturally infected lambs (n=76) were weaned (102.7±1.4 d of age) in May (spring) and randomly assigned in a 2×2 factorial design to receive 2% of BW/d of alfalfa pellets (control) or SL with or without amprolium added to drinking water (n=38/level or 19/treatment). Fecal oocyst counts (FOC), egg counts (FEC), and fecal score (1=solid pellets; 5=slurry) were determined every 7d between weaning and 21 d post-weaning. In Exp. 2, twin rearing ewes were randomly assigned to two groups, and their naturally infected lambs were fed a control creep supplement (16% CP; n=40) or SL pellets (14% CP; n=32) 30 d before weaning. Intake of SL was initially low (100g/lamb daily) and increased to 454 g/lamb daily after weaning. Lambs were weaned at 103.6±0.9 d of age and moved to semi-confinement. The FEC, FOC, packed cell volume (PCV), fecal score, and dag score (soiling around rear of lamb; 1=no soiling; 5=heavy soiling) were determined at d -14, 0 (weaning), 7, 14, and 21. In Exp. 3, lambs were randomly assigned to a control or SL diet (n=12/diet) fed at 1.4 kg/d for 22d and inoculated with 50,000 sporulated oocysts on d 8, 11, and 13. The FEC, FOC, and fecal score were determined every 2 to 3d between d 1 and 29 (d 0=first day of dietary treatment). Data on all experiments were analyzed using mixed models. The FOC and FEC data were log transformed. Chi squared analysis was used to determine differences in incidence of treatment (sulfadimethoxine) for coccidiosis in Exp. 1 and 2. In Exp. 1, FOC and FEC were similar between dietary groups, and FOC declined more rapidly in amprolium treated lambs following weaning (P<0.001). Fecal score was higher in the control compared with the SL fed lambs (P=0.05), suggesting more signs of coccidiosis in control lambs. In Exp. 2, FOC was similar initially but was reduced in SL fed lambs by weaning and remained

  15. In vivo study on alkylation site in DNA by the bifunctional dianhydrogalactitol.

    PubMed

    Institoris, E

    1981-05-01

    In vivo alkylation of Yoshida sarcoma cell DNA by 3H-labelled 1,2:5,6-dianhydrogalactitol (DAG) yielded N-7 monogalactitylguanines and 1,6-di-(guanin-7-yl)-galactitol, similar to the alkylated products obtained by in vitro reaction of DNA with dianhydrogalactitol in neutral solution. The ratio between monoalkylguanines and diguaninyl product was 2-2.5, slightly increasing with doses. Persistence of alkylated products in DNA was followed in function of time. There was no significant loss of either monoalkylated bases or diguaninyl derivative during the observation period i.e. 7-24 h after treatment. In contrast, the physical measurements of the amount of renaturable DNA showed a rapid opening of cross-links in the same period. Taking the presence of diguaninyl moiety as an indicator of cross-links in DNA, these two latter findings show an apparent contradiction which could be reconciled however by the mechanism proposed by Reid and Walker (Biochim. Biophys. Acta, 179 (1969) 179) for the removal of cross-linkage induced by HN2. Accordingly, one arm of the cross-links is removed, probably enzymically, leaving the DNA non-renaturable, while the other arm of cross-link is still covalently attached to the DNA molecule rendering possible the detection of diguaninyl moiety in DNA at some later time. This concept for the removal of cross-links from DNA seems to be supported by our results too.

  16. A role of PLC/PKC-dependent pathway in GLP-1-stimulated insulin secretion.

    PubMed

    Shigeto, Makoto; Cha, Chae Young; Rorsman, Patrik; Kaku, Kohei

    2017-04-01

    Glucagon-like peptide-1 (GLP-1) is an endogenous glucose-lowering hormone and GLP-1 receptor agonists are currently being used as antidiabetic drugs clinically. The canonical signalling pathway (including cAMP, Epac2, protein kinase A (PKA) and K ATP channels) is almost universally accepted as the main mechanism of GLP-1-stimulated insulin secretion. This belief is based on in vitro studies that used nanomolar (1-100 nM) concentrations of GLP-1. Recently, it was found that the physiological concentrations (1-10 pM) of GLP-1 also stimulate insulin secretion from isolated islets, induce membrane depolarization and increase of intracellular [Ca 2+ ] in isolated β cells/pancreatic islets. These responses were unaffected by PKA inhibitors and occurred without detectable increases in intracellular cAMP and PKA activity. These PKA-independent actions of GLP-1 depend on protein kinase C (PKC), involve activation of the standard GLP-1 receptor (GLP1R) and culminate in activation of phospholipase C (PLC), leading to an elevation of diacylglycerol (DAG), increased L-type Ca 2+ and TRPM4/TRPM5 channel activities. Here, we review these recent data and contrast them against the effects of nanomolar concentrations of GLP-1. The differential intracellular signalling activated by low and high concentrations of GLP-1 could provide a clue to explain how GLP-1 exerts different function in the central nervous system and peripheral organs.

  17. Effect of phorbol derivatives and staurosporine on gravitropic response of primary root of maize

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mulkey, T.J.; Kim, S.Y.; Lee, J.S.

    1991-05-01

    Time-lapse videography and computer-based, video image digitization were used to examine the effects of phorbol derivatives (phorbol 12-myristate 13-acetate, TPA; phorbol 12-myristate 13-acetate 4-O-methyl ether, mTPA) and staurosporine on the kinetics of gravicurvature of primary roots of maize (Zea mays L., Pioneer 3343 and Golden Cross Bantam). Pretreatment of roots with TPA (3 hr, 1 {mu}M) decreases the time lag prior to induction of positive gravicurvature in horizontally-oriented roots by > 60%. The rate of curvature is not significantly different than the rate observed in control roots. Wrongway curvature which is observed in 30-40% of control roots is not observedmore » in TPA-pretreated roots. Oscillatory movements observed in control roots after completion of gravitropic reorientation is completely dampened in TPA-pretreated roots. Pretreatment of roots with mTPA(3hr,1{mu}M), the inactive analog of TPA, does not significantly alter the kinetics of gravicurvature of primary roots of maize. Staurosporine (10{sup {minus}8}M), a microbial alkaloid which has been reported to have antifungal activity and to inhibit phospholipid/Ca{sup ++} dependent protein kinase, completely inhibits TPA-induced alteration of the kinetics of gravitropism. DAG (1-oleoyl-2-acetyl-rac-glycerol), a synthetic diglyceride activator of protein kinase C, exhibits similar activity to TPA. TPA-induced alterations in tissue response to auxin are presented.« less

  18. Evolving paradigms in clinical pharmacology and therapeutics for the treatment of Duchenne muscular dystrophy.

    PubMed

    Huard, J; Mu, X; Lu, A

    2016-08-01

    Progressive muscle weakness and degeneration due to the lack of dystrophin eventually leads to the loss of independent ambulation by the middle of the patient's second decade, and a fatal outcome due to cardiac or respiratory failure by the third decade. More specifically, loss of sarcolemmal dystrophin and the dystrophin-associated glycoprotein (DAG) complex promotes muscle fiber damage during muscle contraction. This process results in an efflux of creatine kinase (CK), an influx of calcium ions, and the recruitment of T cells, macrophages, and mast cells to the damaged muscle, causing progressive myofiber necrosis. For the last 20 years, the major goal in the development of therapeutic approaches to alleviate muscle weakness in DMD has been centered on the restoration of dystrophin or proteins that are analogous to dystrophin, such as utrophin, through a variety of modalities including cell therapy, gene therapy, gene correction, and the highly promising techniques utilizing CRISPR/Cas9 technology. Despite the development of new therapeutic options, there still exist numerous challenges that we must face with regard to these new strategies and, consequently, we still do not have any feasible options available to ultimately slow the progression of this devastating disease. The purpose of this article is to highlight the current knowledge and advancements in the evolving paradigms in clinical pharmacology and therapeutics for this devastating musculoskeletal disease. © 2016 American Society for Clinical Pharmacology and Therapeutics.

  19. Maintenance or Collapse: Responses of Extraplastidic Membrane Lipid Composition to Desiccation in the Resurrection Plant Paraisometrum mileense

    PubMed Central

    Yu, Buzhu; Yu, Xiaomei; Li, Weiqi

    2014-01-01

    Resurrection plants usually grow in specific or extreme habitats and have the capacity to survive almost complete water loss. We characterized the physiological and biochemical responses of Paraisometrum mileense to extreme desiccation and found that it is a resurrection plant. We profiled the changes in lipid molecular species during dehydration and rehydration in P. mileense, and compared these with corresponding changes in the desiccation-sensitive plant Arabidopsis thaliana. One day of desiccation was lethal for A. thaliana but not for P. mileense. After desiccation and subsequent rewatering, A. thaliana showed dramatic lipid degradation accompanied by large increases in levels of phosphatidic acid (PA) and diacylglycerol (DAG). In contrast, desiccation and rewatering of P. mileense significantly decreased the level of monogalactosyldiacylglycerol and increased the unsaturation of membrane lipids, without changing the level of extraplastidic lipids. Lethal desiccation in P. mileense caused massive lipid degradation, whereas the PA content remained at a low level similar to that of fresh leaves. Neither damage nor repair processes, nor increases in PA, occurred during non-lethal desiccation in P. mileense. The activity of phospholipase D, the main source of PA, was much lower in P. mileense than in A. thaliana under control conditions, or after either dehydration or rehydration. It was demonstrated that low rates of phospholipase D-mediated PA formation in P. mileense might limit its ability to degrade lipids to PA, thereby maintaining membrane integrity following desiccation. PMID:25068901

  20. Novel green algal isolates from the Egyptian hyper-arid desert oases: a polyphasic approach with a description of Pharao desertorum gen. et sp. nov. (Chlorophyceae, Chlorophyta).

    PubMed

    Saber, Abdullah A; Fučíková, Karolina; McManus, Hilary A; Guella, Graziano; Cantonati, Marco

    2018-03-30

    The biodiversity of terrestrial algae is still grossly understudied, and African deserts in particular are barely touched in this respect. Here, four coccoid green algae from oases in the Western Desert of Egypt were characterized using a combination of morphotaxonomic, ecological and 18S rDNA data, with additional carotenoid and lipid analyses for two of the strains. Three strains were identified as affiliated with known taxa: Mychonastes sp., Asterarcys sp. (first report of this genus from a desert soil), and Stichococcus cf. deasonii. The fourth strain is proposed to represent a new cryptic genus Pharao gen. nov., with the type species P. desertorum sp. nov. The new taxon is sister to the clade of uncharacterized North American desert strains of Radiococcaceae (Chlorophyceae, Chlorophyta). The pigment profile of P. desertorum gen. et sp. nov. revealed carotenoids and chlorophylls typical of green algae. Bioorganic analysis showed a complex lipidome based on phospho- (PC), galacto- (MGDG and DGDG), betaine- (DGTS), and sulfoquinovosyl- (SQDG) membrane lipids, besides significant amounts of storage neutral lipids such as diacyl- (DAG) and triacylglycerols (TAG). The presence of saturated alkyl chains within all the membrane lipid classes in P. desertorum and Asterarcys sp. appears to reflect the need to maintain membrane fluidity and viscosity. In summary, African deserts likely still harbor new taxa to be described, and lipidomic analyses of such taxa may provide clues about their ability to survive in the extremely harsh desert habitats. © 2018 Phycological Society of America.

  1. WEGO 2.0: a web tool for analyzing and plotting GO annotations, 2018 update.

    PubMed

    Ye, Jia; Zhang, Yong; Cui, Huihai; Liu, Jiawei; Wu, Yuqing; Cheng, Yun; Xu, Huixing; Huang, Xingxin; Li, Shengting; Zhou, An; Zhang, Xiuqing; Bolund, Lars; Chen, Qiang; Wang, Jian; Yang, Huanming; Fang, Lin; Shi, Chunmei

    2018-05-18

    WEGO (Web Gene Ontology Annotation Plot), created in 2006, is a simple but useful tool for visualizing, comparing and plotting GO (Gene Ontology) annotation results. Owing largely to the rapid development of high-throughput sequencing and the increasing acceptance of GO, WEGO has benefitted from outstanding performance regarding the number of users and citations in recent years, which motivated us to update to version 2.0. WEGO uses the GO annotation results as input. Based on GO's standardized DAG (Directed Acyclic Graph) structured vocabulary system, the number of genes corresponding to each GO ID is calculated and shown in a graphical format. WEGO 2.0 updates have targeted four aspects, aiming to provide a more efficient and up-to-date approach for comparative genomic analyses. First, the number of input files, previously limited to three, is now unlimited, allowing WEGO to analyze multiple datasets. Also added in this version are the reference datasets of nine model species that can be adopted as baselines in genomic comparative analyses. Furthermore, in the analyzing processes each Chi-square test is carried out for multiple datasets instead of every two samples. At last, WEGO 2.0 provides an additional output graph along with the traditional WEGO histogram, displaying the sorted P-values of GO terms and indicating their significant differences. At the same time, WEGO 2.0 features an entirely new user interface. WEGO is available for free at http://wego.genomics.org.cn.

  2. Drosophila development, physiology, behavior, and lifespan are influenced by altered dietary composition

    PubMed Central

    Ormerod, Kiel G.; LePine, Olivia K.; Abbineni, Prabhodh S.; Bridgeman, Justin M.; Mercier, A. Joffre; Tattersall, Glenn J.

    2017-01-01

    ABSTRACT Diet profoundly influences the behavior of animals across many phyla. Despite this, most laboratories using model organisms, such as Drosophila, use multiple, different, commercial or custom-made media for rearing their animals. In addition to measuring growth, fecundity and longevity, we used several behavioral and physiological assays to determine if and how altering food media influence wild-type (Canton S) Drosophila melanogaster, at larval, pupal, and adult stages. Comparing 2 commonly used commercial food media we observed several key developmental and morphological differences. Third-instar larvae and pupae developmental timing, body weight and size, and even lifespan significantly differed between the 2 diets, and some of these differences persisted into adulthood. Diet was also found to produce significantly different thermal preference, locomotory capacity for geotaxis, feeding rates, and lower muscle response to hormonal stimulation. There were no differences, however, in adult thermal preferences, in the number or viability of eggs laid, or in olfactory learning and memory between the diets. We characterized the composition of the 2 diets and found particularly significant differences in cholesterol and (phospho)lipids between them. Notably, diacylglycerol (DAG) concentrations vary substantially between the 2 diets, and may contribute to key phenotypic differences, including lifespan. Overall, the data confirm that 2 different diets can profoundly influence the behavior, physiology, morphology and development of wild-type Drosophila, with greater behavioral and physiologic differences occurring during the larval stages. PMID:28277941

  3. Changes in Acylglycerols composition, quality characteristics and in vivo effects of dietary pumpkin seed oil upon thermal oxidation

    NASA Astrophysics Data System (ADS)

    Zeb, Alam; Ahmad, Sultan

    2017-07-01

    This study was aimed to determine the acylglycerols composition, quality characteristics and protective role of dietary pumpkin seed oil in rabbits. Pumpkin seed oil was thermally oxidized and analyzed for quality characteristics and acylglycerols composition using reversed phase high performance liquid chromatography with diode array detection (HPLC-DAD). Oxidized and un-oxidized oil samples were fed to the rabbits in different doses for two weeks. The changes in the serum biochemistry, hematology, and liver histology were studied. The levels of quality parameters such peroxide value (PV), anisidine value (AV), total phenolic contents (TPC), thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and conjugated trienes (CT) significantly increased with thermal treatment. HPLC analyses revealed ten individual triacylglycerols (TAGs), total di-acylglycerols (DAGs), mono-acylglycerols (MAGs), and total oxidized TAGs. Trilinolein (LLL), 1-oleoyl-2,3-dilinolinoyl glycerol (OLL), triolein (OOO) and 1,2-distearoyl-3-palmitoyl glycerol (SSP) were present in higher amounts and decreased with thermal treatment. Animal's studies showed that oxidized oils decreased the whole body weight, which was ameliorated by the co-administration of un-oxidized oils. The levels of serum biochemical parameters were improved by co-administration of pumpkin seed oils. There were no significant effects of both oxidized and un-oxidized pumpkin seed oil on the hematological and histological parameters of rabbits. In conclusion, nutritionally important triacylglycerols were present in pumpkin seed oil with protective role against the toxicity of its corresponding oxidized oils.

  4. Exploring digenic inheritance in arrhythmogenic cardiomyopathy.

    PubMed

    König, Eva; Volpato, Claudia Béu; Motta, Benedetta Maria; Blankenburg, Hagen; Picard, Anne; Pramstaller, Peter; Casella, Michela; Rauhe, Werner; Pompilio, Giulio; Meraviglia, Viviana; Domingues, Francisco S; Sommariva, Elena; Rossini, Alessandra

    2017-12-08

    Arrhythmogenic cardiomyopathy (ACM) is an inherited genetic disorder, characterized by the substitution of heart muscle with fibro-fatty tissue and severe ventricular arrhythmias, often leading to heart failure and sudden cardiac death. ACM is considered a monogenic disorder, but the low penetrance of mutations identified in patients suggests the involvement of additional genetic or environmental factors. We used whole exome sequencing to investigate digenic inheritance in two ACM families where previous diagnostic tests have revealed a PKP2 mutation in all affected and some healthy individuals. In family members with PKP2 mutations we determined all genes that harbor variants in affected but not in healthy carriers or vice versa. We computationally prioritized the most likely candidates, focusing on known ACM genes and genes related to PKP2 through protein interactions, functional relationships, or shared biological processes. We identified four candidate genes in family 1, namely DAG1, DAB2IP, CTBP2 and TCF25, and eleven candidate genes in family 2. The most promising gene in the second family is TTN, a gene previously associated with ACM, in which the affected individual harbors two rare deleterious-predicted missense variants, one of which is located in the protein's only serine kinase domain. In this study we report genes that might act as digenic players in ACM pathogenesis, on the basis of co-segregation with PKP2 mutations. Validation in larger cohorts is still required to prove the utility of this model.

  5. Constructing a clinical decision-making framework for image-guided radiotherapy using a Bayesian Network

    NASA Astrophysics Data System (ADS)

    Hargrave, C.; Moores, M.; Deegan, T.; Gibbs, A.; Poulsen, M.; Harden, F.; Mengersen, K.

    2014-03-01

    A decision-making framework for image-guided radiotherapy (IGRT) is being developed using a Bayesian Network (BN) to graphically describe, and probabilistically quantify, the many interacting factors that are involved in this complex clinical process. Outputs of the BN will provide decision-support for radiation therapists to assist them to make correct inferences relating to the likelihood of treatment delivery accuracy for a given image-guided set-up correction. The framework is being developed as a dynamic object-oriented BN, allowing for complex modelling with specific subregions, as well as representation of the sequential decision-making and belief updating associated with IGRT. A prototype graphic structure for the BN was developed by analysing IGRT practices at a local radiotherapy department and incorporating results obtained from a literature review. Clinical stakeholders reviewed the BN to validate its structure. The BN consists of a sub-network for evaluating the accuracy of IGRT practices and technology. The directed acyclic graph (DAG) contains nodes and directional arcs representing the causal relationship between the many interacting factors such as tumour site and its associated critical organs, technology and technique, and inter-user variability. The BN was extended to support on-line and off-line decision-making with respect to treatment plan compliance. Following conceptualisation of the framework, the BN will be quantified. It is anticipated that the finalised decision-making framework will provide a foundation to develop better decision-support strategies and automated correction algorithms for IGRT.

  6. The TORC2-Dependent Signaling Network in the Yeast Saccharomyces cerevisiae.

    PubMed

    Roelants, Françoise M; Leskoske, Kristin L; Martinez Marshall, Maria Nieves; Locke, Melissa N; Thorner, Jeremy

    2017-09-05

    To grow, eukaryotic cells must expand by inserting glycerolipids, sphingolipids, sterols, and proteins into their plasma membrane, and maintain the proper levels and bilayer distribution. A fungal cell must coordinate growth with enlargement of its cell wall. In Saccharomyces cerevisiae, a plasma membrane-localized protein kinase complex, Target of Rapamicin (TOR) complex-2 (TORC2) (mammalian ortholog is mTORC2), serves as a sensor and masterregulator of these plasma membrane- and cell wall-associated events by directly phosphorylating and thereby stimulating the activity of two types of effector protein kinases: Ypk1 (mammalian ortholog is SGK1), along with a paralog (Ypk2); and, Pkc1 (mammalian ortholog is PKN2/PRK2). Ypk1 is a central regulator of pathways and processes required for plasma membrane lipid and protein homeostasis, and requires phosphorylation on its T-loop by eisosome-associated protein kinase Pkh1 (mammalian ortholog is PDK1) and a paralog (Pkh2). For cell survival under various stresses, Ypk1 function requires TORC2-mediated phosphorylation at multiple sites near its C terminus. Pkc1 controls diverse processes, especially cell wall synthesis and integrity. Pkc1 is also regulated by Pkh1- and TORC2-dependent phosphorylation, but, in addition, by interaction with Rho1-GTP and lipids phosphatidylserine (PtdSer) and diacylglycerol (DAG). We also describe here what is currently known about the downstream substrates modulated by Ypk1-mediated and Pkc1-mediated phosphorylation.

  7. [Mechanisms of retroviral immunosuppressive domain-induced immune modulation].

    PubMed

    Blinov, V M; Krasnov, G S; Shargunov, A V; Shurdov, M A; Zverev, V V

    2013-01-01

    Immunosuppressive domains (ISD) of viral envelope glycoproteins provide highly pathogenic phenotypes of various retroviruses. ISD interaction with immune cells leads to an inhibition of a response. In the 1980s it was shown that the fragment of ISD comprising of 17 amino acids (named CKS-17) is carrying out such immune modulation. However the underlying mechanisms were not known. The years of thorough research allowed to identify the regulation of Ras-Raf-MEK-MAPK and PI3K-AKT-mTOR cellular pathways as a result of ISD interaction with immune cells. By the way, this leads to decrease of secretion of stimulatory cytokines (e.g., IL-12) and increase of inhibitory, anti-inflammatory ones (e.g., IL-10). One of the receptor tyrosine kinases inducing signal in these pathways acts as the primary target of ISD while other key regulators--cAMP and diacylglycerol (DAG), act as secondary messengers of signal transduction. Immunosuppressive-like domains can be found not only in retroviruses; the presence of ISD within Ebola viral envelope glycoproteins caused extremely hard clinical course of virus-induced hemorrhagic fever. A number of retroviral-origin fragments encoding ISD can be found in the human genome. These regions are expressed in the placenta within genes of syncytins providing a tolerance of mother's immune system to an embryo. The present review is devoted to molecular aspects of retroviral ISD-induced modulation of host immune system.

  8. EMP Attachment 3 DOE-SC PNNL Site Dose Assessment Guidance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Snyder, Sandra F.

    2011-12-21

    This Dose Assessment Guidance (DAG) describes methods to use to determine the Maximally-Exposed Individual (MEI) location and to estimate dose impact to that individual under the U.S. Department of Energy Office of Science (DOE-SC) Pacific Northwest National Laboratory (PNNL) Site Environmental Monitoring Plan (EMP). This guidance applies to public dose from radioactive material releases to the air from PNNL Site operations. This document is an attachment to the Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP) and describes dose assessment guidance for radiological air emissions. The impact of radiological air emissions from the U.S. Department of Energy Office ofmore » Science (DOE-SC) PNNL Site is indicated by dose estimates to a maximally exposed member of the public, referred to as the maximally exposed individual (MEI). Reporting requirements associated with dose to members of the public from radiological air emissions are in 40 CFR Part 61.94, WAC 246-247-080, and DOE Order 458.1. The DOE Order and state standards for dose from radioactive air emissions are consistent with U.S. Environmental Protection Agency (EPA) dose standards in 40 CFR 61.92 (i.e., 10 mrem/yr to a MEI). Despite the fact that the current Contract Requirements Document (CRD) for the DOE-SC PNNL Site operations does not include the requirement to meet DOE CRD 458.1, paragraph 2.b, public dose limits, the DOE dose limits would be met when EPA limits are met.« less

  9. Wavelet Entropy and Directed Acyclic Graph Support Vector Machine for Detection of Patients with Unilateral Hearing Loss in MRI Scanning.

    PubMed

    Wang, Shuihua; Yang, Ming; Du, Sidan; Yang, Jiquan; Liu, Bin; Gorriz, Juan M; Ramírez, Javier; Yuan, Ti-Fei; Zhang, Yudong

    2016-01-01

    Highlights We develop computer-aided diagnosis system for unilateral hearing loss detection in structural magnetic resonance imaging.Wavelet entropy is introduced to extract image global features from brain images. Directed acyclic graph is employed to endow support vector machine an ability to handle multi-class problems.The developed computer-aided diagnosis system achieves an overall accuracy of 95.1% for this three-class problem of differentiating left-sided and right-sided hearing loss from healthy controls. Aim: Sensorineural hearing loss (SNHL) is correlated to many neurodegenerative disease. Now more and more computer vision based methods are using to detect it in an automatic way. Materials: We have in total 49 subjects, scanned by 3.0T MRI (Siemens Medical Solutions, Erlangen, Germany). The subjects contain 14 patients with right-sided hearing loss (RHL), 15 patients with left-sided hearing loss (LHL), and 20 healthy controls (HC). Method: We treat this as a three-class classification problem: RHL, LHL, and HC. Wavelet entropy (WE) was selected from the magnetic resonance images of each subjects, and then submitted to a directed acyclic graph support vector machine (DAG-SVM). Results: The 10 repetition results of 10-fold cross validation shows 3-level decomposition will yield an overall accuracy of 95.10% for this three-class classification problem, higher than feedforward neural network, decision tree, and naive Bayesian classifier. Conclusions: This computer-aided diagnosis system is promising. We hope this study can attract more computer vision method for detecting hearing loss.

  10. Earthquake Activity in the North Greenland Region

    NASA Astrophysics Data System (ADS)

    Larsen, Tine B.; Dahl-Jensen, Trine; Voss, Peter H.

    2017-04-01

    Many local and regional earthquakes are recorded on a daily basis in northern Greenland. The majority of the earthquakes originate at the Arctic plate boundary between the Eurasian and the North American plates. Particularly active regions away from the plate boundary are found in NE Greenland and in northern Baffin Bay. The seismograph coverage in the region is sparse with the main seismograph stations located at the military outpost, Stations Nord (NOR), the weather station outpost Danmarkshavn (DAG), Thule Airbase (TULEG), and the former ice core drilling camp (NEEM) in the middle of the Greenland ice sheet. Furthermore, data is available from Alert (ALE), Resolute (RES), and other seismographs in northern Canada as well as from a temporary deployment of BroadBand seismographs along the north coast of Greenland from 2004 to 2007. The recorded earthquakes range in magnitude from less than 2 to a 4.8 event, the largest in NE Greenland, and a 5.7 event, the largest recorded in northern Baffin Bay. The larger events are recorded widely in the region allowing for focal mechanisms to be calculated. Only a few existing focal mechanisms for the region can be found in the ISC bulletin. Two in NE Greenland representing primarily normal faulting and one in Baffin Bay resulting from reverse faulting. New calculations of focal mechanisms for the region will be presented as well as improved hypocenters resulting from analysis involving temporary stations and regional stations that are not included in routine processing.

  11. Lipidomic Components Alterations of Human Follicular Fluid Reveal the Relevance of Improving Clinical Outcomes in Women Using Progestin-Primed Ovarian Stimulation Compared to Short-Term Protocol.

    PubMed

    Wen, Xiaowei; Kuang, Yanping; Zhou, Lixia; Yu, Baofeng; Chen, Qiuju; Fu, Yonglun; Yan, Zheng; Guo, Haiyan; Lyu, Qifeng; Xie, Jun; Chai, Weiran

    2018-05-21

    BACKGROUND Increasing the success rate of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) is a duty of clinicians that has made many seek a variety of protocols. This study was undertaken to use a liquid chromatography-mass spectrometry (LC-MS) to define the alterations of follicular fluid (FF) lipid metabolites in patients undergoing progestin-primed ovarian stimulation (PPOS) compared with short-term protocol, revealing potential correlations between the differentially expressed lipids and ameliorative clinical outcomes. MATERIAL AND METHODS Ninety-three infertile women undergoing IVF/ICSI treatment with PPOS (n=62) or a short-term protocol (n=31) were prospectively enrolled in a randomized controlled trial. FF samples were obtained from dominant follicles at the time of oocyte retrieval. Lipid metabolism profiles were analyzed using LC-MS. RESULTS Twelve lipids were found to be higher in patients treated with the PPOS protocol than in those receiving the short-term protocol, including triacylglycerols (TAG-34: 1+NH4, TAG-58: 0+NH4, TAG-64: 3+NH4, and TAG-64: 8+NH4), diacylglycerol DAG-38: 6+NH4, phosphatidylglycerols (PG-26: 0, PG-30: 2, and PG-40: 5), phosphatidylethanolamine PE-32: 2, lysophosphatidylethanolamine LPE-14: 1, lysophosphatidylinositol LPI-12: 0, and lysophosphatidylcholine LPC-16: 0. CONCLUSIONS Our data demonstrate that the PPOS protocol increases the levels of 12 lipids in FF, which reveals a strong association between the differentially elevated lipids and better IVF/ICSI outcomes.

  12. The TORC2-Dependent Signaling Network in the Yeast Saccharomyces cerevisiae

    PubMed Central

    Roelants, Françoise M.; Leskoske, Kristin L.; Martinez Marshall, Maria Nieves

    2017-01-01

    To grow, eukaryotic cells must expand by inserting glycerolipids, sphingolipids, sterols, and proteins into their plasma membrane, and maintain the proper levels and bilayer distribution. A fungal cell must coordinate growth with enlargement of its cell wall. In Saccharomyces cerevisiae, a plasma membrane-localized protein kinase complex, Target of Rapamicin (TOR) complex-2 (TORC2) (mammalian ortholog is mTORC2), serves as a sensor and master regulator of these plasma membrane- and cell wall-associated events by directly phosphorylating and thereby stimulating the activity of two types of effector protein kinases: Ypk1 (mammalian ortholog is SGK1), along with a paralog (Ypk2); and, Pkc1 (mammalian ortholog is PKN2/PRK2). Ypk1 is a central regulator of pathways and processes required for plasma membrane lipid and protein homeostasis, and requires phosphorylation on its T-loop by eisosome-associated protein kinase Pkh1 (mammalian ortholog is PDK1) and a paralog (Pkh2). For cell survival under various stresses, Ypk1 function requires TORC2-mediated phosphorylation at multiple sites near its C terminus. Pkc1 controls diverse processes, especially cell wall synthesis and integrity. Pkc1 is also regulated by Pkh1- and TORC2-dependent phosphorylation, but, in addition, by interaction with Rho1-GTP and lipids phosphatidylserine (PtdSer) and diacylglycerol (DAG). We also describe here what is currently known about the downstream substrates modulated by Ypk1-mediated and Pkc1-mediated phosphorylation. PMID:28872598

  13. Variability and transmission by Aphis glycines of North American and Asian Soybean mosaic virus isolates.

    PubMed

    Domier, L L; Latorre, I J; Steinlage, T A; McCoppin, N; Hartman, G L

    2003-10-01

    The variability of North American and Asian strains and isolates of Soybean mosaic virus was investigated. First, polymerase chain reaction (PCR) products representing the coat protein (CP)-coding regions of 38 SMVs were analyzed for restriction fragment length polymorphisms (RFLP). Second, the nucleotide and predicted amino acid sequence variability of the P1-coding region of 18 SMVs and the helper component/protease (HC/Pro) and CP-coding regions of 25 SMVs were assessed. The CP nucleotide and predicted amino acid sequences were the most similar and predicted phylogenetic relationships similar to those obtained from RFLP analysis. Neither RFLP nor sequence analyses of the CP-coding regions grouped the SMVs by geographical origin. The P1 and HC/Pro sequences were more variable and separated the North American and Asian SMV isolates into two groups similar to previously reported differences in pathogenic diversity of the two sets of SMV isolates. The P1 region was the most informative of the three regions analyzed. To assess the biological relevance of the sequence differences in the HC/Pro and CP coding regions, the transmissibility of 14 SMV isolates by Aphis glycines was tested. All field isolates of SMV were transmitted efficiently by A. glycines, but the laboratory isolates analyzed were transmitted poorly. The amino acid sequences from most, but not all, of the poorly transmitted isolates contained mutations in the aphid transmission-associated DAG and/or KLSC amino acid sequence motifs of CP and HC/Pro, respectively.

  14. Almahata Sitta and Brecciated Ureilites: Insights into the Heterogeneity of Asteroids and Implications for Sample Return

    NASA Technical Reports Server (NTRS)

    Ross, A. J.; Herrin, J. S.; Alexander, L.; Downes, H.; Smith, C. L.; Jenniskens, P.

    2011-01-01

    Analysis of samples returned to terrestrial laboratories enables more precise measurements and a wider range of techniques to be utilized than can be achieved with either remote sensing or rover instruments. Furthermore, returning samples to Earth allows them to be stored and re-examined with future technology. Following the success of the Hayabusa mission, returning samples from asteroids should be a high priority for understanding of early solar system evolution, planetary formation and differentiation. Meteorite falls provide us with materials and insight into asteroidal compositions. Almahata Sitta (AS) was the first meteorite fall from a tracked asteroid (2008 TC3) [1] providing a rare opportunity to compare direct geochemical observations with remote sensing data. Although AS is predominantly ureilitic, multiple chondritic fragments have been associated with this fall [2,3]. This is not unique, with chondritic fragments being found in many howardite samples (as described in a companion abstract [4]) and in brecciated ureilites, some of which are known to represent ureilitic regolith [5-7]. The heterogeneity of ureilite samples, which are thought to all originate from a single asteroidal ureilite parent body (UPB) [5], gives us information about both internal and external asteroidal variations. This has implications both for the planning of potential sample return missions and the interpretation of material returned to Earth. This abstract focuses on multiple fragments of two meteorites: Almahata Sitta (AS); and Dar al Gani (DaG) 1047 (a highly brecciated ureilite, likely representative of ureilite asteroidal regolith).

  15. Oxygen Isotope Ratios of Magnetite in CI-Like Clasts from a Polymict Ureilite

    NASA Technical Reports Server (NTRS)

    Kita, N. T.; Defouilloy, C.; Goodrich, C. A.; Zolensky, M. E.

    2017-01-01

    Polymict ureilites contain a variety of Less than or equal to mm to cm sized non-ureilitic clasts, many of which can be identifed as chondritic and achondritic meteorite types. Among them, dark clasts have been observed in polymict ureilites that are similar to CI chondrites in mineralogy, containing phyllosilicates, magnetite, sulfide and carbonates. Bulk oxygen isotope analyses of a dark clast in Nilpena plot along the CCAM line and above the terrestrial fractionation line, on the O-poor extension of the main group ureilite trend and clearly different from bulk CI chondrites. One possible origins of such dark clast is that they represent aqueously altered precursors of ureilite parent body (UPB) that were preserved on the cold surface of the UPB. Oxygen isotope analyses of dark clasts are key to better understanding their origins. Oxygen isotope ratios of magnetite are of special interest because they reflect the compositions of the fluids in asteroidal bodies. In primitive chondrites, Delta O (= Delta O - 0.52× Delta O) values of magnetites are always higher than those of the bulk meteorites and represent minimum Delta O values of the initial O-poor aqueous fluids in the parent body. Previous SIMS analyses on magnetite and fayalite in dark clasts from the DaG 319 polymict ureilite were analytically difficult due to small grain sizes, though data indicated positive Delta O values of 3-4 per mille, higher than that of the dark clast in Nilpena (1.49per mille).

  16. Electrodynamic soil plate oscillator: Modeling nonlinear mesoscopic elastic behavior and hysteresis in nonlinear acoustic landmine detection

    NASA Astrophysics Data System (ADS)

    Korman, M. S.; Duong, D. V.; Kalsbeck, A. E.

    2015-10-01

    significant curvature when the soil particle velocity is relatively higher. An oscillator with hysteresis modeled by a distribution of parallel spring elements each with a different threshold slip condition seems to describe fairly linear backbone curve behavior [W. D. Iwan, Transactions of the ASME, J. of Applied Mech., 33,(1966), 893-900], while a single bilinear hysteresis element describes the backbone curvature results in the experiments reported here [T. K. Caughey, Transactions of the ASME, J. of Applied Mech., 27, (1960), 640-643]. When "off target" resonances have a different backbone curvature than "on the mine" backbone curves, then false alarms may be eliminated due to resonances from the natural soil layering. See [R. A. Guyer, J. TenCate, and P. Johnson, "Hysteresis and the Dynamic Elasticity of Consolidated Granular Materials," Phys. Rev. Lett., 82, 16 (1999), 3280-3283] for recent models of nonlinear mesoscopic behavior.

  17. LLE Review Quarterly Report July-September 2000

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    2000-12-01

    from D{sub 2}-filled targets) using current-mode detectors (i.e., many detection events per unit time interval). They show that current-mode detectors can be configured to survey a much larger dynamic range than single-event neutron counters. (4) V. A. Smalyuk, T. R. Boehly, L. S. Iwan, T. J. Kessler, J. P. Knauer, F. J. Marshall, D. D. Meyerhofer, C. Stoeckl, B. Yaakobi, and D. K. Bradley detail a method of measuring the positional dependence of x-ray self-absorption with filtered x-ray framing cameras. They show how compressed shell nonuniformities can be measured by carefully modeling the imaging system. This volume concludes with the LLE's Summer High School Research Program, the FY00 Laser Facility Report, and the National Laser Users' Facility News.« less

  18. Wavelet Entropy and Directed Acyclic Graph Support Vector Machine for Detection of Patients with Unilateral Hearing Loss in MRI Scanning

    PubMed Central

    Wang, Shuihua; Yang, Ming; Du, Sidan; Yang, Jiquan; Liu, Bin; Gorriz, Juan M.; Ramírez, Javier; Yuan, Ti-Fei; Zhang, Yudong

    2016-01-01

    Highlights We develop computer-aided diagnosis system for unilateral hearing loss detection in structural magnetic resonance imaging.Wavelet entropy is introduced to extract image global features from brain images. Directed acyclic graph is employed to endow support vector machine an ability to handle multi-class problems.The developed computer-aided diagnosis system achieves an overall accuracy of 95.1% for this three-class problem of differentiating left-sided and right-sided hearing loss from healthy controls. Aim: Sensorineural hearing loss (SNHL) is correlated to many neurodegenerative disease. Now more and more computer vision based methods are using to detect it in an automatic way. Materials: We have in total 49 subjects, scanned by 3.0T MRI (Siemens Medical Solutions, Erlangen, Germany). The subjects contain 14 patients with right-sided hearing loss (RHL), 15 patients with left-sided hearing loss (LHL), and 20 healthy controls (HC). Method: We treat this as a three-class classification problem: RHL, LHL, and HC. Wavelet entropy (WE) was selected from the magnetic resonance images of each subjects, and then submitted to a directed acyclic graph support vector machine (DAG-SVM). Results: The 10 repetition results of 10-fold cross validation shows 3-level decomposition will yield an overall accuracy of 95.10% for this three-class classification problem, higher than feedforward neural network, decision tree, and naive Bayesian classifier. Conclusions: This computer-aided diagnosis system is promising. We hope this study can attract more computer vision method for detecting hearing loss. PMID:27807415

  19. Electroacupuncture improves cerebral blood flow and attenuates moderate ischemic injury via Angiotensin II its receptors-mediated mechanism in rats.

    PubMed

    Li, Jing; He, Jiaojun; Du, Yuanhao; Cui, Jingjun; Ma, Ying; Zhang, Xuezhu

    2014-11-11

    To investigate the effects and potential mechanism of electroacupuncture intervention on expressions of Angiotensin II and its receptors-mediated signaling pathway in experimentally induced cerebral ischemia. Totally 126 male Wistar rats were randomly divided into control group, model group and EA group. The latter two were further divided into ten subgroups (n = 6) following Middle Cerebral Artery Occlusion (MCAO). Changes in regional cerebral blood flow (rCBF) and expressions of Angiotensin II and its receptors (AT1R, AT2R), as well as effector proteins in phosphatidyl inositol signal pathway were monitored before and at different times after MCAO. MCAO-induced decline of ipsilateral rCBF was partially suppressed by electroacupuncture, and contralateral blood flow was also superior to that of model group. Angiotensin II level was remarkably elevated immediately after MCAO, while electroacupuncture group exhibited significantly lower levels at 1 to 3 h and the value was significantly increased thereafter. The enhanced expression of AT1R was partially inhibited by electroacupuncture, while increased AT2R level was further induced. Electroacupuncture stimulation attenuated and postponed the upregulated-expressions of Gq and CaM these upregulations. ELISA results showed sharply increased expressions of DAG and IP3, which were remarkably neutralized by electroacupuncture. MCAO induced significant increases in expression of Angiotensin II and its receptor-mediated signal pathway. These enhanced expressions were significantly attenuated by electroacupuncture intervention, followed by reduced vasoconstriction and improved blood supply in ischemic region, and ultimately conferred beneficial effects on cerebral ischemia.

  20. ITGB5 and AGFG1 variants are associated with severity of airway responsiveness.

    PubMed

    Himes, Blanca E; Qiu, Weiliang; Klanderman, Barbara; Ziniti, John; Senter-Sylvia, Jody; Szefler, Stanley J; Lemanske, Robert F; Zeiger, Robert S; Strunk, Robert C; Martinez, Fernando D; Boushey, Homer; Chinchilli, Vernon M; Israel, Elliot; Mauger, David; Koppelman, Gerard H; Nieuwenhuis, Maartje A E; Postma, Dirkje S; Vonk, Judith M; Rafaels, Nicholas; Hansel, Nadia N; Barnes, Kathleen; Raby, Benjamin; Tantisira, Kelan G; Weiss, Scott T

    2013-08-28

    Airway hyperresponsiveness (AHR), a primary characteristic of asthma, involves increased airway smooth muscle contractility in response to certain exposures. We sought to determine whether common genetic variants were associated with AHR severity. A genome-wide association study (GWAS) of AHR, quantified as the natural log of the dosage of methacholine causing a 20% drop in FEV1, was performed with 994 non-Hispanic white asthmatic subjects from three drug clinical trials: CAMP, CARE, and ACRN. Genotyping was performed on Affymetrix 6.0 arrays, and imputed data based on HapMap Phase 2, was used to measure the association of SNPs with AHR using a linear regression model. Replication of primary findings was attempted in 650 white subjects from DAG, and 3,354 white subjects from LHS. Evidence that the top SNPs were eQTL of their respective genes was sought using expression data available for 419 white CAMP subjects. The top primary GWAS associations were in rs848788 (P-value 7.2E-07) and rs6731443 (P-value 2.5E-06), located within the ITGB5 and AGFG1 genes, respectively. The AGFG1 result replicated at a nominally significant level in one independent population (LHS P-value 0.012), and the SNP had a nominally significant unadjusted P-value (0.0067) for being an eQTL of AGFG1. Based on current knowledge of ITGB5 and AGFG1, our results suggest that variants within these genes may be involved in modulating AHR. Future functional studies are required to confirm that our associations represent true biologically significant findings.

  1. Lifetime Alcohol Use & Cognitive Performance in Older Adults

    PubMed Central

    Kalapatapu, Raj K.; Ventura, Maria I.; Barnes, Deborah E.

    2016-01-01

    Background Substance use is an important clinical issue in the older adult population. As older adults are susceptible to cognitive disorders, the intersection of the fields of substance use and cognitive neuroscience is an active area of research. Prior studies of alcohol use and cognitive performance are mixed, and inconsistencies may be due to under- or over-adjustment for confounders. Aim This manuscript adds to this literature by conducting a secondary analysis of self-reported lifetime history of alcohol use and cognitive performance in older adults (n = 133). We hypothesized that current alcohol users would have poorer cognitive performance compared to never/minimal and former alcohol users. Methods Older adult participants were classified into never/minimal alcohol users, former alcohol users, and current alcohol users. A neurocognitive battery included a global cognitive measure and individual measures of attention, memory, fluency, and executive function. A directed acyclic graph (DAG)-based approach was used to select variables to be included in the multiple linear regression models. Results Though unadjusted analyses showed some significant associations between alcohol use and cognitive performance, all associations between alcohol use and cognitive performance were eliminated after adjusting for age, education, sex, race and smoking pack years. Alcohol drink years were not significantly associated with cognitive performance among current and former alcohol users. Discussion These results suggest that lifetime alcohol use is not significantly associated with cognitive performance in older adults after adjustment for key confounders. Inconsistencies in prior studies may be due to uncontrolled confounding and/or unnecessary adjustment of mediators and/or colliders. PMID:27719514

  2. Autonomous Aircraft Operations using RTCA Guidelines for Airborne Conflict Management

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, Karthik; Wing, David J.; Barmore, Bryan E.; Barhydt, Richard; Palmer, Michael T.; Johnson, Edward J.; Ballin, Mark G.; Eischeid, Todd M.

    2003-01-01

    A human-in-the-loop experiment was performed at the NASA Langley Research Center to study the feasibility of DAG-TM autonomous aircraft operations in highly constrained airspace. The airspace was constrained by a pair of special-use airspace (SUA) regions on either side of the pilot's planned route. Traffic flow management (TFM) constraints were imposed as a required time of arrival and crossing altitude at an en route fix. Key guidelines from the RTCA Airborne Conflict Management (ACM) concept were applied to autonomous aircraft operations for this experiment. These concepts included the RTCA ACM definitions of distinct conflict detection and collision avoidance zones, and the use of a graded system of conflict alerts for the flight crew. Three studies were conducted in the course of the experiment. The first study investigated the effect of hazard proximity upon pilot ability to meet constraints and solve conflict situations. The second study investigated pilot use of the airborne tools when faced with an unexpected loss of separation (LOS). The third study explored pilot interactions in an over-constrained conflict situation, with and without priority rules dictating who should move first. Detailed results from these studies were presented at the 5th USA/Europe Air Traffic Management R&D Seminar (ATM2003). This overview paper focuses on the integration of the RTCA ACM concept into autonomous aircraft operations in highly constrained situations, and provides an overview of the results presented at the ATM2003 seminar. These results, together with previously reported studies, continue to support the feasibility of autonomous aircraft operations.

  3. Scalable Failure Masking for Stencil Computations using Ghost Region Expansion and Cell to Rank Remapping

    DOE PAGES

    Gamell, Marc; Teranishi, Keita; Kolla, Hemanth; ...

    2017-10-26

    In order to achieve exascale systems, application resilience needs to be addressed. Some programming models, such as task-DAG (directed acyclic graphs) architectures, currently embed resilience features whereas traditional SPMD (single program, multiple data) and message-passing models do not. Since a large part of the community's code base follows the latter models, it is still required to take advantage of application characteristics to minimize the overheads of fault tolerance. To that end, this paper explores how recovering from hard process/node failures in a local manner is a natural approach for certain applications to obtain resilience at lower costs in faulty environments.more » In particular, this paper targets enabling online, semitransparent local recovery for stencil computations on current leadership-class systems as well as presents programming support and scalable runtime mechanisms. Also described and demonstrated in this paper is the effect of failure masking, which allows the effective reduction of impact on total time to solution due to multiple failures. Furthermore, we discuss, implement, and evaluate ghost region expansion and cell-to-rank remapping to increase the probability of failure masking. To conclude, this paper shows the integration of all aforementioned mechanisms with the S3D combustion simulation through an experimental demonstration (using the Titan system) of the ability to tolerate high failure rates (i.e., node failures every five seconds) with low overhead while sustaining performance at large scales. In addition, this demonstration also displays the failure masking probability increase resulting from the combination of both ghost region expansion and cell-to-rank remapping.« less

  4. Extracting Hot spots of Topics from Time Stamped Documents

    PubMed Central

    Chen, Wei; Chundi, Parvathi

    2011-01-01

    Identifying time periods with a burst of activities related to a topic has been an important problem in analyzing time-stamped documents. In this paper, we propose an approach to extract a hot spot of a given topic in a time-stamped document set. Topics can be basic, containing a simple list of keywords, or complex. Logical relationships such as and, or, and not are used to build complex topics from basic topics. A concept of presence measure of a topic based on fuzzy set theory is introduced to compute the amount of information related to the topic in the document set. Each interval in the time period of the document set is associated with a numeric value which we call the discrepancy score. A high discrepancy score indicates that the documents in the time interval are more focused on the topic than those outside of the time interval. A hot spot of a given topic is defined as a time interval with the highest discrepancy score. We first describe a naive implementation for extracting hot spots. We then construct an algorithm called EHE (Efficient Hot Spot Extraction) using several efficient strategies to improve performance. We also introduce the notion of a topic DAG to facilitate an efficient computation of presence measures of complex topics. The proposed approach is illustrated by several experiments on a subset of the TDT-Pilot Corpus and DBLP conference data set. The experiments show that the proposed EHE algorithm significantly outperforms the naive one, and the extracted hot spots of given topics are meaningful. PMID:21765568

  5. The rational use of drugs and WHO.

    PubMed

    1985-01-01

    On November 25-29, 1985, the World Health Organization held a Conference in Nairobi of Experts on the Rational Use of Drugs. In the early 1980s, both the International Federation of Pharmaceutical Manufacturers Association (IFPMA) and Health Action International (HAI) had developed codes of pharmaceutical marketing practices in order to come to terms with the malpractices in this field. A more comprehensive approach was needed, however. Prime responsibility for rational drug use must rest with the member governments, operating through national regulatory authorities and assisted in their work by guidelines on minimum requirements for national drug regulation prepared by WHO. The Dag Hammarskjold Foundation organized a seminar on Another Development in Pharmaceuticals as an independent contribution to the international debate on this global issue. The seminar emphasized that development should be need-oriented, self-reliant, and based on structural transformations. Governments view the pharmaceutical crisis as 1 facet of the more general problem of spiralling health costs which put an intolerable burden on already overstretched welfare services. The pharmaceutical industry sees the crisis largely in terms of excessively restrictive regulations which stifle innovation of products. Some doctors and pharmacists feel that increased regulatory measures will erode their rights to prescribe and to control the supply and information to patients. On the other hand, some clinical pharmacologists and administrators express concern about excessive, irrational and uneconomic prescribing and its effects on public health. Consumer groups define the problem in terms of an overbearing and greedy business community. The general public fail to understand the effects of pharmaceuticals.

  6. Ligand binding to telomeric G-quadruplex DNA investigated by funnel-metadynamics simulations

    PubMed Central

    Moraca, Federica; Amato, Jussara; Ortuso, Francesco; Artese, Anna; Novellino, Ettore; Alcaro, Stefano; Parrinello, Michele; Limongelli, Vittorio

    2017-01-01

    G-quadruplexes (G4s) are higher-order DNA structures typically present at promoter regions of genes and telomeres. Here, the G4 formation decreases the replicative DNA at each cell cycle, finally leading to apoptosis. The ability to control this mitotic clock, particularly in cancer cells, is fascinating and passes through a rational understanding of the ligand/G4 interaction. We demonstrate that an accurate description of the ligand/G4 binding mechanism is possible using an innovative free-energy method called funnel-metadynamics (FM), which we have recently developed to investigate ligand/protein interaction. Using FM simulations, we have elucidated the binding mechanism of the anticancer alkaloid berberine to the human telomeric G4 (d[AG3(T2AG3)3]), computing also the binding free-energy landscape. Two ligand binding modes have been identified as the lowest energy states. Furthermore, we have found prebinding sites, which are preparatory to reach the final binding mode. In our simulations, the ions and the water molecules have been explicitly represented and the energetic contribution of the solvent during ligand binding evaluated. Our theoretical results provide an accurate estimate of the absolute ligand/DNA binding free energy (ΔGb0 = −10.3 ± 0.5 kcal/mol) that we validated through steady-state fluorescence binding assays. The good agreement between the theoretical and experimental value demonstrates that FM is a most powerful method to investigate ligand/DNA interaction and can be a useful tool for the rational design also of G4 ligands. PMID:28232513

  7. Metabolic profiling of muscle contraction in lean compared with obese rodents.

    PubMed

    Thyfault, John P; Cree, Melanie G; Tapscott, Edward B; Bell, Jill A; Koves, Timothy R; Ilkayeva, Olga; Wolfe, Robert R; Dohm, G Lynis; Muoio, Deborah M

    2010-09-01

    Interest in the pathophysiological relevance of intramuscular triacylglycerol (IMTG) accumulation has grown from numerous studies reporting that abnormally high glycerolipid levels in tissues of obese and diabetic subjects correlate negatively with glucose tolerance. Here, we used a hindlimb perfusion model to examine the impact of obesity and elevated IMTG levels on contraction-induced changes in skeletal muscle fuel metabolism. Comprehensive lipid profiling was performed on gastrocnemius muscles harvested from lean and obese Zucker rats immediately and 25 min after 15 min of one-legged electrically stimulated contraction compared with the contralateral control (rested) limbs. Predictably, IMTG content was grossly elevated in control muscles from obese rats compared with their lean counterparts. In muscles of obese (but not lean) rats, contraction resulted in marked hydrolysis of IMTG, which was then restored to near resting levels during 25 min of recovery. Despite dramatic phenotypical differences in contraction-induced IMTG turnover, muscle levels of diacylglycerol (DAG) and long-chain acyl-CoAs (LCACoA) were surprisingly similar between groups. Tissue profiles of acylcarnitine metabolites suggested that the surfeit of IMTG in obese rats fueled higher rates of fat oxidation relative to the lean group. Muscles of the obese rats had reduced lactate levels immediately following contraction and higher glycogen resynthesis during recovery, consistent with a lipid-associated glucose-sparing effect. Together, these findings suggest that contraction-induced mobilization of local lipid reserves in obese muscles promotes beta-oxidation, while discouraging glucose utilization. Further studies are necessary to determine whether persistent oxidation of IMTG-derived fatty acids contributes to systemic glucose intolerance in other physiological settings.

  8. Alterations in comprehensive geriatric assessment decrease survival of elderly patients with cancer.

    PubMed

    Frasca, M; Soubeyran, P; Bellera, C; Rainfray, M; Leffondre, K; Mathoulin-Pélissier, S

    2018-02-01

    A comprehensive geriatric assessment (CGA) evaluating several domains of health is recommended for elderly patients with cancer. Effects of altered domains on the risk of death in this population need to be clarified. The aim of this study was to estimate the independent association of each CGA domain to overall survival (OS). Patients included in the ONCODAGE cohort completed a CGA at baseline. Cox models (one per domain) estimated the hazard ratio (HR) of death for each CGA domain. Directed Acyclic Graphs (DAGs) selected specific sets of adjustment factors for each model. The analysis included 1264 patients (mean age: 78 years, women: 70%). Median follow-up was 5.2 years, and 446 patients died. Each altered domain had a detrimental effect on survival, sometimes dependent on gender, age, education or time from inclusion. Nutritional status had a time-varying effect, with higher mortality rates if altered only within the first 3 years of follow-up. In case of altered mobility, the risk of death was higher only for the youngest patients and, in case of altered autonomy, only for the youngest women. An altered neurological state led to higher mortality rates; this effect increased with the level of education. Patients with altered psychological status or more than four comorbidities at baseline had also higher mortality rates. Patients with an altered CGA domain have a higher risk of death than those without any alteration. The effect of some alterations is different in some subgroups or at a given time of the treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. On Complex Networks Representation and Computation of Hydrologycal Quantities

    NASA Astrophysics Data System (ADS)

    Serafin, F.; Bancheri, M.; David, O.; Rigon, R.

    2017-12-01

    Water is our blue gold. Despite results of discovery-based science keep warning public opinion about the looming worldwide water crisis, water is still treated as a not worth taking resource. Could a different multi-scale perspective affect environmental decision-making more deeply? Can also a further pairing to a new graphical representation of processes interaction sway decision-making more effectively and public opinion consequently?This abstract introduces a complex networks driven way to represent catchments eco-hydrology and related flexible informatics to manage it. The representation is built upon mathematical category. A category is an algebraic structure that comprises "objects" linked by "arrows". It is an evolution of Petri Nets said Time Continuous Petri Nets (TCPN). It aims to display (water) budgets processes and catchment interactions using explicative and self-contained symbolism. The result improves readability of physical processes compared to current descriptions. The IT perspective hinges on the Object Modeling System (OMS) v3. The latter is a non-invasive flexible environmental modeling framework designed to support component-based model development. The implementation of a Directed Acyclic Graph (DAG) data structure, named Net3, has recently enhanced its flexibility. Net3 represents interacting systems as complex networks: vertices match up with any sort of time evolving quantity; edges correspond to their data (fluxes) interchange. It currently hosts JGrass-NewAge components, and those implementing travel time analysis of fluxes. Further bio-physical or management oriented components can be easily added.This talk introduces both graphical representation and related informatics exercising actual applications and examples.

  10. Scalable Failure Masking for Stencil Computations using Ghost Region Expansion and Cell to Rank Remapping

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gamell, Marc; Teranishi, Keita; Kolla, Hemanth

    In order to achieve exascale systems, application resilience needs to be addressed. Some programming models, such as task-DAG (directed acyclic graphs) architectures, currently embed resilience features whereas traditional SPMD (single program, multiple data) and message-passing models do not. Since a large part of the community's code base follows the latter models, it is still required to take advantage of application characteristics to minimize the overheads of fault tolerance. To that end, this paper explores how recovering from hard process/node failures in a local manner is a natural approach for certain applications to obtain resilience at lower costs in faulty environments.more » In particular, this paper targets enabling online, semitransparent local recovery for stencil computations on current leadership-class systems as well as presents programming support and scalable runtime mechanisms. Also described and demonstrated in this paper is the effect of failure masking, which allows the effective reduction of impact on total time to solution due to multiple failures. Furthermore, we discuss, implement, and evaluate ghost region expansion and cell-to-rank remapping to increase the probability of failure masking. To conclude, this paper shows the integration of all aforementioned mechanisms with the S3D combustion simulation through an experimental demonstration (using the Titan system) of the ability to tolerate high failure rates (i.e., node failures every five seconds) with low overhead while sustaining performance at large scales. In addition, this demonstration also displays the failure masking probability increase resulting from the combination of both ghost region expansion and cell-to-rank remapping.« less

  11. Comprehensive analysis of phospholipids and glycolipids in the opportunistic pathogen Enterococcus faecalis

    PubMed Central

    Gao, Iris H.; Nair, Zeus J.; Kumar, Jaspal K.; Gao, Liang; Kline, Kimberly A.; Wenk, Markus R.

    2017-01-01

    Enterococcus faecalis is a Gram-positive, opportunistic, pathogenic bacterium that causes a significant number of antibiotic-resistant infections in hospitalized patients. The development of antibiotic resistance in hospital-associated pathogens is a formidable public health threat. In E. faecalis and other Gram-positive pathogens, correlations exist between lipid composition and antibiotic resistance. Resistance to the last-resort antibiotic daptomycin is accompanied by a decrease in phosphatidylglycerol (PG) levels, whereas multiple peptide resistance factor (MprF) converts anionic PG into cationic lysyl-PG via a trans-esterification reaction, providing resistance to cationic antimicrobial peptides. Unlike previous studies that relied on thin layer chromatography and spectrophotometry, we have performed liquid chromatography-tandem mass spectrometry (LC-MS/MS) directly on lipids extracted from E. faecalis, and quantified the phospholipids through multiple reaction monitoring (MRM). In the daptomycin-sensitive E. faecalis strain OG1RF, we have identified 17 PGs, 8 lysyl-PGs (LPGs), 23 cardiolipins (CL), 3 glycerophospho-diglucosyl-diacylglycerols (GPDGDAG), 5 diglucosyl-diacylglycerols (DGDAG), 3 diacylglycerols (DAGs), and 4 triacylglycerols (TAGs). We have quantified PG and shown that PG levels vary during growth of E. faecalis in vitro. We also show that two daptomycin-resistant (DapR) strains of E. faecalis have substantially lower levels of PG and LPG levels. Since LPG levels in these strains are lower, daptomycin resistance is likely due to the reduction in PG. This lipidome map is the first comprehensive analysis of membrane phospholipids and glycolipids in the important human pathogen E. faecalis, for which antimicrobial resistance and altered lipid homeostasis have been intimately linked. PMID:28423018

  12. EDITORIAL: International Workshop on Monte Carlo Techniques in Radiotherapy Delivery and Verification

    NASA Astrophysics Data System (ADS)

    Verhaegen, Frank; Seuntjens, Jan

    2008-03-01

    PhysicsWeb. At McGill we thank the following departments for support: the Cancer Axis of the Research Institute of the McGill University Health Center, the Faculties of Medicine and Science, the Departments of Oncology and Physics and the Medical Physics Unit. The following companies are thanked: TomoTherapy and Standard Imaging. The American Association of Physicists in Medicine and the International Atomic Energy Agency are gratefully acknowledged for endorsing the meeting. A final word of thanks goes out to all of those who contributed to the successful Workshop: first of all our administrative assistant Ms Margery Knewstubb, the website developer Dr François DeBlois, the two heads of the logistics team, Ms Emily Poon and Ms Emily Heath, our local medical physics students and staff, the IOP staff and the authors who shared their new and exciting work with us. Editors: Frank Verhaegen and Jan Seuntjens (McGill University) Associate editors: Luc Beaulieu, Iwan Kawrakow, Tony Popescu and David Rogers

  13. Ancient rice cultivar extensively replaces phospholipids with non-phosphorus glycolipid under phosphorus deficiency.

    PubMed

    Tawaraya, Keitaro; Honda, Soichiro; Cheng, Weiguo; Chuba, Masaru; Okazaki, Yozo; Saito, Kazuki; Oikawa, Akira; Maruyama, Hayato; Wasaki, Jun; Wagatsuma, Tadao

    2018-02-07

    Recycling of phosphorus (P) from P-containing metabolites is an adaptive strategy of plants to overcome soil P deficiency. This study was aimed at demonstrating differences in lipid remodelling between low-P-tolerant and -sensitive rice cultivars using lipidome profiling. The rice cultivars Akamai (low-P-tolerant) and Koshihikari (low-P-sensitive) were grown in a culture solution with [2 mg l -1 (+P)] or without (-P) phosphate for 21 and 28 days after transplantation. Upper and lower leaves were collected. Lipids were extracted from the leaves and their composition was analysed by liquid chromatography/mass spectrometry (LC-MS). Phospholipids, namely phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and phosphatidylinositol (PI), lysophosphatidylcholine (lysoPC), diacylglycerol (DAG), triacylglycerol (TAG) and glycolipids, namely sulfoquinovosyl diacylglycerol (SQDG), digalactosyldiacylglycerol (DGDG), monogalactosyldiacylglycerol (MGDG) and 1,2-diacyl-3-O-alpha-glucuronosyl glycerol (GlcADG), were detected. GlcADG level was higher in both cultivars grown in -P than in +P and the increase was larger in Akamai than in Koshihikari. DGDG, MGDG and SQDG levels were higher in Akamai grown in -P than in +P and the increase was larger in the upper leaves than in the lower leaves. PC, PE, PG and PI levels were lower in both cultivars grown in -P than in +P and the decrease was larger in the lower leaves than in the upper leaves and in Akamai than in Koshihikari. Akamai catabolised more phospholipids in older leaves and synthesised glycolipids in younger leaves. These results suggested that extensive phospholipid replacement with non-phosphorus glycolipids is a mechanism underlying low-P-tolerance in rice cultivars. © 2018 Scandinavian Plant Physiology Society.

  14. Inferring ontology graph structures using OWL reasoning.

    PubMed

    Rodríguez-García, Miguel Ángel; Hoehndorf, Robert

    2018-01-05

    Ontologies are representations of a conceptualization of a domain. Traditionally, ontologies in biology were represented as directed acyclic graphs (DAG) which represent the backbone taxonomy and additional relations between classes. These graphs are widely exploited for data analysis in the form of ontology enrichment or computation of semantic similarity. More recently, ontologies are developed in a formal language such as the Web Ontology Language (OWL) and consist of a set of axioms through which classes are defined or constrained. While the taxonomy of an ontology can be inferred directly from the axioms of an ontology as one of the standard OWL reasoning tasks, creating general graph structures from OWL ontologies that exploit the ontologies' semantic content remains a challenge. We developed a method to transform ontologies into graphs using an automated reasoner while taking into account all relations between classes. Searching for (existential) patterns in the deductive closure of ontologies, we can identify relations between classes that are implied but not asserted and generate graph structures that encode for a large part of the ontologies' semantic content. We demonstrate the advantages of our method by applying it to inference of protein-protein interactions through semantic similarity over the Gene Ontology and demonstrate that performance is increased when graph structures are inferred using deductive inference according to our method. Our software and experiment results are available at http://github.com/bio-ontology-research-group/Onto2Graph . Onto2Graph is a method to generate graph structures from OWL ontologies using automated reasoning. The resulting graphs can be used for improved ontology visualization and ontology-based data analysis.

  15. The transient receptor potential ankyrin-1 mediates mechanical hyperalgesia induced by the activation of B1 receptor in mice.

    PubMed

    Meotti, Flavia Carla; Figueiredo, Cláudia Pinto; Manjavachi, Marianne; Calixto, João B

    2017-02-01

    The kinin receptor B 1 and the transient receptor potential ankyrin 1 (TRPA1) work as initiators and gatekeepers of nociception and inflammation. This study reports that the nociceptive transmission induced by activation of B 1 receptor is dependent on TRPA1 ion channel. The mechanical hyperalgesia was induced by intrathecal (i.t.) injection of B 1 agonist des-Arginine 9 -bradykinin (DABK) or TRPA1 agonist cinnamaldehyde and was evaluated by the withdrawal response after von Frey Hair application in the hind paw. After behavioral experiments, lumbar spinal cord and dorsal root ganglia (DRG) were harvested to assess protein expression and mRNA by immunohistochemistry and real time-PCR, respectively. The pharmacological antagonism (HC030031) or the down-regulation of TRPA1 greatly inhibited the mechanical hyperalgesia induced by DABK. Intrathecal injection of DABK up regulated the ionized calcium binding adaptor molecule (Iba-1) in lumbar spinal cord (L5-L6); TRPA1 protein and mRNA in lumbar spinal cord; and B 1 receptor mRNA in both lumbar spinal cord and DRG. The knockdown of TRPA1 prevented microglia activation induced by DABK. Furthermore, the mechanical hyperalgesia induced by either DABK or by cinnamaldehyde was significantly reduced by inhibition of cyclooxygenase (COX), protein kinase C (PKC) or phospholipase C (PLC). In summary, this study revealed that TRPA1 positively modulates the mechanical hyperalgesia induced by B 1 receptor activation in the spinal cord and that the classical GPCR downstream molecules PLC, diacylglycerol (DAG), 3,4,5-inositide phosphate (IP 3 ) and PKC are involved in the nociceptive transmission triggered by these two receptors. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Inferring gene ontologies from pairwise similarity data

    PubMed Central

    Kramer, Michael; Dutkowski, Janusz; Yu, Michael; Bafna, Vineet; Ideker, Trey

    2014-01-01

    Motivation: While the manually curated Gene Ontology (GO) is widely used, inferring a GO directly from -omics data is a compelling new problem. Recognizing that ontologies are a directed acyclic graph (DAG) of terms and hierarchical relations, algorithms are needed that: analyze a full matrix of gene–gene pairwise similarities from -omics data;infer true hierarchical structure in these data rather than enforcing hierarchy as a computational artifact; andrespect biological pleiotropy, by which a term in the hierarchy can relate to multiple higher level terms. Methods addressing these requirements are just beginning to emerge—none has been evaluated for GO inference. Methods: We consider two algorithms [Clique Extracted Ontology (CliXO), LocalFitness] that uniquely satisfy these requirements, compared with methods including standard clustering. CliXO is a new approach that finds maximal cliques in a network induced by progressive thresholding of a similarity matrix. We evaluate each method’s ability to reconstruct the GO biological process ontology from a similarity matrix based on (a) semantic similarities for GO itself or (b) three -omics datasets for yeast. Results: For task (a) using semantic similarity, CliXO accurately reconstructs GO (>99% precision, recall) and outperforms other approaches (<20% precision, <20% recall). For task (b) using -omics data, CliXO outperforms other methods using two -omics datasets and achieves ∼30% precision and recall using YeastNet v3, similar to an earlier approach (Network Extracted Ontology) and better than LocalFitness or standard clustering (20–25% precision, recall). Conclusion: This study provides algorithmic foundation for building gene ontologies by capturing hierarchical and pleiotropic structure embedded in biomolecular data. Contact: tideker@ucsd.edu PMID:24932003

  17. Predicting miRNA targets for head and neck squamous cell carcinoma using an ensemble method.

    PubMed

    Gao, Hong; Jin, Hui; Li, Guijun

    2018-01-01

    This study aimed to uncover potential microRNA (miRNA) targets in head and neck squamous cell carcinoma (HNSCC) using an ensemble method which combined 3 different methods: Pearson's correlation coefficient (PCC), Lasso and a causal inference method (i.e., intervention calculus when the directed acyclic graph (DAG) is absent [IDA]), based on Borda count election. The Borda count election method was used to integrate the top 100 predicted targets of each miRNA generated by individual methods. Afterwards, to validate the performance ability of our method, we checked the TarBase v6.0, miRecords v2013, miRWalk v2.0 and miRTarBase v4.5 databases to validate predictions for miRNAs. Pathway enrichment analysis of target genes in the top 1,000 miRNA-messenger RNA (mRNA) interactions was conducted to focus on significant KEGG pathways. Finally, we extracted target genes based on occurrence frequency ≥3. Based on an absolute value of PCC >0.7, we found 33 miRNAs and 288 mRNAs for further analysis. We extracted 10 target genes with predicted frequencies not less than 3. The target gene MYO5C possessed the highest frequency, which was predicted by 7 different miRNAs. Significantly, a total of 8 pathways were identified; the pathways of cytokine-cytokine receptor interaction and chemokine signaling pathway were the most significant. We successfully predicted target genes and pathways for HNSCC relying on miRNA expression data, mRNA expression profile, an ensemble method and pathway information. Our results may offer new information for the diagnosis and estimation of the prognosis of HNSCC.

  18. Phorbol ester and hydrogen peroxide synergistically induce the interaction of diacylglycerol kinase gamma with the Src homology 2 and C1 domains of beta2-chimaerin.

    PubMed

    Yasuda, Satoshi; Kai, Masahiro; Imai, Shin-ichi; Kanoh, Hideo; Sakane, Fumio

    2008-01-01

    DGKgamma (diacylglycerol kinase gamma) was reported to interact with beta2-chimaerin, a GAP (GTPase-activating protein) for Rac, in response to epidermal growth factor. Here we found that PMA and H2O2 also induced the interaction of DGKgamma with beta2-chimaerin. It is noteworthy that simultaneous addition of PMA and H2O2 synergistically enhanced the interaction. In this case, PMA was replaceable by DAG (diacylglycerol). The beta2-chimaerin translocation from the cytoplasm to the plasma membrane caused by PMA plus H2O2 was further enhanced by the expression of DGKgamma. Moreover, DGKgamma apparently enhanced the beta2-chimaerin GAP activity upon cell stimulation with PMA. PMA was found to be mainly required for a conversion of beta2-chimaerin into an active form. On the other hand, H2O2 was suggested to induce a release of Zn2+ from the C1 domain of beta2-chimaerin. By stepwise deletion analysis, we demonstrated that the SH2 (Src homology 2) and C1 domains of beta2-chimaerin interacted with the N-terminal half of catalytic region of DGKgamma. Unexpectedly, the SH2 domain of beta2-chimaerin contributes to the interaction independently of phosphotyrosine. Taken together, these results suggest that the functional link between DGKgamma and beta2-chimaerin has a broad significance in response to a wide range of cell stimuli. Our work offers a novel mechanism of protein-protein interaction, that is, the phosphotyrosine-independent interaction of the SH2 domain acting in co-operation with the C1 domain.

  19. Diabetes and mitochondrial function: Role of hyperglycemia and oxidative stress

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rolo, Anabela P.; Palmeira, Carlos M.

    2006-04-15

    Hyperglycemia resulting from uncontrolled glucose regulation is widely recognized as the causal link between diabetes and diabetic complications. Four major molecular mechanisms have been implicated in hyperglycemia-induced tissue damage: activation of protein kinase C (PKC) isoforms via de novo synthesis of the lipid second messenger diacylglycerol (DAG), increased hexosamine pathway flux, increased advanced glycation end product (AGE) formation, and increased polyol pathway flux. Hyperglycemia-induced overproduction of superoxide is the causal link between high glucose and the pathways responsible for hyperglycemic damage. In fact, diabetes is typically accompanied by increased production of free radicals and/or impaired antioxidant defense capabilities, indicating amore » central contribution for reactive oxygen species (ROS) in the onset, progression, and pathological consequences of diabetes. Besides oxidative stress, a growing body of evidence has demonstrated a link between various disturbances in mitochondrial functioning and type 2 diabetes. Mutations in mitochondrial DNA (mtDNA) and decreases in mtDNA copy number have been linked to the pathogenesis of type 2 diabetes. The study of the relationship of mtDNA to type 2 diabetes has revealed the influence of the mitochondria on nuclear-encoded glucose transporters, glucose-stimulated insulin secretion, and nuclear-encoded uncoupling proteins (UCPs) in {beta}-cell glucose toxicity. This review focuses on a range of mitochondrial factors important in the pathogenesis of diabetes. We review the published literature regarding the direct effects of hyperglycemia on mitochondrial function and suggest the possibility of regulation of mitochondrial function at a transcriptional level in response to hyperglycemia. The main goal of this review is to include a fresh consideration of pathways involved in hyperglycemia-induced diabetic complications.« less

  20. Trends in Costs of Thyroid Disease Treatment in Denmark during 1995-2015.

    PubMed

    Møllehave, Line Tang; Linneberg, Allan; Skaaby, Tea; Knudsen, Nils; Ehlers, Lars; Jørgensen, Torben; Thuesen, Betina Heinsbæk

    2018-03-01

    Iodine fortification (IF) may contribute to changes in costs of thyroid disease treatment through changes in disease patterns. From a health economic perspective, assessment of the development in costs of thyroid disease treatment in the population is pertinent. To assess the trends in annual medicine and hospital costs of thyroid disease treatment during 1995-2015 in Denmark, i.e., before and after the introduction of mandatory IF in 2000. Information on treatments for thyroid disease (antithyroid medication, thyroid hormone therapy, thyroid surgery, and radioiodine treatment) was obtained from nationwide registers. Costs were valued at 2015 prices using sales prices for medicines and the Danish Diagnosis-Related Group (DRG) and Danish Ambulatory Grouping System (DAGS) tariffs of surgeries/radioiodine treatments. Results were adjusted for changes in population size and age and sex distribution. The total direct medicine and hospital costs of thyroid disease treatment increased from EUR ∼190,000 per 100,000 persons in 1995 to EUR ∼270,000 per 100,000 persons in 2015. This was mainly due to linearly increased costs of thyroid hormone therapy and increased costs of thyroid surgery since 2008. Costs of antithyroid medication increased slightly and transiently after IF, while costs of radioiodine treatment remained constant. Costs of thyroid hormone therapy and thyroid surgery did not follow the development in the prevalence of hypothyroidism and structural thyroid diseases observed in concurrent studies. The costs of total direct medicine and hospital costs for thyroid disease treatment in Denmark increased from 1995 to 2015. This is possibly due to several factors, e.g., changes in treatment practices, and the direct effect of IF alone remains to be estimated.