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Sample records for nowell gm taylor

  1. Sense of Community, a Theory Not a Value: A Response to Nowell and Boyd

    ERIC Educational Resources Information Center

    McMillan, David W.

    2011-01-01

    This is a response to the Nowell and Boyd (2010) article printed in this journal titled: Viewing Community as Responsibility as Well as Resource: Deconstructing the Theoretical Roots of Psychological Sense of Community. In that article, they argued that the McMillan theory of Sense of Community is a simplistic, needs-based theory that excludes…

  2. Sense of Community, a Theory Not a Value: A Response to Nowell and Boyd

    ERIC Educational Resources Information Center

    McMillan, David W.

    2011-01-01

    This is a response to the Nowell and Boyd (2010) article printed in this journal titled: Viewing Community as Responsibility as Well as Resource: Deconstructing the Theoretical Roots of Psychological Sense of Community. In that article, they argued that the McMillan theory of Sense of Community is a simplistic, needs-based theory that excludes…

  3. Taylor-Made Libraries

    ERIC Educational Resources Information Center

    Lonergan, David

    2011-01-01

    Frederick Winslow Taylor (1856-1915) was an efficiency expert whose concerns were less about avoiding worker fatigue and more about increasing profit margins by any means necessary. Taylor was devoted to finding the One Best Way to carry out a task and then training workers to do that task unvaryingly; attempts by employees to improve their own…

  4. Taylor-Made Libraries

    ERIC Educational Resources Information Center

    Lonergan, David

    2011-01-01

    Frederick Winslow Taylor (1856-1915) was an efficiency expert whose concerns were less about avoiding worker fatigue and more about increasing profit margins by any means necessary. Taylor was devoted to finding the One Best Way to carry out a task and then training workers to do that task unvaryingly; attempts by employees to improve their own…

  5. GM Risk Assessment.

    PubMed

    Sparrow, Penny A C

    2009-01-01

    GM risk assessments play an important role in the decision-making process surrounding the regulation, notification and permission to handle Genetically Modified Organisms (GMOs). Ultimately the role of a GM risk assessment will be to ensure the safe handling and containment of the GMO; and to assess any potential impacts on the environment and human health. A risk assessment should answer all 'what if' scenarios, based on scientific evidence. This chapter sets out to provide researchers with helpful guidance notes on producing their own GM risk assessment. While reference will be made to UK and EU regulations, the underlying principles and points to consider are generic to most countries.

  6. GM-611 (Chugai Pharmaceutical).

    PubMed

    Peeters, T L

    2001-04-01

    GM-611 is an erythromycin derivative that acts as an agonist at the motilin receptor. It is being developed by Chugai as a potential treatment for gastric motility disorder [169036], as well as reflux esophagitis, non-ulcer dyspepsia and diabetic gastroparesis [347963]. GM-611 is in phase II trials in the US for reflux esophagitis [322624], [347955], [399349]. GM-611 acts by a novel mechanism whereby it stimulates and promotes peristalsis in the stomach and other segments of the gastrointestinal tract [334994]. The drug was shown to produce a dose-dependent sustained depolarization of rabbit duodenal smooth muscle. Depolarization appeared to be associated with activation of monovalent cation-selective channels [273336]. In December 2000, Credit Suisse First Boston predicted that successful development of GM-611 could lead to sales over $500 million [400228].

  7. GM Risk Assessment

    NASA Astrophysics Data System (ADS)

    Sparrow, Penny A. C.

    GM risk assessments play an important role in the decision-making process surrounding the regulation, notification and permission to handle Genetically Modified Organisms (GMOs). Ultimately the role of a GM risk assessment will be to ensure the safe handling and containment of the GMO; and to assess any potential impacts on the environment and human health. A risk assessment should answer all ‘what if’ scenarios, based on scientific evidence.

  8. Reply to Taylor.

    ERIC Educational Resources Information Center

    Stanovich, Keith E.; West, Richard F.

    1994-01-01

    Responds to Denny Taylor's critique in the same issue of an article by Richard F. West, Keith E. Stanovich, and H. R. Mitchell entitled "Reading in the Real World and Its Correlates," published in an earlier issue of "Reading Research Quarterly." (HB)

  9. Baker & Taylor's George Coe

    ERIC Educational Resources Information Center

    Fialkoff, Francine

    2009-01-01

    In his 30 years as a library wholesaler, first as VP and general manager of Brodart Books, Library, and School Automation divisions and since 2000 as president of the Library & Education division of Baker & Taylor (B&T), George Coe has been instrumental in a whole host of innovations. They go way beyond the selection, processing, and delivery of…

  10. Baker & Taylor's George Coe

    ERIC Educational Resources Information Center

    Fialkoff, Francine

    2009-01-01

    In his 30 years as a library wholesaler, first as VP and general manager of Brodart Books, Library, and School Automation divisions and since 2000 as president of the Library & Education division of Baker & Taylor (B&T), George Coe has been instrumental in a whole host of innovations. They go way beyond the selection, processing, and delivery of…

  11. Reply to Taylor.

    ERIC Educational Resources Information Center

    Stanovich, Keith E.; West, Richard F.

    1994-01-01

    Responds to Denny Taylor's critique in the same issue of an article by Richard F. West, Keith E. Stanovich, and H. R. Mitchell entitled "Reading in the Real World and Its Correlates," published in an earlier issue of "Reading Research Quarterly." (HB)

  12. Will GM animals follow the GM plant fate?

    PubMed

    Vàzquez-Salat, Núria; Houdebine, Louis-Marie

    2013-02-01

    Despite being both Genetically Modified Organisms (GMOs), GM plants and GM animals share few similarities outside the laboratory premises. Whilst GM plants were soon embraced by industry and became a commercial success, only recently have GM animals reached the market. However, an area where GM animals are likely to follow the GM plant path is on their potential to cause social unrest. One of the major flaws of the 90s GMO crisis was the underestimation of the influence that different players can have in the adoption of new biotechnological applications. In this article we describe the unique evolution of GM animals in two of the most important fields: the pharmaceutical and the breeding sectors. For our analysis, we have subdivided the production chain into three governance domains: Science, Market and Public. We describe the influence and interaction of each of these domains as a vehicle for predicting the future adoptability of GM animals and to highlight conflicting areas.

  13. GM1 and GM2 gangliosides: recent developments.

    PubMed

    Bisel, Blaine; Pavone, Francesco S; Calamai, Martino

    2014-03-01

    GM1 and GM2 gangliosides are important components of the cell membrane and play an integral role in cell signaling and metabolism. In this conceptual overview, we discuss recent developments in our understanding of the basic biological functions of GM1 and GM2 and their involvement in several diseases. In addition to a well-established spectrum of disorders known as gangliosidoses, such as Tay-Sachs disease, more and more evidence points at an involvement of GM1 in Alzheimer's and Parkinson's diseases. New emerging methodologies spanning from single-molecule imaging in vivo to simulations in silico have complemented standard studies based on ganglioside extraction.

  14. Taylor dispersion of nanoparticles

    NASA Astrophysics Data System (ADS)

    Balog, Sandor; Urban, Dominic A.; Milosevic, Ana M.; Crippa, Federica; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

    2017-08-01

    The ability to detect and accurately characterize particles is required by many fields of nanotechnology, including materials science, nanotoxicology, and nanomedicine. Among the most relevant physicochemical properties of nanoparticles, size and the related surface-to-volume ratio are fundamental ones. Taylor dispersion combines three independent phenomena to determine particle size: optical extinction, translational diffusion, and sheer-enhanced dispersion of nanoparticles subjected to a steady laminar flow. The interplay of these defines the apparent size. Considering that particles in fact are never truly uniform nor monodisperse, we rigorously address particle polydispersity and calculate the apparent particle size measured by Taylor dispersion analysis. We conducted case studies addressing aqueous suspensions of model particles and large-scale-produced "industrial" particles of both academic and commercial interest of various core materials and sizes, ranging from 15 to 100 nm. A comparison with particle sizes determined by transmission electron microscopy confirms that our approach is model-independent, non-parametric, and of general validity that provides an accurate account of size polydispersity—independently on the shape of the size distribution and without any assumption required a priori.

  15. Can GM sorghum impact Africa?

    PubMed

    Botha, Gerda M; Viljoen, Christopher D

    2008-02-01

    It is said that genetic modification (GM) of grain sorghum has the potential to alleviate hunger in Africa. To this end, millions of dollars have been committed to developing GM sorghum. Current developments in the genetic engineering of sorghum are similar to efforts to improve cassava and other traditional African crops, as well as rice in Asia. On closer analysis, GM sorghum is faced with the same limitations as 'Golden Rice' (GM rice) in the context of combating vitamin A deficiency (VAD) efficiently and sustainably. Thus, it is questionable whether the cost of developing GM sorghum can be justified when compared to the cost of investing in sustainable agricultural practice in Africa.

  16. Large deviations in Taylor dispersion

    NASA Astrophysics Data System (ADS)

    Kahlen, Marcel; Engel, Andreas; Van den Broeck, Christian

    2017-01-01

    We establish a link between the phenomenon of Taylor dispersion and the theory of empirical distributions. Using this connection, we derive, upon applying the theory of large deviations, an alternative and much more precise description of the long-time regime for Taylor dispersion.

  17. GM risk assessment.

    PubMed

    Sparrow, P A C

    2010-03-01

    GM risk assessments (GMRAs) play an important role in the decision-making process surrounding the regulation, notification and permission to handle Genetically Modified Organisms (GMOs). Ultimately the role of each GMRA will be able to ensure the safe handling and containment of the GMO; and to asses any potential impacts on the environment and human health. A risk assessment should answer all "what if" scenarios, based on scientific evidence. This article sets out to provide researchers with helpful guidance notes on producing their own GMRA. While reference is made to UK and EU regulations, the underlying principles and points to consider are generic to most countries.

  18. Expression machinery of GM4: the excess amounts of GM3/GM4S synthase (ST3GAL5) are necessary for GM4 synthesis in mammalian cells.

    PubMed

    Uemura, Satoshi; Go, Shinji; Shishido, Fumi; Inokuchi, Jin-ichi

    2014-02-01

    The ganglioside GM4 is a sialic acid-containing glycosphingolipid mainly expressed in mammalian brain and erythrocytes. GM4 is synthesized by the sialylation of galactosylceramide (GalCer), while the ganglioside GM3 is synthesized by the sialylation of lactosylceramide (LacCer). Recently, the enzyme GM3 synthase was found to be responsible for the synthesis of GM4 in vitro and in vivo, yet the mechanism behind GM4 expression in cells remains unclear. In this study, we attempted to establish GM4-reconstituted cells to reveal the regulation of GM4 synthesis. Interestingly, GM4 was not detected in RPMI 1846 cells expressing LacCer, GalCer, and GM3. Similarly, GM4 was not detected in CHO-K1 cells, even when such cells expressing LacCer and GM3 were stably transfected with the GalCer synthase (GalCerS) gene. GM4 became detectable only when the GM3/GM4 synthase (GM3/GM4S, ST3GAL5) gene was overexpressed in either RPMI 1846 or CHO-K1/GalCerS cells. A mutant of the B16 melanoma cell line, GM-95, lacks GlcCer and LacCer, due to an absence of GlcCer synthase, but carries endogenous LacCer synthase and GM3/GM4S. GalCer became detectable after transfection of GalCerS into GM95 cells, but the GM95/GalCerS reconstituted cells did not express GM4, indicating that competition between the substrates LacCer and GalCer for GM3/GM4S does not cause the failure of GM4 synthesis. These results suggest that the expression machinery of GM4 under physiological conditions is independent from that of GM3.

  19. Incompressible Rayleigh–Taylor Turbulence

    NASA Astrophysics Data System (ADS)

    Boffetta, Guido; Mazzino, Andrea

    2017-01-01

    Basic fluid equations are the main ingredient in the development of theories of Rayleigh–Taylor buoyancy-induced instability. Turbulence arises in the late stage of the instability evolution as a result of the proliferation of active scales of motion. Fluctuations are maintained by the unceasing conversion of potential energy into kinetic energy. Although the dynamics of turbulent fluctuations is ruled by the same equations controlling the Rayleigh–Taylor instability, here only phenomenological theories are currently available. The present review provides an overview of the most relevant (and often contrasting) theoretical approaches to Rayleigh–Taylor turbulence together with numerical and experimental evidence for their support. Although the focus is mainly on the classical Boussinesq Rayleigh–Taylor turbulence of miscible fluids, the review extends to other fluid systems with viscoelastic behavior, affected by rotation of the reference frame, and, finally, in the presence of reactions.

  20. Risk Management of GM Crops

    EPA Science Inventory

    Driven by biofuel demand, a significant increase in GM corn acreage is anticipated for the 2007 growing season with future planted GM corn acreage approaching 80% of the corn crop by 2009. As demand increases, grower non-compliance with mandated planting requirements is likely to...

  1. Risk Management of GM Crops

    EPA Science Inventory

    Driven by biofuel demand, a significant increase in GM corn acreage is anticipated for the 2007 growing season with future planted GM corn acreage approaching 80% of the corn crop by 2009. As demand increases, grower non-compliance with mandated planting requirements is likely to...

  2. Moving beyond the GM Debate

    PubMed Central

    Leyser, Ottoline

    2014-01-01

    Once again, there are calls to reopen the debate on genetically modified (GM) crops. I find these calls frustrating and unnecessarily decisive. In my opinion the GM debate, on both sides, continues to hamper the urgent need to address the diverse and pressing challenges of global food security and environmental sustainability. The destructive power of the debate comes from its conflation of unrelated issues, coupled with deeply rooted misconceptions of the nature of agriculture. PMID:24914954

  3. Moving beyond the GM debate.

    PubMed

    Leyser, Ottoline

    2014-06-01

    Once again, there are calls to reopen the debate on genetically modified (GM) crops. I find these calls frustrating and unnecessarily decisive. In my opinion the GM debate, on both sides, continues to hamper the urgent need to address the diverse and pressing challenges of global food security and environmental sustainability. The destructive power of the debate comes from its conflation of unrelated issues, coupled with deeply rooted misconceptions of the nature of agriculture.

  4. Overview of Rayleigh-Taylor instability

    SciTech Connect

    Sharp, D.H.

    1983-01-01

    The aim of this talk is to survey Rayleigh-Taylor instability, describing the phenomenology that occurs at a Taylor unstable interface, and reviewing attempts to understand these phenomena quantitatively.

  5. The Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Piriz, A. R.; Cortázar, O. D.; López Cela, J. J.; Tahir, N. A.

    2006-12-01

    A new approach to the Rayleigh-Taylor instability is presented that yields exact solutions for the simplest cases and provides approximate but still very accurate analytical expressions for important and more complex cases involving nonideal fluids. The approach is based on Newton's second law and allows for an intuitive and physically appealing explanation of the mechanisms underlying the instability.

  6. The Remainder in Taylor's Formula.

    ERIC Educational Resources Information Center

    Poffald, Esteban I.

    1990-01-01

    Presented is a mean-value theorem that generalizes the Taylor-Lagrange formula. Discussed is the asymptotic behavior of the remainder term of the formula. Several numerical schemes are derived to approximate the solution to initial-valued first order differential equations. (KR)

  7. The future of starch bioengineering: GM microorganisms or GM plants?

    PubMed

    Hebelstrup, Kim H; Sagnelli, Domenico; Blennow, Andreas

    2015-01-01

    Plant starches regularly require extensive modification to permit subsequent applications. Such processing is usually done by the use of chemical and/or physical treatments. The use of recombinant enzymes produced by large-scale fermentation of GM microorganisms is increasingly used in starch processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar recombinant enzymes may also be expressed in planta in the developing starch storage organ such as in roots, tubers and cereal grains to provide a GM crop as an alternative to the use of enzymes from GM microorganisms. We here discuss these techniques in relation to important structural features and modifications of starches such as: starch phosphorylation, starch hydrolysis, chain transfer/branching and novel concepts of hybrid starch-based polysaccharides. In planta starch bioengineering is generally challenged by yield penalties and inefficient production of the desired product. However, in some situations, GM crops for starch bioengineering without deleterious effects have been achieved.

  8. Rotating Rayleigh-Taylor turbulence

    NASA Astrophysics Data System (ADS)

    Boffetta, G.; Mazzino, A.; Musacchio, S.

    2016-09-01

    The turbulent Rayleigh-Taylor system in a rotating reference frame is investigated by direct numerical simulations within the Oberbeck-Boussinesq approximation. On the basis of theoretical arguments, supported by our simulations, we show that the Rossby number decreases in time, and therefore the Coriolis force becomes more important as the system evolves and produces many effects on Rayleigh-Taylor turbulence. We find that rotation reduces the intensity of turbulent velocity fluctuations and therefore the growth rate of the temperature mixing layer. Moreover, in the presence of rotation the conversion of potential energy into turbulent kinetic energy is found to be less effective, and the efficiency of the heat transfer is reduced. Finally, during the evolution of the mixing layer we observe the development of a cyclone-anticyclone asymmetry.

  9. Rayleigh-Taylor Shock Waves

    SciTech Connect

    Olson, B J; Cook, A W

    2007-08-30

    Beginning from a state of hydrostatic equilibrium, in which a heavy gas rests atop a light gas in a constant gravitational field, Rayleigh-Taylor instability at the interface will launch a shock wave into the upper fluid. The rising bubbles of lighter fluid act like pistons, compressing the heavier fluid ahead of the fronts and generating shocklets. These shocklets coalesce in multidimensional fashion into a strong normal shock, which increases in strength as it propagates upwards. Large-eddy simulations demonstrate that the shock Mach number increases faster in three dimensions than it does in two dimensions. The generation of shocks via Rayleigh-Taylor instability could have profound implications for astrophysical flows.

  10. Acceptability of GM foods among Pakistani consumers

    PubMed Central

    Ali, Akhter; Rahut, Dil Bahadur; Imtiaz, Muhammad

    2016-01-01

    ABSTRACT In Pakistan majority of the consumers do not have information about genetically modified (GM) foods. In developing countries particularly in Pakistan few studies have focused on consumers' acceptability about GM foods. Using comprehensive primary dataset collected from 320 consumers in 2013 from Pakistan, this study analyzes the determinants of consumers' acceptability of GM foods. The data was analyzed by employing the bivariate probit model and censored least absolute deviation (CLAD) models. The empirical results indicated that urban consumers are more aware of GM foods compared to rural consumers. The acceptance of GM foods was more among females' consumers as compared to male consumers. In addition, the older consumers were more willing to accept GM food compared to young consumers. The acceptability of GM foods was also higher among wealthier households. Low price is the key factor leading to the acceptability of GM foods. The acceptability of the GM foods also reduces the risks among Pakistani consumers. PMID:27494790

  11. Acceptability of GM foods among Pakistani consumers.

    PubMed

    Ali, Akhter; Rahut, Dil Bahadur; Imtiaz, Muhammad

    2016-04-02

    In Pakistan majority of the consumers do not have information about genetically modified (GM) foods. In developing countries particularly in Pakistan few studies have focused on consumers' acceptability about GM foods. Using comprehensive primary dataset collected from 320 consumers in 2013 from Pakistan, this study analyzes the determinants of consumers' acceptability of GM foods. The data was analyzed by employing the bivariate probit model and censored least absolute deviation (CLAD) models. The empirical results indicated that urban consumers are more aware of GM foods compared to rural consumers. The acceptance of GM foods was more among females' consumers as compared to male consumers. In addition, the older consumers were more willing to accept GM food compared to young consumers. The acceptability of GM foods was also higher among wealthier households. Low price is the key factor leading to the acceptability of GM foods. The acceptability of the GM foods also reduces the risks among Pakistani consumers.

  12. [The regulation of ganglioside GM3 synthesis].

    PubMed

    Uemura, Satoshi

    2012-01-01

    Glycosphingolipids (GSLs) exist in the outer leaflet of the plasma membrane, where they form lipid microdomains that function as platforms for the regulation of trans-membrane signal transduction. In mammals, complex GSLs differing in the number and/or type of sugar species are produced in a cell-type specific manner, and the variety of glycan structures in GSLs are believed to determine specific cell functions. The glycan moieties of GSLs are synthesized at the luminal side of the Golgi apparatus by multiple Golgi-resident glycosyltransferases. Since the expression levels of most endogenous glycosyltransferases are relatively low, their detection is generally difficult. Nevertheless, we have succeeded in detecting endogenous mouse GM3 synthase (GM3S), the primary glycosyltransferase responsible for the biosynthesis of ganglio-series gangliosides. Mouse GM3S (mGM3S) has three isoforms (M1-GM3S, M2-GM3S, and M3-GM3S), each with a distinct length in its NH2-terminal cytoplasmic tail. These isoforms are produced by leaky scanning from two mRNA variants, mGM3Sa and mGM3Sb. M1-GM3S is stably localized in the endoplasmic reticulum (ER), as a result of retrograde transport signals (arginine [R]-based motifs); consequently, its in vivo GM3 synthesis activity is very low compared with that of other isoforms. In contrast, both M2-GM3S and M3-GM3S are localized in the Golgi apparatus, yet each exhibits a distinct intracellular fate. M2-GM3S is rapidly degraded in the lysosomes, whereas M3-GM3S is retained in the Golgi apparatus. A system that produces GM3S isoforms having such distinct characteristics is likely to be of critical importance in the regulation of GM3 biosynthesis under various pathological and physiological conditions.

  13. Exact axisymmetric Taylor states for shaped plasmas

    SciTech Connect

    Cerfon, Antoine J. O'Neil, Michael

    2014-06-15

    We present a general construction for exact analytic Taylor states in axisymmetric toroidal geometries. In this construction, the Taylor equilibria are fully determined by specifying the aspect ratio, elongation, and triangularity of the desired plasma geometry. For equilibria with a magnetic X-point, the location of the X-point must also be specified. The flexibility and simplicity of these solutions make them useful for verifying the accuracy of numerical solvers and for theoretical studies of Taylor states in laboratory experiments.

  14. On Taylor's justification of medical informed consent.

    PubMed

    Varelius, Jukka

    2012-05-01

    In contemporary Western biomedical ethics, informed consent practices are commonly justified in terms of the intrinsic value of patient autonomy. James Stacey Taylor maintains that this conception of the moral grounding of medical informed consent is mistaken. On the basis of his reasoning to that effect, Taylor argues that medical informed consent is justified by the instrumental value of personal autonomy. In this article, I examine whether Taylor's justification of medical informed consent is plausible.

  15. Ionic emission from Taylor cones

    NASA Astrophysics Data System (ADS)

    Castro Reina, Sergio

    Electrified Taylor cones have been seen as an efficient way to generate thrust for space propulsion. Especially the pure ionic regime (PIR) combines a very high specific impulse (thrust per unit mass) and efficiency, which is very important to reduce fuel transportation costs. The PIR has been primarily based on electrosprays of liquid metals [Swatik and Hendricks 1968, Swatik 1969]. However, emissions dominated by or containing exclusively ions have also been observed from nonmetallic purely ionic substances, initially sulfuric acid [Perel et al. 1969], and more recently room temperature molten salts referred to as ionic liquids (ILs) [Romero-Sanz et al. 2003]. The recent use of the liquid metal ion source (LMIS) with ILs, becoming this "new" source to be known as ionic liquid ion source (ILIS) [Lozano and Martinez-Sanchez 2005], has shown important differences on the emission from Taylor cones with the traditional hollow capillary. This new source seems to be more flexible than the capillary [Paulo, Sergio, carlos], although its low emission level (low thrust) is an important drawback from the space propulsion point of view. Throughout the thesis I have studied some aspects of the ionic emission from ionic liquid Taylor cones and the influence of the properties of the liquids and the characteristic of source on the emission. I have unraveled the reason why ILIS emits such low currents (˜200 nA) and found a way to solve this problem increasing the current up to capillary levels (˜1000 nA) [Castro and Fernandez de la Mora 2009]. I have also tried to reduce ion evaporation while reducing the emitted droplet size in order to increase the thrust generated while keeping the efficiency relatively high and I have measured the energy of evaporation of several cations composing ionic liquids, mandatory step to understand ionic evaporation.

  16. Rotating Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Scase, M. M.; Baldwin, K. A.; Hill, R. J. A.

    2017-02-01

    The effect of rotation upon the classical Rayleigh-Taylor instability is investigated. We consider a two-layer system with an axis of rotation that is perpendicular to the interface between the layers. In general, we find that a wave mode's growth rate may be reduced by rotation. We further show that in some cases, unstable axisymmetric wave modes may be stabilized by rotating the system above a critical rotation rate associated with the mode's wavelength, the Atwood number, and the flow's aspect ratio.

  17. Quasiperiodic Taylor-Couette Flow

    NASA Astrophysics Data System (ADS)

    Coughlin, Katie

    1990-01-01

    We present analysis and computations of the transition from wavy vortex flow to modulated wavy (or quasiperiodic) flow in the axially periodic Taylor-Couette system. We derive the correct functional form for quasiperiodic solutions to the Navier-Stokes equations, and show that all the space -time symmetry properties follow directly. The fluid equations are solved numerically using a pseudo-spectral initial value code for a number of wave, modulated wave, and weakly chaotic flows. At high Reynolds number R > 7R_{c}, where R _{c} is the critical value for transition to Taylor vortex flow, our solutions can be compared directly to experimentally observed flows. A simple physical picture is associated with the modulation, which we argue arises as an instability of the vortex outflow jet. Numerical evidence suggests that the transition from modulated waves to chaos in these flows is also associated with an instability of the outflow, and can be described with a low-dimensional model. In addition, we have discovered examples of modulated waves at low Reynolds number. This quasiperiodic flow goes through a period-doubling cascade to chaos, with the modulation period relative to the frame rotating with the first wave doubling as R increases.

  18. Bursting the Taylor cone bubble

    NASA Astrophysics Data System (ADS)

    Pan, Zhao; Truscott, Tadd

    2014-11-01

    A soap bubble fixed on a surface and placed in an electric field will take on the shape of a cone rather than constant curvature (dome) when the electrical field is not present. The phenomenon was introduced by J. Zeleny (1917) and studied extensively by C.T. Wilson & G.I. Taylor (1925). We revisit the Taylor cone problem by studying the deformation and bursting of soap bubbles in a point charge electric field. A single bubble takes on the shape of a cone in the electric field and a high-speed camera equipped with a micro-lens is used to observe the unsteady dynamics at the tip. Rupture occurs as a very small piece of the tip is torn away from the bubble toward the point charge. Based on experiments, a theoretical model is developed that predicts when rupture should occur. This study may help in the design of foam-removal techniques in engineering and provide a better understanding of an electrified air-liquid interface.

  19. GM2A — EDRN Public Portal

    Cancer.gov

    GM2A, a small glycolipid transport protein, acts as a substrate specific co-factor for the lysosomal enzyme beta-hexosaminidase A. Beta-hexosaminidase A, together with GM2 ganglioside activator, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Mutations in this gene result in GM2-gangliosidosis type AB or the AB variant of Tay-Sachs disease. Alternative splicing of the GM2A gene results in multiple transcript variants. In post-translational modification the serines in positions 32 and 33 are absent in 80% of the sequenced protein.

  20. Membrane lipids regulate ganglioside GM2 catabolism and GM2 activator protein activity[S

    PubMed Central

    Anheuser, Susi; Breiden, Bernadette; Schwarzmann, Günter; Sandhoff, Konrad

    2015-01-01

    Ganglioside GM2 is the major lysosomal storage compound of Tay-Sachs disease. It also accumulates in Niemann-Pick disease types A and B with primary storage of SM and with cholesterol in type C. Reconstitution of GM2 catabolism with β-hexosaminidase A and GM2 activator protein (GM2AP) at uncharged liposomal surfaces carrying GM2 as substrate generated only a physiologically irrelevant catabolic rate, even at pH 4.2. However, incorporation of anionic phospholipids into the GM2 carrying liposomes stimulated GM2 hydrolysis more than 10-fold, while the incorporation of plasma membrane stabilizing lipids (SM and cholesterol) generated a strong inhibition of GM2 hydrolysis, even in the presence of anionic phospholipids. Mobilization of membrane lipids by GM2AP was also inhibited in the presence of cholesterol or SM, as revealed by surface plasmon resonance studies. These lipids also reduced the interliposomal transfer rate of 2-NBD-GM1 by GM2AP, as observed in assays using Förster resonance energy transfer. Our data raise major concerns about the usage of recombinant His-tagged GM2AP compared with untagged protein. The former binds more strongly to anionic GM2-carrying liposomal surfaces, increases GM2 hydrolysis, and accelerates intermembrane transfer of 2-NBD-GM1, but does not mobilize membrane lipids. PMID:26175473

  1. Membrane lipids regulate ganglioside GM2 catabolism and GM2 activator protein activity.

    PubMed

    Anheuser, Susi; Breiden, Bernadette; Schwarzmann, Günter; Sandhoff, Konrad

    2015-09-01

    Ganglioside GM2 is the major lysosomal storage compound of Tay-Sachs disease. It also accumulates in Niemann-Pick disease types A and B with primary storage of SM and with cholesterol in type C. Reconstitution of GM2 catabolism with β-hexosaminidase A and GM2 activator protein (GM2AP) at uncharged liposomal surfaces carrying GM2 as substrate generated only a physiologically irrelevant catabolic rate, even at pH 4.2. However, incorporation of anionic phospholipids into the GM2 carrying liposomes stimulated GM2 hydrolysis more than 10-fold, while the incorporation of plasma membrane stabilizing lipids (SM and cholesterol) generated a strong inhibition of GM2 hydrolysis, even in the presence of anionic phospholipids. Mobilization of membrane lipids by GM2AP was also inhibited in the presence of cholesterol or SM, as revealed by surface plasmon resonance studies. These lipids also reduced the interliposomal transfer rate of 2-NBD-GM1 by GM2AP, as observed in assays using Förster resonance energy transfer. Our data raise major concerns about the usage of recombinant His-tagged GM2AP compared with untagged protein. The former binds more strongly to anionic GM2-carrying liposomal surfaces, increases GM2 hydrolysis, and accelerates intermembrane transfer of 2-NBD-GM1, but does not mobilize membrane lipids.

  2. 33 CFR 117.335 - Taylor Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Taylor Creek. 117.335 Section 117.335 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.335 Taylor Creek. The draw of US441 bridge, mile 0...

  3. Douglas Taylor School: Rooted in Community

    ERIC Educational Resources Information Center

    Rourke, James; Boone, Elizabeth

    2009-01-01

    Inspiring students to become teachers and community leaders is a goal of Douglas Taylor School's leadership team. A feeling of continuity and connection are important to the school, which opened in the 19th century. Housed in a beautiful old school building in Chicago's South Side, Douglas Taylor School contains grades preK-8. To maintain the…

  4. 33 CFR 117.335 - Taylor Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Creek. 117.335 Section 117.335 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.335 Taylor Creek. The draw of US441 bridge, mile...

  5. Spectral stability of Taylor's vortex array

    NASA Technical Reports Server (NTRS)

    Lin, S. P.; Tobak, M.

    1986-01-01

    In a global sense it is shown that the two-dimensional Taylor vortex array, an exact solution of the Navier-Stokes equation, is absolutely and monotonically stable with respect to infinitesimal disturbances of all discrete frequencies as long as the viscosity is positive. It is suggested that the Taylor vortex array may also be stable with respect to finite amplitude disturbances.

  6. Taylorism and the Logic of Learning Outcomes

    ERIC Educational Resources Information Center

    Stoller, Aaron

    2015-01-01

    This essay examines the shared philosophical foundations of Fredrick W. Taylor's scientific management principles and the contemporary learning outcomes movement (LOM). It analyses the shared philosophical ground between the focal point of Taylor's system--"the task"--and the conceptualization and deployment of "learning…

  7. Douglas Taylor School: Rooted in Community

    ERIC Educational Resources Information Center

    Rourke, James; Boone, Elizabeth

    2009-01-01

    Inspiring students to become teachers and community leaders is a goal of Douglas Taylor School's leadership team. A feeling of continuity and connection are important to the school, which opened in the 19th century. Housed in a beautiful old school building in Chicago's South Side, Douglas Taylor School contains grades preK-8. To maintain the…

  8. Taylorism and the Logic of Learning Outcomes

    ERIC Educational Resources Information Center

    Stoller, Aaron

    2015-01-01

    This essay examines the shared philosophical foundations of Fredrick W. Taylor's scientific management principles and the contemporary learning outcomes movement (LOM). It analyses the shared philosophical ground between the focal point of Taylor's system--"the task"--and the conceptualization and deployment of "learning…

  9. Spectral stability of Taylor's vortex array

    NASA Technical Reports Server (NTRS)

    Lin, S. P.; Tobak, M.

    1986-01-01

    In a global sense it is shown that the two-dimensional Taylor vortex array, an exact solution of the Navier-Stokes equation, is absolutely and monotonically stable with respect to infinitesimal disturbances of all discrete frequencies as long as the viscosity is positive. It is suggested that the Taylor vortex array may also be stable with respect to finite amplitude disturbances.

  10. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  11. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  12. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  13. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  14. 33 CFR 117.987 - Taylor Bayou.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Taylor Bayou. 117.987 Section 117.987 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.987 Taylor Bayou. The draws of the Union...

  15. Taylor instability in rhyolite lava flows

    NASA Technical Reports Server (NTRS)

    Baum, B. A.; Krantz, W. B.; Fink, J. H.; Dickinson, R. E.

    1989-01-01

    A refined Taylor instability model is developed to describe the surface morphology of rhyolite lava flows. The effect of the downslope flow of the lava on the structures resulting from the Taylor instability mechanism is considered. Squire's (1933) transformation is developed for this flow in order to extend the results to three-dimensional modes. This permits assessing why ridges thought to arise from the Taylor instability mechanism are preferentially oriented transverse to the direction of lava flow. Measured diapir and ridge spacings for the Little and Big Glass Mountain rhyolite flows in northern California are used in conjunction with the model in order to explore the implications of the Taylor instability for flow emplacement. The model suggests additional lava flow features that can be measured in order to test whether the Taylor instability mechanism has influenced the flows surface morphology.

  16. Taylor instability in rhyolite lava flows

    NASA Technical Reports Server (NTRS)

    Baum, B. A.; Krantz, W. B.; Fink, J. H.; Dickinson, R. E.

    1989-01-01

    A refined Taylor instability model is developed to describe the surface morphology of rhyolite lava flows. The effect of the downslope flow of the lava on the structures resulting from the Taylor instability mechanism is considered. Squire's (1933) transformation is developed for this flow in order to extend the results to three-dimensional modes. This permits assessing why ridges thought to arise from the Taylor instability mechanism are preferentially oriented transverse to the direction of lava flow. Measured diapir and ridge spacings for the Little and Big Glass Mountain rhyolite flows in northern California are used in conjunction with the model in order to explore the implications of the Taylor instability for flow emplacement. The model suggests additional lava flow features that can be measured in order to test whether the Taylor instability mechanism has influenced the flows surface morphology.

  17. Nested Taylor decomposition in multivariate function decomposition

    NASA Astrophysics Data System (ADS)

    Baykara, N. A.; Gürvit, Ercan

    2014-12-01

    Fluctuationlessness approximation applied to the remainder term of a Taylor decomposition expressed in integral form is already used in many articles. Some forms of multi-point Taylor expansion also are considered in some articles. This work is somehow a combination these where the Taylor decomposition of a function is taken where the remainder is expressed in integral form. Then the integrand is decomposed to Taylor again, not necessarily around the same point as the first decomposition and a second remainder is obtained. After taking into consideration the necessary change of variables and converting the integration limits to the universal [0;1] interval a multiple integration system formed by a multivariate function is formed. Then it is intended to apply the Fluctuationlessness approximation to each of these integrals one by one and get better results as compared with the single node Taylor decomposition on which the Fluctuationlessness is applied.

  18. Taylor impact of glass bars

    NASA Astrophysics Data System (ADS)

    Murray, Natalie; Bourne, Neil; Field, John

    1997-07-01

    Brar and Bless pioneeered the use of plate impact upon bars as a technique for investigating the 1D stress loading of glass. We wish to extend this technique by applying VISAR and embedded stress gauge measurements to a symmetrical version of the test. In this configuration two rods impact one upon the other in a symmetrical version of the Taylor test geometry in which the impact is perfectly rigid in the centre of mass frame. Previous work in the laboratory has characterised the three glass types (float, borosilicate and a high density lead glass). These experiments will identify the 1D stress failure mechanisms from high-speed photography and the stress and particle velocity histories will be interpreted in the light of these results. The differences in response of the three glasses will be highlighted.

  19. Genetically Modified (GM) Foods and Ethical Eating.

    PubMed

    Dizon, Francis; Costa, Sarah; Rock, Cheryl; Harris, Amanda; Husk, Cierra; Mei, Jenny

    2016-02-01

    The ability to manipulate and customize the genetic code of living organisms has brought forth the production of genetically modified organisms (GMOs) and consumption of genetically modified (GM) foods. The potential for GM foods to improve the efficiency of food production, increase customer satisfaction, and provide potential health benefits has contributed to the rapid incorporation of GM foods into the American diet. However, GM foods and GMOs are also a topic of ethical debate. The use of GM foods and GM technology is surrounded by ethical concerns and situational judgment, and should ideally adhere to the ethical standards placed upon food and nutrition professionals, such as: beneficence, nonmaleficence, justice and autonomy. The future of GM foods involves many aspects and trends, including enhanced nutritional value in foods, strict labeling laws, and potential beneficial economic conditions in developing nations. This paper briefly reviews the origin and background of GM foods, while delving thoroughly into 3 areas: (1) GMO labeling, (2) ethical concerns, and (3) health and industry applications. This paper also examines the relationship between the various applications of GM foods and their corresponding ethical issues. Ethical concerns were evaluated in the context of the code of ethics developed by the Academy of Nutrition and Dietetics (AND) that govern the work of food and nutrition professionals. Overall, there is a need to stay vigilant about the many ethical implications of producing and consuming GM foods and GMOs.

  20. The world of "GM-free".

    PubMed

    Moses, Vivian; Brookes, Graham

    2013-01-01

    The rapid global development of agricultural production systems using seeds derived from genetic modification (GM) has been paralleled by the growth of attempts to keep at least a part of the world's agriculture and food as free from GM-crops and their products as possible. The ideal for some proponents of such "GM-free" activity would be a total absence, usually styled "zero content"; others, perhaps more realistically, opt for a definition usually not precisely defined that allows for minimal trace levels of GM material. The reasons for wanting "GM-free" agriculture and its products are varied; they include philosophical and religious beliefs, concern for human (and animal) health--and for "the environment"-as well as commercial and political interests. With such a variety of motivations, and in the absence of legal rulings, the definitions of "GM-free" vary according to inclination and circumstances. Whatever the precise meaning, the maintenance of a "GM-free" product stream in a world where GM crop production is widespread requires the establishment of identity preservation and segregation systems in which traceability and testing are cornerstones. Inevitably these have cost implications for the supply chain and/or the ultimate consumer. In a number of countries different forms of "GM-free" labels exist for some products; the style of such labels is variable with schemes and labels typically voluntary or privately organized. In more recent years, some governments have begun to regularize the definition and meaning of "GM-free." We conclude our analysis by exploring consumer reactions both to "GM-free" and to "GM-free" labels, and ask who ultimately benefits from preserving a product stream substantially or entirely devoid of GM-content.

  1. Nonideal Rayleigh–Taylor mixing

    PubMed Central

    Lim, Hyunkyung; Iwerks, Justin; Glimm, James; Sharp, David H.

    2010-01-01

    Rayleigh–Taylor mixing is a classical hydrodynamic instability that occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh–Taylor (RT) mixing are regularizations (physical and numerical), which produce deviations from a pure Euler equation, scale invariant formulation, and nonideal (i.e., experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We interpret mathematical theories of existence and nonuniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations; in other words, indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as nonunique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, in the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and Prandtl numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength initial conditions and long wavelength perturbations are observed to play a role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing in different proportions in these two different contexts. PMID:20615983

  2. Nonideal Rayleigh-Taylor mixing.

    PubMed

    Lim, Hyunkyung; Iwerks, Justin; Glimm, James; Sharp, David H

    2010-07-20

    Rayleigh-Taylor mixing is a classical hydrodynamic instability that occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh-Taylor (RT) mixing are regularizations (physical and numerical), which produce deviations from a pure Euler equation, scale invariant formulation, and nonideal (i.e., experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We interpret mathematical theories of existence and nonuniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations; in other words, indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as nonunique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, in the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and Prandtl numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength initial conditions and long wavelength perturbations are observed to play a role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing in different proportions in these two different contexts.

  3. Nonideal Rayleigh-Taylor mixing

    SciTech Connect

    Sharp, David Howland; Lin, Hyun K; Iwerks, Justin G; Gliman, James G

    2009-01-01

    Rayleigh-Taylor mixing is a classical hydrodynamic Instability, which occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh-Taylor (RT) mixing are regularizations (physical and numerical) which produce deviations from a pure Euler equation, scale Invariant formulation, and non Ideal (i.e. experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We Interpret mathematical theories of existence and non-uniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations, in other words indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as non unique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, In the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and PrandtJ numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength Initial conditions and long wavelength perturbations are observed to playa role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing In different proportions In these two different contexts.

  4. Economic impact of GM crops

    PubMed Central

    Brookes, Graham; Barfoot, Peter

    2014-01-01

    A key part of any assessment of the global value of crop biotechnology in agriculture is an examination of its economic impact at the farm level. This paper follows earlier annual studies which examined economic impacts on yields, key costs of production, direct farm income and effects, and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialization of genetically modified (GM) crops has continued to occur at a rapid rate, with important changes in both the overall level of adoption and impact occurring in 2012. This annual updated analysis shows that there have been very significant net economic benefits at the farm level amounting to $18.8 billion in 2012 and $116.6 billion for the 17-year period (in nominal terms). These economic gains have been divided roughly 50% each to farmers in developed and developing countries. GM technology have also made important contributions to increasing global production levels of the four main crops, having added 122 million tonnes and 230 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid-1990s. PMID:24637520

  5. 76 FR 18378 - Amendment of Class E Airspace; Taylor, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal... Taylor Airport, Taylor, AZ, to accommodate aircraft using the CAMBO One Departure, and the Area Navigation (RNAV) standard instrument approach procedures at Taylor Airport. This will improve the safety...

  6. Synthetic Division, Taylor Polynomials, Partial Fractions.

    ERIC Educational Resources Information Center

    Lambert, Howard B.

    1989-01-01

    Reviews the underpinnings of synthetic division. Shows how to quickly obtain the coefficients of the Taylor expansion of a polynomial about a point, and a partial fraction decomposition of a polynomial. (MVL)

  7. Taylor dispersion analysis of mixtures.

    PubMed

    Cottet, Hervé; Biron, Jean-Philippe; Martin, Michel

    2007-12-01

    Taylor dispersion analysis (TDA) is a fast and simple method for determining hydrodynamic radii. In the case of sample mixtures, TDA, as the other nonseparative methods, leads to an average diffusion coefficient on the different molecules constituting the mixture. We set in this work the equations giving, on a consistent basis, the average values obtained by TDA with detectors with linear response functions. These equations confronted TDA experiments of sample mixtures containing different proportions of a small molecule and a polymer standard. Very good agreement between theory and experiment was obtained. In a second part of this work, on the basis of monomodal or bimodal molar mass distributions of polymers, the different average diffusion coefficients corresponding to TDA were compared to the z-average diffusion coefficient (D(z)) obtained from dynamic light scattering (DLS) experiments and to the weight average diffusion coefficient (D(w)). This latter value is sometimes considered as the most representative of the sample mixture. From these results, it appears that, for monomodal distribution and relatively low polydispersity (I = 1.15), the average diffusion coefficient generally derived from TDA is very close to Dw. However, for highly polydisperse samples (e.g., bimodal polydisperse distributions), important differences could be obtained (up to 35% between TDA and D(w)). In all the cases, the average diffusion coefficient obtained by TDA for a mass concentration detector was closer to the Dw value than the z-average obtained by DLS.

  8. Taylor impact of glass rods

    SciTech Connect

    Willmott, G.R.; Radford, D.D.

    2005-05-01

    The deformation and fracture behavior of soda-lime and borosilicate glass rods was examined during classic and symmetric Taylor impact experiments for impact pressures to 4 and 10 GPa, respectively. High-speed photography and piezoresistive gauges were used to measure the failure front velocities in both glasses, and for impact pressures below {approx}2 GPa the failure front velocity increases rapidly with increasing pressure. As the pressure was increased above {approx}3 GPa, the failure front velocities asymptotically approached maximum values between the longitudinal and shear wave velocities of each material; at {approx}4 GPa, the average failure front velocities were 4.7{+-}0.5 and 4.6{+-}0.5 mm {mu}s{sup -1} for the soda-lime and borosilicate specimens, respectively. The observed mechanism of failure in these experiments involved continuous pressure-dependent nucleation and growth of microcracks behind the incident wave. As the impact pressure was increased, there was a decrease in the time to failure. The density of cracks within the failed region was material dependent, with the more open-structured borosilicate glass showing a larger fracture density.

  9. Rayleigh--Taylor spike evaporation

    SciTech Connect

    Schappert, G. T.; Batha, S. H.; Klare, K. A.; Hollowell, D. E.; Mason, R. J.

    2001-09-01

    Laser-based experiments have shown that Rayleigh--Taylor (RT) growth in thin, perturbed copper foils leads to a phase dominated by narrow spikes between thin bubbles. These experiments were well modeled and diagnosed until this '' spike'' phase, but not into this spike phase. Experiments were designed, modeled, and performed on the OMEGA laser [T. R. Boehly, D. L. Brown, R. S. Craxton , Opt. Commun. 133, 495 (1997)] to study the late-time spike phase. To simulate the conditions and evolution of late time RT, a copper target was fabricated consisting of a series of thin ridges (spikes in cross section) 150 {mu}m apart on a thin flat copper backing. The target was placed on the side of a scale-1.2 hohlraum with the ridges pointing into the hohlraum, which was heated to 190 eV. Side-on radiography imaged the evolution of the ridges and flat copper backing into the typical RT bubble and spike structure including the '' mushroom-like feet'' on the tips of the spikes. RAGE computer models [R. M. Baltrusaitis, M. L. Gittings, R. P. Weaver, R. F. Benjamin, and J. M. Budzinski, Phys. Fluids 8, 2471 (1996)] show the formation of the '' mushrooms,'' as well as how the backing material converges to lengthen the spike. The computer predictions of evolving spike and bubble lengths match measurements fairly well for the thicker backing targets but not for the thinner backings.

  10. Investigating GM Risk Perceptions: A Survey of Anti-GM and Environmental Campaign Group Members

    ERIC Educational Resources Information Center

    Hall, Clare; Moran, Dominic

    2006-01-01

    This study investigates how members of anti-GM campaign groups and environment groups perceive the risks and benefits of genetically modified (GM) technology in food and agriculture. The study targeted these groups as the most risk-averse sector of society when considering GM technology. Survey respondents were asked to rank the current and future…

  11. Investigating GM Risk Perceptions: A Survey of Anti-GM and Environmental Campaign Group Members

    ERIC Educational Resources Information Center

    Hall, Clare; Moran, Dominic

    2006-01-01

    This study investigates how members of anti-GM campaign groups and environment groups perceive the risks and benefits of genetically modified (GM) technology in food and agriculture. The study targeted these groups as the most risk-averse sector of society when considering GM technology. Survey respondents were asked to rank the current and future…

  12. GmDREB1 overexpression affects the expression of microRNAs in GM wheat seeds.

    PubMed

    Jiang, Qiyan; Sun, Xianjun; Niu, Fengjuan; Hu, Zheng; Chen, Rui; Zhang, Hui

    2017-01-01

    MicroRNAs (miRNAs) are small regulators of gene expression that act on many different molecular and biochemical processes in eukaryotes. To date, miRNAs have not been considered in the current evaluation system for GM crops. In this study, small RNAs from the dry seeds of a GM wheat line overexpressing GmDREB1 and non-GM wheat cultivars were investigated using deep sequencing technology and bioinformatic approaches. As a result, 23 differentially expressed miRNAs in dry seeds were identified and confirmed between GM wheat and a non-GM acceptor. Notably, more differentially expressed tae-miRNAs between non-GM wheat varieties were found, indicating that the degree of variance between non-GM cultivars was considerably higher than that induced by the transgenic event. Most of the target genes of these differentially expressed miRNAs between GM wheat and a non-GM acceptor were associated with abiotic stress, in accordance with the product concept of GM wheat in improving drought and salt tolerance. Our data provided useful information and insights into the evaluation of miRNA expression in edible GM crops.

  13. Specific binding of GM1-binding peptides to high-density GM1 in lipid membranes.

    PubMed

    Matsubara, Teruhiko; Iijima, Kazutoshi; Nakamura, Miwa; Taki, Takao; Okahata, Yoshio; Sato, Toshinori

    2007-01-16

    The ganglioside Galbeta1-3GalNAcbeta1-4(Neu5Acalpha2-3)Galbeta1-4Glcbeta1-1'Cer (GM1) is an important receptor. We have previously identified GM1-binding peptides based on affinity selection from a random peptide library. In the present study, we determined the amino acids essential for binding GM1 and investigated the specific interaction with GM1 in the lipid membrane. Arginines and aromatic amino acids in the consensus sequence (W/F)RxL(xP/Px)xFxx(Rx/xR)xP contributed to the ability of the peptides to bind GM1. The peptide p3, VWRLLAPPFSNRLLP, having the consensus sequence, showed high affinity for GM1 with a dissociation constant of 1.2 microM. Furthermore, the density-dependent binding of p3 was investigated using mixed monolayers of GM1 and Glcbeta1-1'Cer (GlcCer). p3 binds preferentially to high-density GM1, and its interaction with GM1 was found to be cooperative based on a Hill plot. These results indicated that a lateral assembly of GM1 molecules was required for the recognition of carbohydrates by p3. The GM1-binding peptide played a role as a unique anti-GM1 probe differing from the cholera toxin B subunit or antibodies.

  14. Rayleigh-Taylor mixing in supernova experiments

    SciTech Connect

    Swisher, N. C.; Abarzhi, S. I.; Kuranz, C. C.; Arnett, D.; Hurricane, O.; Remington, B. A.; Robey, H. F.

    2015-10-15

    We report a scrupulous analysis of data in supernova experiments that are conducted at high power laser facilities in order to study core-collapse supernova SN1987A. Parameters of the experimental system are properly scaled to investigate the interaction of a blast-wave with helium-hydrogen interface, and the induced Rayleigh-Taylor instability and Rayleigh-Taylor mixing of the denser and lighter fluids with time-dependent acceleration. We analyze all available experimental images of the Rayleigh-Taylor flow in supernova experiments and measure delicate features of the interfacial dynamics. A new scaling is identified for calibration of experimental data to enable their accurate analysis and comparisons. By properly accounting for the imprint of the experimental conditions, the data set size and statistics are substantially increased. New theoretical solutions are reported to describe asymptotic dynamics of Rayleigh-Taylor flow with time-dependent acceleration by applying theoretical analysis that considers symmetries and momentum transport. Good qualitative and quantitative agreement is achieved of the experimental data with the theory and simulations. Our study indicates that in supernova experiments Rayleigh-Taylor flow is in the mixing regime, the interface amplitude contributes substantially to the characteristic length scale for energy dissipation; Rayleigh-Taylor mixing keeps order.

  15. Rayleigh-Taylor mixing in supernova experiments

    NASA Astrophysics Data System (ADS)

    Swisher, N. C.; Kuranz, C. C.; Arnett, D.; Hurricane, O.; Remington, B. A.; Robey, H. F.; Abarzhi, S. I.

    2015-10-01

    We report a scrupulous analysis of data in supernova experiments that are conducted at high power laser facilities in order to study core-collapse supernova SN1987A. Parameters of the experimental system are properly scaled to investigate the interaction of a blast-wave with helium-hydrogen interface, and the induced Rayleigh-Taylor instability and Rayleigh-Taylor mixing of the denser and lighter fluids with time-dependent acceleration. We analyze all available experimental images of the Rayleigh-Taylor flow in supernova experiments and measure delicate features of the interfacial dynamics. A new scaling is identified for calibration of experimental data to enable their accurate analysis and comparisons. By properly accounting for the imprint of the experimental conditions, the data set size and statistics are substantially increased. New theoretical solutions are reported to describe asymptotic dynamics of Rayleigh-Taylor flow with time-dependent acceleration by applying theoretical analysis that considers symmetries and momentum transport. Good qualitative and quantitative agreement is achieved of the experimental data with the theory and simulations. Our study indicates that in supernova experiments Rayleigh-Taylor flow is in the mixing regime, the interface amplitude contributes substantially to the characteristic length scale for energy dissipation; Rayleigh-Taylor mixing keeps order.

  16. GM2 ganglioside and pyramidal neuron dendritogenesis.

    PubMed

    Walkley, S U; Siegel, D A; Dobrenis, K

    1995-11-01

    GM2 ganglioside, although scarce in normal adult brain, is the predominant ganglioside accumulating in several types of lysosomal disorders, most notably Tay-Sachs disease. Pyramidal neurons of cerebral cortex in Tay-Sachs, as well as many other types of neuronal storage disorders, are known to exhibit a phenomenon believed unique to storage disorders: growth of ectopic dendrites. Recent studies have shown that a common metabolic abnormality shared by storage diseases with ectopic dendrite growth is the abnormal accumulation of GM2 ganglioside. The correlation between increased levels of GM2 and the presence of ectopic dendrites has been found in both ganglioside and nonganglioside storage disorders, the latter including sphingomyelin-cholesterol lipidosis, mucopolysaccharidosis, and alpha-mannosidosis. Quantitative HPTLC analysis has shown that increases in GM2 occur in proportion to the incidence of ectopic dendrite growth, whereas other gangliosides, including GM1, lack similar increases. Immunocytochemical studies of all nonganglioside storage diseases which exhibit ectopic dendritogenesis have revealed heightened GM2 ganglioside-immunoreactivity in the cortical pyramidal cell population, whereas nerurons in normal adult brain exhibit little or no staining for this ganglioside. Further, studies examining disease development have consistently shown that accumulation of GM2 ganglioside precedes growth of ectopic dendrites, indicating that it is not simply occurring secondary to new membrane production. These findings have prompted an examination for a similar relationship between GM2 ganglioside and dendritogenesis in cortical neurons of normal developing brain. Results show that GM2 ganglioside-immunoreactivity is consistently elevated in immature neurons during the period when they are undergoing active dendritic initiation, but this staining diminishes dramatically as the dendritic trees of these cells mature. Collectively, these studies on diseased and normal

  17. Degradation of G(M1) and G(M2) by mammalian sialidases.

    PubMed Central

    Li, S C; Li, Y T; Moriya, S; Miyagi, T

    2001-01-01

    In mammalian tissues, the pathway known for the catabolism of G(M1) [Galbeta3GalNAcbeta4(Neu5Acalpha3)Galbeta4GlcCer; where Cer is ceramide] is the conversion of this ganglioside into G(M2) [GalNAcbeta4(Neu5Acalpha3)Galbeta4GlcbetaCer] by beta-galactosidase followed by the conversion of G(M2) into G(M3) (Neu5Acalpha3Galbeta4GlcbetaCer) by beta-N-acetylhexosaminidase A (Hex A). However, the question of whether or not G(M1) and G(M2) can also be respectively converted into asialo-G(M1) (Galbeta3GalNAcbeta4Galbeta4GlcCer; G(A1)) and asialo-G(M2) (GalNAcbeta4Galbeta4GlcbetaCer, G(A2)) by mammalian sialidases has not been resolved. This is due to the fact that sialidases purified from mammalian tissues always contained detergents that interfered with the in vitro hydrolysis of G(M1) and G(M2) in the presence of an activator protein. The mouse model of human type B Tay-Sachs disease created by the disruption of the Hexa gene showed no neurological abnormalities, with milder clinical symptoms than the human counterpart, and the accumulation of G(M2) in the brains of affected mice was only limited to certain regions [Sango, Yamanaka, Hoffmann, Okuda, Grinberg, Westphal, McDonald, Crawley, Sandhoff, Suzuki and Proia (1995) Nat. Genet. 11, 170-176]. These results suggest the possible presence of an alternative catabolic pathway (the G(A2) pathway) in mouse to convert G(M2) into G(A2) by sialidase. To show the existence of this pathway, we have used recombinant mammalian cytosolic sialidase and membrane-associated sialidase to study the desialylation of G(M1) and G(M2). We found that the mouse membrane-bound sialidase was able to convert G(M1) and G(M2) into their respective asialo-derivatives in the presence of human or mouse G(M2) activator protein. The cytosolic sialidase did not exhibit this activity. Our results suggest that, in vivo, the stable NeuAc of G(M1) and G(M2) may be removed by the mammalian membrane-associated sialidase in the presence of G(M2) activator

  18. Resistance law for a turbulent Taylor-Couette flow at very large Taylor numbers

    NASA Astrophysics Data System (ADS)

    Balonishnikov, A. M.

    2016-11-01

    Based on the semi-empirical model of the transport of the specific rate of turbulence energy dissipation, it has been concluded that the resistance laws are observed for a turbulent Taylor-Couette flow between independently rotating coaxial cylinders for very large Taylor numbers.

  19. Suppressing Taylor vortices in a Taylor-Couette flow system with free surface

    NASA Astrophysics Data System (ADS)

    Bouabdallah, A.; Oualli, H.; Mekadem, M.; Gad-El-Hak, M.

    2016-11-01

    Taylor-Couette flows have been extensively investigated due to their many industrial applications, such as catalytic reactors, electrochemistry, photochemistry, biochemistry, and polymerization. Mass transfer applications include extraction, tangential filtration, crystallization, and dialysis. A 3D study is carried out to simulate a Taylor-Couette flow with a rotating and pulsating inner cylinder. We utilize FLUENT to simulate the incompressible flow with a free surface. The study reveals that flow structuring is initiated with the development of an Ekman vortex at low Taylor number, Ta = 0 . 01 . For all encountered flow regimes, the Taylor vortices are systematically inhibited by the pulsatile motion of the inner cylinder. A spectral analysis shows that this pulsatile motion causes a rapid decay of the free surface oscillations, from a periodic wavy movement to a chaotic one, then to a fully turbulent motion. This degenerative free surface behavior is interpreted as the underlying mechanism responsible for the inhibition of the Taylor vortices.

  20. Direct numerical simulations of type Ia supernovae flames II: The Rayleigh-Taylor instability

    SciTech Connect

    Bell, J.B.; Day, M.S.; Rendleman, C.A.; Woosley, S.E.; Zingale, M.

    2004-01-12

    A Type Ia supernova explosion likely begins as a nuclear runaway near the center of a carbon-oxygen white dwarf. The outward propagating flame is unstable to the Landau-Darrieus, Rayleigh-Taylor, and Kelvin-Helmholtz instabilities, which serve to accelerate it to a large fraction of the speed of sound. We investigate the Rayleigh-Taylor unstable flame at the transition from the flamelet regime to the distributed-burning regime, around densities of 10e7 gm/cc, through detailed, fully resolved simulations. A low Mach number, adaptive mesh hydrodynamics code is used to achieve the necessary resolution and long time scales. As the density is varied, we see a fundamental change in the character of the burning--at the low end of the density range the Rayleigh-Taylor instability dominates the burning, whereas at the high end the burning suppresses the instability. In all cases, significant acceleration of the flame is observed, limited only by the size of the domain we are able to study. We discuss the implications of these results on the potential for a deflagration to detonation transition.

  1. Accelerated Taylor plumes for MIF targets

    NASA Astrophysics Data System (ADS)

    Brown, M. R.; Schaffner, D. A.; Parks, H. L.; Rock, A. B.

    2015-11-01

    The SSX plasma device has been converted to a 2.5 m merging plasma wind tunnel configuration. Experiments are underway to study merging and stagnation of high density, helical Taylor states to employ as a potential target for magneto-inertial fusion. Eventually, SSX Taylor states will be accelerated to over 100 km / s and compressed to small volumes either by stagnation or merging. Initial un-accelerated merging studies produce peak proton densities of 5 ×1015cm-3 . Densities are measured with a precision quadrature He-Ne laser interferometer. Typical merged plasma parameters are Ti = 20 eV, Te = 10 eV, B = 0 . 4 T with lifetimes of 100 μs. Results from a single prototype acceleration coil will be presented, as well as initial simulation studies of Taylor state plasma acceleration using multiple staged, pulsed theta-pinch coils. Work supported by DOE ARPA-E ALPHA program.

  2. GM crops: science, politics and communication.

    PubMed

    Arntzen, Charles J; Coghlan, Andy; Johnson, Brian; Peacock, Jim; Rodemeyer, Michael

    2003-10-01

    As the public debate in Europe about genetically modified (GM) crops heats up and the trade row between the United States and the European Union over GM food escalates, what better time to examine the issues with an international group of experts (Box 1). Their views are diverse, but they all agree that we need more impartial communication, less propaganda and an effective regulatory regime that is based on a careful case-by-case consideration of GM technology. It seems that GM crops are here to stay, so let us hope that these requirements are met and that the developing nations that perhaps have the most to gain from this technology can start to reap its benefits.

  3. GM1 gangliosidosis type 1 in twins.

    PubMed Central

    Ginsburg, C M; Long, C G

    1977-01-01

    This report describes 7-month-old monozygotic twin female infants with GM1 gangliosidosis type I. In addition to the usual clinical and biochemical abnormalities generalized intracutaneous telangiectasis were present in both infants. Images PMID:404410

  4. Americans Divided Over Organic, GM Foods: Poll

    MedlinePlus

    ... said GM foods are healthier, the researchers found. Genetically modified foods come from plants, animals or microorganisms in which ... re more pessimistic than men about the effect genetically modified foods may have on society. Broken down by age, ...

  5. Genetics Home Reference: GM3 synthase deficiency

    MedlinePlus

    ... GM3 synthase deficiency is characterized by recurrent seizures (epilepsy) and problems with brain development. Within the first ... Testing (1 link) Genetic Testing Registry: Amish infantile epilepsy syndrome Other Diagnosis and Management Resources (2 links) ...

  6. Test of Taylor's Hypothesis with Distributed Temperature

    NASA Astrophysics Data System (ADS)

    Cheng, Y.; Gentine, P.; Sayde, C.; Tanner, E.; Ochsner, T. E.; Dong, J.

    2016-12-01

    Taylor's hypothesis[Taylor, 1938] assumes that mean wind speed carries the spatial pattern of turbulent motion past a fixed point in a "frozen" way, which has been widely used to relate streamwise wavenumber and angular frequency . Experiments[Fisher, 1964; Tong, 1996] have shown some deviation from Taylor's hypothesis at highly turbulent intensity flows and at high wavenumbers. However, the velocity or scalar measurements have always been fixed at a few spatial points rather than distributed in space. This experiment was designed for the first time to directly compare the time and spatial spectrum of temperature to test Taylor's hypothesis, measuring temperature with high resolution in both time and space by Distributed Temperature Sensing utilizing the attenuation difference of Raman scattering in the optic fiber at the MOISST site Oklahoma. The length of transact is 233 meters along the dominant wind direction. The temperature sampling distance is 0.127m and sampling time frequency is 1 Hz. The heights of the 4 fiber cables parallel to ground are 1m, 1.254m, 1.508m and 1.762m respectively. Also, eddy covariance instrument was set up near the Distributed Temperature Sensing as comparison for temperature data. The temperature spatial spectrum could be obtained with one fixed time point, while the temperature time spectrum could be obtained with one fixed spatial point in the middle of transact. The preliminary results would be presented in the AGU fall meeting. Reference Fisher, M. J., and Davies, P.O.A.L (1964), Correlation measurements in a non-frozen pattern of turbulence, Journal of fluid mechanics, 18(1), 97-116. Taylor, G. I. (1938), The spectrum of turbulence, Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 164(919), 476-490. Tong, C. (1996), Taylor's Hypothesis and Two-point Coherence Measurements, Boundary-Layer Meteorology, 81(3), 399-410.

  7. Taylorism in a post-modern age?

    PubMed

    Freemantle, N

    1995-02-01

    F.W. Taylor made an early and important contribution to the organisation of work in an industrial society. His ideas, or versions of his ideas, are once again receiving attention. Some commentators even describe a new or neo Taylorism (Pollitt, 1990). This paper argues that the only theoretical justification for the re-introduction of Taylorist strategies in the workplace is found in the notion of the post-modern world; where rationality is replaced by a ritual of signs and work becomes part of that ritual; where form replaces rationale, and strategies for work are governed by processes of survival in the remnants of modernity.

  8. On the Taylor Approximation of Control Systems.

    DTIC Science & Technology

    1984-01-01

    ABSTRACT Let gi (i - 1 , ... , m) be smooth vector fields on Rd, and let Tn - 1 gi be their Taylor expansions of order n - I at the origin. The system...control systems, Picard iterates, Taylor expansion. Work Unit Number 5 (Optimization and Large Scale Systems) Istituto di Matematica Applicata...control system on Ad: I _~~d x~)= m g(x(t))ou (t), x(o) = O ii 1 Given a control u, in general there exists no explicit formula to exactly compute the

  9. Targeting GM-CSF in rheumatoid arthritis.

    PubMed

    Avci, Ali Berkant; Feist, Eugen; Burmester, Gerd-Rüdiger

    2016-01-01

    Granulocyte-macrophage colony-stimulating factor (GM-CSF) is well-known as a haemopoietic growth factor. However, it is also essential in regulating functions of mature myeloid cells such as macrophages. Preclinical studies and observations of flares of arthritis in patients following GM-CSF treatment supported its important contribution to the pathogenesis of rheumatoid arthritis (RA). As the most advanced compound, mavrilimumab, a monoclonal antibody against GM-CSF receptor, has already completed phase II trials with a long term of follow-up period of 74 weeks. During this exposure period, an acceptable sustained safety and tolerability profile has been observed addressing the concerns of development of cytopenias or pulmonary alveolar proteinosis. Of note, a rapid and sustained efficacy and normalisation of acute phase reactants were consistently shown in studies both targeting GM-CSF and its receptor. Its tumour necrosis factor (TNF) independent mode of action with concurrent blockade of GM-CSF as well as IL-17 signalling reported from preclinical studies supports the assumption that it can be a useful biologic and an alternative agent in TNF inhibitor resistant patients with RA. Therefore, subsequent studies are warranted to investigate the safety and efficacy of GM-CSF blocking agents in different subgroups of RA.

  10. Soybean cyclophilin GmCYP1 interacts with an isoflavonoid regulator GmMYB176

    PubMed Central

    Mainali, Hemanta Raj; Vadivel, Arun Kumaran Anguraj; Li, Xuyan; Gijzen, Mark; Dhaubhadel, Sangeeta

    2017-01-01

    Cyclophilins (CYPs) belong to the immunophilin superfamily with peptidyl-prolyl cis-trans isomerase (PPIase) activity. They catalyze the interconversion of the cis- and trans-rotamers of the peptidyl-prolyl amide bond of peptides. A yeast-two-hybrid screening using the isoflavonoid regulator GmMYB176 as bait identified GmCYP1 as one of the interacting proteins in soybean embryos. GmCYP1 localizes both in the nucleus and cytoplasm, and interacts in planta with GmMYB176, in the nucleus, and with SGF14l (a soybean 14-3-3 protein) in the nucleus and the cytoplasm. GmCYP1 contains a single cyclophilin-like domain and displays a high sequence identity with other plant CYPs that are known to have stress-specific function. Tissue-specific expression of GmCYP1 revealed higher expression in developing seeds compared to other vegetative tissues, suggesting their seed-specific role. Furthermore, GmCYP1 transcript level was reduced in response to stress. Since isoflavonoids are involved in plant stress resistance against biotic and abiotic factors, the interaction of GmCYP1 with the isoflavonoid regulators GmMYB176 and 14-3-3 protein suggests its role in defense in soybean. PMID:28074922

  11. Cathedral house & crocker fence, Taylor Street east and north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cathedral house & crocker fence, Taylor Street east and north elevations, perspective view from the northeast - Grace Cathedral, George William Gibbs Memorial Hall, 1051 Taylor Street, San Francisco, San Francisco County, CA

  12. 20. TURNTABLE WITH CABLE CAR BAY & TAYLOR: View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. TURNTABLE WITH CABLE CAR - BAY & TAYLOR: View to northwest of the Bay and Taylor turntable. The gripman and conductor are turning the car around. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  13. Damage modeling for Taylor impact simulations

    NASA Astrophysics Data System (ADS)

    Anderson, C. E., Jr.; Chocron, I. S.; Nicholls, A. E.

    2006-08-01

    G. I. Taylor showed that dynamic material properties could be deduced from the impact of a projectile against a rigid boundary. The Taylor anvil test became very useful with the advent of numerical simulations and has been used to infer and/or to validate material constitutive constants. A new experimental facility has been developed to conduct Taylor anvil impacts to support validation of constitutive constants used in simulations. Typically, numerical simulations are conducted assuming 2-D cylindrical symmetry, but such computations cannot hope to capture the damage observed in higher velocity experiments. A computational study was initiated to examine the ability to simulate damage and subsequent deformation of the Taylor specimens. Three-dimensional simulations, using the Johnson-Cook damage model, were conducted with the nonlinear Eulerian wavecode CTH. The results of the simulations are compared to experimental deformations of 6061-T6 aluminum specimens as a function of impact velocity, and conclusions regarding the ability to simulate fracture and reproduce the observed deformations are summarized.

  14. CURTIS TAYLOR, PRESIDENT OF LINC RESEARCH CORP.

    NASA Image and Video Library

    2016-04-27

    CURTIS O. TAYLOR, PRESIDENT OF LINC RESEARCH CORP, (L), AND JEFF LINDNER, CHIEF ENGINEER, POSE WITH HARDWARE FOR THEIR PATENTED TECHNOLOGY, FLUID STRUCTURE COUPLING, WHICH USES SIMPLE PHYSICS TO DAMPEN POTENTIALLY HARMFUL SHAKING IN STRUCTURES. INSTALLATION OF THE FLUID STRUCTURE COUPLING TECHNOLOGY IN A BUILDING WILL TAKE PLACE IN SUMMER OF 2016.

  15. Modelling VLSI circuits using Taylor series

    NASA Astrophysics Data System (ADS)

    Kocina, Filip; Nečasová, Gabriela; Veigend, Petr; Chaloupka, Jan; Šátek, Václav; Kunovský, Jiří

    2017-07-01

    The paper introduces the capacitor substitution for CMOS logic gates, i.e. NANDs, NORs and inverters. It reveals the necessity of a very accurate and fast method for solving this problem. Therefore the Modern Taylor Series Method (MTSM) is used which provides an automatic choice of a higher order during the computation and a larger integration step size while keeping desired accuracy.

  16. Characterization of Taylor plumes on SSX

    NASA Astrophysics Data System (ADS)

    Brown, M. R.; Kaur, M.; Han, J.; Shrock, J. E.; Schaffner, D. A.

    2016-10-01

    We have added a 1 m glass extension to the SSX plasma wind tunnel device. Initial experiments have been performed to characterize velocity, density, and magnetic field of relaxed helical Taylor states formed in the glass boundary. We are also experimenting with resistive and mesh liners to provide some flux conservation of the Taylor states. Under construction is a theta pinch coil and pulsed power supply to accelerate the fully relaxed (tilted) Taylor states. Once characterization studies are complete, one or two prototype theta pinch coils will be used to accelerate the Taylor states to over 100 km / s and compressed to small volumes by stagnation. A segmented resistive or mesh flux conserver may also be employed. Preliminary un-accelerated characterizaton studies produce peak proton densities of 1015cm-3 . Densities are measured with a precision quadrature He-Ne laser interferometer located in an expansion volume downstream of the glass extension. Temperatures will be measured by an ion Doppler spectrometer. Stagnated plasma parameters will be ne 1016cm-3 with Ti >= 20eV , B >= 0.5 T with lifetimes over 100 μs . Results from a single prototype acceleration coil will be presented. Work supported by DOE ARPA-E ALPHA program.

  17. Tree ecophysiology research at Taylor Woods

    Treesearch

    Thomas E. Kolb; Nate G. McDowell

    2008-01-01

    We summarize the key findings of tree ecophysiology studies performed at Taylor Woods, Fort Valley Experimental Forest, Arizona between 1994 and 2003 that provide unique insight on impacts of long-term stand density management in ponderosa pine forests on tree water relations, leaf gas exchange, radial growth, leaf area-to-sapwood-area ratio, growth efficiency, leaf...

  18. Biographical Note--Robert S. Taylor.

    ERIC Educational Resources Information Center

    Van der Veer Martens, Betsy

    1999-01-01

    In an age of specialists, Robert Saxon Taylor has been one of the great generalists in the theory and practice of information transfer and use. This sidebar discusses his seminal scholarly contributions, influence on students and senior colleagues alike, memberships and chairmanships, tenure as dean (1972-1981) and professor at what became the…

  19. Nonlinear stability of Taylor's vortex array

    NASA Technical Reports Server (NTRS)

    Lin, S. P.; Tobak, M.

    1987-01-01

    It is proved that the two-dimensional Taylor vortex array, which is an exact unsteady solution of the Navier-Stokes equation, is globally and asymptotically stable in the mean with respect to three-dimensional periodic disturbances. A time-dependent bound on the decay rate of the kinetic energy of disturbances is obtained.

  20. Application of Taylor's series to trajectory propagation

    NASA Technical Reports Server (NTRS)

    Stanford, R. H.; Berryman, K. W.; Breckheimer, P. J.

    1986-01-01

    This paper describes the propagation of trajectories by the application of the preprocessor ATOMCC which uses Taylor's series to solve initial value problems in ordinary differential equations. Comparison of the results obtained with those from other methods are presented. The current studies indicate that the ATOMCC preprocessor is an easy, yet fast and accurate method for generating trajectories.

  1. Neo-Taylorism in Educational Administration?

    ERIC Educational Resources Information Center

    Gronn, Peter C.

    1982-01-01

    Reviews eight recent observational studies of school administrators and criticizes the studies' use of "time and motion" assumptions drawn from Frederick Winslow Taylor's ideas. Outlines an alternate approach based on "thick" description of administrators' work, including their talk, as exemplified in James Boswell's biography…

  2. Cusp formation in drops inside Taylor cones

    NASA Astrophysics Data System (ADS)

    Marin, Alvaro G.; Loscertales, Ignacio G.; Barrero, Antonio

    2005-11-01

    Here, we report the formation of cusp in insulating drops inside compound Taylor cones. The action of the electrical shear stress acting on the outer interface, which is transmitted by viscous forces inside the Taylor cone, tends to deform the drop of insulating liquid placed inside. For appropriate values of the capillary number, the insulating drop develops a steady cusp angle which depends on both the capillary number and the conducting to insulating viscosity ratio. A self-similar analysis has been developed to qualitatively describe the flow inside these compounds Taylor cones. Any perturbation of the cusp gives rise to an intermittent emission of tiny droplets; this effect may recall the tip-streaming observed by G.I. Taylor in his four-roll mill device. This emission can be stabilized by an appropriate control of the injected flow rate of the insulating liquid. When the capillary number increases, the cusped interface turns into a spout which flows coated by the conducting liquid forming the electrified coaxial jet which has been successfully employed for the production of nanocapsules, coaxial nanofibers and nanotubes (Science 295, n. 5560, 1695, 2002; JACS 126, 5376, 2004).

  3. Neo-Taylorism in Educational Administration?

    ERIC Educational Resources Information Center

    Gronn, Peter C.

    1982-01-01

    Reviews eight recent observational studies of school administrators and criticizes the studies' use of "time and motion" assumptions drawn from Frederick Winslow Taylor's ideas. Outlines an alternate approach based on "thick" description of administrators' work, including their talk, as exemplified in James Boswell's biography…

  4. Nonlinear stability of Taylor's vortex array

    NASA Technical Reports Server (NTRS)

    Lin, S. P.; Tobak, M.

    1987-01-01

    It is proved that the two-dimensional Taylor vortex array, which is an exact unsteady solution of the Navier-Stokes equation, is globally and asymptotically stable in the mean with respect to three-dimensional periodic disturbances. A time-dependent bound on the decay rate of the kinetic energy of disturbances is obtained.

  5. Application of Taylor's series to trajectory propagation

    NASA Technical Reports Server (NTRS)

    Stanford, R. H.; Berryman, K. W.; Breckheimer, P. J.

    1986-01-01

    This paper describes the propagation of trajectories by the application of the preprocessor ATOMCC which uses Taylor's series to solve initial value problems in ordinary differential equations. Comparison of the results obtained with those from other methods are presented. The current studies indicate that the ATOMCC preprocessor is an easy, yet fast and accurate method for generating trajectories.

  6. 5 CFR 531.243 - Promotion of a GM employee.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Promotion of a GM employee. 531.243... Promotion of a GM employee. (a) Upon promotion, an employee's status as a GM employee ends, as provided in § 531.241(b). (b) When an employee loses status as a GM employee because of a temporary promotion and...

  7. 5 CFR 531.243 - Promotion of a GM employee.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Promotion of a GM employee. 531.243... Promotion of a GM employee. (a) Upon promotion, an employee's status as a GM employee ends, as provided in § 531.241(b). (b) When an employee loses status as a GM employee because of a temporary promotion and is...

  8. Immunohistochemical detection of hepatic GM1 and GM2 gangliosides in streptozotocin-induced diabetic rats.

    PubMed

    Abregú, Adela V.; Genta, Susana B.; Sánchez Riera, Alicia N.; Sánchez, Sara S.

    2002-11-01

    This study was undertaken to investigate the consequences of diabetes on the expression of GM1 and GM2 gangliosides in rat liver. Experimental diabetes was induced by treatment with Streptozotocin (STZ) in adult male Sprague-Dawley rats. Two-dimensional thin-layer chromatography of total ganglioside preparations of liver tissues from STZ-induced diabetic rats showed an increased amount of GM1, while GM2 could not be detected. In order to identify ganglioside expression and corroborate possible changes after short-term diabetes (3 weeks), frozen sections of the liver were stained with two monoclonal antibodies, GMB16 (GM1 specific) and GMB28 (GM2 specific). Although both antibodies were capable of immunostaining the diabetic hepatocytes at the cell surface, strong reactivity was observed for GMB16 while GMB28 developed only a weak labeling. The hepatic ganglioside expression of insulin-stabilized diabetic rats was restored, resembling the profile of normal rats. The important alterations in the expression of GM1 and GM2 gangliosides in short-term diabetes were accompanied by certain microscopic changes in the liver, so that these gangliosides may be useful markers in the detection of early liver diabetic complications.

  9. Regulating coexistence of GM and non-GM crops without jeopardizing economic incentives.

    PubMed

    Demont, Matty; Devos, Yann

    2008-07-01

    The ongoing debate about the coexistence of genetically modified (GM) and non-GM crops in the European Union (EU) mainly focuses on preventive measures needed to keep the adventitious presence of GM material in non-GM products below established tolerance thresholds, as well as on issues covering questions of liability and the duty to redress the incurred economic harm once adventitious mixing in non-GM products has occurred. By contrast, the interplay between the economic incentives and costs of coexistence has attracted little attention. The current overemphasis on the technical aspects and cost of coexistence over its economic incentives might lead EU policy-makers to adopt too stringent and rigid regulations on coexistence. Therefore, we argue for flexible coexistence regulations that explicitly take into account the economic incentives for coexistence. Our arguments provide a timely and important framework for EU policy-makers, who are currently struggling to implement coherent coexistence regulations in all member states.

  10. Soybean GmMYB76, GmMYB92, and GmMYB177 genes confer stress tolerance in transgenic Arabidopsis plants.

    PubMed

    Liao, Yong; Zou, Hong-Feng; Wang, Hui-Wen; Zhang, Wan-Ke; Ma, Biao; Zhang, Jin-Song; Chen, Shou-Yi

    2008-10-01

    MYB-type transcription factors contain the conserved MYB DNA-binding domain of approximately 50 amino acids and are involved in the regulation of many aspects of plant growth, development, metabolism and stress responses. From soybean plants, we identified 156 GmMYB genes using our previously obtained 206 MYB unigenes, and 48 were found to have full-length open-reading frames. Expressions of all these identified genes were examined, and we found that expressions of 43 genes were changed upon treatment with ABA, salt, drought and/or cold stress. Three GmMYB genes, GmMYB76, GmMYB92 and GmMYB177, were chosen for further analysis. Using the yeast assay system, GmMYB76 and GmMYB92 were found to have transactivation activity and can form homodimers. GmMYB177 did not appear to have transactivation activity but can form heterodimers with GmMYB76. Yeast one-hybrid assay revealed that all the three GmMYBs could bind to cis-elements TAT AAC GGT TTT TT and CCG GAA AAA AGG AT, but with different affinity, and GmMYB92 could also bind to TCT CAC CTA CC. The transgenic Arabidopsis plants overexpressing GmMYB76 or GmMYB177 showed better performance than the GmMYB92-transgenic plants in salt and freezing tolerance. However, these transgenic plants exhibited reduced sensitivity to ABA treatment at germination stage in comparison with the wild-type plants. The three GmMYB genes differentially affected a subset of stress-responsive genes in addition to their regulation of a common subset of stress-responsive genes. These results indicate that the three GmMYB genes may play differential roles in stress tolerance, possibly through regulation of stress-responsive genes.

  11. GmMYB58 and GmMYB205 are seed-specific activators for isoflavonoid biosynthesis in Glycine max.

    PubMed

    Han, Xiaoyan; Yin, Qinggang; Liu, Jinyue; Jiang, Wenbo; Di, Shaokang; Pang, Yongzhen

    2017-09-13

    GmMYB58 and GmMYB205 are key positive regulators that are involved in isoflavonoid biosynthesis in seeds of Glycine max, and they activate the expression of several structural genes in the isoflavonoid pathway. MYB transcription factors (TFs) are major regulators involved in flavonoid/isoflavonoid biosynthesis in many plant species. However, functions of most MYB TFs remain unknown in flavonoid/isoflavonoid pathway in Glycine max. In this study, we identified 321 MYB TFs by genome-wide searching, and further isolated and functionally characterized two MYB TFs, GmMYB58 and GmMYB205. The deduced GmMYB58 and GmMYB205 proteins contain highly conserved R2R3 repeat domain at the N-terminal region that is the signature motif of R2R3-type MYB TFs. GmMYB58 and GmMYB205 were highly expressed in early seed development stages than in the other tested organs. GmMYB58 and GmMYB205 GFP fusion proteins were found to be localized in the nucleus when they were transiently expressed in Arabidopsis thaliana mesophyll protoplast. Both GmMYB58 and GmMYB205 can activate the promoter activities of GmCHS, GmIFS2, and GmHID in the transient trans-activation assays, and the activation of GmHID by both GmMYB58 and GmMYB205 was further confirmed by yeast one-hybrid assay. In addition, over-expression of GmMYB58 and GmMYB205 resulted in significant increases in expression levels of several pathway genes in soybean hairy roots, in particular, IFS2 by more than fivefolds in GmMYB205-over-expressing lines. Moreover, isoflavonoid contents were remarkably enhanced in the GmMYB58 and GmMYB205 over-expressing hairy roots than in the control. Our results suggest that GmMYB58 and GmMYB205 are seed-specific TFs, and they can enhance isoflavonoid biosynthesis mainly through the regulation of GmIFS2 and GmHID in G. max.

  12. GmWRKY27 interacts with GmMYB174 to reduce expression of GmNAC29 for stress tolerance in soybean plants.

    PubMed

    Wang, Fang; Chen, Hao-Wei; Li, Qing-Tian; Wei, Wei; Li, Wei; Zhang, Wan-Ke; Ma, Biao; Bi, Ying-Dong; Lai, Yong-Cai; Liu, Xin-Lei; Man, Wei-Qun; Zhang, Jin-Song; Chen, Shou-Yi

    2015-07-01

    Soybean (Glycine max) is an important crop for oil and protein resources worldwide. The molecular mechanism of the abiotic stress response in soybean is largely unclear. We previously identified multiple stress-responsive WRKY genes from soybean. Here, we further characterized the roles of one of these genes, GmWRKY27, in abiotic stress tolerance using a transgenic hairy root assay. GmWRKY27 expression was increased by various abiotic stresses. Over-expression and RNAi analysis demonstrated that GmWRKY27 improves salt and drought tolerance in transgenic soybean hairy roots. Measurement of physiological parameters, including reactive oxygen species and proline contents, supported this conclusion. GmWRKY27 inhibits expression of a downstream gene GmNAC29 by binding to the W-boxes in its promoter region. The GmNAC29 is a negative factor of stress tolerance as indicated by the performance of transgenic hairy roots under stress. GmWRKY27 interacts with GmMYB174, which also suppresses GmNAC29 expression and enhances drought stress tolerance. The GmWRKY27 and GmMYB174 may have evolved to bind to neighbouring cis elements in the GmNAC29 promoter to co-reduce promoter activity and gene expression. Our study discloses a valuable mechanism in soybean for regulation of the stress response by two associated transcription factors. Manipulation of these genes should facilitate improvements in stress tolerance in soybean and other crops.

  13. Filipin recognizes both GM1 and cholesterol in GM1 gangliosidosis mouse brain.

    PubMed

    Arthur, Julian R; Heinecke, Karie A; Seyfried, Thomas N

    2011-07-01

    Filipin is an antibiotic polyene widely used as a histochemical marker for cholesterol. We previously reported cholesterol/filipin-positive staining in brain of β-galactosidase (β-gal) knockout ((-/-)) mice (GM1 gangliosidosis). The content and distribution of cholesterol and gangliosides was analyzed in plasma membrane (PM) and microsomal (MS) fractions from whole-brain tissue of 15 week-old control (β-gal(+/-)) and GM1 gangliosidosis (β-gal(-/-)) mice. Total ganglioside content (μg sialic acid/mg protein) was 3-fold and 7-fold greater in the PM and MS fractions, respectively, in βgal(-/-) mice than in βgal(+/-) mice. GM1 content was 30-fold and 50-fold greater in the PM and MS fractions, respectively. In contrast, unesterified cholesterol content (μg/mg protein) was similar in the PM and the MS fractions of the βgal(-/-) and βgal(+/-) mice. Filipin is known to bind to various sterol derivatives and phospholipids on thin-layer chromatograms. Biochemical evidence is presented showing that filipin also binds to GM1 with an affinity similar to that for cholesterol, with a corresponding fluorescent reaction. Our data suggest that the GM1 storage seen in the β-gal(-/-) mouse contributes to the filipin ultraviolet fluorescence observed in GM1 gangliosidosis brain. The data indicate that in addition to cholesterol, filipin can also be useful for detecting GM1.

  14. Rayleigh-Taylor Mix experiment on Pegasus

    SciTech Connect

    Sheppard, M.G.; Atchison, W.L.; Anderson, W.E.

    1997-09-01

    The Rayleigh-Taylor Mix project will attempt to diagnose and understand the growth of a mixing layer at the interface between an imploding metal liner and a polystyrene foam core in a series of pulsed power experiments on the Pegasus capacitor bank. Understanding the effects of material strength will be an important part of the study. During the initial phase of the implosion, the linear/foam interface is Rayleigh-Taylor (RT) stable; however, as the foam is compressed, it decelerates the liner, causing it to bound and to go RT unstable. This paper reports 1D and 2D MHD simulations of the first experiment in the series and preliminary results.

  15. PEOPLE IN PHYSICS: Interview with Charles Taylor

    NASA Astrophysics Data System (ADS)

    Pople, Conducted by Stephen

    1996-07-01

    Charles Taylor started his university teaching career at UMIST in 1948. In 1965 he became Professor and Head of the Department of Physics at University College, Cardiff. He was a Vice-President of the Institute of Physics from 1970 to 1975, and Professor of Experimental Physics at the Royal Institution from 1977 until 1989. Over the years, Professor Taylor has delighted audiences of all ages with his demonstration lectures, including the Royal Institution Christmas Lectures televised in 1971 and 1989. In 1986 he became the first recipient of the Royal Society's Michael Faraday Award for contributions to the public understanding of science. His many books include Exploring Music, The Art and Science of the Lecture Demonstration, and also the Oxford Children's Book of Science, co-written with interviewer Stephen Pople.

  16. CTH simulation of PBX-9501 Taylor tests /

    SciTech Connect

    Koby, Joseph R.

    2011-09-01

    During March-May 2011, multiple Taylor impact tests were conducted at LANL, examining the behavior of PBXN-9 and PBX-9501 under rapid loading. Subsequently, a computational hydrodynamics code (CTH) model was developed to mimic the deformation behavior observed in these impact tests with PBX-9501 would likely initiate upon impact. Also examined was whether an inert slud behind the explosive would lead to initiation at lower, more easily attainable velocities. The simplified model used here showed a minimum velocity for ignition of 530 m/s which was unchanged by the addition of a plastic slud behind the sample. The use of a lead slug did lower the minimum velocity to 460 m/s. These values are likely more qualitative at this point because multiple simplifications are currently used in the materials properties and test geometry. The results do show that this approach is capable of determining ignition due to Taylor impact.

  17. GM2 Activator Deficiency Caused by a Homozygous Exon 2 Deletion in GM2A.

    PubMed

    Hall, Patricia L; Laine, Regina; Alexander, John J; Ankala, Arunkanth; Teot, Lisa A; Lidov, Hart G W; Anselm, Irina

    2017-05-25

    GM2 activator (GM2A) deficiency (OMIM 613109) is a rare lysosomal storage disorder, with onset typically in infancy or early childhood. Clinically, it is almost indistinguishable from Tay-Sachs disease (OMIM 272800) or Sandhoff disease (OMIM 268800); however, traditionally available biochemical screening tests will most likely reveal normal results. We report a 2-year-old male with initially normal development until the age of 9 months, when he presented with developmental delay and regression. Workup at that time was unrevealing; at 15 months, he had abnormal brain MRI findings and a cherry red spot on ophthalmological examination. Family history and all laboratory studies were uninformative. The combination of a cherry red spot and developmental regression was strongly suggestive of a lysosomal storage disorder. Sequence analysis of GM2A did not reveal any pathogenic variants; however, exon 2 of GM2A could not be amplified by PCR, raising suspicion for a large, homozygous deletion. Subsequent copy number analysis confirmed a homozygous deletion of exon 2 in GM2A. This is the first reported case of GM2A deficiency being caused by a whole exon deletion. We describe previously unreported electron microscopy findings in this disease, thus expanding the clinical and variant spectrum for GM2 activator deficiency. These findings demonstrate the increased degree of suspicion required for diagnosis of this rare disorder. Brief Summary: This case of GM2 activator deficiency was caused by a homozygous deletion in GM2A, demonstrating the need to include exon level copy number analysis in any workup to fully exclude this disorder.

  18. Stability of compressible Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Chow, Chuen-Yen

    1991-01-01

    Compressible stability equations are solved using the spectral collocation method in an attempt to study the effects of temperature difference and compressibility on the stability of Taylor-Couette flow. It is found that the Chebyshev collocation spectral method yields highly accurate results using fewer grid points for solving stability problems. Comparisons are made between the result obtained by assuming small Mach number with a uniform temperature distribution and that based on fully incompressible analysis.

  19. Stability of compressible Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Chow, Chuen-Yen

    1991-01-01

    Compressible stability equations are solved using the spectral collocation method in an attempt to study the effects of temperature difference and compressibility on the stability of Taylor-Couette flow. It is found that the Chebyshev collocation spectral method yields highly accurate results using fewer grid points for solving stability problems. Comparisons are made between the result obtained by assuming small Mach number with a uniform temperature distribution and that based on fully incompressible analysis.

  20. Magnetically Induced Rotating Rayleigh-Taylor Instability.

    PubMed

    Scase, Matthew M; Baldwin, Kyle A; Hill, Richard J A

    2017-03-03

    Classical techniques for investigating the Rayleigh-Taylor instability include using compressed gasses(1), rocketry(2) or linear electric motors(3) to reverse the effective direction of gravity, and accelerate the lighter fluid toward the denser fluid. Other authors(e.g.)(4)(,)(5)(,)(6) have separated a gravitationally unstable stratification with a barrier that is removed to initiate the flow. However, the parabolic initial interface in the case of a rotating stratification imposes significant technical difficulties experimentally. We wish to be able to spin-up the stratification into solid-body rotation and only then initiate the flow in order to investigate the effects of rotation upon the Rayleigh-Taylor instability. The approach we have adopted here is to use the magnetic field of a superconducting magnet to manipulate the effective weight of the two liquids to initiate the flow. We create a gravitationally stable two-layer stratification using standard flotation techniques. The upper layer is less dense than the lower layer and so the system is Rayleigh-Taylor stable. This stratification is then spun-up until both layers are in solid-body rotation and a parabolic interface is observed. These experiments use fluids with low magnetic susceptibility, |χ| ~ 10(-6) - 10(-5), compared to a ferrofluids. The dominant effect of the magnetic field applies a body-force to each layer changing the effective weight. The upper layer is weakly paramagnetic while the lower layer is weakly diamagnetic. When the magnetic field is applied, the lower layer is repelled from the magnet while the upper layer is attracted towards the magnet. A Rayleigh-Taylor instability is achieved with application of a high gradient magnetic field. We further observed that increasing the dynamic viscosity of the fluid in each layer, increases the length-scale of the instability.

  1. New trends in Taylor series based applications

    NASA Astrophysics Data System (ADS)

    Kocina, Filip; Šátek, Václav; Veigend, Petr; Nečasová, Gabriela; Valenta, Václav; Kunovský, Jiří

    2016-06-01

    The paper deals with the solution of large system of linear ODEs when minimal comunication among parallel processors is required. The Modern Taylor Series Method (MTSM) is used. The MTSM allows using a higher order during the computation that means a larger integration step size while keeping desired accuracy. As an example of complex systems we can take the Telegraph Equation Model. Symbolic and numeric solutions are compared when harmonic input signal is used.

  2. Fisheries Aspects of Seamounts and Taylor Columns

    DTIC Science & Technology

    1986-09-01

    NAVAL POSTGRADUATE SCHOOL DTI I V4 D THESIS FISH ERIES ASPECT S OF SEAMOUNTS AND) TAYLOR COLUMNS by Russell E. Brainard September 1986 Thesis Co...Takahashi and Sasaki, 1977; Genin and Boehlert, 1985). In fact, many seamounts are now known to be excellent fishing grounds for both pelagic nekton, such as...Pentaceros richardsoni and alfonsin, Baryx splendeus on the southern Emperor-northern Hawaiian Ridge seamounts. Both of these rare fish are eagerly

  3. [Comparison of soyasaponin and isoflavone contents between genetically modified (GM) and non-GM soybeans].

    PubMed

    Goda, Yukihiro; Akiyama, Hiroshi; Suyama, Emiko; Takahashi, Satoshi; Kinjo, Junei; Nohara, Toshihiro; Toyoda, Masatake

    2002-12-01

    Soyasaponins and isoflavones are main secondary metabolites in soybeans. In this report we compared the content of secondary metabolites between genetically modified (GM) and non-GM soybeans. Six cultivars/lines of GM and six cultivars/lines of non-GM soybeans were extracted with methanol. Each extract was partitioned with aqueous methanol and hexane and the aqueous methanol fraction was partially purified by HP-20 and LH-20 column chromatography to afford crude soyasaponin and isoflavone fractions. The main A-type soyasaponin, acetylsoyasaponin A1 (AcA1), and the main B-type soyasaponins, soyasaponins I and II (I and II), in the crude fractions were identified by LC/MS analyses with authentic samples. The main isoflavones, daidzin, genistin, daidzein and genistein (DI, GI, DE and GE), in the crude fractions were identified by LC photo-diode array analyses with authentic samples. The contents of AcA1, I and II in the crude soyasaponin fractions and those of DI, GI, DE and GE in the crude isoflavone fractions were analyzed by reversed-phase HPLC. The average contents (mg/100 g) of AcA1, I, II and total of B-type soyasaponins in GM soybeans were 36.4 +/- 24.2, 51.2 +/- 11.8, 26.4 +/- 7.6 and 77.7 +/- 18.5, respectively, and those in non-GM ones were 22.3 +/- 14.7, 46.3 +/- 17.8, 19.8 +/- 9.1 and 65.9 +/- 26.9, respectively. The average contents (mg/100 g) of DI, GI, DE, GE and total isoflavones in GM soybeans were 93.1 +/- 15.5, 121.8 +/- 19.4, 0.073 +/- 0.178, 0.320 +/- 0.082 and 215.3 +/- 33.3, respectively, and those in non-GM ones were 78.8 +/- 34.6, 106.7 +/- 28.3, 2.206 +/- 4.468, 0.822 +/- 0.754 and 188.5 +/- 26.7, respectively. There were no statistically significant differences in soyasaponin and isoflavone contents between GM and non-GM soybeans. Therefore, it was estimated that the GM soybeans are equivalent to the non-GM ones in terms of the composition of the main secondary metabolites.

  4. Fluctuation scaling, Taylor's law, and crime.

    PubMed

    Hanley, Quentin S; Khatun, Suniya; Yosef, Amal; Dyer, Rachel-May

    2014-01-01

    Fluctuation scaling relationships have been observed in a wide range of processes ranging from internet router traffic to measles cases. Taylor's law is one such scaling relationship and has been widely applied in ecology to understand communities including trees, birds, human populations, and insects. We show that monthly crime reports in the UK show complex fluctuation scaling which can be approximated by Taylor's law relationships corresponding to local policing neighborhoods and larger regional and countrywide scales. Regression models applied to local scale data from Derbyshire and Nottinghamshire found that different categories of crime exhibited different scaling exponents with no significant difference between the two regions. On this scale, violence reports were close to a Poisson distribution (α = 1.057 ± 0.026) while burglary exhibited a greater exponent (α = 1.292 ± 0.029) indicative of temporal clustering. These two regions exhibited significantly different pre-exponential factors for the categories of anti-social behavior and burglary indicating that local variations in crime reports can be assessed using fluctuation scaling methods. At regional and countrywide scales, all categories exhibited scaling behavior indicative of temporal clustering evidenced by Taylor's law exponents from 1.43 ± 0.12 (Drugs) to 2.094 ± 0081 (Other Crimes). Investigating crime behavior via fluctuation scaling gives insight beyond that of raw numbers and is unique in reporting on all processes contributing to the observed variance and is either robust to or exhibits signs of many types of data manipulation.

  5. Novel GM animal technologies and their governance.

    PubMed

    Bruce, Ann; Castle, David; Gibbs, Corrina; Tait, Joyce; Whitelaw, C Bruce A

    2013-08-01

    Scientific advances in methods of producing genetically modified (GM) animals continue, yet few such animals have reached commercial production. Existing regulations designed for early techniques of genetic modification pose formidable barriers to commercial applications. Radically improved techniques for producing GM animals invite a re-examination of current regulatory regimes. We critically examine current GM animal regulations, with a particular focus on the European Union, through a framework that recognises the importance of interactions among regulatory regimes, innovation outcomes and industry sectors. The current focus on the regulation of risk is necessary but is unable to discriminate among applications and tends to close down broad areas of application rather than facilitate innovation and positive industry interactions. Furthermore, the fields of innovative animal biosciences appear to lack networks of organisations with co-ordinated future oriented actions. Such networks could drive coherent programmes of innovation towards particular visions and contribute actively to the development of regulatory systems for GM animals. The analysis presented makes the case for regulatory consideration of each animal bioscience related innovation on the basis of the nature of the product itself and not the process by which it was developed.

  6. Microbial Energetics Beneath the Taylor Glacier, Antarctica

    NASA Astrophysics Data System (ADS)

    Mikucki, J. A.; Turchyn, A. V.; Farquhar, J.; Priscu, J. C.; Schrag, D. P.; Pearson, A.

    2007-12-01

    Subglacial microbiology is controlled by glacier hydrology, bedrock lithology, and the preglacial ecosystem. These factors can all affect metabolic function by influencing electron acceptor and donor availability in the subglacial setting leaving biogeochemical signatures that can be used to determine ecosystem processes. Blood Falls, an iron-rich, episodic subglacial outflow from the Taylor Glacier in the McMurdo Dry Valleys Antarctica provides an example of how microbial community structure and function can provide insight into subglacial hydrology. This subglacial outflow contains cryoconcentrated, Pliocene-age seawater salts that pooled in the upper Taylor Valley and was subsequently covered by the advance of the Taylor Glacier. Biogeochemical measurements, culture-based techniques, and genomic analysis were used to characterize microbes and chemistry associated with the subglacial outflow. The isotopic composition of important geochemical substrates (i.e., δ34Ssulfate, Δ33Ssulfate, δ18Osulfate, δ18Owater, Δ14SDIC) were also measured to provide more detail on subglacial microbial energetics. Typically, subglacial systems, when driven to anoxia by the hydrolysis of organic matter, will follow a continuum of redox chemistries utilizing electron acceptors with decreasing reduction potential (e.g., Fe (III), sulfate, CO2). Our data provide no evidence for sulfate reduction below the Taylor Glacier despite high dissolved organic carbon (450 μM C) and measurable metabolic activity. We contend that, in the case of the Taylor Glacier, the in situ bioenergetic reduction potential has been 'short-circuited' at Fe(III)-reduction and excludes sulfate reduction and methanogenesis. Given the length of time that this marine system has been isolated from phototrophic production (~2 Mya) the ability to degrade and consume increasingly recalcitrant organic carbon is likely an important component to the observed redox chemistry. Our work indicates that glacier hydrology

  7. Predicting Urban Medical Services Demand in China: An Improved Grey Markov Chain Model by Taylor Approximation

    PubMed Central

    Duan, Jinli; Jiao, Feng; Zhang, Qishan

    2017-01-01

    The sharp increase of the aging population has raised the pressure on the current limited medical resources in China. To better allocate resources, a more accurate prediction on medical service demand is very urgently needed. This study aims to improve the prediction on medical services demand in China. To achieve this aim, the study combines Taylor Approximation into the Grey Markov Chain model, and develops a new model named Taylor-Markov Chain GM (1,1) (T-MCGM (1,1)). The new model has been tested by adopting the historical data, which includes the medical service on treatment of diabetes, heart disease, and cerebrovascular disease from 1997 to 2015 in China. The model provides a predication on medical service demand of these three types of disease up to 2022. The results reveal an enormous growth of urban medical service demand in the future. The findings provide practical implications for the Health Administrative Department to allocate medical resources, and help hospitals to manage investments on medical facilities. PMID:28783088

  8. Predicting Urban Medical Services Demand in China: An Improved Grey Markov Chain Model by Taylor Approximation.

    PubMed

    Duan, Jinli; Jiao, Feng; Zhang, Qishan; Lin, Zhibin

    2017-08-06

    The sharp increase of the aging population has raised the pressure on the current limited medical resources in China. To better allocate resources, a more accurate prediction on medical service demand is very urgently needed. This study aims to improve the prediction on medical services demand in China. To achieve this aim, the study combines Taylor Approximation into the Grey Markov Chain model, and develops a new model named Taylor-Markov Chain GM (1,1) (T-MCGM (1,1)). The new model has been tested by adopting the historical data, which includes the medical service on treatment of diabetes, heart disease, and cerebrovascular disease from 1997 to 2015 in China. The model provides a predication on medical service demand of these three types of disease up to 2022. The results reveal an enormous growth of urban medical service demand in the future. The findings provide practical implications for the Health Administrative Department to allocate medical resources, and help hospitals to manage investments on medical facilities.

  9. Effect on soil chemistry of genetically modified (GM) vs. non-GM maize.

    PubMed

    Liu, Na; Zhu, Ping; Peng, Chang; Kang, Lingsheng; Gao, Hongjun; Clarke, Nicholas J; Clarke, Jihong Liu

    2010-01-01

    The effects of genetically modified (GM) maize (Zea mays L.) expressing the Bacillus thuringiensis Berliner Cry1Fa2 protein (Bt) and phosphinothricin or glyphosate herbicide tolerance on soil chemistry (organic matter, N, P, K and pH), compared with non-GM controls, were assessed in field and pot experiments. In the field experiment, NH(4)(+) was significantly higher in soil under the crop modified for herbicide tolerance compared to the control (mean values of 11 and 9.6 mg N/kg respectively) while P was significantly higher in soil under the control compared to under the GM crop (mean values of 6.9 and 6.4 dg P/kg, respectively). No significant differences were found as a result of growing Bt/herbicide tolerant maize. In the pot experiment, using soils from three sites (Gongzhuling, Dehui and Huadian), significant effects of using Bt maize instead of conventional maize were found for all three soils. In the Gongzhuling soil, P was significantly higher in soil under the control compared to under the GM crop (mean values of 4.8 and 4.0 dg P/kg, respectively). For the Dehui soil, the pH was significantly higher in soil under the control compared to under the GM crop (mean values for {H(+)} of 1.1 and 2.4 μM for the control and the GM crop respectively). In the Huadian soil, organic matter and total N were both higher in soil under the GM crop than under the control. For organic matter, the mean values were 3.0 and 2.9% for the GM crop and the control, respectively, while for total nitrogen the mean values were 2.02 and 1.96% for the GM crop and the control respectively. Our results indicate that growing GM crops instead of conventional crops may alter soil chemistry, but not greatly, and that effects will vary with both the specific genetic modification and the soil. © 2010 Landes Bioscience

  10. Safety of GM crops: compositional analysis.

    PubMed

    Brune, Philip D; Culler, Angela Hendrickson; Ridley, William P; Walker, Kate

    2013-09-04

    The compositional analysis of genetically modified (GM) crops has continued to be an important part of the overall evaluation in the safety assessment program for these materials. The variety and complexity of genetically engineered traits and modes of action that will be used in GM crops in the near future, as well as our expanded knowledge of compositional variability and factors that can affect composition, raise questions about compositional analysis and how it should be applied to evaluate the safety of traits. The International Life Sciences Institute (ILSI), a nonprofit foundation whose mission is to provide science that improves public health and well-being by fostering collaboration among experts from academia, government, and industry, convened a workshop in September 2012 to examine these and related questions, and a series of papers has been assembled to describe the outcomes of that meeting.

  11. Epistemological depth in a GM crops controversy.

    PubMed

    Hicks, Daniel J

    2015-04-01

    This paper examines the scientific controversy over the yields of genetically modified [GM] crops as a case study in epistemologically deep disagreements. Appeals to "the evidence" are inadequate to resolve such disagreements; not because the interlocutors have radically different metaphysical views (as in cases of incommensurability), but instead because they assume rival epistemological frameworks and so have incompatible views about what kinds of research methods and claims count as evidence. Specifically, I show that, in the yield debate, proponents and opponents of GM crops cite two different sets of claims as evidence, which correspond to two rival epistemological frameworks, classical experimental epistemology and Nancy Cartwright's evidence for use. I go on to argue that, even if both sides of the debate accepted Cartwright's view, they might still disagree over what counts as evidence, because evidence for use ties standards of evidence to what is sometimes called the "context of application." Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Natural History of Infantile GM2 Gangliosidosis

    PubMed Central

    Bley, Annette E.; Giannikopoulos, Ourania A.; Hayden, Doug; Kubilus, Kim; Tifft, Cynthia J.

    2011-01-01

    OBJECTIVE: GM2 gangliosidoses are caused by an inherited deficiency of lysosomal β-hexosaminidase and result in ganglioside accumulation in the brain. Onset during infancy leads to rapid neurodegeneration and death before 4 years of age. We set out to quantify the rate of functional decline in infantile GM2 gangliosidosis on the basis of patient surveys and a comprehensive review of existing literature. METHODS: Patients with infantile GM2 gangliosidosis (N = 237) were surveyed via questionnaire by the National Tay Sachs & Allied Diseases Association (NTSAD). These data were supplemented by survival data from the NTSAD database and a literature survey. Detailed retrospective surveys from 97 patients were available. Five patients who had received hematopoietic stem cell transplantation were evaluated separately. The mortality rate of the remaining 92 patients was comparable to that of the 103 patients from the NTSAD database and 121 patients reported in the literature. RESULTS: Common symptoms at onset were developmental arrest (83%), startling (65%), and hypotonia (60%). All 55 patients who had learned to sit without support lost that ability within 1 year. Individual functional measures correlated with each other but not with survival. Gastric tube placement was associated with prolonged survival. Tay Sachs and Sandhoff variants did not differ. Hematopoietic stem cell transplantation was not associated with prolonged survival. CONCLUSIONS: We studied the timing of regression in 97 cases of infantile GM2 gangliosidosis and conclude that clinical disease progression does not correlate with survival, likely because of the impact of improved supportive care over time. However, functional measures are quantifiable and can inform power calculations and study design of future interventions. PMID:22025593

  13. Inward propagating chemical waves in Taylor vortices.

    PubMed

    Thompson, Barnaby W; Novak, Jan; Wilson, Mark C T; Britton, Melanie M; Taylor, Annette F

    2010-04-01

    Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses--also observed experimentally.

  14. Predictability of Rayleigh-Taylor instability

    SciTech Connect

    Viecelli, J.A.

    1986-03-27

    Numerical experiments modeling the Rayleigh Taylor instability are carried out using a two-dimensional incompressible Eulerian hydrodynamic code VFTS. The method of integrating the Navier-Stokes equations including the viscous terms is similar to that described in Kim and Moin, except that Lagrange particles have been added and provision for body forces is given. The Eulerian method is 2nd order accurate in both space and time, and the Poisson equation for the effective pressure field is solved exactly at each time step using a cyclic reduction method. 3 refs., 3 figs.

  15. Curvature suppresses the Rayleigh-Taylor instability

    SciTech Connect

    Trinh, Philippe H.; Kim, Hyoungsoo; Hammoud, Naima; Howell, Peter D.; Chapman, S. Jonathan; Stone, Howard A.

    2014-05-01

    The dynamics of a thin liquid #12;lm on the underside of a curved cylindrical substrate is studied. The evolution of the liquid layer is investigated as the #12;lm thickness and the radius of curvature of the substrate are varied. A dimensionless parameter (a modi#12;ed Bond number) that incorporates both geometric parameters, gravity, and surface tension is identified, and allows the observations to be classified according to three different flow regimes: stable films, films with transient growth of perturbations followed by decay, and unstable films. Experiments and theory confirm that, below a critical value of the Bond number, curvature of the substrate suppresses the Rayleigh-Taylor instability.

  16. Inward propagating chemical waves in Taylor vortices

    NASA Astrophysics Data System (ADS)

    Thompson, Barnaby W.; Novak, Jan; Wilson, Mark C. T.; Britton, Melanie M.; Taylor, Annette F.

    2010-04-01

    Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses—also observed experimentally.

  17. The pathology of feline GM2 gangliosidosis.

    PubMed

    Cork, L C; Munnell, J F; Lorenz, M D

    1978-03-01

    An 11-week-old and a 6-month-old kitten with feline GM2 gangliosidosis and deficiency in both A and B isoenzymes of beta-D-N-acetyl hexosaminidase were studied by light transmission (TEM), and scanning electron microscopy (SEM). Neurons throughout the nervous system contained cytoplasmic, membrane-bound inclusions which were PAS-positive at the fine structure level these inclusions were composed of membranous arrays in whorls, vesicles, or multilaminated stacks. Fusion of the bounding membranes of adjacent inclusions resulted in large inclusion-containing vacuoles. Hepatocytes and Kupffer cells contained inclusions slightly different from those in the central nervous system. SEM of cryofractured liver demonstrated their coalescence to form larger composite vacuoles. Vacuoles with inclusions were also seen in pancreatic acinar cells, endothelial cells, vascular smooth muscle, fibroblasts, myocardial cells, renal interstitial cells, corneal stromal cells, and R-E cells of bone marrow and spleen. The specific granules of eosinophils were swollen and took on bizarre forms. Pathologic manifestations of feline GM2 gangliosidosis differ from those seen in feline GM1 gangliosidosis but closely resemble those of Sandhoff disease in humans.

  18. The pathology of feline GM2 gangliosidosis.

    PubMed Central

    Cork, L. C.; Munnell, J. F.; Lorenz, M. D.

    1978-01-01

    An 11-week-old and a 6-month-old kitten with feline GM2 gangliosidosis and deficiency in both A and B isoenzymes of beta-D-N-acetyl hexosaminidase were studied by light transmission (TEM), and scanning electron microscopy (SEM). Neurons throughout the nervous system contained cytoplasmic, membrane-bound inclusions which were PAS-positive at the fine structure level these inclusions were composed of membranous arrays in whorls, vesicles, or multilaminated stacks. Fusion of the bounding membranes of adjacent inclusions resulted in large inclusion-containing vacuoles. Hepatocytes and Kupffer cells contained inclusions slightly different from those in the central nervous system. SEM of cryofractured liver demonstrated their coalescence to form larger composite vacuoles. Vacuoles with inclusions were also seen in pancreatic acinar cells, endothelial cells, vascular smooth muscle, fibroblasts, myocardial cells, renal interstitial cells, corneal stromal cells, and R-E cells of bone marrow and spleen. The specific granules of eosinophils were swollen and took on bizarre forms. Pathologic manifestations of feline GM2 gangliosidosis differ from those seen in feline GM1 gangliosidosis but closely resemble those of Sandhoff disease in humans. Images Figure 4 Figure 5 Figure 6 Figure 1 Figure 2 Figure 3 PMID:415617

  19. Fully nonlinear mode competitions of nearly bicritical spiral or Taylor vortices in Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Deguchi, K.; Altmeyer, S.

    2013-04-01

    Interactions between nearly bicritical modes in Taylor-Couette flow, which have been concerned with the framework of weakly nonlinear theory, are extended to fully nonlinear Navier-Stokes computation. For this purpose, a standard Newton solver for axially periodic flows is generalized to compute any mixed solutions having up to two phases, which typically arise from interactions of two spiral or Taylor vortex modes. Also, a simple theory is developed in order to classify the mixed solutions. With these methods, we elucidate pattern formation phenomena, which have been observed in a Taylor-Couette flow experiment. Focusing on the counter-rotating parameter range, all possible classes of interaction of various solutions with different azimuthal and axial wave numbers are considered within our computational restriction, and we observe numerous connection branches, e.g., footbridge solutions. Some of the mixed solutions result in a three-dimensional wavy spiral solution with axial relative periodicity or an axially doubly periodic toroidally closed vortex solution. The possible connection of the former solution family to spiral turbulence, which has been observed in highly counter-rotating Taylor-Couette flow, is discussed.

  20. Fully nonlinear mode competitions of nearly bicritical spiral or Taylor vortices in Taylor-Couette flow.

    PubMed

    Deguchi, K; Altmeyer, S

    2013-04-01

    Interactions between nearly bicritical modes in Taylor-Couette flow, which have been concerned with the framework of weakly nonlinear theory, are extended to fully nonlinear Navier-Stokes computation. For this purpose, a standard Newton solver for axially periodic flows is generalized to compute any mixed solutions having up to two phases, which typically arise from interactions of two spiral or Taylor vortex modes. Also, a simple theory is developed in order to classify the mixed solutions. With these methods, we elucidate pattern formation phenomena, which have been observed in a Taylor-Couette flow experiment. Focusing on the counter-rotating parameter range, all possible classes of interaction of various solutions with different azimuthal and axial wave numbers are considered within our computational restriction, and we observe numerous connection branches, e.g., footbridge solutions. Some of the mixed solutions result in a three-dimensional wavy spiral solution with axial relative periodicity or an axially doubly periodic toroidally closed vortex solution. The possible connection of the former solution family to spiral turbulence, which has been observed in highly counter-rotating Taylor-Couette flow, is discussed.

  1. 76 FR 76689 - Cibola National Forest, Mount Taylor Ranger District, NM, Mount Taylor Combined Exploratory Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ... Exploratory Drilling AGENCY: Forest Service, USDA. ACTION: Notice of intent to prepare an environmental impact... drilling on the Cibola National Forest, Mount Taylor Ranger District. There are two areas identified for... vicinity of the town of San Mateo. In total, there are up to 279 drill holes that would be drilled over...

  2. 76 FR 3570 - Proposed Amendment of Class E Airspace; Taylor, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ...This action proposes to modify Class E airspace at Taylor Airport, Taylor, AZ. Controlled airspace is necessary to accommodate aircraft using the CAMBO One Departure Area Navigation (RNAV) out of Taylor Airport. The FAA is proposing this action to enhance the safety and management of aircraft operations at Taylor Airport, Taylor, AZ.

  3. Energy transfer in Rayleigh-Taylor instability.

    PubMed

    Cook, Andrew W; Zhou, Ye

    2002-08-01

    The spatial structure and energy budget for Rayleigh-Taylor instability are examined using results from a 512 x 512 x 2040 point direct numerical simulation. The outer-scale Reynolds number of the flow follows a rough t(3) power law and reaches a final value of about 5500. Taylor microscales and Reynolds numbers are plotted to characterize anisotropy in the flow and document progress towards the mixing transition. A mixing parameter is defined which characterizes the relative rates of entrainment and mixing in the flow. The spectrum of each term in the kinetic energy equation is plotted, at regular time intervals, as a function of the inhomogeneous direction and the two-dimensional wave number for the homogeneous directions. The energy spectrum manifests the beginning of an inertial range by the latter stages of the simulation. The production and dissipation spectra become increasingly opposite and separate in wave space as the flow evolves. The transfer spectrum depends strongly on the inhomogeneous direction, with the net transfer being from large to small scales. Energy transfer at the bubble/spike fronts is strictly positive. Extensive cancellation occurs between the pressure and advection terms. The dilatation term produces negligible energy transfer, but its overall effect is to move energy from high to low density regions.

  4. Dynamic Fracture Studies using Sleeved Taylor Specimens

    NASA Astrophysics Data System (ADS)

    Gilmore, Martin; Foster, Joseph, Jr.; Wilson, Leonard L.; Cullis, Ian

    2001-06-01

    The characterization of the inelastic response of materials to high rates of loading is a challenging engineering problem. As the load rate increases, the interpretation of the data recovered from the experiment become more difficult. At very high rates of loading, even the inertia of the test specimen must be accounted for in the interpretation of the data. The Taylor impact experiment is specifically designed to exploit the inertia of the specimen to produce very high loading rates and has been used to study the high strain (50materials for many years. Many high-rate loading problems produce failure in the material. This paper addresses the use of the Taylor impact experiment to study these failures. Continuum codes have been used to design sleeved impact specimens to study the failure of materials under high rates of loading. Ductile core materials are used as drivers to control rupture of more brittle sleeves of the material of interest. Annealed copper cores are used to drive dynamic failure a selection of steels. High rate plastic deformation data is presented for the driver and the sleeve together with the fracture data.

  5. A Taylor vortex analogy in granular flows.

    PubMed

    Conway, Stephen L; Shinbrot, Troy; Glasser, Benjamin J

    2004-09-23

    Fluids sheared between concentric rotating cylinders undergo a series of three-dimensional instabilities. Since Taylor's archetypal 1923 study, these have proved pivotal to understanding how fluid flows become unstable and eventually undergo transitions to chaotic or turbulent states. In contrast, predicting the dynamics of granular systems--from nano-sized particles to debris flows--is far less reliable. Under shear these materials resemble fluids, but solid-like responses, non-equilibrium structures and segregation patterns develop unexpectedly. As a result, the analysis of geophysical events and the performance of largely empirical particle technologies might suffer. Here, using gas fluidization to overcome jamming, we show experimentally that granular materials develop vortices consistent with the primary Taylor instability in fluids. However, the vortices observed in our fluidized granular bed are unlike those in fluids in that they are accompanied by novel mixing-segregation transitions. The vortices seem to alleviate increased strain by spawning new vortices, directly modifying the scale of kinetic interactions. Our observations provide insights into the mechanisms of shear transmission by particles and their consequent convective mixing.

  6. A cosmological Slavnov-Taylor identity

    SciTech Connect

    Collins, Hael; Holman, R.; Vardanyan, Tereza E-mail: rh4a@andrew.cmu.edu

    2014-12-01

    We develop a method for treating the consistency relations of inflation that includes the full time-evolution of the state. This approach relies only on the symmetries of the inflationary setting, in particular a residual conformal symmetry in the spatial part of the metric, along with general properties which hold for any quantum field theory. As a result, the consistency relations that emerge, which are essentially the Slavnov-Taylor identities associated with this residual conformal symmetry, apply very generally: they are true of the full Green's functions, hold largely independently of the particular inflationary model, and can be used for arbitrary states. We illustrate these techniques by showing the form assumed by the standard consistency relation between the two and three-point functions for the primordial scalar fluctuations when they are in a Bunch-Davies state. But because we have included the full evolution of the state, this approach works for a general initial state as well and does not need to have assumed that inflation began in the Bunch-Davies state. We explain how the Slavnov-Taylor identity is modified for these more general states.

  7. SUMO E3 Ligases GmSIZ1a and GmSIZ1b regulate vegetative growth in soybean .

    PubMed

    Cai, Bin; Kong, Xiangxiong; Zhong, Chao; Sun, Suli; Zhou, Xiao Feng; Jin, Yin Hua; Wang, Youning; Li, Xia; Zhu, Zhendong; Jin, Jing Bo

    2017-01-01

    SIZ1 is a small ubiquitin-related modifier (SUMO) E3 ligase that mediates post-translational SUMO modification of target proteins and thereby regulates developmental processes and hormonal and environmental stress responses in Arabidopsis. However, the role of SUMO E3 ligases in crop plants is largely unknown. Here, we identified and characterized two Glycine max (soybean) SUMO E3 ligases, GmSIZ1a and GmSIZ1b. Expression of GmSIZ1a and GmSIZ1b was induced in response to salicylic acid (SA), heat, and dehydration treatment, but not in response to cold, abscisic acid (ABA), and NaCl treatment. Although GmSIZ1a was expressed at higher levels than GmSIZ1b, both genes encoded proteins with SUMO E3 ligase activity in vivo. Heterologous expression of GmSIZ1a or GmSIZ1b rescued the mutant phenotype of Arabidopsis siz1-2, including dwarfism, constitutively activated expression of pathogen-related genes, and ABA-sensitive seed germination. Simultaneous downregulation of GmSIZ1a and GmSIZ1b (GmSIZ1a/b) using RNA interference (RNAi)-mediated gene silencing decreased heat shock-induced SUMO conjugation in soybean. Moreover, GmSIZ1RNAi plants exhibited reduced plant height and leaf size. However, unlike Arabidopsis siz1-2 mutant plants, flowering time and SA levels were not significantly altered in GmSIZ1RNAi plants. Taken together, our results indicate that GmSIZ1a and GmSIZ1b mediate SUMO modification and positively regulate vegetative growth in soybean. © 2016 The Authors. Journal of Integrative Plant Biology Published by John Wiley & Sons Australia, Ltd on behalf of Institute of Botany, Chinese Academy of Sciences.

  8. 15. TURNTABLE RECONSTRUCTION BAY & TAYLOR: Photocopy of January ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. TURNTABLE RECONSTRUCTION - BAY & TAYLOR: Photocopy of January 1941 photograph taken during reconstruction of the Bay and Taylor turntable. View to the south. The 'spider' that carries the actual turntable is in place in the pit. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  9. DSM-5 and ADHD - an interview with Eric Taylor.

    PubMed

    Taylor, Eric

    2013-09-12

    In this podcast we talk to Prof Eric Taylor about the changes to the diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) in DSM-5 and how these changes will affect clinical practice. The podcast for this interview is available at: http://www.biomedcentral.com/sites/2999/download/Taylor.mp3.

  10. G.I. Taylor and the Trinity Test

    ERIC Educational Resources Information Center

    Deakin, Michael A. B.

    2011-01-01

    The story is often told of the calculation by G.I. Taylor of the yield of the first ever atomic bomb exploded in New Mexico in 1945. It has indeed become a staple of the classroom whenever dimensional analysis is taught. However, while it is true that Taylor succeeded in calculating this figure at a time when it was still classified, most versions…

  11. G.I. Taylor and the Trinity Test

    ERIC Educational Resources Information Center

    Deakin, Michael A. B.

    2011-01-01

    The story is often told of the calculation by G.I. Taylor of the yield of the first ever atomic bomb exploded in New Mexico in 1945. It has indeed become a staple of the classroom whenever dimensional analysis is taught. However, while it is true that Taylor succeeded in calculating this figure at a time when it was still classified, most versions…

  12. Animating Nested Taylor Polynomials to Approximate a Function

    ERIC Educational Resources Information Center

    Mazzone, Eric F.; Piper, Bruce R.

    2010-01-01

    The way that Taylor polynomials approximate functions can be demonstrated by moving the center point while keeping the degree fixed. These animations are particularly nice when the Taylor polynomials do not intersect and form a nested family. We prove a result that shows when this nesting occurs. The animations can be shown in class or…

  13. 78 FR 12307 - Taylor, G. Tom; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Taylor, G. Tom; Notice of Filing Take notice that on February 14, 2013, G. Tom Taylor filed an application to hold interlocking positions pursuant to section 305(b) of...

  14. 16. TURNTABLE RECONSTRUCTION BAY & TAYLOR: Photocopy of January ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. TURNTABLE RECONSTRUCTION - BAY & TAYLOR: Photocopy of January 1941 photograph taken during reconstruction of the Bay and Taylor turntable. View to northwest taken two days after CA-12-22. Reconstruction work is nearly complete in this view. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  15. Animating Nested Taylor Polynomials to Approximate a Function

    ERIC Educational Resources Information Center

    Mazzone, Eric F.; Piper, Bruce R.

    2010-01-01

    The way that Taylor polynomials approximate functions can be demonstrated by moving the center point while keeping the degree fixed. These animations are particularly nice when the Taylor polynomials do not intersect and form a nested family. We prove a result that shows when this nesting occurs. The animations can be shown in class or…

  16. The GM2 gangliosidoses databases: allelic variation at the HEXA, HEXB, and GM2A gene loci.

    PubMed

    Cordeiro, P; Hechtman, P; Kaplan, F

    2000-01-01

    The GM2 gangliosidoses are a group of recessive disorders characterized by accumulation of GM2 ganglioside in neuronal cells. The genes responsible for these disorders are HEXA (Tay-Sachs disease and variants), HEXB (Sandhoff disease and variants), and GM2A (AB variant of GM2 gangliosidosis). We report the establishment of three relational locus-specific databases recording allelic variation at the HEXA, HEXB, and GM2A genes and accessed at the GM2 gangliosidoses home page (http://data.mch.mcgill.ca/gm2-gangliosidoses). Submission forms are available for the addition of new mutations to the databases. The databases are available online for users to search and retrieve information about specific alleles by a number of fields describing mutations, phenotypes, or author(s).

  17. String-theoretic deformation of the Parke-Taylor factor

    NASA Astrophysics Data System (ADS)

    Mizera, Sebastian; Zhang, Guojun

    2017-09-01

    Scattering amplitudes in a range of quantum field theories can be computed using the Cachazo-He-Yuan (CHY) formalism. In theories with color ordering, the key ingredient is the so-called Parke-Taylor factor. In this paper we give a fully SL (2 ,C )-covariant definition and study the properties of a new integrand called the "string Parke-Taylor" factor. It has an α' expansion whose leading coefficient is the field-theoretic Parke-Taylor factor. Its main application is that it leads to a CHY formulation of open string tree-level amplitudes. In fact, the definition of the string Parke-Taylor factor was motivated by trying to extend the compact formula for the first α' correction found by He and Zhang, while the main ingredient in its definition is a determinant of a matrix introduced in the context of string theory by Stieberger and Taylor.

  18. Impact of GM crops on biodiversity.

    PubMed

    Carpenter, Janet E

    2011-01-01

    The potential impact of GM crops on biodiversity has been a topic of interest both in general as well as specifically in the context of the Convention on Biological Diversity. Agricultural biodiversity has been defined at levels from genes to ecosystems that are involved or impacted by agricultural production (www.cbd.int/agro/whatis.shtml). After fifteen years of commercial cultivation, a substantial body of literature now exists addressing the potential impacts of GM crops on the environment. This review takes a biodiversity lens to this literature, considering the impacts at three levels: the crop, farm and landscape scales. Within that framework, this review covers potential impacts of the introduction of genetically engineered crops on: crop diversity, biodiversity of wild relatives, non-target soil organisms, weeds, land use, non-target above-ground organisms, and area-wide pest suppression. The emphasis of the review is peer-reviewed literature that presents direct measures of impacts on biodiversity. In addition, possible impacts of changes in management practises such as tillage and pesticide use are also discussed to complement the literature on direct measures. The focus of the review is on technologies that have been commercialized somewhere in the world, while results may emanate from non-adopting countries and regions. Overall, the review finds that currently commercialized GM crops have reduced the impacts of agriculture on biodiversity, through enhanced adoption of conservation tillage practices, reduction of insecticide use and use of more environmentally benign herbicides and increasing yields to alleviate pressure to convert additional land into agricultural use.

  19. Gm and Km allotypes in autoimmune diseases.

    PubMed

    Dugoujon, J M; Guitard, E; Senegas, M T

    1992-01-01

    The associations or linkages between the polymorphisms of the Gm and Km immunoglobulin allotypes and the susceptibility to autoimmune diseases, including diseases with immuno-pathological pathogenesis are reported in this review. These diseases include multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, insulin-dependent diabetes mellitus, Crohn's disease, coeliac disease, Graves' disease, atrophic thyroiditis, Hashimoto's thyroiditis, myasthenia gravis, chronic active hepatitis, alopecia areata, uveitis, vitiligo, Turner's syndrome, glomerular nephritis, Berger's disease and idiopathic dilated cardiomyopathy. Immunoglobulin allotypes are described as well as the statistical methods used to analyse the data.

  20. Rayleigh-Taylor instability in elastic solids

    NASA Astrophysics Data System (ADS)

    Piriz, A. R.; Cela, J. J. López; Cortázar, O. D.; Tahir, N. A.; Hoffmann, D. H. H.

    2005-11-01

    We present an analytical model for the Rayleigh-Taylor instability that allows for an approximate but still very accurate and appealing description of the instability physics in the linear regime. The model is based on the second law of Newton and it has been developed with the aim of dealing with the instability of accelerated elastic solids. It yields the asymptotic instability growth rate but also describes the initial transient phase determined by the initial conditions. We have applied the model to solid/solid and solid/fluid interfaces with arbitrary Atwood numbers. The results are in excellent agreement with previous models that yield exact solutions but which are of more limited validity. Our model allows for including more complex physics. In particular, the present approach is expected to lead to a more general theory of the instability that would allow for describing the transition to the plastic regime.

  1. Reverse Taylor Tests on Ultrafine Grained Copper

    SciTech Connect

    Mishra, A.; Meyers, M. A.; Martin, M.; Thadhani, N. N.; Gregori, F.; Asaro, R. J.

    2006-07-28

    Reverse Taylor impact tests have been carried out on ultrafine grained copper processed by Equal Channel Angular Pressing (ECAP). Tests were conducted on an as-received OFHC Cu rod and specimens that had undergone sequential ECAP passes (2 and 8). The average grain size ranged from 30 {mu}m for the initial sample to less than 0.5 {mu}m for the 8-pass samples. The dynamic deformation states of the samples, captured by high speed digital photography were compared with computer simulations run in AUTODYN-2D using the Johnson-Cook constitutive equation with constants obtained from stress-strain data and by fitting to an experimentally measured free surface velocity trace. The constitutive response of copper of varying grain sizes was obtained through quasistatic and dynamic mechanical tests and incorporation into constitutive models.

  2. From Taylor state to model-Z

    NASA Astrophysics Data System (ADS)

    Braginsky, Stanislav I.; Roberts, Paul H.

    This is a sequel to an earlier paper [Roberts, Geophys. Astrophys. Fluid Dynam. v. 49, p. 143 (1989)] in which one of us claimed, on the basis of two sequences of integrations of a particular intermediate model of the geodynamo, that, as the dynamo number increases, a smooth transition occurs from Taylor-like behavior to model-Z-type behavior. A more complete survey of parameter space for this model is presented here which tends to corroborate this conclusion. Also, the relationship provided by this model between the external dipole moment of the field and the heat flux from the core is examined. The asymptotic dependence of solutions in the large dynamo number limit is considered.

  3. New Trends in Taylor Series Based Computations

    NASA Astrophysics Data System (ADS)

    Kunovský, Jiří; Kraus, Michal; Šátek, Václav

    2009-09-01

    Motto: For the derivatives of all decent functions analytic formulas can be found but with integration this is only true for very special decent functions. The aim of our paper is to describe a new modern numerical method based on the Taylor Series Method and to show how to evaluate the high accuracy and speed of the corresponding computations. It is also the aim of our paper to show how to calculate finite integrals that are the fundamental part in signal processing, especially in Fourier analysis and how to use it for symbolic operations. It is a fact that the accuracy and stability of the algorithms we have designed significantly exceeds the presently known systems. In particular, the paper wants to concentrate, using the previous results and latest development trends, on the simulation of dynamic systems and on extremely exact mathematical computations.

  4. Curvature suppresses the Rayleigh-Taylor instability

    DOE PAGES

    Trinh, Philippe H.; Kim, Hyoungsoo; Hammoud, Naima; ...

    2014-05-20

    We studied the dynamics of a thin liquid film on the underside of a curved cylindrical substrate. The evolution of the liquid layer is investigated as the film thickness and the radius of curvature of the substrate are varied. A dimensionless parameter (a modified Bond number) that incorporates both geometric parameters, gravity, and surface tension is identified, and allows the observations to be classified according to three different flow regimes: stable films, films with transient growth of perturbations followed by decay, and unstable films. We found that the experiments and theory confirm that, below a critical value of the Bondmore » number, curvature of the substrate suppresses the Rayleigh-Taylor instability.« less

  5. Dynamo transition under Taylor-Green forcing

    NASA Astrophysics Data System (ADS)

    Yadav, R.; Chandra, M.; Verma, M. K.; Paul, S.; Wahi, P.

    2010-09-01

    We perform pseudo-spectral simulations of the Taylor-Green dynamo for magnetic Prandtl number of one and produce a bifurcation diagram near the dynamo transition. We observe that the primary dynamo transition is through a supercritical pitchfork bifurcation. We show that the planar magnetic structures near the dynamo transition are due to the emergence of the B(0, 0, 1) and B(0, 0, 2) magnetic Fourier modes, which are born as a result of triadic interactions. Near the transition, the kinetic energy (Eu) and the magnetic energy (Eb) grow linearly with the forcing amplitude F0 with the same slope. The ratio Eb/Eu for F0=[0, 40] ranges from 0 to 3. Beyond the transition, the numerical simulations reveal complex dynamo states with windows of constant, periodic, quasiperiodic, and chaotic magnetic field configurations.

  6. Rayleigh-Taylor instability in elastic solids.

    PubMed

    Piriz, A R; Cela, J J López; Cortázar, O D; Tahir, N A; Hoffmann, D H H

    2005-11-01

    We present an analytical model for the Rayleigh-Taylor instability that allows for an approximate but still very accurate and appealing description of the instability physics in the linear regime. The model is based on the second law of Newton and it has been developed with the aim of dealing with the instability of accelerated elastic solids. It yields the asymptotic instability growth rate but also describes the initial transient phase determined by the initial conditions. We have applied the model to solid/solid and solid/fluid interfaces with arbitrary Atwood numbers. The results are in excellent agreement with previous models that yield exact solutions but which are of more limited validity. Our model allows for including more complex physics. In particular, the present approach is expected to lead to a more general theory of the instability that would allow for describing the transition to the plastic regime.

  7. Small Atwood number Rayleigh-Taylor experiments.

    PubMed

    Andrews, Malcolm J; Dalziel, Stuart B

    2010-04-13

    Consideration is given to small Atwood number (non-dimensional density difference) experiments to investigate mixing driven by Rayleigh-Taylor (R-T) instability. The past 20 years have seen the development of novel experiments to investigate R-T mixing and, simultaneously, the advent of high-fidelity diagnostics. Indeed, the developments of experiments and diagnostics have gone hand in hand, and as a result modern R-T experiments rival the capabilities and research scope of shear-driven mixing experiments. Thus, research into the small Atwood number limit has made significant progress over the past 20 years, and has offered important insights into natural mixing processes as well as the general R-T problem. This review of small Atwood number experiments serves as an opportunity to discuss progress, and also to provoke thoughts about future high Atwood number designs and difficulties.

  8. Anelastic Rayleigh-Taylor mixing layers

    NASA Astrophysics Data System (ADS)

    Schneider, N.; Gauthier, S.

    2016-07-01

    Anelastic Rayleigh-Taylor mixing layers for miscible fluids are investigated with a recently built model (Schneider and Gauthier 2015 J. Eng. Math. 92 55-71). Four Chebyshev-Fourier-Fourier direct numerical simulations are analyzed. They use different values for the compressibility parameters: Atwood number (the dimensionless difference of the heavy and light fluid densities) and stratification (accounts for the vertical variation of density due to gravity). For intermediate Atwood numbers and finite stratification, compressibility effects quickly occurs. As a result only nonlinear behaviours are reached. The influence of the compressibility parameters on the growth speed of the RTI is discussed. The 0.1—Atwood number/0.4—stratification configuration reaches a turbulent regime. This turbulent mixing layer is analyzed with statistical tools such as moments, PDFs, anisotropy indicators and spectra.

  9. Classical Rayleigh Taylor experiments on Nova

    SciTech Connect

    Budil, K.S.; Remington, B.A.; Peyser, T.A.

    1995-07-01

    The evolution of the Rayleigh-Taylor (RT) instability in a compressible medium was investigated both at an accelerating embedded interface and at the ablation front in a new series of experiments on Nova. The x-ray drive generated in a hohlraum ablatively accelerated a planar target consisting of a doped plastic pusher which was in some cases backed by a higher density titanium payload. Both target types were diagnosed by face-on and side-on radiography. Experiments have been done with a variety of wavelengths and initial amplitudes. In the case where the perturbed RT-unstable embedded interface is isolated from the ablation front, short wavelength perturbations are observed to grow strongly. When the perturbation is at the ablation front, the short wavelengths are observed to be severely stabilized.

  10. Aluminum Rayleigh Taylor Strength Measurements and Calculations

    SciTech Connect

    Lindquist, M J; Cavallo, R M; Lorenz, K T; Pollaine, S M; Remington, B A; Raevsky, V A

    2007-01-10

    A traditional approach to the study of material strength has been revitalized at the Russian Federal Nuclear Center (VNIIEF). Rayleigh Taylor strength experiments have long been utilized to measure the material response of metals at high pressure and strain rates. A modulated (sinusoidal or sawtooth perturbation) surface is shocklessly (quasi-isentropically) accelerated by a high explosive (HE) driver, and radiography is used to measure the perturbation amplitude as a function of time. The Aluminum T-6061 targets are designed with several sets of two-dimensional sawtooth perturbations machined on the loading surface. The HE driver was designed to reach peak pressures in the range of 200 to 300 kbar and strain rates in the range of 10{sup 4} - 10{sup 6} s{sup -1}. The standard constitutive strength models, Steinberg-Guinan (SG) [1], Steinberg-Lund (SL) [2], Preston-Tonks-Wallace (PTW) [3], Johnson-Cooke (JC) [4], and Mechanical Threshold Stress (MTS) [5], have been calibrated by traditional techniques: (Hopkinson-Bar, Taylor impact, flyer plate/shock-driven experiments). The VNIIEF experimental series accesses a strain rate regime not attainable using traditional methods. We have performed a detailed numerical study with a two-dimensional Arbitrary Lagrangian Eulerian hydrodynamics computer code containing several constitutive strength models to predict the perturbation growth. Results show that the capabilities of the computational methodology predict the amplitude growth to within 5 percent of the measured data, thus validating both the code and the strength models under the given conditions and setting the stage for credible future design work using different materials.

  11. Physiopathological function of hematoside (GM3 ganglioside)

    PubMed Central

    INOKUCHI, Jin-ichi

    2011-01-01

    Since I was involved in the molecular cloning of GM3 synthase (SAT-I), which is the primary enzyme for the biosynthesis of gangliosides in 1998, my research group has been concentrating on our efforts to explore the physiological and pathological implications of gangliosides especially for GM3. During the course of study, we demonstrated the molecular pathogenesis of type 2 diabetes and insulin resistance focusing on the interaction between insulin receptor and gangliosides in membrane microdomains and propose a new concept: Life style-related diseases, such as type 2 diabetes, are a membrane microdomain disorder caused by aberrant expression of gangliosides. We also encountered an another interesting aspect indicating the indispensable role of gangliosides in auditory system. After careful behavioral examinations of SAT-I knockout mice, their hearing ability was seriously impaired with selective degeneration of the stereocilia of hair cells in the organ of Corti. This is the first observation demonstrating a direct link between gangliosides and hearing functions. PMID:21558756

  12. Genome edited animals: Learning from GM crops?

    PubMed

    Bruce, Ann

    2017-06-01

    Genome editing of livestock is poised to become commercial reality, yet questions remain as to appropriate regulation, potential impact on the industry sector and public acceptability of products. This paper looks at how genome editing of livestock has attempted to learn some of the lessons from commercialisation of GM crops, and takes a systemic approach to explore some of the complexity and ambiguity in incorporating genome edited animals in a food production system. Current applications of genome editing are considered, viewed from the perspective of past technological applications. The question of what is genome editing, and can it be considered natural is examined. The implications of regulation on development of different sectors of livestock production systems are studied, with a particular focus on the veterinary sector. From an EU perspective, regulation of genome edited animals, although not necessarily the same as for GM crops, is advocated from a number of different perspectives. This paper aims to open up new avenues of research on genome edited animals, extending from the current primary focus on science and regulation, to engage with a wider-range of food system actors.

  13. Functional analysis of structurally related soybean GmWRKY58 and GmWRKY76 in plant growth and development

    PubMed Central

    Yang, Yan; Chi, Yingjun; Wang, Ze; Zhou, Yuan; Fan, Baofang; Chen, Zhixiang

    2016-01-01

    WRKY transcription factors constitute a large protein superfamily with a predominant role in plant stress responses. In this study we report that two structurally related soybean WRKY proteins, GmWRKY58 and GmWRKY76, play a critical role in plant growth and flowering. GmWRKY58 and GmWRKY76 are both Group III WRKY proteins with a C2HC zinc finger domain and are close homologs of AtWRKY70 and AtWRKY54, two well-characterized Arabidopsis WRKY proteins with an important role in plant responses to biotic and abiotic stresses. GmWRKY58 and GmWRKY76 are both localized to the nucleus, recognize the TTGACC W-box sequence with a high specificity, and function as transcriptional activators in both yeast and plant cells. Expression of GmWRKY58 and GmWRKY76 was detected at low levels in roots, stem, leaves, flowers, and pods. Expression of the two genes in leaves increased substantially during the first 4 weeks after germination but steadily declined thereafter with increased age. To determine their biological functions, transgenic Arabidopsis plants were generated overexpressing GmWRKY58 or GmWRKY76. Unlike AtWRKY70 and AtWRKY54, overexpression of GmWRKY58 or GmWRKY76 had no effect on disease resistance and only small effects on abiotic stress tolerance of the transgenic plants. Significantly, transgenic Arabidopsis plants overexpressing GmWRKY58 or GmWRKY76 flowered substantially earlier than control plants and this early flowering phenotype was associated with increased expression of several flowering-promoting genes, some of which are enriched in W-box sequences in their promoters recognized by GmWRKY58 and GmWRKY76. In addition, virus-induced silencing of GmWRKY58 and GmWRKY76 in soybean resulted in stunted plants with reduced leaf expansion and terminated stem growth. These results provide strong evidence for functional divergence among close structural homologs of WRKY proteins from different plant species. PMID:27335454

  14. Functional analysis of structurally related soybean GmWRKY58 and GmWRKY76 in plant growth and development.

    PubMed

    Yang, Yan; Chi, Yingjun; Wang, Ze; Zhou, Yuan; Fan, Baofang; Chen, Zhixiang

    2016-08-01

    WRKY transcription factors constitute a large protein superfamily with a predominant role in plant stress responses. In this study we report that two structurally related soybean WRKY proteins, GmWRKY58 and GmWRKY76, play a critical role in plant growth and flowering. GmWRKY58 and GmWRKY76 are both Group III WRKY proteins with a C2HC zinc finger domain and are close homologs of AtWRKY70 and AtWRKY54, two well-characterized Arabidopsis WRKY proteins with an important role in plant responses to biotic and abiotic stresses. GmWRKY58 and GmWRKY76 are both localized to the nucleus, recognize the TTGACC W-box sequence with a high specificity, and function as transcriptional activators in both yeast and plant cells. Expression of GmWRKY58 and GmWRKY76 was detected at low levels in roots, stem, leaves, flowers, and pods. Expression of the two genes in leaves increased substantially during the first 4 weeks after germination but steadily declined thereafter with increased age. To determine their biological functions, transgenic Arabidopsis plants were generated overexpressing GmWRKY58 or GmWRKY76 Unlike AtWRKY70 and AtWRKY54, overexpression of GmWRKY58 or GmWRKY76 had no effect on disease resistance and only small effects on abiotic stress tolerance of the transgenic plants. Significantly, transgenic Arabidopsis plants overexpressing GmWRKY58 or GmWRKY76 flowered substantially earlier than control plants and this early flowering phenotype was associated with increased expression of several flowering-promoting genes, some of which are enriched in W-box sequences in their promoters recognized by GmWRKY58 and GmWRKY76. In addition, virus-induced silencing of GmWRKY58 and GmWRKY76 in soybean resulted in stunted plants with reduced leaf expansion and terminated stem growth. These results provide strong evidence for functional divergence among close structural homologs of WRKY proteins from different plant species. © The Author 2016. Published by Oxford University Press on

  15. Extensive Analysis of GmFTL and GmCOL Expression in Northern Soybean Cultivars in Field Conditions

    PubMed Central

    Zhu, Jinlong; Lu, Mingyang; Chen, Fulu; Liu, Linpo; Xi, Zhang-Ying; Bachmair, Andreas; Chen, Qingshan; Fu, Yong-Fu

    2015-01-01

    The FLOWERING LOCUS T (FT) gene is a highly conserved florigen gene among flowering plants. Soybean genome encodes six homologs of FT, which display flowering activity in Arabidopsis thaliana. However, their contributions to flowering time in different soybean cultivars, especially in field conditions, are unclear. We employed six soybean cultivars with different maturities to extensively investigate expression patterns of GmFTLs (Glycine max FT-like) and GmCOLs (Glycine max CO-like) in the field conditions. The results show that GmFTL3 is an FT homolog with the highest transcript abundance in soybean, but other GmFTLs may also contribute to flower induction with different extents, because they have more or less similar expression patterns in developmental-, leaf-, and circadian-specific modes. And four GmCOL genes (GmCOL1/2/5/13) may confer to the expression of GmFTL genes. Artificial manipulation of GmFTL expression by transgenic strategy (overexpression and RNAi) results in a distinct change in soybean flowering time, indicating that GmFTLs not only impact on the control of flowering time, but have potential applications in the manipulation of photoperiodic adaptation in soybean. Additionally, transgenic plants show that GmFTLs play a role in formation of the first flowers and in vegetative growth. PMID:26371882

  16. Pivotal Roles of GM-CSF in Autoimmunity and Inflammation

    PubMed Central

    Shiomi, Aoi; Usui, Takashi

    2015-01-01

    Granulocyte macrophage-colony stimulating factor (GM-CSF) is a hematopoietic growth factor, which stimulates the proliferation of granulocytes and macrophages from bone marrow precursor cells. In autoimmune and inflammatory diseases, Th17 cells have been considered as strong inducers of tissue inflammation. However, recent evidence indicates that GM-CSF has prominent proinflammatory functions and that this growth factor (not IL-17) is critical for the pathogenicity of CD4+ T cells. Therefore, the mechanism of GM-CSF-producing CD4+ T cell differentiation and the role of GM-CSF in the development of autoimmune and inflammatory diseases are gaining increasing attention. This review summarizes the latest knowledge of GM-CSF and its relationship with autoimmune and inflammatory diseases. The potential therapies targeting GM-CSF as well as their possible side effects have also been addressed in this review. PMID:25838639

  17. Impairment of neuropsychological behaviors in ganglioside GM3-knockout mice.

    PubMed

    Niimi, Kimie; Nishioka, Chieko; Miyamoto, Tomomi; Takahashi, Eiki; Miyoshi, Ichiro; Itakura, Chitoshi; Yamashita, Tadashi

    2011-03-25

    The ganglioside GM3 synthase (SAT-I), encoded by a single-copy gene, is a primary glycosyltransferase for the synthesis of complex gangliosides. Although its expression is tightly controlled during early embryo development and postnatal development and maturation in the brain, the physiological role of ganglioside GM3 in the regulation of neuronal functions has not been elucidated. In the present study, we examined motor activity, cognitive and emotional behaviors, and drug administration in juvenile GM3-knockout (GM3-KO) mice. GM3-KO male and female mice showed hyperactivity in the motor activity test, Y-maze test, and elevated plus maze test. In the Y-maze test, there was significantly less spontaneous alternation behavior in GM3-KO male mice than in wild-type mice. In the elevated plus maze test, the amount of time spent on the open arms by GM3-KO male mice was significantly higher than that of sex-matched wild-type mice. In contrast, there was no significant difference between GM3-KO and wild-type female mice in these tests. Thus, juvenile GM3-KO mice show gender-specific phenotypes resembling attention-deficit hyperactivity disorder (ADHD), namely hyperactivity, reduced attention, and increased impulsive behaviors. However, administration of methylphenidate hydrochloride (MPH) did not ameliorate hyperactivity in either male or female GM3-KO mice. Although these data demonstrate the involvement of ganglioside GM3 in ADHD and the ineffectiveness of MPH, the first-choice psychostimulant for ADHD medication, our studies indicate that juvenile GM3-KO mice are a useful tool for neuropsychological studies. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Immunoglobulin G heavy chain (Gm) allotypes in multiple sclerosis.

    PubMed Central

    Pandey, J P; Goust, J M; Salier, J P; Fudenberg, H H

    1981-01-01

    Serum samples from 70 Caucasian patients with multiple sclerosis were typed for nine Gm markers. Significant association was found with the Gm 1,17;21 phenotype, and the relative risk for individuals with this phenotype was calculated at 3.6. The data indicate that Caucasians positive for Gm 1,17;21 are almost four times more likely to develop multiple sclerosis than those without this phenotype. PMID:6787085

  19. Immunoglobulin G heavy chain (Gm) allotypes in multiple sclerosis.

    PubMed

    Pandey, J P; Goust, J M; Salier, J P; Fudenberg, H H

    1981-06-01

    Serum samples from 70 Caucasian patients with multiple sclerosis were typed for nine Gm markers. Significant association was found with the Gm 1,17;21 phenotype, and the relative risk for individuals with this phenotype was calculated at 3.6. The data indicate that Caucasians positive for Gm 1,17;21 are almost four times more likely to develop multiple sclerosis than those without this phenotype.

  20. Characterization of pathogenic human monoclonal autoantibodies against GM-CSF

    PubMed Central

    Wang, Yanni; Thomson, Christy A.; Allan, Lenka L.; Jackson, Linda M.; Olson, Melanie; Hercus, Timothy R.; Nero, Tracy L.; Turner, Amanda; Parker, Michael W.; Lopez, Angel L.; Waddell, Thomas K.; Anderson, Gary P.; Hamilton, John A.; Schrader, John W.

    2013-01-01

    The origin of pathogenic autoantibodies remains unknown. Idiopathic pulmonary alveolar proteinosis is caused by autoantibodies against granulocyte–macrophage colony-stimulating factor (GM-CSF). We generated 19 monoclonal autoantibodies against GM-CSF from six patients with idiopathic pulmonary alveolar proteinosis. The autoantibodies used multiple V genes, excluding preferred V-gene use as an etiology, and targeted at least four nonoverlapping epitopes on GM-CSF, suggesting that GM-CSF is driving the autoantibodies and not a B-cell epitope on a pathogen cross-reacting with GM-CSF. The number of somatic mutations in the autoantibodies suggests that the memory B cells have been helped by T cells and re-entered germinal centers. All autoantibodies neutralized GM-CSF bioactivity, with general correlations to affinity and off-rate. The binding of certain autoantibodies was changed by point mutations in GM-CSF that reduced binding to the GM-CSF receptor. Those monoclonal autoantibodies that potently neutralize GM-CSF may be useful in treating inflammatory disease, such as rheumatoid arthritis and multiple sclerosis, cancer, and pain. PMID:23620516

  1. Univariate approximate integration via nested Taylor multivariate function decomposition

    NASA Astrophysics Data System (ADS)

    Gürvit, Ercan; Baykara, N. A.

    2014-12-01

    This work is based on the idea of nesting one or more Taylor decompositions in the remainder term of a Taylor decomposition of a function. This provides us with a better approximation quality to the original function. In addition to this basic idea each side of the Taylor decomposition is integrated and the limits of integrations are arranged in such a way to obtain a universal [0;1] interval without losing from the generality. Thus a univariate approximate integration technique is formed at the cost of getting multivariance in the remainder term. Moreover the remainder term expressed as an integral permits us to apply Fluctuationlessness theorem to it and obtain better results.

  2. Correction of deformities in children using the Taylor spatial frame.

    PubMed

    Eidelman, Mark; Bialik, Viktor; Katzman, Alexander

    2006-11-01

    The Taylor spatial frame is a unique external fixator. Despite its growing popularity, few reports on its use have been published. We evaluated the effectiveness of the Taylor spatial frame in the treatment of various deformities in 31 children and adolescents. All but one patient were anatomically corrected. Complications included superficial pin tract infection (45%), three fractures of the femoral regenerate, transient peroneal palsy, and injury to the genicular artery. Despite many challenging problems, our results compared favorably with the results achieved by others. We believe that the Taylor spatial frame is a very capable and accurate fixator for the precise correction of complex deformities.

  3. Taylor dispersion of colloidal particles in narrow channels

    NASA Astrophysics Data System (ADS)

    Sané, Jimaan; Padding, Johan T.; Louis, Ard A.

    2015-09-01

    We use a mesoscopic particle-based simulation technique to study the classic convection-diffusion problem of Taylor dispersion for colloidal discs in confined flow. When the disc diameter becomes non-negligible compared to the diameter of the pipe, there are important corrections to the original Taylor picture. For example, the colloids can flow more rapidly than the underlying fluid, and their Taylor dispersion coefficient is decreased. For narrow pipes, there are also further hydrodynamic wall effects. The long-time tails in the velocity autocorrelation functions are altered by the Poiseuille flow.

  4. Forecasting the Feasibility of Implementing Isolation Perimeters Between GM and non-GM Maize Fields Under Agricultural Conditions

    NASA Astrophysics Data System (ADS)

    Devos, Yann; Cougnon, Mathias; Thas, Olivier; De Clercq, Eva M.; Cordemans, Karl; Reheul, Dirk

    2008-10-01

    Although spatially isolating genetically modified (GM) maize fields from non-GM maize fields is a robust on-farm strategy to keep the adventitious presence of GM material in the harvests of neighboring non-GM maize fields due to cross-fertilizations below established labeling thresholds (and thus to ensure the spatial co-existence between maize cropping systems), the practical implementation of isolation perimeters attracted little research efforts. In this study, the feasibility of implementing isolation perimeters around GM maize fields is investigated. Using Geographic Information System datasets and Monte Carlo simulations, various scenarios differing in shares and spatial distributions of GM maize were tested for various isolation perimeters in six agricultural areas in Flanders. Factors that affect the feasibility of implementing isolation perimeters are discussed.

  5. Taylor Expansion Method for Paleosecular Variation

    NASA Astrophysics Data System (ADS)

    Kono, M.

    2004-12-01

    Constable and Parker (1988) first suggested that auss coefficients can be treated as independent normal random variables with variances depending only on the degree. Kono et al. (2000) and Kono and Roberts (2002) demonstrated that this postulate is well satisfied in the long time behavior of various numerical dynamo models. However, significant deviations from the original model of Constable and Parker were also found by the analysis of the paleomagnetic data of the last 5 Ma; most notably the large amplitude in the fluctuation of the (2,1) harmonic. In order to express these facts better, Kono and Tanaka (1995) developed Taylor expansion method. But its performance was not satisfactory enough because the approximation used in the calculation was only up to the second order. This paper presents the Taylor expansion method extended to arbitrarily high approximation. We assume that the long term behavior of the geomagnetic field can be modeled as the sum of two parts; the mean field and the fluctuation m=μ +Δ m, where all the elements of Δ m, mj, are zero-mean normal variates with the variance σ j2. The mean value of a nonlinear quantity can be obtained by averaging the Taylor series about the mean model, with summation rules such as E[Δ mjΔ mk] = σ j2δ jk, etc. Summation of the series to high orders is made possible because the nonlinear quantities (or their first derivatives with respect to a Gauss coefficient) used in paleomagnetism (inclination I, declination D, virtual geomagnetic pole (VGP) position θ p, φ p, etc.) can be expressed as the product of the linear quantities and nonlinear quantities such as the total intensity F. These nonlinear quantities can always be expressed as the square root of the sum of squared linear quantities (e.g., F = √ {X2+Y^2+Z^2}). Because of this property, the general form of the derivatives of nonlinear quantities can be written down in a form that is convenient for calculation using the computers. The assumption of

  6. TALE nucleases and next generation GM crops.

    PubMed

    Mahfouz, Magdy M; Li, Lixin

    2011-01-01

    Site-specific and adaptable DNA binding domains are essential modules to develop genome engineering technologies for crop improvement. Transcription activator-like effectors (TALEs) proteins are used to provide a highly specific and adaptable DNA binding modules. TALE chimeric nucleases (TALENs) were used to generate site-specific double strand breaks (DSBs) in vitro and in yeast, Caenorhabditis elegans, mammalian and plant cells. The genomic DSBs can be generated at predefined and user-selected loci and repaired by either the non-homologous end joining (NHEJ) or homology dependent repair (HDR). Thus, TALENs can be used to achieve site-specific gene addition, stacking, deletion or inactivation. TALE-based genome engineering tools should be powerful to develop new agricultural biotechnology approaches for crop improvement. Here, we discuss the recent research and the potential applications of TALENs to accelerate the generation of genomic variants through targeted mutagenesis and to produce a non-transgenic GM crops with the desired phenotype.

  7. GmTIR1/GmAFB3-based auxin perception regulated by miR393 modulates soybean nodulation.

    PubMed

    Cai, Zhaoming; Wang, Youning; Zhu, Lin; Tian, Yinping; Chen, Liang; Sun, Zhengxi; Ullah, Ihteram; Li, Xia

    2017-07-01

    Auxins play important roles in the nodulation of legumes. However, the mechanism by which auxin signaling regulates root nodulation is largely unknown. In particular, the role of auxin receptors and their regulation in determinate nodule development remains elusive. We checked the expression pattern of the auxin receptor GmTIR1/GmAFB3 genes in soybean. We analyzed the functions of GmTIR1/AFB3 in the regulation of rhizobial infection and nodule number, and also tested the functions of miR393 during nodulation and its relationship with GmTIR1/AFB3. The results showed that GmTIR1 and GmAFB3 genes exhibit diverse expression patterns during nodulation and overexpression of GmTIR1 genes significantly increased inflection foci and eventual nodule number. GmTIR1/AFB3 genes were post-transcriptionally cleaved by miR393 family and knock-down of the miR393 family members significantly increased rhizobial infection and the nodule number. Overexpression of the mutated form of GmTIR1C at the miR393 cleavage site that is resistant to miR393 cleavage led to a further increase in the number of infection foci and nodules, suggesting that miR393s modulate nodulation by directly targeting GmTIR1C. This study demonstrated that GmTIR1- and GmAFB3-mediated auxin signaling, that is spatio-temporally regulated by miR393, plays a crucial role in determinate nodule development in soybean. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  8. Presence of an unusual GM2 derivative, taurine-conjugated GM2, in Tay-Sachs brain.

    PubMed

    Li, Yu-Teh; Maskos, Karol; Chou, Chau-Wen; Cole, Richard B; Li, Su-Chen

    2003-09-12

    Tay-Sachs disease (TSD) is a classical glycosphingolipid (GSL) storage disease. Although the genetic and biochemical bases for a massive cerebral accumulation of ganglioside GM2 in TSD have been well established, the mechanism for the neural dysfunction in TSD remains elusive. Upon analysis of GSLs from a variant B TS brain, we have detected a novel GSL that has not been previously revealed. We have isolated this GSL in pure form. Using NMR spectroscopy, mass spectrometry, and chemical synthesis, the structure of this unusual GSL was established to be a taurine-conjugated GM2 (tauro-GM2) in which the carboxyl group of N-acetylneuraminic acid was amidated by taurine. Using a rabbit anti-tauro-GM2 serum, we also detected the presence of tauro-GM2 in three other small brain samples from one variant B and two variant O TSD patients. On the other hand, tauro-GM2 was not found in three normal human brain samples. The presence of tauro-GM2 in TS brains, but not in normal brains, indicates the possible association of this unusual GM2 derivative with the pathogenesis of TSD. Our findings point to taurine conjugation as a heretofore unelucidated mechanism for TS brain to cope with water-insoluble GM2.

  9. GM2-ganglioside metabolism in hexosaminidase A deficiency states: determination in situ using labeled GM2 added to fibroblast cultures

    SciTech Connect

    Raghavan, S.S.; Krusell, A.; Krusell, J.; Lyerla, T.A.; Kolodny, E.H.

    1985-11-01

    To clarify the relationship between hexosaminidase A (HEX A) activity and GM2-ganglioside hydrolysis in atypical clinical situations of HEX A deficiency, we have developed a simple method to assess GM2-ganglioside metabolism in cultured fibroblasts utilizing GM2 labeled with tritium in the sphingosine portion of the molecule. The radioactive lipid is added to the media of cultured skin fibroblasts, and after 10 days the cells are thoroughly washed, then harvested, and their lipid composition analyzed by HPLC. The degree of hydrolysis of the ingested GM2 is determined by comparing the amount of radioactive counts recovered in undegraded substrate with total cellular radioactivity. A deficiency in GM2-ganglioside hydrolysis was demonstrated in seven HEX A-deficient adults with neurological signs and in two healthy-appearing adolescents with older affected siblings. In each case, an analysis of endogenous monosialoganglioside composition revealed an increase in GM2-ganglioside, confirming the presence of a block in the metabolism of GM2. No defect in GM2-catabolism was found in four other healthy individuals with HEX A deficiency. This method of assay is especially helpful in the evaluation of atypical cases of HEX A deficiency for the definitive diagnosis of GM2-gangliosidosis.

  10. GM2-ganglioside metabolism in hexosaminidase A deficiency states: determination in situ using labeled GM2 added to fibroblast cultures.

    PubMed Central

    Raghavan, S S; Krusell, A; Krusell, J; Lyerla, T A; Kolodny, E H

    1985-01-01

    To clarify the relationship between hexosaminidase A (HEX A) activity and GM2-ganglioside hydrolysis in atypical clinical situations of HEX A deficiency, we have developed a simple method to assess GM2-ganglioside metabolism in cultured fibroblasts utilizing GM2 labeled with tritium in the sphingosine portion of the molecule. The radioactive lipid is added to the media of cultured skin fibroblasts, and after 10 days the cells are thoroughly washed, then harvested, and their lipid composition analyzed by HPLC. The degree of hydrolysis of the ingested GM2 is determined by comparing the amount of radioactive counts recovered in undegraded substrate with total cellular radioactivity. A deficiency in GM2-ganglioside hydrolysis was demonstrated in seven HEX A-deficient adults with neurological signs and in two healthy-appearing adolescents with older affected siblings. In each case, an analysis of endogenous monosialoganglioside composition revealed an increase in GM2-ganglioside, confirming the presence of a block in the metabolism of GM2. No defect in GM2-catabolism was found in four other healthy individuals with HEX A deficiency. This method of assay is especially helpful in the evaluation of atypical cases of HEX A deficiency for the definitive diagnosis of GM2-gangliosidosis. Images Fig. 1 PMID:2934978

  11. The New Taylorism: Hacking at the Philosophy of the University's End

    ERIC Educational Resources Information Center

    Goodman, Robin Truth

    2012-01-01

    This article looks at the critical writings of Mark C. Taylor. It suggests that Mark C. Taylor is rewriting a global imaginary devoid of the kind of citizenship that Henry Giroux claims as the basis for public education. Instead, Taylor wants to see the university take shape as profit-generating. According to Taylor, in lieu of learning to take…

  12. The New Taylorism: Hacking at the Philosophy of the University's End

    ERIC Educational Resources Information Center

    Goodman, Robin Truth

    2012-01-01

    This article looks at the critical writings of Mark C. Taylor. It suggests that Mark C. Taylor is rewriting a global imaginary devoid of the kind of citizenship that Henry Giroux claims as the basis for public education. Instead, Taylor wants to see the university take shape as profit-generating. According to Taylor, in lieu of learning to take…

  13. ChuckTaylor: Principal Investigator, Game Changing Development Program

    NASA Image and Video Library

    Charles (Chuck) Taylor is the Principal Investigator in the Space Technology's Game Changing Development Program for 3 major projects:Solar Electric Propulsion, Ride The Light (RTL), and Space Powe...

  14. McMurdo LTER: streamflow measurements in Taylor Valley

    USGS Publications Warehouse

    McKnight, D.; House, H.; Von Guerard, P.

    1994-01-01

    Has established a stream gaging network for the three major lake basins in Taylor Valley. These data are critical for determining nutrient budgets for the lake ecosystems and for understanding physical factors controlling microbial mats in the streams.

  15. The Spirit and Action of Citizenship: Alex Taylor Community School.

    ERIC Educational Resources Information Center

    Haggerson, Nelson L.; And Others

    1987-01-01

    Describes a study of the prosocial atmosphere and citizenship spirit found at Alex Taylor Community School in Edmonton, Canada. Includes a brief background of the project and a description of several motivating citizenship activities within the school. (BSR)

  16. Mixing in Rayleigh-Taylor Instabilities

    NASA Astrophysics Data System (ADS)

    Calder, A. C.; Fryxell, B.; Rosner, R.; Dursi, L. J.; Olson, K.; Ricker, P. M.; Timmes, F. X.; Zingale, M.; Tufo, H. M.; MacNeice, P.

    2000-12-01

    Fluid instabilities and subsequent mixing can play a fundamental role in many astrophysical processes, including the shock of a core-collapse supernova propagating through the outer layers of a massive star and the propagation of a burning front through a white dwarf in a thermonuclear runaway supernova. We present direct numerical simulations of mixing at Rayleigh-Taylor unstable interfaces performed with the Flash code, developed at the ASCI/Alliances Center for Astrophysical Thermonuclear Flashes at the University of Chicago. We present results of both single- and multi-mode studies in 2- and 3-dimensions. Our results indicate that 3-d perturbations grow significantly faster than 2-d perturbations and that grid resolution can have a significant effect on instability growth rates. We also find that unphysical diffusive mixing occurs at the fluid interface, particularly in poorly resolved simulations, making it difficult to maintain the purity of our fluids. This work was supported by the U.S Department of Energy under grant No. B341495.

  17. Numerical Simulation of Taylor Cone-Jet

    NASA Astrophysics Data System (ADS)

    Toledo, Ronne

    The Taylor cone-jet is a particular type of electrohydrodynamic phenomenon where electrostatic stresses and surface tension effects shape the interface of the jet in a peculiar conical shape. A thin jet is issued from the cone apex that further breaks up into a fine aerosol. Due to its monodispersive properties, this fine aerosol has found a number of applications, ranging from mass spectrometry, colloidal space propulsion, combustion, nano-fabrication, coating/painting, and many others. In this study, a general non-dimensional analysis is performed to derive the governing equations and boundary conditions. In accordance with the observations of Gamero-Castano (2010), noting that droplet electric potential is insensitive to the flow rate conditions, a particular set of characteristic parameters is proposed, based on the terminal jet diameter. In order to solve the non-dimensional set of governing equations and boundary conditions, a numerical method combining the Boundary Element Method and the Finite Volume Method is developed. Results of electric current have shown good agreement with numerical and experimental data available in the literature. The main feature of the algorithm developed is related to the decoupling of the electrostatic from the hydrodynamic problem, allowing us to accurately prescribe the far field electric potential boundary conditions away from the hydrodynamic computational domain used to solve the hydrodynamics of the transition region near the cone apex.

  18. Janet Taylor Spence (1923-2015).

    PubMed

    Deaux, Kay

    2016-01-01

    The long and remarkable life of Janet Taylor Spence, the sixth woman to serve as president of the American Psychological Association (APA), ended on March 16, 2015, after a short illness. Janet's 1978 book, Masculinity & Femininity, coauthored with Robert Helmreich, was a major contribution to our understanding of the complex relationships between personal attributes, self-esteem, and attitudes toward women, as well their links to both achievement motivation and parental characteristics. Janet's interest in achievement motivation was an extension of her gender work, as she attempted to learn more about the ways in which presumed differences in achievement motivation might be related to the key dimensions of instrumentality and expressiveness. Janet's election to the presidency of the APA was the culmination of a long and broad involvement in the organization. She served on the Board of Directors from 1976 to 1978, and again in 1983 to 1984 during her presidential term. Earlier she served on the Board of Scientific Affairs and edited Contemporary Psychology in the 1970s. Janet was a fellow in four divisions (3, 8, 12, and 35), and in 2004 she received the APA Gold Medal Award for Life Achievement in the Science of Psychology. (c) 2016 APA, all rights reserved).

  19. Dynamic Fracture Studies Using Sleeved Taylor Specimens

    NASA Astrophysics Data System (ADS)

    Gilmore, Martin R.; Foster, Joseph C., Jr; Wilson, Leo L.

    2002-07-01

    The characterization of the inelastic response of materials to high rates of loading is a challenging engineering problem. As the load rate increases, the interpretation of the data recovered from the experiment become more difficult. At very high rates of loading, even the inertia of the test specimen must be accounted for in the interpretation of the data 1. The Taylor impact experiment is specifically designed to exploit the inertia of the specimen to produce very high loading rates and has been used to study the high strain (50%), high strain rate (103-4) behavior of materials for many years 2. Many high-rate loading problems produce failure in the material. Continuum codes have been used to design sleeved impact specimens to study the failure of materials under high rates of loading. Ductile core materials are used as drivers to control rupture of more brittle sleeves of the material of interest. Annealed copper cores are used to drive dynamic failure in AF1410 steel. High rate plastic deformation data are presented for the driver and the sleeve together with the fracture data.

  20. Rayleigh-Taylor instability simulations with CRASH

    NASA Astrophysics Data System (ADS)

    Chou, C.-C.; Fryxell, B.; Drake, R. P.

    2012-03-01

    CRASH is a code package developed for the predictive study of radiative shocks. It is based on the BATSRUS MHD code used extensively for space-weather research. We desire to extend the applications of this code to the study of hydrodynamically unstable systems. We report here the results of Rayleigh-Taylor instability (RTI) simulations with CRASH, as a necessary step toward the study of such systems. Our goal, motivated by the previous comparison of simulations and experiment, is to be able to simulate the magnetic RTI with self-generated magnetic fields produced by the Biermann Battery effect. Here we show results for hydrodynamic RTI, comparing the effects of different solvers and numerical parameters. We find that the early-time behavior converges to the analytical result of the linear theory. We observe that the late-time morphology is sensitive to the numerical scheme and limiter beta. At low-resolution limit, the growth of RTI is highly dependent on the setup and resolution, which we attribute to the large numerical viscosity at low resolution.

  1. Rayleigh-Taylor mixing in supernova experiments

    NASA Astrophysics Data System (ADS)

    Swisher, Nora; Kuranz, Carolyn; Arnett, David; Hurricane, Omar; Remington, Bruce; Robey, Harry; Abarzhi, Snezhana

    2015-11-01

    We report a scrupulous analysis of data in supernova experiments that are conducted at high power laser facilities in order to study core-collapse supernova SN1987A. Parameters of the experimental system are properly scaled to investigate the interaction of a blast-wave with helium-hydrogen interface, and the induced Rayleigh-Taylor (RT) mixing of the denser and lighter fluids with time-dependent acceleration. We analyze all available experimental images of RT flow in supernova experiments, and measure delicate features of the interfacial dynamics. A new scaling is identified for calibration of experimental data to enable their accurate analysis and comparisons. By proper accounting for the imprint of the experimental conditions, the data set size and statistics are substantially increased. New theoretical solutions are identified to describe asymptotic dynamics of RT flow with time-dependent acceleration by applying theoretical analysis. Good qualitative and quantitative agreement is achieved of the experimental data with the theory and simulations. Our study indicates that in supernova experiments, the RT flow is in the mixing regime, the interface amplitude contributes substantially to the characteristic length scale for energy dissipation; the mixing flow may keep order. Support of the National Science Foundation is warmly appreciated.

  2. Non-adiabatic Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Canfield, Jesse; Denissen, Nicholas; Reisner, Jon

    2016-11-01

    Onset of Rayleigh-Taylor instability (RTI) in a non-adiabatic environment is investigated with the multi-physics numerical model, FLAG. This work was inspired by laboratory experiments of non-adiabatic RTI, where a glass vessel with a layer of tetrahyrdofuran (THF) below a layer of toluene was placed inside a microwave. THF, a polar solvent, readily absorbs electromagnetic energy from microwaves. Toluene, a non-polar solvent, is nearly transparent to microwave heating. The presence of a heat source in the THF layer produced convection and a time-dependent Atwood number (At). The system, initially in stable hydrostatic equilibrium At < 0 , was set into motion by microwave induced, volumetric heating of the THF. The point when At > 0 , indicates that the system is RTI unstable. The observed dominant mode at the onset of RTI was the horizontal length scale of the vessel. This scale is contrary to classical RTI, where the modes start small and increases in scale with time. It is shown that the dominant RTI mode observed in the experiments was determined by the THF length scale prior to RTI. The dominant length scale transitions from the THF to the toluene via the updrafts and downdrafts in the convective cells. This happens when At passes from negative to positive. This work was funded by the Advanced Simulation and Computing Program.

  3. Slavnov-Taylor identities for primordial perturbations

    SciTech Connect

    Berezhiani, Lasha; Khoury, Justin E-mail: jkhoury@sas.upenn.edu

    2014-02-01

    Correlation functions of adiabatic modes in cosmology are constrained by an infinite number of consistency relations, which relate N + 1-point correlation functions with a soft-momentum scalar or tensor mode to a symmetry transformation on N-point correlation functions of hard-momentum modes. They constrain, at each order n, the q{sup n} behavior of the soft limits. In this paper we show that all consistency relations derive from a single, master identity, which follows from the Slavnov-Taylor identity for spatial diffeomorphisms. This master identity is valid at any value of q and therefore goes beyond the soft limit. By differentiating it n times with respect to the soft momentum, we recover the consistency relations at each q order. Our approach underscores the role of spatial diffeomorphism invariance at the root of cosmological consistency relations. It also offers new insights on the necessary conditions for their validity: a physical contribution to the vertex functional must satisfy certain analyticity properties in the soft limit in order for the consistency relations to hold. For standard inflationary models, this is equivalent to requiring that mode functions have constant growing-mode solutions. For more exotic models in which modes do not ''freeze'' in the usual sense, the analyticity requirement offers an unambiguous criterion.

  4. Suppression of Rayleigh Taylor instability in strongly coupled plasmas

    SciTech Connect

    Das, Amita; Kaw, Predhiman

    2014-06-15

    The Rayleigh Taylor instability in a strongly coupled plasma medium has been investigated using the equations of generalized hydrodynamics. It is demonstrated that the visco-elasticity of the strongly coupled medium due to strong inter particle correlations leads to a suppression of the Rayleigh Taylor instability unless certain threshold conditions are met. The relevance of these results to experiments on laser compression of matter to high densities including those related to inertial confinement fusion using lasers has also been shown.

  5. Observation of the Taylor instability in a dusty plasma

    SciTech Connect

    Pacha, K. A.; Heinrich, J. R.; Kim, S.-H.; Merlino, R. L.

    2012-01-15

    Observations of the Taylor instability in a laboratory dusty plasma are presented. The dust cloud, formed in a dc argon glow-discharge plasma, is stratified into regions of high and low dust densities. The instability was triggered by a spontaneous intrusion of the low density dust fluid into the high density dust fluid at the interface. The instability in the dust fluid was phenomenologically similar to the hydrodynamic Taylor instability that occurs when a light fluid is accelerated into a heavy fluid.

  6. Synthesis of Taylor and Bayliss patterns for linear antenna arrays

    NASA Astrophysics Data System (ADS)

    Shelton, J. P.

    1981-08-01

    The history of synthesis techniques for designing linear antenna arrays with low sidelobe patterns is reviewed briefly, and the limitations that are encountered with very low sidelobes and/or small arrays are pointed out. Taylor's continuous aperture synthesis procedure is outlined, and a technique for transforming it for application to a discrete array is described. Discrete-array design equation for Taylor and Bayliss synthesis procedures are given. A set of programs for use on a programmable calculator are presented.

  7. Integrating insect-resistant GM Crops in pest management systems

    USDA-ARS?s Scientific Manuscript database

    In 2006, GM cotton and maize with insect resistance were grown on 12.1 and 20.1 million hectares in 9 and 13 countries, respectively. These insect resistant GM crops produce various Cry toxins from Bacillus thuringiensis (Bt) and provide highly selective and effective control of lepidopteran and col...

  8. Examining consumer behavior toward genetically modified (GM) food in Britain.

    PubMed

    Spence, Alexa; Townsend, Ellen

    2006-06-01

    This study examined behavior toward genetically modified (GM) food in a British community-based sample. We used an equivalent gain task in which participants actually received the options they chose to encourage truthful responding. In conjunction with this, theory of planned behavior (TPB) components were evaluated so as to examine the relative importance of behavioral influences in this domain. Here, the TPB was extended to include additional components to measure self-identity, moral norms, and emotional involvement. Results indicated that the monetary amounts participants accepted in preference to GM food were significantly lower than those accepted in preference to non-GM food. However, the vast majority of participants were indifferent between GM and non-GM food options. All TPB components significantly predicted behavioral intentions to try GM food, with attitudes toward GM being the strongest predictor. Self-identity and emotional involvement were also found to be significant predictors of behavioral intentions but moral norms were not. In addition, behavioral intentions significantly predicted behavior; however, PBC did not. An additional measure of participants' propensity to respond in a socially desirable manner indicated that our results were not influenced by self-presentation issues, giving confidence to our findings. Overall, it appears that the majority of participants (74.5%) would purchase GM food at some price.

  9. GM-PHD filter multitarget tracking in sonar images

    NASA Astrophysics Data System (ADS)

    Clark, Daniel; Vo, Ba-Ngu; Bell, Judith

    2006-05-01

    The Gaussian Mixure Probability Hypothesis Density (GM-PHD) Multi-target Tracker was developed as an extension to the GM-PHD filter to provide track continuity. The algorithm is demonstrated on forward-looking sonar data with clutter and is compared with the results from the Particle PHD filter.

  10. Finite Larmor radius magnetohydrodynamics of the Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Huba, J. D.

    1996-07-01

    The evolution of the Rayleigh-Taylor instability is studied using finite Larmor radius (FLR) magnetohydrodynamic (MHD) theory. Finite Larmor radius effects are introduced in the momentum equation through an anisotropic ion stress tensor. Roberts and Taylor [Phys. Rev. Lett. 3, 197 (1962)], using fluid theory, demonstrated that FLR effects can stabilize the Rayleigh-Taylor instability in the short-wavelength limit (kLn≫1, where k is the wave number and Ln is the density gradient scale length). In this paper a linear mode equation is derived that is valid for arbitrary kLn. Analytic solutions are presented in both the short-wavelength (kLn≫1) and long-wavelength (kLn≪1) regimes, and numerical solutions are presented for the intermediate regime (kLn˜1). The long-wavelength modes are shown to be the most difficult to stabilize. More important, the nonlinear evolution of the Rayleigh-Taylor instability is studied using a newly developed two-dimensional (2-D) FLR MHD code. The FLR effects are shown to be a stabilizing influence on the Rayleigh-Taylor instability; the short-wavelength modes are the easiest to stabilize, consistent with linear theory. In the nonlinear regime, the FLR effects cause the ``bubbles and spikes'' that develop because of the Rayleigh-Taylor instability to convect along the density gradient and to tilt. Applications of this model to space and laboratory plasma phenomena are discussed.

  11. The Life and Legacy of G. I. Taylor

    NASA Astrophysics Data System (ADS)

    Batchelor, G. K.

    1996-07-01

    G.I. Taylor, one of the most distinguished physical scientists of this century, used his deep insight and originality to increase our understanding of phenomena such as the turbulent flow of fluids. His interest in the science of fluid flow was not confined to theory; he was one of the early pioneers of aeronautics, and designed a new type of anchor that was inspired by his passion for sailing. Taylor spent most of his working life in the Cavendish Laboratory in Cambridge, where he investigated the mechanics of fluid and solid materials; his discoveries and ideas have had application throughout mechanical, civil, and chemical engineering, meteorology, oceanography and materials science. He was also a noted research leader, and his group in Cambridge became one of the most productive centers for the study of fluid mechanics. How was Taylor able to be innovative in so many different ways? This interesting and unusual biography helps answer that question. Professor Batchelor, himself a student and close collaborator of Taylor, is ideally placed to describe Taylor's life, achievements and background. He does so without introducing any mathematical details, making this book enjoyable reading for a wide range of people--and especially those whose own interests have brought them into contact with the legacy of Taylor.

  12. Media attention to GM food cases: An innovation perspective.

    PubMed

    Flipse, Steven M; Osseweijer, Patricia

    2013-02-01

    Media attention to genetically modified (GM) foods has been described as negative, especially in Europe. At the turn of the century appreciation of GM foods was at an all-time low in Europe. Food manufacturers are still careful in the use, development and communication of GM based food products, and their caution influences innovation processes. In this study we explore the link between media attention and innovation practice. Media attention to three specific high-profile GM food cases is described and linked to innovation practice. We elucidate the order of events in these cases and show that publics could only to a limited extent have formed an opinion on GM based food products based on scientifically valid data through written English media. Innovators in food biotechnology may benefit from this knowledge for future product development and marketing, and we suggest that innovation may benefit from early stakeholder involvement and communication activities.

  13. New directions for Rayleigh-Taylor mixing.

    PubMed

    Glimm, James; Sharp, David H; Kaman, Tulin; Lim, Hyunkyung

    2013-11-28

    We study the Rayleigh-Taylor (RT) mixing layer, presenting simulations in agreement with experimental data. This problem is an idealized subproblem of important scientific and engineering problems, such as gravitationally induced mixing in oceanography and performance assessment for inertial confinement fusion. Engineering codes commonly achieve correct simulations through the calibration of adjustable parameters. In this sense, they are interpolative and not predictive. As computational science moves from the interpolative to the predictive and reduces the reliance on experiment, the quality of decision making improves. The diagnosis of errors in a multi-parameter, multi-physics setting is daunting, so we address this issue in the proposed idealized setting. The validation tests presented are thus a test for engineering codes, when used for complex problems containing RT features. The RT growth rate, characterized by a dimensionless but non-universal parameter α, describes the outer edge of the mixing zone. Increasingly accurate front tracking/large eddy simulations reveal the non-universality of the growth rate and agreement with experimental data. Increased mesh resolution allows reduction in the role of key subgrid models. We study the effect of long-wavelength perturbations on the mixing growth rate. A self-similar power law for the initial perturbation amplitudes is here inferred from experimental data. We show a maximum ±5% effect on the growth rate. Large (factors of 2) effects, as predicted in some models and many simulations, are inconsistent with the experimental data of Youngs and co-authors. The inconsistency of the model lies in the treatment of the dynamics of bubbles, which are the shortest-wavelength modes for this problem. An alternative theory for this shortest wavelength, based on the bubble merger model, was previously shown to be consistent with experimental data.

  14. GM2 gangliosidosis in British Jacob sheep.

    PubMed

    Wessels, M E; Holmes, J P; Jeffrey, M; Jackson, M; Mackintosh, A; Kolodny, E H; Zeng, B J; Wang, C B; Scholes, S F E

    2014-01-01

    GM2 gangliosidosis (Tay-Sachs disease) was diagnosed in 6- to 8-month-old pedigree Jacob lambs from two unrelated flocks presenting clinically with progressive neurological dysfunction of 10 day's to 8 week's duration. Clinical signs included hindlimb ataxia and weakness, recumbency and proprioceptive defects. Histopathological examination of the nervous system identified extensive neuronal cytoplasmic accumulation of material that stained with periodic acid--Schiff and Luxol fast blue. Electron microscopy identified membranous cytoplasmic bodies within the nervous system. Serum biochemistry detected a marked decrease in hexosaminidase A activity in the one lamb tested, when compared with the concentration in age matched controls and genetic analysis identified a mutation in the sheep hexa allele G444R consistent with Tay-Sachs disease in Jacob sheep in North America. The identification of Tay-Sachs disease in British Jacob sheep supports previous evidence that the mutation in North American Jacob sheep originated from imported UK stock. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  15. GM foods: is there a way forward?

    PubMed

    Jones, Huw D

    2015-08-01

    There are many quality targets in cereals that could generate step-change improvements in nutritional or food-processing characteristics. For instance, levels of acrylamide, soluble and insoluble fibre, antioxidants, allergens and intolerance factors in food are, to a large extent, determined by the genetics of the raw materials used. However, improvements to these traits pose significant challenges to plant breeders. For some traits, this is because the underlying genetic and biochemical basis of the traits is not fully understood but for others, there is simply a lack of natural genetic variation in commercially useful germplasm. One strategy to overcome the latter hindrance is to use wide crosses with more exotic germplasm; however, this can bring other difficulties such as yield loss and linkage drag of deleterious alleles. As DNA sequencing becomes cheaper and faster, it drives the research fields of reverse genetics and functional genomics which in turn will enable the incorporation of desirable traits into crop varieties via molecular breeding and biotechnology. I will discuss the evolution of these techniques from conventional genetic modification to more recent developments in targeted gene editing and the potential of biotechnology to complement conventional breeding methods. I will also discuss the role of risk assessment and regulation in the commercialisation of GM crops.

  16. 33 CFR 207.170d - Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee, Okeechobee, Fla.; use, administration..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170d Taylor Creek, navigation lock...

  17. 33 CFR 207.170d - Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee, Okeechobee, Fla.; use, administration..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170d Taylor Creek, navigation...

  18. Optimization of GM(1,1) power model

    NASA Astrophysics Data System (ADS)

    Luo, Dang; Sun, Yu-ling; Song, Bo

    2013-10-01

    GM (1,1) power model is the expansion of traditional GM (1,1) model and Grey Verhulst model. Compared with the traditional models, GM (1,1) power model has the following advantage: The power exponent in the model which best matches the actual data values can be found by certain technology. So, GM (1,1) power model can reflect nonlinear features of the data, simulate and forecast with high accuracy. It's very important to determine the best power exponent during the modeling process. In this paper, according to the GM(1,1) power model of albino equation is Bernoulli equation, through variable substitution, turning it into the GM(1,1) model of the linear albino equation form, and then through the grey differential equation properly built, established GM(1,1) power model, and parameters with pattern search method solution. Finally, we illustrate the effectiveness of the new methods with the example of simulating and forecasting the promotion rates from senior secondary schools to higher education in China.

  19. Exposure of livestock to GM feeds: Detectability and measurement.

    PubMed

    Nadal, Anna; De Giacomo, Marzia; Einspanier, Ralf; Kleter, Gijs; Kok, Esther; McFarland, Sarah; Onori, Roberta; Paris, Alain; Toldrà, Mònica; van Dijk, Jeroen; Wal, Jean-Michel; Pla, Maria

    2017-08-25

    This review explores the possibilities to determine livestock consumption of genetically modified (GM) feeds/ingredients including detection of genetically modified organism (GMO)-related DNA or proteins in animal samples, and the documentary system that is in place for GM feeds under EU legislation. The presence and level of GMO-related DNA and proteins can generally be readily measured in feeds, using established analytical methods such as polymerase chain reaction and immuno-assays, respectively. Various technical challenges remain, such as the simultaneous detection of multiple GMOs and the identification of unauthorized GMOs for which incomplete data on the inserted DNA may exist. Given that transfer of specific GMO-related DNA or protein from consumed feed to the animal had seldom been observed, this cannot serve as an indicator of the individual animal's prior exposure to GM feeds. To explore whether common practices, information exchange and the specific GM feed traceability system in the EU would allow to record GM feed consumption, the dairy chain in Catalonia, where GM maize is widely grown, was taken as an example. It was thus found that this system would neither enable determination of an animal's consumption of specific GM crops, nor would it allow for quantitation of the exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. GmFT2a and GmFT5a Redundantly and Differentially Regulate Flowering through Interaction with and Upregulation of the bZIP Transcription Factor GmFDL19 in Soybean

    PubMed Central

    Lu, Sijia; Tang, Lili; Yuan, Xiaohui; Liu, Baohui; Kong, Fanjiang

    2014-01-01

    FLOWERING LOCUS T (FT) is the key flowering integrator in Arabidopsis (Arabidopsis thaliana), and its homologs encode florigens in many plant species regardless of their photoperiodic response. Two FT homologs, GmFT2a and GmFT5a, are involved in photoperiod-regulated flowering and coordinately control flowering in soybean. However, the molecular and genetic understanding of the roles played by GmFT2a and GmFT5a in photoperiod-regulated flowering in soybean is very limited. In this study, we demonstrated that GmFT2a and GmFT5a were able to promote early flowering in soybean by overexpressing these two genes in the soybean cultivar Williams 82 under noninductive long-day (LD) conditions. The soybean homologs of several floral identity genes, such as GmAP1, GmSOC1 and GmLFY, were significantly upregulated by GmFT2a and GmFT5a in a redundant and differential pattern. A bZIP transcription factor, GmFDL19, was identified as interacting with both GmFT2a and GmFT5a, and this interaction was confirmed by yeast two-hybridization and bimolecular fluorescence complementation (BiFC). The overexpression of GmFDL19 in soybean caused early flowering, and the transcription levels of the flowering identity genes were also upregulated by GmFDL19, as was consistent with the upregulation of GmFT2a and GmFT5a. The transcription of GmFDL19 was also induced by GmFT2a. The results of the electrophoretic mobility shift assay (EMSA) indicated that GmFDL19 was able to bind with the cis-elements in the promoter of GmAP1a. Taken together, our results suggest that GmFT2a and GmFT5a redundantly and differentially control photoperiod-regulated flowering in soybean through both physical interaction with and transcriptional upregulation of the bZIP transcription factor GmFDL19, thereby inducing the expression of floral identity genes. PMID:24845624

  1. Taylor line swimming in microchannels and cubic lattices of obstacles

    NASA Astrophysics Data System (ADS)

    Münch, Jan L.; Alizadehrad, Davod; Babu, Sujin B.; Stark, Holger

    Microorganisms naturally move in microstructured fluids. Using the simulation method of multi-particle collision dynamics, we study an undulatory Taylor line swimming in a two-dimensional microchannel and in a cubic lattice of obstacles, which represent simple forms of a microstructured environment. In the microchannel the Taylor line swims at an acute angle along a channel wall with a clearly enhanced swimming speed due to hydrodynamic interactions with the bounding wall. While in a dilute obstacle lattice swimming speed is also enhanced, a dense obstacle lattice gives rise to geometric swimming. This new type of swimming is characterized by a drastically increased swimming speed. Since the Taylor line has to fit into the free space of the obstacle lattice, the swimming speed is close to the phase velocity of the bending wave traveling along the Taylor line. While adjusting its swimming motion within the lattice, the Taylor line chooses a specific swimming direction, which we classify by a lattice vector. When plotting the swimming velocity versus the magnitude of the lattice vector, all our data collapse on a single master curve. Finally, we also report more complex trajectories within the obstacle lattice.

  2. Taylor line swimming in microchannels and cubic lattices of obstacles.

    PubMed

    Münch, Jan L; Alizadehrad, Davod; Babu, Sujin B; Stark, Holger

    2016-09-21

    Microorganisms naturally move in microstructured fluids. Using the simulation method of multi-particle collision dynamics, we study in two dimensions an undulatory Taylor line swimming in a microchannel and in a cubic lattice of obstacles, which represent simple forms of a microstructured environment. In the microchannel the Taylor line swims at an acute angle along a channel wall with a clearly enhanced swimming speed due to hydrodynamic interactions with the bounding wall. While in a dilute obstacle lattice swimming speed is also enhanced, a dense obstacle lattice gives rise to geometric swimming. This new type of swimming is characterized by a drastically increased swimming speed. Since the Taylor line has to fit into the free space of the obstacle lattice, the swimming speed is close to the phase velocity of the bending wave traveling along the Taylor line. While adjusting its swimming motion within the lattice, the Taylor line chooses a specific swimming direction, which we classify by a lattice vector. When plotting the swimming velocity versus the magnitude of the lattice vector, all our data collapse on a single master curve. Finally, we also report more complex trajectories within the obstacle lattice.

  3. Gene flow from herbicide-tolerant GM rice and the heterosis of GM rice-weed F2 progeny.

    PubMed

    Chun, Young Jin; Kim, Dae In; Park, Kee Woong; Kim, Hyo-Jeong; Jeong, Soon-Chun; An, Ju Hee; Cho, Kang Hyun; Back, Kyoungwhan; Kim, Hwan Mook; Kim, Chang-Gi

    2011-04-01

    Gene flow from genetically modified (GM) crops to non-GM cultivars or weedy relatives may lead to the development of more aggressive weeds. We quantified the amount of gene flow from herbicide-tolerant GM rice (Protox GM, derived from the cultivar Dongjin) to three cultivars (Dongjin, Aranghyangchal and Hwaseong) and a weedy rice line. Gene flow frequency generally decreased with increasing distance from the pollen donor. At the shortest distance (0.5 m), we observed a maximum frequency (0.039%) of gene flow. We found that the cultivar Dongjin received the greatest amount of gene flow, with the second being weedy rice. Heterosis of F2 inbred progeny was also examined between Protox GM and weedy rice. We compared growth and reproduction between F2 progeny (homozygous or hemizygous for the Protox gene) and parental rice lines (GM and weedy rice). Here, transgene-homozygous F2 progeny was significantly taller and produced more seeds than the transgene-hemizygous F2 progeny and parental lines. Although the gene flow frequency was generally low, our results suggest that F2 progeny between GM and weedy relatives may exhibit heterosis.

  4. GmWRKY31 and GmHDL56 Enhances Resistance to Phytophthora sojae by Regulating Defense-Related Gene Expression in Soybean

    PubMed Central

    Fan, Sujie; Dong, Lidong; Han, Dan; Zhang, Feng; Wu, Junjiang; Jiang, Liangyu; Cheng, Qun; Li, Rongpeng; Lu, Wencheng; Meng, Fanshan; Zhang, Shuzhen; Xu, Pengfei

    2017-01-01

    Phytophthora root and stem rot of soybean [Glycine max (L.) Merr.] caused by the oomycete Phytophthora sojae, is a destructive disease worldwide. The molecular mechanism of the soybean response to P. sojae is largely unclear. We report a novel WRKY transcription factor (TF) in soybean, GmWRKY31, in the host response to P. sojae. Overexpression and RNA interference analysis demonstrated that GmWRKY31 enhanced resistance to P. sojae in transgenic soybean plants. GmWRKY31 was targeted to the nucleus, where it bound to the W-box and acted as an activator of gene transcription. Moreover, we determined that GmWRKY31 physically interacted with GmHDL56, which improved resistance to P. sojae in transgenic soybean roots. GmWRKY31 and GmHDL56 shared a common target GmNPR1 which was induced by P. sojae. Overexpression and RNA interference analysis demonstrated that GmNPR1 enhanced resistance to P. sojae in transgenic soybean plants. Several pathogenesis-related (PR) genes were constitutively activated, including GmPR1a, GmPR2, GmPR3, GmPR4, GmPR5a, and GmPR10, in soybean plants overexpressing GmNPR1 transcripts. By contrast, the induction of PR genes was compromised in transgenic GmNPR1-RNAi lines. Taken together, these findings suggested that the interaction between GmWRKY31 and GmHDL56 enhances resistance to P. sojae by regulating defense-related gene expression in soybean. PMID:28553307

  5. Genetics Home Reference: GM2-gangliosidosis, AB variant

    MedlinePlus

    ... Chen B, Rigat B, Curry C, Mahuran DJ. Structure of the GM2A gene: identification of an exon 2 nonsense mutation and a naturally occurring transcript with an in-frame deletion of exon 2. Am J Hum Genet. ...

  6. Risk, regulation and biotechnology: The case of GM crops

    PubMed Central

    Smyth, Stuart J; Phillips, Peter WB

    2014-01-01

    The global regulation of products of biotechnology is increasingly divided. Regulatory decisions for genetically modified (GM) crops in North America are predictable and efficient, with numerous countries in Latin and South America, Australia and Asia following this lead. While it might have been possible to argue that Europe's regulations were at one time based on real concerns about minimizing risks and ensuring health and safety, it is increasingly apparent that the entire European Union (EU) regulatory system for GM crops and foods is now driven by political agendas. Countries within the EU are at odds with each other as some have commercial production of GM crops, while others refuse to even develop regulations that could provide for the commercial release of GM crops. This divide in regulatory decision-making is affecting international grain trade, creating challenges for feeding an increasing global population. PMID:25437235

  7. Applying a weed risk assessment approach to GM crops.

    PubMed

    Keese, Paul K; Robold, Andrea V; Myers, Ruth C; Weisman, Sarah; Smith, Joe

    2014-12-01

    Current approaches to environmental risk assessment of genetically modified (GM) plants are modelled on chemical risk assessment methods, which have a strong focus on toxicity. There are additional types of harms posed by plants that have been extensively studied by weed scientists and incorporated into weed risk assessment methods. Weed risk assessment uses robust, validated methods that are widely applied to regulatory decision-making about potentially problematic plants. They are designed to encompass a broad variety of plant forms and traits in different environments, and can provide reliable conclusions even with limited data. The knowledge and experience that underpin weed risk assessment can be harnessed for environmental risk assessment of GM plants. A case study illustrates the application of the Australian post-border weed risk assessment approach to a representative GM plant. This approach is a valuable tool to identify potential risks from GM plants.

  8. Science policy and society: the British debate over GM agriculture.

    PubMed

    Gaskell, George

    2004-06-01

    The outcome of 'GM Nation?'--a public debate on genetic modification and the commercial growing of GM crops in Britain--was published in 2003. The objective of this public consultation was 'to promote an innovative, effective and deliberative programme of debate, against the background of the possible commercial production of GM crops in the UK...[and] provide meaningful information to Government about the nature and spectrum of the public's views, particularly at the grass roots level, to inform decision making'. Complementing an independent evaluation of GM Nation?, this article puts the debate into context, comments on the legitimacy of this, and similar exercises in public consultation, and develops some ideas on the future of public consultation on technological innovation.

  9. Ecological Compatibility of GM Crops and Biological Control

    USDA-ARS?s Scientific Manuscript database

    Insect-resistant and herbicide-tolerant genetically modified (GM) crops pervade many modern cropping systems, and present challenges and opportunities for developing biologically-based pest management programs. Interactions between biological control agents (insect predators, parasitoids, and pathog...

  10. Are GM Crops for Yield and Resilience Possible?

    PubMed

    Paul, Matthew J; Nuccio, Michael L; Basu, Shib Sankar

    2017-09-29

    Crop yield improvements need to accelerate to avoid future food insecurity. Outside Europe, genetically modified (GM) crops for herbicide- and insect-resistance have been transformative in agriculture; other traits have also come to market. However, GM of yield potential and stress resilience has yet to impact on food security. Genes have been identified for yield such as grain number, size, leaf growth, resource allocation, and signaling for drought tolerance, but there is only one commercialized drought-tolerant GM variety. For GM and genome editing to impact on yield and resilience there is a need to understand yield-determining processes in a cell and developmental context combined with evaluation in the grower environment. We highlight a sugar signaling mechanism as a paradigm for this approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Risk, regulation and biotechnology: the case of GM crops.

    PubMed

    Smyth, Stuart J; Phillips, Peter W B

    2014-07-03

    The global regulation of products of biotechnology is increasingly divided. Regulatory decisions for genetically modified (GM) crops in North America are predictable and efficient, with numerous countries in Latin and South America, Australia and Asia following this lead. While it might have been possible to argue that Europe's regulations were at one time based on real concerns about minimizing risks and ensuring health and safety, it is increasingly apparent that the entire European Union (EU) regulatory system for GM crops and foods is now driven by political agendas. Countries within the EU are at odds with each other as some have commercial production of GM crops, while others refuse to even develop regulations that could provide for the commercial release of GM crops. This divide in regulatory decision-making is affecting international grain trade, creating challenges for feeding an increasing global population.

  12. Linear stability of compressible Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Chow, Chuen-Yen

    1992-01-01

    A temporal stability analysis of compressible Taylor-Couette flow is presented. The viscous flow studied in this paper is contained between two concentric cylinders of infinite length, which are rotating with different angular velocities and are kept at different surface temperatures. The effects of differential rotation and temperature difference on the stability of Taylor-Couette flow are contrasted for a range of Mach numbers ranging from incompressible to Mach 3.0. The relative motion of the cylinders dramatically affects the characteristics of the Couette flow at the onset of instability. The flow is stabilized or destabilized depending upon the temperature ratio and speeds of the two cylinders. Independent of Mach number and temperature ratio, increasing Reynolds number generally promotes a destabilizing effect, indicating the inviscid nature of the Taylor-Couette flow.

  13. Photonic arbitrary waveform generator based on Taylor synthesis method.

    PubMed

    Liao, Shasha; Ding, Yunhong; Dong, Jianji; Yan, Siqi; Wang, Xu; Zhang, Xinliang

    2016-10-17

    Arbitrary waveform generation has been widely used in optical communication, radar system and many other applications. We propose and experimentally demonstrate a silicon-on-insulator (SOI) on chip optical arbitrary waveform generator, which is based on Taylor synthesis method. In our scheme, a Gaussian pulse is launched to some cascaded microrings to obtain first-, second- and third-order differentiations. By controlling amplitude and phase of the initial pulse and successive differentiations, we can realize an arbitrary waveform generator according to Taylor expansion. We obtain several typical waveforms such as square waveform, triangular waveform, flat-top waveform, sawtooth waveform, Gaussian waveform and so on. Unlike other schemes based on Fourier synthesis or frequency-to-time mapping, our scheme is based on Taylor synthesis method. Our scheme does not require any spectral disperser or large dispersion, which are difficult to fabricate on chip. Our scheme is compact and capable for integration with electronics.

  14. On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers

    NASA Technical Reports Server (NTRS)

    LeBoeuf, Richard L.; Mehta, Rabindra D.

    1995-01-01

    In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged ('real') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.

  15. On using Taylor's hypothesis for three-dimensional mixing layers

    NASA Astrophysics Data System (ADS)

    LeBoeuf, Richard L.; Mehta, Rabindra D.

    1995-06-01

    In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged (``real'') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.

  16. Rayleigh-Taylor instability of violently collapsing bubbles

    NASA Astrophysics Data System (ADS)

    Lin, Hao; Storey, Brian D.; Szeri, Andrew J.

    2002-08-01

    In a classical paper Plesset has determined conditions under which a bubble changing in volume maintains a spherical shape. The stability analysis was further developed by Prosperetti to include the effects of liquid viscosity on the evolving shape modes. In the present work the theory is further modified to include the changing density of the bubble contents. The latter is found to be important in violent collapses where the densities of the gas and vapor within a bubble may approach densities of the liquid outside. This exerts a stabilizing influence on the Rayleigh-Taylor mechanism of shape instability of spherical bubbles. A comparison with experimental data shows good agreement with the new theory; the Rayleigh-Taylor instability does provide an extinction threshold for violently collapsing bubbles. It is also explained why earlier works did not produce a slope in the Rayleigh-Taylor stability curve that conforms with that of the present work.

  17. Rayleigh-Taylor instability of cylindrical jets with radial motion

    SciTech Connect

    Chen, Xiang M.; Schrock, V.E.; Peterson, P.F.

    1995-09-01

    Rayleigh-Taylor instability of an interface between fluids with different densities subjected to accelleration normal to itself has interested researchers for almost a century. The classic analyses of a flat interface by Rayleigh and Taylor have shown that this type of instability depends on the direction of acceleration and the density differences of the two fluids. Plesset later analyzed the stability of a spherically symmetric flows (and a spherical interface) and concluded that the instability also depends on the velocity of the interface as well as the direction and magnitude of radial acceleration. The instability induced by radial motion in cylindrical systems seems to have been neglected by previous researchers. This paper analyzes the Rayleigh-Taylor type of the spherical case, the radial velocity also plays an important role. As an application, the example of a liquid jet surface in an Inertial Confinement Fusion (ICF) reactor design is analyzed.

  18. Linear stability of compressible Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Chow, Chuen-Yen

    1992-01-01

    A temporal stability analysis of compressible Taylor-Couette flow is presented. The viscous flow studied in this paper is contained between two concentric cylinders of infinite length, which are rotating with different angular velocities and are kept at different surface temperatures. The effects of differential rotation and temperature difference on the stability of Taylor-Couette flow are contrasted for a range of Mach numbers ranging from incompressible to Mach 3.0. The relative motion of the cylinders dramatically affects the characteristics of the Couette flow at the onset of instability. The flow is stabilized or destabilized depending upon the temperature ratio and speeds of the two cylinders. Independent of Mach number and temperature ratio, increasing Reynolds number generally promotes a destabilizing effect, indicating the inviscid nature of the Taylor-Couette flow.

  19. PREFACE: The 15th International Couette-Taylor Worskhop

    NASA Astrophysics Data System (ADS)

    Mutabazi, Innocent; Crumeyrolle, Olivier

    2008-07-01

    The 15th International Couette-Taylor Worskhop (ICTW15) was held in Le Havre, France from 9-12 July 2007. This regular international conference started in 1979 in Leeds, UK when the research interest in simple models of fluid flows was revitalized by systematic investigation of Rayleigh-Bénard convection and the Couette-Taylor flow. These two flow systems are good prototypes for the study of the transition to chaos and turbulence in closed flows. The workshop themes have been expanded from the original Couette-Taylor flow to include other centrifugal instabilities (Dean, Görtler, Taylor-Dean), spherical Couette flows, thermal convection instabilities, MHD, nonlinear dynamics and chaos, transition to turbulence, development of numerical and experimental techniques. The impressive longevity of the ICTW is due to the close interaction and fertile exchanges between international research groups from different disciplines: Physics and Astrophysics, Applied Mathematics, Mechanical Engineering, Chemical Engineering. The present workshop was attended by 100 participants, the program included over 83 contributions with 4 plenary lectures, 68 oral communications and 17 posters. The topics include, besides the classical Couette-Taylor flows, the centrifugal flows with longitudinal vortices, the shear flows, the thermal convection in curved geometries, the spherical Couette-Taylor flow, the geophysical flows, the magneto-hydrodynamic effects including the dynamo effect, the complex flows (viscoelasticity, immiscible fluids, bubbles and migration). Selected papers have been processed through the peer review system and are published in this issue of the Journal of Physics: Conference Series. The Workshop has been sponsored by Le Havre University, the Region Council of Haute-Normandie, Le Havre City Council, CNRS (ST2I, GdR-DYCOEC), and the European Space Agency through GEOFLOW program. The French Ministry of Defense (DGA), the Ministry of Foreign Affairs, the Ministry of

  20. Cell kinetics of GM-CFC in the steady state

    SciTech Connect

    Hagan, M.P.; MacVittie, T.J.; Dodgen, D.P.

    1985-07-01

    The kinetics of cell turnover for myeloid/monocyte cells that form colonies in agar (GM-CFC) were measured through the progressive increase in their sensitivity to 313-nm light during a period of cell labeling with BrdCyd. Two components of cell killing with distinctly separate labeling kinetics revealed both the presence of two generations within the GM-CFC compartment and the properties of the kinetics of the precursors of the GM-CFC. These precursors of the GM-CFC were not assayable in a routine GM-CFC assay when pregnant mouse uterus extract and mouse L-cell-conditioned medium were used to stimulate colony formation but were revealed by the labeling kinetics of the assayable GM-CFC. Further, these precursor cells appeared to enter the assayable GM-CFC population from a noncycling state. This was evidenced by the failure of the majority of these cells to incorporate BrdCyd during five days of infusion. The half-time for cell turnover within this precursor compartment was measured to be approximately 5.5 days. Further, these normally noncycling cells proliferated rapidly in response to endotoxin. High-proliferative-potential colony-forming cells (HPP-CFC) were tested as a candidate for this precursor population. The results of the determination of the kinetics for these cells showed that the HPP-CFC exist largely in a Go state, existing at an average rate of once every four days. The slow turnover time for these cells and their response to endotoxin challenge are consistent with a close relationship between the HPP-CFC and the Go pool of cells that is the direct precursor of the GM-CFC.

  1. Anti-GM-CSF antibodies in paediatric pulmonary alveolar proteinosis.

    PubMed

    Latzin, P; Tredano, M; Wüst, Y; de Blic, J; Nicolai, T; Bewig, B; Stanzel, F; Köhler, D; Bahuau, M; Griese, M

    2005-01-01

    Auto-antibodies against granulocyte-macrophage colony stimulating factor (GM-CSF) may be central to the pathogenesis of adult sporadic pulmonary alveolar proteinosis (PAP). The role of anti-GM-CSF auto-antibodies in paediatric forms of PAP is as yet unclear. Anti-GM-CSF auto-antibodies were determined with the help of an antigen capture assay using serum and/or bronchoalveolar lavage (BAL) fluid from 27 patients with PAP (nine adults, 15 children, three neonates) and from 185 children with different diseases as disease controls (various pulmonary conditions and patients with malignancies). Anti-GM-CSF auto-antibodies were detected in the serum of five of seven adult PAP patients. They were not found in the serum of any of the children or neonates with PAP nor in any of the disease control patients. Raised anti-GM-CSF titres were found in BAL fluid from three of four adult patients with PAP. Anti-GM-CSF auto-antibodies were detected in BAL fluid of only one of the 15 children (age at diagnosis 11 years, age at BAL 24 years) and in none of the neonates with PAP, nor in any of the disease control patients. The presence of anti-GM-CSF auto-antibodies seems to define an autoimmune disease underlying most of the adult sporadic type of PAP, but age at diagnosis may cause an overlap with children in some rare instances. In most of the children and all of the neonates the anti-GM-CSF titres were not significantly increased, indicating that alternative explanations are needed for the pathogenesis of the disease in these patients.

  2. Controlled formation of multiple Taylor cones in electrospinning process

    NASA Astrophysics Data System (ADS)

    Vaseashta, A.

    2007-02-01

    Electrospinning is a versatile technique for preparation of micro- and nanoscale fibers using polymer solutions. The study presented here describes an observation of multiple Taylor cones in electrospinning processes. Plausible physical models explaining the formation and modeling of multiple Taylor cones in terms of the process and polymer solution parameters are presented. A thorough understanding of the process will lead to the preparation of fibers by design, system on fibers, and e-textiles having applications ranging from biomedical devices, environmental pollution and prevention, to global security and defense.

  3. G.I. Taylor and the Trinity test

    NASA Astrophysics Data System (ADS)

    Deakin, Michael A. B.

    2011-12-01

    The story is often told of the calculation by G.I. Taylor of the yield of the first ever atomic bomb exploded in New Mexico in 1945. It has indeed become a staple of the classroom whenever dimensional analysis is taught. However, while it is true that Taylor succeeded in calculating this figure at a time when it was still classified, most versions of the story are quite inaccurate historically. The reality is more complex than the usual accounts have it. This article sets out to disentangle fact from fiction.

  4. Student understanding of Taylor series expansions in statistical mechanics

    NASA Astrophysics Data System (ADS)

    Smith, Trevor I.; Thompson, John R.; Mountcastle, Donald B.

    2013-12-01

    One goal of physics instruction is to have students learn to make physical meaning of specific mathematical expressions, concepts, and procedures in different physical settings. As part of research investigating student learning in statistical physics, we are developing curriculum materials that guide students through a derivation of the Boltzmann factor using a Taylor series expansion of entropy. Using results from written surveys, classroom observations, and both individual think-aloud and teaching interviews, we present evidence that many students can recognize and interpret series expansions, but they often lack fluency in creating and using a Taylor series appropriately, despite previous exposures in both calculus and physics courses.

  5. Dynamic stabilization of classical Rayleigh-Taylor instability

    SciTech Connect

    Piriz, A. R.; Piriz, S. A.; Tahir, N. A.

    2011-09-15

    Dynamic stabilization of classical Rayleigh-Taylor instability is studied by modeling the interface vibration with the simplest possible wave form, namely, a sequence of Dirac deltas. As expected, stabilization results to be impossible. However, in contradiction to previously reported results obtained with a sinusoidal driving, it is found that in general the perturbation amplitude is larger than in the classical case. Therefore, no beneficial effect can be obtained from the vertical vibration of a Rayleigh-Taylor unstable interface between two ideal fluids.

  6. Solving wave equation using finite differences and Taylor series

    NASA Astrophysics Data System (ADS)

    Nečasová, Gabriela; Kocina, Filip; Veigend, Petr; Chaloupka, Jan; Šátek, Václav; Kunovský, Jiří

    2017-07-01

    The paper deals with the numerical solution of partial differential equations (PDEs), especially wave equation. Two methods are used to obtain numerical solution of the wave equation. The Finite Difference Method (FDM) is used for transformation of wave equation to the system of ordinary differential equations (ODEs), different types of difference formulas are used. The influence of arithmetic to higher order difference formulas is also presented. The Modern Taylor Series Method (MTSM) allows to solve ODEs numerically with extremely high precision. An important feature of this method is an automatic integration order setting, i.e. using as many Taylor series terms as the defined accuracy requires.

  7. Pitchfork bifurcations in small aspect ratio Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Mullin, Tom; Satchwell, Doug; Toya, Yorinobu

    We present a discussion of steady bifurcation phenomena in Taylor-Couette flow. The emphasis is on the role of pitchfork bifurcations in mathematical models and their relevance to the physical problem. The general features of such bifurcations are reviewed before we discuss the numerical and experimental techniques used to explore their properties. New results are then presented for a wide-gap small aspect ratio version of Taylor-Couette flow. We find good agreement between numerical a nd experimental results and show that the qualitative features of the bifurcation sequence are the same as those found with other radius ratios.

  8. Narrow fingers in the Saffman-Taylor instability

    NASA Astrophysics Data System (ADS)

    Couder, Y.; Gerard, N.; Rabaud, M.

    1986-12-01

    Saffman-Taylor fingers with a relative width much smaller than the classical limit lambda = 0.5 are found when a small isolated bubble is located at their tip. These solutions are members of a family found by Saffman and Taylor (1958) neglecting superficial tension. Recent theories have shown that when capillary forces are taken into account an unphysical cusplike singularity would appear at the tip of all the fingers with lambda less than 0.5. Conversely, here the replacement of the tip by a small bubble makes these solutions possible. At large velocity these fingers show dendritic instability.

  9. Rapid Calculation of Spacecraft Trajectories Using Efficient Taylor Series Integration

    NASA Technical Reports Server (NTRS)

    Scott, James R.; Martini, Michael C.

    2011-01-01

    A variable-order, variable-step Taylor series integration algorithm was implemented in NASA Glenn's SNAP (Spacecraft N-body Analysis Program) code. SNAP is a high-fidelity trajectory propagation program that can propagate the trajectory of a spacecraft about virtually any body in the solar system. The Taylor series algorithm's very high order accuracy and excellent stability properties lead to large reductions in computer time relative to the code's existing 8th order Runge-Kutta scheme. Head-to-head comparison on near-Earth, lunar, Mars, and Europa missions showed that Taylor series integration is 15.8 times faster than Runge- Kutta on average, and is more accurate. These speedups were obtained for calculations involving central body, other body, thrust, and drag forces. Similar speedups have been obtained for calculations that include J2 spherical harmonic for central body gravitation. The algorithm includes a step size selection method that directly calculates the step size and never requires a repeat step. High-order Taylor series integration algorithms have been shown to provide major reductions in computer time over conventional integration methods in numerous scientific applications. The objective here was to directly implement Taylor series integration in an existing trajectory analysis code and demonstrate that large reductions in computer time (order of magnitude) could be achieved while simultaneously maintaining high accuracy. This software greatly accelerates the calculation of spacecraft trajectories. At each time level, the spacecraft position, velocity, and mass are expanded in a high-order Taylor series whose coefficients are obtained through efficient differentiation arithmetic. This makes it possible to take very large time steps at minimal cost, resulting in large savings in computer time. The Taylor series algorithm is implemented primarily through three subroutines: (1) a driver routine that automatically introduces auxiliary variables and

  10. Biochemical characterization of GM1 micelles-Amphotericin B interaction.

    PubMed

    Leonhard, Victoria; Alasino, Roxana V; Bianco, Ismael D; Garro, Ariel G; Heredia, Valeria; Beltramo, Dante M

    2015-01-01

    In this work a thorough characterization of the GM1 micelle-Amphotericin B (AmB) interaction was performed. The micelle formation as well as the drug loading occurs spontaneously, although influenced by the physicochemical conditions, pH and temperature. The chromatographic profile of GM1-AmB complexes at different molar ratios shows the existence of two populations. The differential absorbance of GM1, monomeric and aggregate AmB, allowed us to discriminate the presence of all of them in both fractions. Thus, we noted that at higher proportion of AmB in the complex, increases the larger population which is composed mainly of aggregated AmB. The physical behavior of these micelles shows that both GM1- AmB complexes were stable in solution for at least 30 days. However upon freeze-thawing or lyophilization-solubilization cycles, only the smallest population, enriched in monomeric AmB, showed a complete solubilization. In vitro, GM1-AmB micelles were significantly less toxic on cultured cells than other commercial micellar formulations as Fungizone, but had a similar behavior to liposomal formulations as Ambisome. Regarding the antifungal activity of the new formulation, it was very similar to that of other formulations. The characterization of these GM1-AmB complexes is discussed as a potential new formulation able to improve the antifungal therapeutic efficiency of AmB.

  11. Delivery of GM-CSF to Protect against Influenza Pneumonia

    PubMed Central

    Subramaniam, Renuka; Hillberry, Zachary; Chen, Han; Feng, Yan; Fletcher, Kalyn; Neuenschwander, Pierre; Shams, Homayoun

    2015-01-01

    Background Since adaptive immunity is thought to be central to immunity against influenza A virus (IAV) pneumonias, preventive strategies have focused primarily on vaccines. However, vaccine efficacy has been variable, in part because of antigenic shift and drift in circulating influenza viruses. Recent studies have highlighted the importance of innate immunity in protecting against influenza. Methods Granulocyte-macrophage colony stimulating factor (GM-CSF) contributes to maturation of mononuclear phagocytes, enhancing their capacity for phagocytosis and cytokine production. Results Overexpression of granulocyte macrophage-colony stimulating factor (GM-CSF) in the lung of transgenic mice provides remarkable protection against IAV, which depends on alveolar macrophages (AM). In this study, we report that pulmonary delivery of GM-CSF to wild type young and aged mice abrogated mortality from IAV. Conclusion We also demonstrate that protection is species specific and human GM-CSF do not protect the mice nor stimulates mouse immunity. We also show that IAV-induced lung injury is the culprit for side-effects of GM-CSF in treating mice after IAV infection, and introduce a novel strategy to deliver the GM-CSF to and retain it in the alveolar space even after IAV infection. PMID:25923215

  12. The distinct properties of natural and GM cry insecticidal proteins.

    PubMed

    Latham, Jonathan R; Love, Madeleine; Hilbeck, Angelika

    2017-04-01

    The Cry toxins are a family of crystal-forming proteins produced by the bacterium Bacillus thuringiensis. Their mode of action is thought to be to create pores that disrupt the gut epithelial membranes of juvenile insects. These pores allow pathogen entry into the hemocoel, thereby killing the insect. Genes encoding a spectrum of Cry toxins, including Cry mutants, Cry chimaeras and other Cry derivatives, are used commercially to enhance insect resistance in genetically modified (GM) crops. In most countries of the world, such GM crops are regulated and must be assessed for human and environmental safety. However, such risk assessments often do not test the GM crop or its tissues directly. Instead, assessments rely primarily on historical information from naturally occurring Cry proteins and on data collected on Cry proteins (called 'surrogates') purified from laboratory strains of bacteria engineered to express Cry protein. However, neither surrogates nor naturally occurring Cry proteins are identical to the proteins to which humans or other nontarget organisms are exposed by the production and consumption of GM plants. To-date there has been no systematic survey of these differences. This review fills this knowledge gap with respect to the most commonly grown GM Cry-containing crops approved for international use. Having described the specific differences between natural, surrogate and GM Cry proteins this review assesses these differences for their potential to undermine the reliability of risk assessments. Lastly, we make specific recommendations for improving risk assessments.

  13. [Biology and clinical applications of GM-CSF].

    PubMed

    Robak, T

    1994-01-01

    Granulocyte, macrophage colony stimulating factor (GM-CSF) and granulocyte--colony--stimulating factor (G-CSF) are two of the growing number of recognized cytokines involved in the regulation of hematopoiesis. The purification of these factors and the subsequent cloning of the DNAs which encode these proteins have led to their widespread clinical use in the setting up of therapy of disease-induced myelosuppression. GM-CSF has a broader spectrum of potential targets than G-CSF and promotes growth of progenitors of several myeloid lines and, to a lesser extent, of the megakaryocyte line. The pleiotropic effects of GM-CSF could therefore, theoretically, be an advantage compared with the more restricted activity of G-CSF. Its greatest potential use appears to be in the amelioration of neutropenia following myelosuppressive therapy. GM-CSF has demonstrated efficacy in decreasing the duration of neutropenia, decreasing the attendant infection, and enhancing the ability to deliver full doses of myelosuppressive therapy. GM-CSF can also reverse the neutropenia of myelodysplastic syndrome and aplastic anemia. It enhances recovery from bone marrow transplantation and thus reduce the attendant morbidity of this procedure. This hematopoietic growth factor may also enhance recruitment and harvest to peripheral stem cells. At clinically usefull dosages GM-CSF is generally well tolerated.

  14. Differential uPAR recruitment in caveolar-lipid rafts by GM1 and GM3 gangliosides regulates endothelial progenitor cells angiogenesis

    PubMed Central

    Margheri, Francesca; Papucci, Laura; Schiavone, Nicola; D'Agostino, Riccardo; Trigari, Silvana; Serratì, Simona; Laurenzana, Anna; Biagioni, Alessio; Luciani, Cristina; Chillà, Anastasia; Andreucci, Elena; Del Rosso, Tommaso; Margheri, Giancarlo; Del Rosso, Mario; Fibbi, Gabriella

    2015-01-01

    Gangliosides and the urokinase plasminogen activator receptor (uPAR) tipically partition in specialized membrane microdomains called lipid-rafts. uPAR becomes functionally important in fostering angiogenesis in endothelial progenitor cells (EPCs) upon recruitment in caveolar-lipid rafts. Moreover, cell membrane enrichment with exogenous GM1 ganglioside is pro-angiogenic and opposite to the activity of GM3 ganglioside. On these basis, we first checked the interaction of uPAR with membrane models enriched with GM1 or GM3, relying on the adoption of solid-supported mobile bilayer lipid membranes with raft-like composition formed onto solid hydrophilic surfaces, and evaluated by surface plasmon resonance (SPR) the extent of uPAR recruitment. We estimated the apparent dissociation constants of uPAR-GM1/GM3 complexes. These preliminary observations, indicating that uPAR binds preferentially to GM1-enriched biomimetic membranes, were validated by identifying a pro-angiogenic activity of GM1-enriched EPCs, based on GM1-dependent uPAR recruitment in caveolar rafts. We have observed that addition of GM1 to EPCs culture medium promotes matrigel invasion and capillary morphogenesis, as opposed to the anti-angiogenesis activity of GM3. Moreover, GM1 also stimulates MAPKinases signalling pathways, typically associated with an angiogenesis program. Caveolar-raft isolation and Western blotting of uPAR showed that GM1 promotes caveolar-raft partitioning of uPAR, as opposed to control and GM3-challenged EPCs. By confocal microscopy, we have shown that in EPCs uPAR is present on the surface in at least three compartments, respectively, associated to GM1, GM3 and caveolar rafts. Following GM1 exogenous addition, the GM3 compartment is depleted of uPAR which is recruited within caveolar rafts thereby triggering angiogenesis. PMID:25313007

  15. Differential uPAR recruitment in caveolar-lipid rafts by GM1 and GM3 gangliosides regulates endothelial progenitor cells angiogenesis.

    PubMed

    Margheri, Francesca; Papucci, Laura; Schiavone, Nicola; D'Agostino, Riccardo; Trigari, Silvana; Serratì, Simona; Laurenzana, Anna; Biagioni, Alessio; Luciani, Cristina; Chillà, Anastasia; Andreucci, Elena; Del Rosso, Tommaso; Margheri, Giancarlo; Del Rosso, Mario; Fibbi, Gabriella

    2015-01-01

    Gangliosides and the urokinase plasminogen activator receptor (uPAR) tipically partition in specialized membrane microdomains called lipid-rafts. uPAR becomes functionally important in fostering angiogenesis in endothelial progenitor cells (EPCs) upon recruitment in caveolar-lipid rafts. Moreover, cell membrane enrichment with exogenous GM1 ganglioside is pro-angiogenic and opposite to the activity of GM3 ganglioside. On these basis, we first checked the interaction of uPAR with membrane models enriched with GM1 or GM3, relying on the adoption of solid-supported mobile bilayer lipid membranes with raft-like composition formed onto solid hydrophilic surfaces, and evaluated by surface plasmon resonance (SPR) the extent of uPAR recruitment. We estimated the apparent dissociation constants of uPAR-GM1/GM3 complexes. These preliminary observations, indicating that uPAR binds preferentially to GM1-enriched biomimetic membranes, were validated by identifying a pro-angiogenic activity of GM1-enriched EPCs, based on GM1-dependent uPAR recruitment in caveolar rafts. We have observed that addition of GM1 to EPCs culture medium promotes matrigel invasion and capillary morphogenesis, as opposed to the anti-angiogenesis activity of GM3. Moreover, GM1 also stimulates MAPKinases signalling pathways, typically associated with an angiogenesis program. Caveolar-raft isolation and Western blotting of uPAR showed that GM1 promotes caveolar-raft partitioning of uPAR, as opposed to control and GM3-challenged EPCs. By confocal microscopy, we have shown that in EPCs uPAR is present on the surface in at least three compartments, respectively, associated to GM1, GM3 and caveolar rafts. Following GM1 exogenous addition, the GM3 compartment is depleted of uPAR which is recruited within caveolar rafts thereby triggering angiogenesis.

  16. Environmental stress is the major cause of transcriptomic and proteomic changes in GM and non-GM plants.

    PubMed

    Batista, Rita; Fonseca, Cátia; Planchon, Sébastien; Negrão, Sónia; Renaut, Jenny; Oliveira, M Margarida

    2017-09-06

    The approval of genetically modified (GM) crops is preceded by years of intensive research to demonstrate safety to humans and environment. We recently showed that in vitro culture stress is the major factor influencing proteomic differences of GM vs. non-GM plants. This made us question the number of generations needed to erase such "memory". We also wondered about the relevance of alterations promoted by transgenesis as compared to environment-induced ones. Here we followed three rice lines (1-control, 1-transgenic and 1-negative segregant) throughout eight generations after transgenesis combining proteomics and transcriptomics, and further analyzed their response to salinity stress on the F6 generation. Our results show that: (a) differences promoted during genetic modification are mainly short-term physiological changes, attenuating throughout generations, and (b) environmental stress may cause far more proteomic/transcriptomic alterations than transgenesis. Based on our data, we question what is really relevant in risk assessment design for GM food crops.

  17. Isoflavone Malonyltransferases GmIMaT1 and GmIMaT3 Differently Modify Isoflavone Glucosides in Soybean (Glycine max) under Various Stresses

    PubMed Central

    Ahmad, Muhammad Z.; Li, Penghui; Wang, Junjie; Rehman, Naveed Ur; Zhao, Jian

    2017-01-01

    Malonylated isoflavones are the major forms of isoflavonoids in soybean plants, the genes responsible for their biosyntheses are not well understood, nor their physiological functions. Here we report a new benzylalcohol O-acetyltransferase, anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase, deacetylvindoline 4-O-acetyltransferase (BAHD) family isoflavone glucoside malonyltransferase GmIMaT1, and GmIMaT3, which is allelic to the previously characterized GmMT7 and GmIF7MaT. Biochemical studies showed that recombinant GmIMaT1 and GmIMaT3 enzymes used malonyl-CoA and several isoflavone 7-O-glucosides as substrates. The Km values of GmIMaT1 for glycitin, genistin, and daidzin were 13.11, 23.04, and 36.28 μM, respectively, while these of GmIMaT3 were 12.94, 26.67, and 30.12 μM, respectively. Transgenic hairy roots overexpressing both GmIMaTs had increased levels of malonyldaidzin and malonylgenistin, and contents of daidzin and glycitin increased only in GmIMaT1-overexpression lines. The increased daidzein and genistein contents were detected only in GmIMaT3-overexpression lines. Knockdown of GmIMaT1 and GmIMaT3 reduced malonyldaidzin and malonylgenistin contents, and affected other isoflavonoids differently. GmIMaT1 is primarily localized to the endoplasmic reticulum while GmIMaT3 is primarily in the cytosol. By examining their transcript changes corresponding to the altered isoflavone metabolic profiles under various environmental and hormonal stresses, we probed the possible functions of GmIMaTs. Two GmIMaTs displayed distinct tissue expression patterns and respond differently to various factors in modifying isoflavone 7-O-glucosides under various stresses. PMID:28559900

  18. Evidence for mate guarding behavior in the Taylor's checkerspot butterfly

    Treesearch

    Victoria J. Bennett; Winston P. Smith; Matthew G. Betts

    2011-01-01

    Discerning the intricacies of mating systems in butterflies can be difficult, particularly when multiple mating strategies are employed and are cryptic and not exclusive. We observed the behavior and habitat use of 113 male Taylor's checkerspot butterflies (Euphydryas editha taylori). We confirmed that two distinct mating strategies were...

  19. 14. INTERIOR VIEW WITH JOHNNY TAYLOR REMOVING A MOLD HALF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. INTERIOR VIEW WITH JOHNNY TAYLOR REMOVING A MOLD HALF FROM THE PATTERN ON THE MOLDING MACHINE, REVEALING THE CAVITY THAT WILL BE FILLED WITH MOLTEN IRON AFTER IT IS ASSEMBLED WITH THE OTHER MOLD HALF INSIDE GREY IRON UNIT NO. 1. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  20. Tree ecophysiology research at Taylor Woods (P-53)

    Treesearch

    Thomas E. Kolb; Nate G. McDowell

    2008-01-01

    We summarize the key findings of tree ecophysiology studies performed at Taylor Woods, Fort Valley Experimental Forest, Arizona between 1994 and 2003 that provide unique insight on impacts of long-term stand density management in ponderosa pine forests on tree water relations, leaf gas exchange, radial growth, leaf area-to-sapwood-area ratio, growth efficiency, leaf...

  1. Rayleigh-Taylor instability experiments in a cylindrically convergent geometry

    SciTech Connect

    Goodwin, B.; Weir, S.

    1995-08-25

    Due to the sensitivity of Rayleigh-Taylor instabilities to initial conditions and due to the difficulty of forming well controlled cylindrical or spherical fluid interfaces, Rayleigh-Taylor experiments are often performed with simple, planar interfaces. Rayleigh-Taylor instability phenomena of practical interest, however, (e.g., underwater explosions, supernova core collapses, and inertial confinement fusion capsule implosions) are typically associated with cylindrical or spherical interfaces in which convergent flow effects have an important influence on the dynamics of instability growth. Recently, Meshkov et.al. have developed a novel technique for studying Rayleigh-Taylor instability growth in a cylindrically convergent geometry. Their experiments utilized low-strength gelatin rings which are imploded by a detonating gas mixture of oxygen and acetylene. Since the gelatin itself has sufficient strength to resist significant deformation by gravity, no membranes are needed to define the ring shape. This experimental technique is attractive because it offers a high degree of control over the interfacial geometry and over the material`s strength and rigidity, which can be varied by adjusting the gelatin concentration. Finally, since both the gelatin and the explosive product gases are transparent, optical diagnostics can be used.

  2. Turbulent strength in ultimate Taylor-Couette turbulence

    NASA Astrophysics Data System (ADS)

    Ezeta, Rodrigo; Huisman, Sander G.; Sun, Chao; Lohse, Detlef

    2016-11-01

    We provide the local scaling of the Taylor-Reynolds number (Reλ) as a function of driving strength (Ta), in the ultimate regime of Taylor-Couette flow for the inner cylinder rotation case. The calculation is done via local flow measurements using Particle Image Velocimetry (PIV) to reconstruct the velocity fields. We approximate the value of the local dissipation rate ɛ (r) using the scaling for the second order structure functions in the longitudinal and transversal directions within the inertial regime where Taylor's hypothesis is not invoked. We find an effective local scaling of < ɛ (r) > r / (ν3d-4) Ta 1 . 4 , which is the same as the global dissipation rate obtained from both torque measurements and Direct Numerical Simulations (DNS). Additionally, we calculate the Kolmogorov length scale and find < η (r) > r / d Ta - 0 . 35 . The turbulence intensity is also calculated and it is found to scale with the driving strength as iθ Ta - 0 . 056 . Finally, with both the local dissipation rate and the local fluctuations available we find that the Taylor-Reynolds number scales as Reλ Ta 0 . 18 . Stichting voor Fundamenteel Onderzoek der Materie (FOM).

  3. Taylor vortices formed in the melt during paratellurite crystal growth

    SciTech Connect

    Kolesnikov, A. I. Grechishkin, R. M.; Tret'yakov, S. A.; Gritsunova, O. V.; Vorontsova, E. Yu.

    2008-12-15

    The hydrodynamics of tellurium dioxide melt during Czochralski growth of paratellurite crystals with a diameter up to 80 mm was experimentally investigated. The images of the melt surface during crystal growth are obtained. It is shown that a stable system of Taylor vortices in the form of two convection cells is formed at definite Reynolds numbers.

  4. Frank Bursley Taylor - Forgotten Pioneer of Continental Drift.

    ERIC Educational Resources Information Center

    Black, George W., Jr.

    1979-01-01

    Frank B. Taylor was an American geologist who specialized in the glacial geology of the Great Lakes. This article discusses his work on the Continental Drift theory, which preceeded the work of Alfred Wegener by a year and a half. (MA)

  5. Using Taylor Expansions to Prepare Students for Calculus

    ERIC Educational Resources Information Center

    Lutzer, Carl V.

    2011-01-01

    We propose an alternative to the standard introduction to the derivative. Instead of using limits of difference quotients, students develop Taylor expansions of polynomials. This alternative allows students to develop many of the central ideas about the derivative at an intuitive level, using only skills and concepts from precalculus, and…

  6. 13. INTERIOR VIEW WITH JOHNNY TAYLOR HAND LEVELING FRESHLY DEPOSITED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. INTERIOR VIEW WITH JOHNNY TAYLOR HAND LEVELING FRESHLY DEPOSITED SAND INTO A FLASK PRIOR TO COMPRESSION BY THE MOLDING MACHINE INSIDE GREY IRON UNIT NO. 1. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  7. Rayleigh Taylor instability of viscoelastic drops at high Weber numbers

    NASA Astrophysics Data System (ADS)

    Joseph, D. D.; Beavers, G. S.; Funada, T.

    2002-02-01

    Movies of the breakup of viscous and viscoelastic drops in the high-speed airstream behind a shock wave in a shock tube have been reported by Joseph, Belanger & Beavers (1999). They performed a Rayleigh Taylor stability analysis for the initial breakup of a drop of Newtonian liquid and found that the most unstable Rayleigh Taylor wave fits nearly perfectly with waves measured on enhanced images of drops from the movies, but the effects of viscosity cannot be neglected. Here we construct a Rayleigh Taylor stability analysis for an Oldroyd-B fluid using measured data for acceleration, density, viscosity and relaxation time [lambda]1. The most unstable wave is a sensitive function of the retardation time [lambda]2 which fits experiments when [lambda]2/[lambda]1 = O(10-3). The growth rates for the most unstable wave are much larger than for the comparable viscous drop, which agrees with the surprising fact that the breakup times for viscoelastic drops are shorter. We construct an approximate analysis of Rayleigh Taylor instability based on viscoelastic potential flow which gives rise to nearly the same dispersion relation as the unapproximated analysis.

  8. Multiple Representations and the Understanding of Taylor Polynomials

    ERIC Educational Resources Information Center

    Habre, Samer

    2009-01-01

    The study of Maclaurin and Taylor polynomials entails the comprehension of various new mathematical ideas. Those polynomials are initially discussed at the college level in a calculus class and then again in a course on numerical methods. This article investigates the understanding of these polynomials by students taking a numerical methods class…

  9. Some observations of a sheared Rayleigh-Taylor/Benard instability

    NASA Technical Reports Server (NTRS)

    Humphrey, J. A. C.; Marcus, D. L.

    1987-01-01

    An account is provided of preliminary flow visualization observations made in an unstably stratified flow with shear superimposed. The structures observed appear to be the superposition of a Rayleigh-Taylor/Benard instability and a Kelvin-Helmholtz instability. Aside from its intrinsic fundamental value, the study of these structures is of special interest to theoreticians developing nonlinear stability calculation methodologies.

  10. Taylor-Couette flow with radial fluid injection

    NASA Astrophysics Data System (ADS)

    Wilkinson, Nikolas; Dutcher, Cari S.

    2017-08-01

    Taylor-Couette cells have been shown to improve a number of industrial processes due to the wide variety of hydrodynamic flow states accessible. Traditional designs, however, limit the ability to introduce new fluids into the annulus during device operation due to geometric confinement and complexity. In this paper, a co- and counter-rotating Taylor-Couette cell with radial fluid injection has been constructed. The incorporation of 16 ports in the inner cylinder enables radial fluid injection during rotation of both cylinders. The design is also capable of continuous axial flow, enabling large injection volumes. The new inner cylinder design does not modify the critical Re for flow instabilities and can precisely inject a desired mass at a desired flow rate. A range of injection rates and masses were explored to quantify the effect of radial injection on the stability of the turbulent Taylor vortex structure. Only the highest injection rate and total mass studied (5.9 g/s, 100 g) modified the turbulent Taylor vortex structure after injection for a sustained period. The post-injection vortices remained larger than the pre-injection vortices, whereas at lower injection rates or masses, the vortex structure quickly returned to the pre-injection structure. This new system allows for in situ study of hydrodynamic effects on fluid-fluid (gas and liquid) mixing and multiphase complexation, growth, and structure. We demonstrated this new design's potential for studying the flocculation of bentonite using cationic polyacrylamide for enhancing water treatment operations.

  11. Taylorism, Tylerism, and Performance Indicators: Defending the Indefensible?

    ERIC Educational Resources Information Center

    Helsby, Gill; Saunders, Murray

    1993-01-01

    Explores the antecedents to the growing interest in the use of educational performance indicators. Discusses this issue in relation to the work of economist F. W. Taylor and evaluator Ralph Tyler. Describes a five-year project that demonstrates the promise of teacher-developed performance indicators. (CFR)

  12. Why We Will Lose: Taylorism in America's High Schools.

    ERIC Educational Resources Information Center

    Gray, Kenneth

    1993-01-01

    Taylorism (rewards based on merit) and tracking in high schools should be abolished because these practices alienate successful students from less successful ones and encourage elitism instead of egalitarianism. Curriculum integration may be achieved by creating opportunities for student interaction in various existing subject areas. Teamwork and…

  13. Frank Bursley Taylor - Forgotten Pioneer of Continental Drift.

    ERIC Educational Resources Information Center

    Black, George W., Jr.

    1979-01-01

    Frank B. Taylor was an American geologist who specialized in the glacial geology of the Great Lakes. This article discusses his work on the Continental Drift theory, which preceeded the work of Alfred Wegener by a year and a half. (MA)

  14. Why We Will Lose: Taylorism in America's High Schools.

    ERIC Educational Resources Information Center

    Gray, Kenneth

    1993-01-01

    Taylorism (rewards based on merit) and tracking in high schools should be abolished because these practices alienate successful students from less successful ones and encourage elitism instead of egalitarianism. Curriculum integration may be achieved by creating opportunities for student interaction in various existing subject areas. Teamwork and…

  15. Taylorism, Tylerism, and Performance Indicators: Defending the Indefensible?

    ERIC Educational Resources Information Center

    Helsby, Gill; Saunders, Murray

    1993-01-01

    Explores the antecedents to the growing interest in the use of educational performance indicators. Discusses this issue in relation to the work of economist F. W. Taylor and evaluator Ralph Tyler. Describes a five-year project that demonstrates the promise of teacher-developed performance indicators. (CFR)

  16. On implicit Taylor series methods for stiff ODEs

    SciTech Connect

    Kirlinger, G. . Inst. fuer Angewandte und Numerische Mathematik); Corliss, G.F. )

    1991-01-01

    Several versions of implicit Taylor series methods (ITSM) are presented and evaluated. Criteria for the approximate solution of ODEs via ITSM are given. Some ideas, motivations, and remarks on the inclusion of the solution of stiff ODEs are outlined. 25 refs., 3 figs.

  17. On implicit Taylor series methods for stiff ODEs

    SciTech Connect

    Kirlinger, G.; Corliss, G.F.

    1991-12-31

    Several versions of implicit Taylor series methods (ITSM) are presented and evaluated. Criteria for the approximate solution of ODEs via ITSM are given. Some ideas, motivations, and remarks on the inclusion of the solution of stiff ODEs are outlined. 25 refs., 3 figs.

  18. Using Taylor Expansions to Prepare Students for Calculus

    ERIC Educational Resources Information Center

    Lutzer, Carl V.

    2011-01-01

    We propose an alternative to the standard introduction to the derivative. Instead of using limits of difference quotients, students develop Taylor expansions of polynomials. This alternative allows students to develop many of the central ideas about the derivative at an intuitive level, using only skills and concepts from precalculus, and…

  19. Some observations of a sheared Rayleigh-Taylor/Benard instability

    NASA Technical Reports Server (NTRS)

    Humphrey, J. A. C.; Marcus, D. L.

    1987-01-01

    An account is provided of preliminary flow visualization observations made in an unstably stratified flow with shear superimposed. The structures observed appear to be the superposition of a Rayleigh-Taylor/Benard instability and a Kelvin-Helmholtz instability. Aside from its intrinsic fundamental value, the study of these structures is of special interest to theoreticians developing nonlinear stability calculation methodologies.

  20. Slavnov-Taylor identities for noncommutative QED{sub 4}

    SciTech Connect

    Charneski, B.; Gomes, M.; Silva, A. J. da; Mariz, T.; Nascimento, J. R.

    2010-05-15

    In this work we present an analysis of the one-loop Slavnov-Taylor identities in noncommutative QED{sub 4}. The vectorial fermion-photon and the triple photon vertex functions were studied, with the conclusion that no anomalies arise.

  1. 5 CFR 531.246 - Within-grade increases for GM employees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Within-grade increases for GM employees....246 Within-grade increases for GM employees. GM employees are entitled to within-grade increases as provided under subpart D of this part. A within-grade increase may not cause a GM employee's GS rate to...

  2. The construction of exact Taylor states. I: The full sphere

    NASA Astrophysics Data System (ADS)

    Livermore, P. W.; Ierley, G.; Jackson, A.

    2009-11-01

    The dynamics of the Earth's fluid core are described by the so-called magnetostrophic balance between Coriolis, pressure, buoyancy and Lorentz forces. In this regime the geomagnetic field is subject to a continuum of theoretical conditions, which together comprise Taylor's constraint, placing restrictions on its internal structure. Examples of such fields, so-called Taylor states, have proven difficult to realize except in highly restricted cases. In previous theoretical developments, we showed that it was possible to reduce this infinite class of conditions to a finite number of coupled quadratic homogeneous equations when adopting a certain regular truncated spectral expansion for the magnetic field. In this paper, we illustrate the power of these results by explicitly constructing two families of exact Taylor states in a full sphere that match the same low-degree observationally derived model of the radial field at the core-mantle boundary. We do this by prescribing a smooth purely poloidal field that fits this observational model and adding to it an expediently chosen unconstrained set of interior toroidal harmonics of azimuthal wavenumbers 0 and 1. Formulated in terms of the toroidal coefficients, the resulting system is purely linear and can be readily solved to find Taylor states. By calculating the extremal members of the two families that minimize the Ohmic dissipation, we argue on energetic ground that the toroidal field in the Earth's core is likely to be dominated by low order azimuthal modes, similar to the observed poloidal field. Finally, we comment on the extension of finding Taylor states within a general truncated spectral expansion with arbitrary poloidal and toroidal coefficients.

  3. GM-CSF alters dendritic cells in autoimmune diseases.

    PubMed

    Li, Bao-Zhu; Ye, Qian-Ling; Xu, Wang-Dong; Li, Jie-Hua; Ye, Dong-Qing; Xu, Yuekang

    2013-11-01

    Autoimmune diseases arise from an inappropriate immune response against self components, including macromolecules, cells, tissues, organs etc. They are often triggered or accompanied by inflammation, during which the levels of granulocyte macrophage colony-stimulating factor (GM-CSF) are elevated. GM-CSF is an inflammatory cytokine that has profound impact on the differentiation of immune system cells of myeloid lineage, especially dendritic cells (DCs) that play critical roles in immune initiation and tolerance, and is involved in the pathogenesis of autoimmune diseases. Although GM-CSF was discovered decades ago, recent studies with some new findings have shed an interesting light on the old hematopoietic growth factor. In the inflammatory autoimmune diseases, GM-CSF redirects the normal developmental pathway of DCs, conditions their antigen presentation capacities and endows them with unique cytokine signatures to affect autoimmune responses. Here we review the latest advances in the field, with the aim of demonstrating the effects of GM-CSF on DCs and their influences on autoimmune diseases. The summarized knowledge will help to design DC-based strategies for the treatment of autoimmune diseases.

  4. Regulatory control of genetically modified (GM) foods: likely developments.

    PubMed

    Schilter, Benoît; Constable, Anne

    2002-02-28

    The placing of genetically modified (GM) crops on the European market requires a regulatory approval supported by a thorough safety evaluation. This approach has been applied to all GM crops presently on the market. Despite this stringent process there has been an increasing public concern about the impact of GM foods on human health and the environment. In this context, regulatory control may develop in several directions. One response to the public concern is to strengthen the data requirements for the risk assessment process. Several avenues have been proposed. They include the application of technologies such as proteomics and metabolomics to assess unintended changes, and the development of predictive methods to evaluate allergenicity. Obligations for post-launch surveillance have appeared in regulations. Criteria are required to define when and why such approaches are necessary. Significant challenges including feasibility and validation of the methods, and safety relevance of the data generated will have to be addressed before any general application of these new approaches. Effective monitoring requires the ability to identify the presence of GM products and trace their origin. Traceability and labeling are therefore important developments in the GM food regulatory arena. Both require the development of reliable analytical detection tools.

  5. [Recent advances in molecular genetics of GM2 gangliosidosis].

    PubMed

    Wakamatsu, N

    1995-12-01

    Recent advances in molecular genetics of GM2 gangliosidosis are reviewed. GM2 gangliosidosis is an autosomal recessive, neurodegenerative disease caused by a deficiency of beta-hexosaminidase (Hex, EC 3.2.1.52) A activity, resulting in accumulation of GM2 ganglioside in the lysosomes of neuronal cells. There are two catalytically active forms of this enzyme: Hex A, composed of one alpha and one beta subunits. Three forms of this disease, Tay-Sachs disease, Sandhoff disease, and GM2 activator deficiency, have been recognized according to whether the defect involves the alpha subunit, beta subunit, or GM2 activator protein, respectively. A number of gene abnormalities responsible for the disease have been identified and mutations specific for phenotypes and racial backgrounds are summarized. Recently, the murine models of human Tay-Sachs disease and Sandhoff disease have been produced. With the finding of dramatically clinical phenotypes in these mice, these models could be useful for research on the pathogenesis or therapy of these diseases.

  6. The FMCA-GM assays, high throughput non-clonogenic alternatives to CFU-GM in preclinical hematotoxicity testing.

    PubMed

    Haglund, Caroline; Aleskog, Anna; Håkansson, Lena Douhan; Höglund, Martin; Jacobsson, Stefan; Larsson, Rolf; Lindhagen, Elin

    2010-05-04

    One of the most common dose limiting adverse effects in cancer treatment is myelotoxicity. The aim of this study was to develop an in vitro method for measuring potential myelotoxic properties of a drug candidate in a high throughput setting. Human CD34(+) progenitor cells from umbilical cord blood were plated in 384-well microplates with drugs in liquid culture, supplemented with specific cytokines for the granulocytopoietic-macrophage lineage. After 7 or 14 days of proliferation and differentiation the cells were analyzed using the automated non-clonogenic fluorometric microculture cytotoxicity assay (FMCA). Two types of assays setups were evaluated, the FMCA-GM7 where cells were exposed to drugs directly after thawing and cytotoxicity measured on day 7 in contrast to the FMCA-GM14 where the cells were cultured 7 days prior to plating and drug exposure, with viability analysis on day 14 of differentiation. Drug sensitivity was similar in both assays and method validation was performed using 24 drugs with known myelotoxic profile (acyclovir, bortezomib, busulfan, carboplatin, chloramphenicol, chlorpromazine, cisplatin, cytarabine, clozapine, doxorubicin, erlotinib, etoposide, 5-fluorouracil, fludarabine, gefitinib, gemcitabine, hydroxyurea, imatinib, lomustine, melphalan, sorafenib, sunitinib, taxol and 6-thioguanine). The 50% inhibitory concentrations (IC(50)) from the FMCA-GM7 and the FMCA-GM14 correlated highly (r = 0.83) and (r = 0.82), respectively, with IC(50) from the established clonogenic assay (CFU-GM), obtained from the literature. The current data suggests that the FMCA-GM could offer a simple and robust alternative to the CFU-GM assay in preclinical hematotoxicity studies.

  7. Environmental Assessment for the Installation of the Taylor Mountain Long-Range Radar System Taylor Mountain, Alaska

    DTIC Science & Technology

    2005-06-01

    diameter (Photograph 2). Drill log samples collected from Taylor Mountain indicate that a moderately weathered granodiorite extends to 10 feet below...ground surface followed by granodiorite bedrock. Regional geology maps indicate that Kechumstuk Mountain has the similar lithology. 3.1.3.3 Soils

  8. Genome-wide analysis of DWD proteins in soybean (Glycine max): Significance of Gm08DWD and GmMYB176 interaction in isoflavonoid biosynthesis.

    PubMed

    Bian, Shaomin; Li, Xuyan; Mainali, Hemanta; Chen, Ling; Dhaubhadel, Sangeeta

    2017-01-01

    A subset of WD40 proteins with DWD motif has been proposed to serve as substrate receptor of DDB-CUL4-ROC1 complex, thereby getting involved in protein degradation via ubiquitination pathway. Here, we identified a total of 161 potential DWD proteins in soybean (Glycine max) by searching DWD motif against the genome-wide WD40 repeats, and classified them into 20 groups on the basis of their functional domains and annotations. These putative DWD genes in soybean displayed tissue-specific expression patterns, and their genome localization and analysis of evolutionary relationship identified 48 duplicated gene pairs within 161 GmDWDs. Among the 161 soybean DWD proteins, Gm08DWD was previously found to interact with an isoflavonoid regulator, GmMYB176. Therefore, Gm08DWD and its homologue Gm05DWD were further investigated. Expression profile of both genes in different soybean tissues revealed that Gm08DWD was expressed higher in embryo, while Gm05DWD exhibited maximum transcript accumulation in leaf. Our protein-protein interaction studies demonstrated that Gm08DWD interacts with GmMYB176. Although Gm08DWD was localized both in nucleus and cytoplasm, the resulting complex of Gm08DWD and GmMYB176 was mainly observed in the nucleus. This finding is consistent with the functional localization of CUL4-E3 ligase complex. In conclusion, the survey on soybean potential DWD protein is useful reference for the further functional investigation of their DDB1-binding ability. Based on the functional investigation of Gm08DWD, we speculate that protein-protein interaction between Gm08DWD and GmMYB176 may lead to the degradation of GmMYB176 through CUL4-DDB1complex.

  9. NMR-Metabolic Methodology in the Study of GM Foods

    PubMed Central

    Sobolev, Anatoly P.; Capitani, Donatella; Giannino, Donato; Nicolodi, Chiara; Testone, Giulio; Santoro, Flavio; Frugis, Giovanna; Iannelli, Maria A.; Mattoo, Autar K.; Brosio, Elvino; Gianferri, Raffaella; D’Amico, Irene; Mannina, Luisa

    2010-01-01

    The 1H-NMR methodology used in the study of genetically modified (GM) foods is discussed. Transgenic lettuce (Lactuca sativa cv "Luxor") over-expressing the ArabidopsisKNAT1 gene is presented as a case study. Twenty-two water-soluble metabolites (amino acids, organic acids, sugars) present in leaves of conventional and GM lettuce were monitored by NMR and quantified at two developmental stages. The NMR spectra did not reveal any difference in metabolite composition between the GM lettuce and the wild type counterpart. Statistical analyses of metabolite variables highlighted metabolism variation as a function of leaf development as well as the transgene. A main effect of the transgene was in altering sugar metabolism. PMID:22253988

  10. GM crops and the rat digestive tract: a critical review.

    PubMed

    Zdziarski, I M; Edwards, J W; Carman, J A; Haynes, J I

    2014-12-01

    The aim of this review is to examine the relationship between genetically modified (GM) crops and health, based on histopathological investigations of the digestive tract in rats. We reviewed published long-term feeding studies of crops containing one or more of three specific traits: herbicide tolerance via the EPSPS gene and insect resistance via cry1Ab or cry3Bb1 genes. These genes are commonly found in commercialised GM crops. Our search found 21 studies for nine (19%) out of the 47 crops approved for human and/or animal consumption. We could find no studies on the other 38 (81%) approved crops. Fourteen out of the 21 studies (67%) were general health assessments of the GM crop on rat health. Most of these studies (76%) were performed after the crop had been approved for human and/or animal consumption, with half of these being published at least nine years after approval. Our review also discovered an inconsistency in methodology and a lack of defined criteria for outcomes that would be considered toxicologically or pathologically significant. In addition, there was a lack of transparency in the methods and results, which made comparisons between the studies difficult. The evidence reviewed here demonstrates an incomplete picture regarding the toxicity (and safety) of GM products consumed by humans and animals. Therefore, each GM product should be assessed on merit, with appropriate studies performed to indicate the level of safety associated with them. Detailed guidelines should be developed which will allow for the generation of comparable and reproducible studies. This will establish a foundation for evidence-based guidelines, to better determine if GM food is safe for human and animal consumption. Copyright © 2014. Published by Elsevier Ltd.

  11. [Molecular pathogenesis and therapeutic approach of GM2 gangliosidosis].

    PubMed

    Tsuji, Daisuke

    2013-01-01

    Tay-Sachs and Sandhoff diseases (GM2 gangliosidoses) are autosomal recessive lysosomal storage diseases caused by gene mutations in HEXA and HEXB, each encoding human lysosomal β-hexosaminidase α-subunits and β-subunits, respectively. In Tay-Sachs disease, excessive accumulation of GM2 ganglioside (GM2), mainly in the central nervous system, is caused by a deficiency of the HexA isozyme (αβ heterodimer), resulting in progressive neurologic disorders. In Sandhoff disease, combined deficiencies of HexA and HexB (ββ homodimer) cause not only the accumulation of GM2 but also of oligosaccharides carrying terminal N-acetylhexosamine residues (GlcNAc-oligosaccharides), resulting in systemic manifestations including hepatosplenomegaly as well as neurologic symptoms. Hence there is little clinically effective treatment for these GM2 gangliosidoses. Recent studies on the molecular pathogenesis in Sandhoff disease patients and disease model mice have shown the involvement of microglial activation and chemokine induction in neuroinflammation and neurodegeneration in this disease. Experimental and therapeutic approaches, including recombinant enzyme replacement, have been performed using Sandhoff disease model mice, suggesting the future application of novel techniques to treat GM2 gangliosidoses (Hex deficiencies), including Sandhoff disease as well as Tay-Sachs disease. In this study, we isolated astrocytes and microglia from the neonatal brain of Sandhoff disease model mice and demonstrated abnormalities of glial cells. Moreover, we demonstrated the therapeutic effect of an intracerebroventricular administration of novel recombinant human HexA carrying a high content of M6P residue in Sandhoff disease model mice.

  12. SUMO E3 Ligases GmSIZ1a and GmSIZ1b regulate vegetative growth in soybean† 

    PubMed Central

    Cai, Bin; Kong, Xiangxiong; Zhong, Chao; Sun, Suli; Zhou, Xiao Feng; Jin, Yin Hua; Wang, Youning; Li, Xia; Zhu, Zhendong

    2017-01-01

    Abstract SIZ1 is a small ubiquitin‐related modifier (SUMO) E3 ligase that mediates post‐translational SUMO modification of target proteins and thereby regulates developmental processes and hormonal and environmental stress responses in Arabidopsis. However, the role of SUMO E3 ligases in crop plants is largely unknown. Here, we identified and characterized two Glycine max (soybean) SUMO E3 ligases, GmSIZ1a and GmSIZ1b. Expression of GmSIZ1a and GmSIZ1b was induced in response to salicylic acid (SA), heat, and dehydration treatment, but not in response to cold, abscisic acid (ABA), and NaCl treatment. Although GmSIZ1a was expressed at higher levels than GmSIZ1b, both genes encoded proteins with SUMO E3 ligase activity in vivo. Heterologous expression of GmSIZ1a or GmSIZ1b rescued the mutant phenotype of Arabidopsis siz1‐2, including dwarfism, constitutively activated expression of pathogen‐related genes, and ABA‐sensitive seed germination. Simultaneous downregulation of GmSIZ1a and GmSIZ1b (GmSIZ1a/b) using RNA interference (RNAi)‐mediated gene silencing decreased heat shock‐induced SUMO conjugation in soybean. Moreover, GmSIZ1RNAi plants exhibited reduced plant height and leaf size. However, unlike Arabidopsis siz1‐2 mutant plants, flowering time and SA levels were not significantly altered in GmSIZ1RNAi plants. Taken together, our results indicate that GmSIZ1a and GmSIZ1b mediate SUMO modification and positively regulate vegetative growth in soybean. PMID:27762067

  13. Beyond linear fields: the Lie-Taylor expansion

    NASA Astrophysics Data System (ADS)

    Arter, Wayne

    2017-01-01

    The work extends the linear fields' solution of compressible nonlinear magnetohydrodynamics (MHD) to the case where the magnetic field depends on superlinear powers of position vector, usually, but not always, expressed in Cartesian components. Implications of the resulting Lie-Taylor series expansion for physical applicability of the Dolzhansky-Kirchhoff (D-K) equations are found to be positive. It is demonstrated how resistivity may be included in the D-K model. Arguments are put forward that the D-K equations may be regarded as illustrating properties of nonlinear MHD in the same sense that the Lorenz equations inform about the onset of convective turbulence. It is suggested that the Lie-Taylor series approach may lead to valuable insights into other fluid models.

  14. A Taylor weak-statement algorithm for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Baker, A. J.; Kim, J. W.

    1987-01-01

    Finite element analysis, applied to computational fluid dynamics (CFD) problem classes, presents a formal procedure for establishing the ingredients of a discrete approximation numerical solution algorithm. A classical Galerkin weak-statement formulation, formed on a Taylor series extension of the conservation law system, is developed herein that embeds a set of parameters eligible for constraint according to specification of suitable norms. The derived family of Taylor weak statements is shown to contain, as special cases, over one dozen independently derived CFD algorithms published over the past several decades for the high speed flow problem class. A theoretical analysis is completed that facilitates direct qualitative comparisons. Numerical results for definitive linear and nonlinear test problems permit direct quantitative performance comparisons.

  15. Singularities in water waves and Rayleigh-Taylor instability

    NASA Technical Reports Server (NTRS)

    Tanveer, S.

    1991-01-01

    Singularities in inviscid two-dimensional finite-amplitude water waves and inviscid Rayleigh-Taylor instability are discussed. For the deep water gravity waves of permanent form, through a combination of analytical and numerical methods, results describing the precise form, number, and location of singularities in the unphysical domain as the wave height is increased are presented. It is shown how the information on the singularity in the unphysical region has the same form as for deep water waves. However, associated with such a singularity is a series of image singularities at increasing distances from the physical plane with possibly different behavior. Furthermore, for the Rayleigh-Taylor problem of motion of fluid over a vacuum and for the unsteady water wave problem, integro-differential equations valid in the unphysical region are derived, and how these equations can give information on the nature of singularities for arbitrary initial conditions is shown.

  16. Pediatric and adolescent applications of the Taylor Spatial Frame.

    PubMed

    Paloski, Michael; Taylor, Benjamin C; Iobst, Christopher; Pugh, Kevin J

    2012-06-01

    Limb deformity can occur in the pediatric and adolescent populations from multiple etiologies: congenital, traumatic, posttraumatic sequelae, oncologic, and infection. Correcting these deformities is important for many reasons. Ilizarov popularized external fixation to accomplish this task. Taylor expanded on this by designing an external fixator in 1994 with 6 telescoping struts that can be sequentially manipulated to achieve multiaxial correction of deformity without the need for hinges or operative frame alterations. This frame can be used to correct deformities in children and has shown good anatomic correction with minimal morbidity. The nature of the construct and length of treatment affects psychosocial factors that the surgeon and family must be aware of prior to treatment. An understanding of applications of the Taylor Spatial Frame gives orthopedic surgeons an extra tool to correct simple and complex deformities in pediatric and adolescent patients.

  17. Intraoperative measurement of mounting parameters for the Taylor Spatial Frame.

    PubMed

    Gantsoudes, George D; Fragomen, Austin T; Rozbruch, S Robert

    2010-04-01

    The Taylor Spatial Frame (Smith & Nephew, Memphis, TN) is a powerful tool in providing gradual correction of deformity. The Taylor Spatial Frame has the potential to allow for very accurate corrections achieved over one or more schedules through the use of the software on www.spatialframe.com. The accuracy of the frame is contingent upon the input of precise parameters. The correction occurs about a virtual hinge in space called the origin. The location of the origin is defined by its spatial relationship to the reference ring. Mounting parameters are the measurements that define the location of the origin (virtual hinge). We present a simple practical method for obtaining mounting parameters during surgery using standard equipment.

  18. Is the magnetopause Rayleigh-Taylor unstable sometimes?

    SciTech Connect

    Gratton, F.T.; Farrugia, C.J.; Cowley, S.W.H.

    1996-03-01

    The authors examine the question of whether the magnetopause is Rayleigh-Taylor stable. The magnetopause tends to be in continuous motion because of the effect of the dyanmic pressure from the solar wind. When there is a sudden drop in solar wind pressure, and the magnetopause tends to accelerate sunward, a situation is created where the magnetopause may go unstable. The authors look at two possible stabilizing effects, first the magnetic shear which exists across the magnetopause, and then the viscous nature of the magnetosheath plasma. They find that large shear leads to stability for the Rayleigh-Taylor mode. When there is a strong northward component in the magnetosheath field, they find that the magnetopause may be unstable to this mode for both global and internal modes. They also discuss the effect of such instabilities on observations.

  19. Taylor bubbles in liquid filled annuli: Some new observations

    NASA Astrophysics Data System (ADS)

    Agarwal, V.; Jana, A. K.; Das, G.; Das, P. K.

    2007-10-01

    Taylor bubbles rising through a vertical concentric annulus do not wrap around the inner tube completely. The two edges of the bubble are separated by a liquid bridge which increases with an increase of the inner radius. However, the change in the shape of the Taylor bubbles in annuli with extremely small inner diameter has not yet been reported. In the present investigation, several experiments have been performed in circular and noncircular annuli to understand the influence of the inner and outer wall on the bubble shape. The bubble has been observed to assume a completely different shape in both circular and square annuli with a very thin inner rod. Nevertheless, the rise velocity for such situations agree with the prediction of the model proposed by Das et al. [Chem. Eng. Sci. 53, 977 (1998)] when the outer pipe is circular but fails for a square outer pipe.

  20. A Taylor weak-statement algorithm for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Baker, A. J.; Kim, J. W.

    1987-01-01

    Finite element analysis, applied to computational fluid dynamics (CFD) problem classes, presents a formal procedure for establishing the ingredients of a discrete approximation numerical solution algorithm. A classical Galerkin weak-statement formulation, formed on a Taylor series extension of the conservation law system, is developed herein that embeds a set of parameters eligible for constraint according to specification of suitable norms. The derived family of Taylor weak statements is shown to contain, as special cases, over one dozen independently derived CFD algorithms published over the past several decades for the high speed flow problem class. A theoretical analysis is completed that facilitates direct qualitative comparisons. Numerical results for definitive linear and nonlinear test problems permit direct quantitative performance comparisons.

  1. Structures in Transitional Taylor-Couette Flows Identified using POD

    NASA Astrophysics Data System (ADS)

    Balabani, Stavroula; Imomoh, Eboshogwe; Dusting, Jonathan

    2009-11-01

    The flow in the gap between concentric cylinders, or Taylor-Couette flow, has been used to study transition to turbulence for decades, and is also utilised for various biotechnological and industrial processes. Transitional flow states depend highly on vessel geometry; they are also three-dimensional and often time dependent limiting the use of experimental techniques for their characterisation. In this talk the transition to turbulence in a Taylor-Couette flow is studied by means of time resolved PIV velocity fields and Proper Orthogonal Decomposition (POD). It is found that for the particular geometry studied the transition to turbulence occurs via a quasi periodic regime characterised by a fast moving azimuthal wave (FMAW). Aspects of the FMAW structure, such as a series of co-rotating vortices that increase in strength away from the endwalls, are also revealed by spatially resolved POD.

  2. Effect of Charge Density on the Taylor Cone in Electrospinning

    NASA Astrophysics Data System (ADS)

    Stanger, Jonathan; Tucker, Nick; Kirwan, Kerry; Staiger, Mark P.

    A detailed understanding of charge density and its origins during the electrospinning process is desirable for developing new electrospinnable polymer-solvent systems and ensuring mathematical models of the process are accurate. In this work, two different approaches were taken to alter the charge density in order to measure its effect on the Taylor cone, mass deposition rate and initial jet diameter. It was found that an increase in charge density results in a decrease in the mass deposition rate and initial jet diameter. A theory is proposed for this behaviour in that an increase in charge density leads to the tip of the Taylor cone forming a smaller radius of curvature resulting in the concentration of electric stresses at the tip. This leads to the electrostatic forces drawing the initial jet from a smaller effective area or "virtual orifice".

  3. Slavnov-Taylor Identities from the Causal Point of View

    NASA Astrophysics Data System (ADS)

    Dütsch, Michael

    We continue the investigation of quantized Yang-Mills theories coupled to matter fields in the framework of causal perturbation theory which goes back to Epstein and Glaser. In this approach gauge invariance is expressed by a simple commutator relation for the S matrix and the corresponding gauge transformations are simple transformations of the free fields only. In spite of this simplicity, gauge invariance implies the usual Slavnov-Taylor identities. The main purpose of this paper is to prove the latter statement. Since the Slavnov-Taylor identities are formulated in terms of Green functions, we investigate the agreement of two perturbative definitions of Green functions, namely Epstein and Glaser's definition with the Gell-Mann-Low series.

  4. Anisotropy and feedthrough in magneto-Rayleigh-Taylor instability

    SciTech Connect

    Lau, Y. Y.; Zier, J. C.; Rittersdorf, I. M.; Weis, M. R.; Gilgenbach, R. M.

    2011-06-15

    The magneto-Rayleigh-Taylor instability (MRT) of a finite slab is studied analytically using the ideal MHD model. The slab may be accelerated by an arbitrary combination of magnetic pressure and fluid pressure, thus allowing an arbitrary degree of anisotropy intrinsic to the acceleration mechanism. The effect of feedthrough in the finite slab is also analyzed. The classical feedthrough solution obtained by Taylor in the limit of zero magnetic field, the single interface MRT solution of Chandrasekhar in the limit of infinite slab thickness, and Harris' stability condition on purely magnetic driven MRT, are all readily recovered in the analytic theory as limiting cases. In general, we find that MRT retains robust growth if it exists. However, feedthrough may be substantially reduced if there are magnetic fields on both sides of the slab, and if the MRT mode invokes bending of the magnetic field lines.

  5. Anisotropy and feedthrough in magneto-Rayleigh-Taylor instability.

    PubMed

    Lau, Y Y; Zier, J C; Rittersdorf, I M; Weis, M R; Gilgenbach, R M

    2011-06-01

    The magneto-Rayleigh-Taylor instability (MRT) of a finite slab is studied analytically using the ideal MHD model. The slab may be accelerated by an arbitrary combination of magnetic pressure and fluid pressure, thus allowing an arbitrary degree of anisotropy intrinsic to the acceleration mechanism. The effect of feedthrough in the finite slab is also analyzed. The classical feedthrough solution obtained by Taylor in the limit of zero magnetic field, the single interface MRT solution of Chandrasekhar in the limit of infinite slab thickness, and Harris' stability condition on purely magnetic driven MRT, are all readily recovered in the analytic theory as limiting cases. In general, we find that MRT retains robust growth if it exists. However, feedthrough may be substantially reduced if there are magnetic fields on both sides of the slab, and if the MRT mode invokes bending of the magnetic field lines.

  6. Influence of velocity shear on the Rayleigh-Taylor instability

    SciTech Connect

    Guzdar, P.N.; Satyanarayana, P.; Huba, J.D.; Ossakow, S.L.

    1982-05-01

    The influence of a transverse velocity shear on the Rayleigh-Taylor instability is investigated. It is found that a sheared velocity flow can substantially reduce the growth rate of the Rayleigh-Taylor instability in short wavelength regime (i.e., kL>1 where L is the scale length of the density inhomogeneity), and causes the growth rate to maximize at kL<1.0. Applications of this result to ionospheric phenomena (equatorial spread F (ESF) and ionospheric plasma clouds) are discussed. In particular, the effect of shear could account for, at times, the 100's of km modulation observed on the bottomside of the ESF ionosphere and the km scale size wavelengths observed in barium cloud prompt striation phenomena.

  7. Beyond linear fields: the Lie-Taylor expansion.

    PubMed

    Arter, Wayne

    2017-01-01

    The work extends the linear fields' solution of compressible nonlinear magnetohydrodynamics (MHD) to the case where the magnetic field depends on superlinear powers of position vector, usually, but not always, expressed in Cartesian components. Implications of the resulting Lie-Taylor series expansion for physical applicability of the Dolzhansky-Kirchhoff (D-K) equations are found to be positive. It is demonstrated how resistivity may be included in the D-K model. Arguments are put forward that the D-K equations may be regarded as illustrating properties of nonlinear MHD in the same sense that the Lorenz equations inform about the onset of convective turbulence. It is suggested that the Lie-Taylor series approach may lead to valuable insights into other fluid models.

  8. Alteration of ganglioside synthesis by GM3 synthase knockout in murine embryonic fibroblasts.

    PubMed

    Shevchuk, Nikolai A; Hathout, Yetrib; Epifano, Olga; Su, Yan; Liu, Yihui; Sutherland, Margaret; Ladisch, Stephan

    2007-09-01

    To probe the functions of membrane gangliosides, the availability of ganglioside-depleted cells would be a valuable resource. To attempt to identify a useful genetic model of ganglioside depletion, we assessed ganglioside metabolism in murine GM3 synthase (GM3S)-/- knockout primary embryonic fibroblasts (MEF), because normal fibroblast gangliosides (GM3, GM2, GM1, and GD1a), all downstream products of GM3S, should be absent. We found that heterozygote MEF (GM3S+/-) did have a 36% reduced content of qualitatively normal gangliosides (7.0+/-0.8 nmol LBSA/mg cell protein; control: 11+/-1.6 nmol). However, two unexpected findings characterized the homozygous (GM3-/-) MEF. Despite complete knockout of GM3S, (i) GM3-/- MEF retained substantial ganglioside content (21% of normal or 2.3+/-1.1 nmol) and (ii) these gangliosides were entirely different from those of wild type MEF by HPTLC. Mass spectrometry identified them as GM1b, GalNAc-GM1b, and GD1alpha, containing both N-acetyl and N-glycolylneuraminic acid and diverse ceramide structures. All are products of the 0 pathway of ganglioside synthesis, not normally expressed in fibroblasts. The results suggest that complete, but not partial, inhibition of GM3 synthesis results in robust activation of an alternate pathway that may compensate for the complete absence of the products of GM3S.

  9. Taylor's Theorem: The Elusive "c" Is Not So Elusive

    ERIC Educational Resources Information Center

    Kreminski, Richard

    2010-01-01

    For a suitably nice, real-valued function "f" defined on an open interval containing [a,b], f(b) can be expressed as p[subscript n](b) (the nth Taylor polynomial of f centered at a) plus an error term of the (Lagrange) form f[superscript (n+1)](c)(b-a)[superscript (n+1)]/(n+1)! for some c in (a,b). This article is for those who think that not…

  10. Taylor's Theorem: The Elusive "c" Is Not So Elusive

    ERIC Educational Resources Information Center

    Kreminski, Richard

    2010-01-01

    For a suitably nice, real-valued function "f" defined on an open interval containing [a,b], f(b) can be expressed as p[subscript n](b) (the nth Taylor polynomial of f centered at a) plus an error term of the (Lagrange) form f[superscript (n+1)](c)(b-a)[superscript (n+1)]/(n+1)! for some c in (a,b). This article is for those who think that not…

  11. Viscous Rayleigh-Taylor instability in spherical geometry

    SciTech Connect

    Mikaelian, Karnig O.

    2016-02-08

    We consider viscous fluids in spherical geometry, a lighter fluid supporting a heavier one. Chandrasekhar [Q. J. Mech. Appl. Math. 8, 1 (1955)] analyzed this unstable configuration providing the equations needed to find, numerically, the exact growth rates for the ensuing Rayleigh-Taylor instability. He also derived an analytic but approximate solution. We point out a weakness in his approximate dispersion relation (DR) and offer one that is to some extent improved.

  12. Nested Taylor decomposition of univariate functions under fluctuationlessness approximation

    NASA Astrophysics Data System (ADS)

    Gürvit, Ercan; Baykara, N. A.

    2014-10-01

    Taylor decomposition of an analytic function and the use of the remainder part of this decomposition expressed in integral form on which Fluctuationlessness theorem is applied was already known in the litterature, but application of Fluctuationlessness approximation twice on the remainder part adds up an amelioration to the approximation. Organisation of the decomposition in such a way that this is made possible is explained in detail in this work.

  13. Rayleigh-Taylor instability in an equal mass plasma

    SciTech Connect

    Adak, Ashish; Ghosh, Samiran; Chakrabarti, Nikhil

    2014-09-15

    The Rayleigh-Taylor (RT) instability in an inhomogeneous pair-ion plasma has been analyzed. Considering two fluid model for two species of ions (positive and negative), we obtain the possibility of the existence of RT instability. The growth rate of the RT instability as usual depends on gravity and density gradient scale length. The results are discussed in context of pair-ion plasma experiments.

  14. Rayleigh-Taylor vortices in a pair-ion plasma

    SciTech Connect

    Adak, Ashish Khan, Manoranjan

    2015-04-15

    The Rayleigh-Taylor (RT) vortices and the analytical solution of three-mode coupling in pair-ion plasmas are investigated. It is shown that the E×B convection of polarization drift is responsible for the saturation of growing RT instability and as a result the localized dipole vortex structures are formed. The shear flow generation due to the destruction of vortex structures is discussed by the Fourier mode analysis.

  15. Linear instability in Rayleigh-stable Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Deguchi, Kengo

    2017-02-01

    Rayleigh's stability criterion describes the inviscid stability of rotating fluid flows. Despite the limitations of the criterion due to the assumptions used, it has been widely viewed as a general stability barrier in various rapidly rotating flows. However, contrary to previous belief, a linear instability is identified in Rayleigh-stable Taylor-Couette flow. The instability is found in cyclonic rapid rotation regime, for almost the entire range of the radius ratio of the cylinders.

  16. General theory of Taylor dispersion phenomena. Part 3. Surface transport

    SciTech Connect

    Dill, L.H.; Brenner, H.

    1982-01-01

    An asymptotic theory of Brownian tracer particle transport phenomena within a bulk fluid, as augmented by surface transport, is presented in the context of generalized Taylor dispersion theory. The analysis expands upon prior work, which was limited to transport wholly within a continuous phase, so as to now include surface adsorption, diffusion, and convection of the tracer along a continuous surface bounding the continuous fluid phase.

  17. Numerical study of a Taylor bubble rising in stagnant liquids.

    PubMed

    Kang, Chang-Wei; Quan, Shaoping; Lou, Jing

    2010-06-01

    The dynamics of a Taylor bubble rising in stagnant liquids is numerically investigated using a front tracking coupled with finite difference method. Parametric studies on the dynamics of the rising Taylor bubble including the final shape, the Reynolds number (Re(T)), the Weber number (We(T)), the Froude number (Fr), the thin liquid film thickness (w/D), and the wake length (l(w)/D) are carried out. The effects of density ratio (η), viscosity ratio (λ), Eötvös number (Eo), and Archimedes number (Ar) are examined. The simulations demonstrate that the density ratio and the viscosity ratio under consideration have minimal effect on the dynamics of the Taylor bubble. Eötvös number and Archimedes number influence the elongation of the tail and the wake structures, where higher Eo and Ar result in longer wake. To explain the sudden extension of the tail, a Weber number (We(l)) based on local curvature and velocity is evaluated and a critical We(l) is detected around unity. The onset of flow separation at the wake occurs in between Ar=2×10(3) and Ar=1×10(4), which corresponds to Re(T) between 13.39 and 32.55. Archimedes number also drastically affects the final shape of Taylor bubble, the terminal velocity, the thickness of thin liquid film, as well as the wall shear stress. It is found that w/D=0.32 Ar(-0.1).

  18. Rayleigh-Taylor instability in dusty plasma experiment

    SciTech Connect

    Avinash, K.; Sen, A.

    2015-08-15

    The stability of a stratified dust cloud levitated in an anodic plasma is studied in the weakly and strongly coupled dust regimes. It is shown that the cloud is predominantly unstable to a Rayleigh-Taylor (RT) instability driven by a component of the ambient gravity in a direction opposite to the direction of dust density stratification in the cloud. The elasticity of the strongly coupled dust is shown to set a threshold for the RT instability, which is consistent with experimental observations.

  19. Ablative stabilization of the deceleration phase rayleigh-taylor instability

    PubMed

    Lobatchev; Betti

    2000-11-20

    The growth rates of the deceleration-phase Rayleigh-Taylor instability for imploding inertial confinement fusion capsules are calculated and compared with the results of numerical simulations. It is found that the unstable spectrum and the growth rates are significantly reduced by the finite ablation flow at the shell's inner surface. For typical direct-drive capsules designed for the National Ignition Facility, the unstable spectrum exhibits a cutoff for l approximately 90.

  20. Linear instability in Rayleigh-stable Taylor-Couette flow.

    PubMed

    Deguchi, Kengo

    2017-02-01

    Rayleigh's stability criterion describes the inviscid stability of rotating fluid flows. Despite the limitations of the criterion due to the assumptions used, it has been widely viewed as a general stability barrier in various rapidly rotating flows. However, contrary to previous belief, a linear instability is identified in Rayleigh-stable Taylor-Couette flow. The instability is found in cyclonic rapid rotation regime, for almost the entire range of the radius ratio of the cylinders.

  1. Nonlinear Rayleigh-Taylor instability of rotating inviscid fluids.

    PubMed

    Tao, J J; He, X T; Ye, W H; Busse, F H

    2013-01-01

    It is demonstrated theoretically that the nonlinear stage of the Rayleigh-Taylor instability can be retarded at arbitrary Atwood numbers in a rotating system with the axis of rotation normal to the acceleration of the interface between two uniform inviscid fluids. The Coriolis force provides an effective restoring force on the perturbed interface, and the uniform rotation will always decrease the nonlinear saturation amplitude of the interface at any disturbance wavelength.

  2. Subcritical dynamo bifurcation in the Taylor-Green flow.

    PubMed

    Ponty, Y; Laval, J-P; Dubrulle, B; Daviaud, F; Pinton, J-F

    2007-11-30

    We report direct numerical simulations of dynamo generation for flow generated using a Taylor-Green forcing. We find that the bifurcation is subcritical and show its bifurcation diagram. We connect the associated hysteretic behavior with hydrodynamics changes induced by the action of the Lorentz force. We show the geometry of the dynamo magnetic field and discuss how the dynamo transition can be induced when an external field is applied to the flow.

  3. Solving ODE Initial Value Problems With Implicit Taylor Series Methods

    NASA Technical Reports Server (NTRS)

    Scott, James R.

    2000-01-01

    In this paper we introduce a new class of numerical methods for integrating ODE initial value problems. Specifically, we propose an extension of the Taylor series method which significantly improves its accuracy and stability while also increasing its range of applicability. To advance the solution from t (sub n) to t (sub n+1), we expand a series about the intermediate point t (sub n+mu):=t (sub n) + mu h, where h is the stepsize and mu is an arbitrary parameter called an expansion coefficient. We show that, in general, a Taylor series of degree k has exactly k expansion coefficients which raise its order of accuracy. The accuracy is raised by one order if k is odd, and by two orders if k is even. In addition, if k is three or greater, local extrapolation can be used to raise the accuracy two additional orders. We also examine stability for the problem y'= lambda y, Re (lambda) less than 0, and identify several A-stable schemes. Numerical results are presented for both fixed and variable stepsizes. It is shown that implicit Taylor series methods provide an effective integration tool for most problems, including stiff systems and ODE's with a singular point.

  4. High-Reynolds Number Taylor-Couette Turbulence

    NASA Astrophysics Data System (ADS)

    Grossmann, Siegfried; Lohse, Detlef; Sun, Chao

    2016-01-01

    Taylor-Couette flow, the flow between two coaxial co- or counter-rotating cylinders, is one of the paradigmatic systems in the physics of fluids. The (dimensionless) control parameters are the Reynolds numbers of the inner and outer cylinders, the ratio of the cylinder radii, and the aspect ratio. One key response of the system is the torque required to retain constant angular velocities, which can be connected to the angular velocity transport through the gap. Whereas the low-Reynolds number regime was well explored in the 1980s and 1990s of the past century, in the fully turbulent regime major research activity developed only in the past decade. In this article, we review this recent progress in our understanding of fully developed Taylor-Couette turbulence from the experimental, numerical, and theoretical points of view. We focus on the parameter dependence of the global torque and on the local flow organization, including velocity profiles and boundary layers. Next, we discuss transitions between different (turbulent) flow states. We also elaborate on the relevance of this system for astrophysical disks (quasi-Keplerian flows). The review ends with a list of challenges for future research on turbulent Taylor-Couette flow.

  5. The effect of crossflow on Taylor vortices: A model problem

    NASA Technical Reports Server (NTRS)

    Otto, S. R.; Bassom, Andrew P.

    1993-01-01

    A number of practically relevant problems involving the impulsive motion or the rapid rotation of bodies immersed in fluid are susceptible to vortex-like instability modes. Depending upon the configuration of any particular problem the stability properties of any high-wavenumber vortices can take on one of two distinct forms. One of these is akin to the structure of Gortler vortices in boundary layer flows while the other is similar to the situation for classical Taylor vortices. Both the Gortler and Taylor problems have been extensively studied when crossflow effects are excluded from the underlying base flows. Recently, studies were made concerning the influence of crossflow on Gortler modes and a linearized stability analysis is used to examine crossflow properties for the Taylor mode. This work allows us to identify the most unstable vortex as the crossflow component increases and it is shown how, like the Gortler case, only a very small crossflow component is required in order to completely stabilize the flow. Our investigation forms the basis for an extension to the nonlinear problem and is of potential applicability to a range of pertinent flows.

  6. Taylor bubbles at high viscosity ratios: experiments and numerical simulations

    NASA Astrophysics Data System (ADS)

    Hewakandamby, Buddhika; Hasan, Abbas; Azzopardi, Barry; Xie, Zhihua; Pain, Chris; Matar, Omar

    2015-11-01

    The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube, often occurring in gas-liquid slug flows in many industrial applications, particularly oil and gas production. The objective of this study is to investigate the fluid dynamics of three-dimensional Taylor bubble rising in highly viscous silicone oil in a vertical pipe. An adaptive unstructured mesh modelling framework is adopted here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rising and reduce computational effort without sacrificing accuracy. The numerical framework consists of a mixed control volume and finite element formulation, a `volume of fluid'-type method for the interface-capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Experimental results for the Taylor bubble shape and rise velocity are presented, together with numerical results for the dynamics of the bubbles. A comparison of the simulation predictions with experimental data available in the literature is also presented to demonstrate the capabilities of our numerical method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  7. Boundary effects and the onset of Taylor vortices

    NASA Astrophysics Data System (ADS)

    Rucklidge, A. M.; Champneys, A. R.

    2004-05-01

    It is well established that the onset of spatially periodic vortex states in the Taylor-Couette flow between rotating cylinders occurs at the value of Reynolds number predicted by local bifurcation theory. However, the symmetry breaking induced by the top and bottom plates means that the true situation should be a disconnected pitchfork. Indeed, experiments have shown that the fold on the disconnected branch can occur at more than double the Reynolds number of onset. This leads to an apparent contradiction: why should Taylor vortices set in so sharply at the Reynolds number predicted by the symmetric theory, given such large symmetry-breaking effects caused by the boundary conditions? This paper offers a generic explanation. The details are worked out using a Swift-Hohenberg pattern formation model that shares the same qualitative features as the Taylor-Couette flow. Onset occurs via a wall mode whose exponential tail penetrates further into the bulk of the domain as the driving parameter increases. In a large domain of length L, we show that the wall mode creates significant amplitude in the centre at parameter values that are O( L-2) away from the value of onset in the problem with ideal boundary conditions. We explain this as being due to a Hamiltonian Hopf bifurcation in space, which occurs at the same parameter value as the pitchfork bifurcation of the temporal dynamics. The disconnected anomalous branch remains O(1) away from the onset parameter since it does not arise as a bifurcation from the wall mode.

  8. Taylor--Couette--Poiseuille flow with a permeable inner cylinder

    NASA Astrophysics Data System (ADS)

    Tilton, Nils; Martinand, Denis; Serre, Eric; Lueptow, Richard

    2010-11-01

    We consider laminar Taylor--Couette--Poiseuille flow between an outer, fixed, impermeable cylinder and a concentric, inner, rotating, permeable cylinder with radial suction. Due to centrifugal instabilities the steady flow transitions to Taylor vortex flow. This system is used in filtration because the vortices wash contaminants away from the permeable cylinder. The coupling between the axial pressure drop driving the annular Poiseuille flow, and the transmembrane pressure driving the suction induces axial variations of the velocity field of the subcritical flow, which can evolve from suction to injection (cross flow reversal) or consume the whole axial flow (axial flow exhaustion). Moreover, the stability of this flow departs from that of Taylor--Couette flow. We propose an asymptotic solution to the subcritical flow assuming slow axial variations of the velocity and pressure fields. The transmembrane suction and pressure are coupled through Darcy's law. This solution is then used as a base flow to study the appearance of instabilities in the form of global modes. The analytical results for the subcritical and supercritical flows are then compared with dedicated 3-D spectral direct numerical simulations implementing Darcy's law on the inner cylinder.

  9. Numerical study of Taylor bubbles with adaptive unstructured meshes

    NASA Astrophysics Data System (ADS)

    Xie, Zhihua; Pavlidis, Dimitrios; Percival, James; Pain, Chris; Matar, Omar; Hasan, Abbas; Azzopardi, Barry

    2014-11-01

    The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube. This type of bubble flow regime often occurs in gas-liquid slug flows in many industrial applications, including oil-and-gas production, chemical and nuclear reactors, and heat exchangers. The objective of this study is to investigate the fluid dynamics of Taylor bubbles rising in a vertical pipe filled with oils of extremely high viscosity (mimicking the ``heavy oils'' found in the oil-and-gas industry). A modelling and simulation framework is presented here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rise and reduce the computational effort without sacrificing accuracy. The numerical framework consists of a mixed control-volume and finite-element formulation, a ``volume of fluid''-type method for the interface capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Numerical examples of some benchmark tests and the dynamics of Taylor bubbles are presented to show the capability of this method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  10. Patterns of the turbulent Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Prigent, Arnaud; Talioua, Abdessamad; Mutabazi, Innocent

    2016-11-01

    We are interested in the study of the transition to turbulence in the Taylor-Couette flow, the flow between two independently rotating coaxial cylinders. Once the geometry is fixed, the flow is controlled by the inner and outer Reynolds numbers and present a large variety of flow regimes. In counter-rotation, the transition is characterized by a succession of more or less turbulent flow regimes: intermittency with turbulent spots, spiral turbulence, featureless turbulence. For larger values of the inner Reynolds number, turbulent Taylor roll re-emerge from the featureless turbulence and remain for very large values of the Reynolds numbers. Bifurcations between different turbulent rolls states are even observed in the ultimate turbulence regime. Nevertheless the transition from the featureless turbulence to the turbulent rolls still requires a detailed study and the mechanism which causes and sustains turbulent spots or turbulent spirals remains unknown. In this study we present new experimental information on the organization of the flow for the different regimes with turbulence. The experiments are conducted in a Taylor-Couette flow with η = 0 . 8 . Stereo-Particle Image Velocimetry measurements and visualizations of the different flow regimes are realized and discussed. This work was supported by the ANR TRANSFLOW - ANR-13-BS09-0025.

  11. Public Acceptance of Plant Biotechnology and GM Crops

    PubMed Central

    Lucht, Jan M.

    2015-01-01

    A wide gap exists between the rapid acceptance of genetically modified (GM) crops for cultivation by farmers in many countries and in the global markets for food and feed, and the often-limited acceptance by consumers. This review contrasts the advances of practical applications of agricultural biotechnology with the divergent paths—also affecting the development of virus resistant transgenic crops—of political and regulatory frameworks for GM crops and food in different parts of the world. These have also shaped the different opinions of consumers. Important factors influencing consumer’s attitudes are the perception of risks and benefits, knowledge and trust, and personal values. Recent political and societal developments show a hardening of the negative environment for agricultural biotechnology in Europe, a growing discussion—including calls for labeling of GM food—in the USA, and a careful development in China towards a possible authorization of GM rice that takes the societal discussions into account. New breeding techniques address some consumers’ concerns with transgenic crops, but it is not clear yet how consumers’ attitudes towards them will develop. Discussions about agriculture would be more productive, if they would focus less on technologies, but on common aims and underlying values. PMID:26264020

  12. The Unusual Photometric Variability of the PMS Star GM Cep

    NASA Astrophysics Data System (ADS)

    Semkov, E. H.; Ibryamov, S. I.; Peneva, S. P.; Milanov, T. R.; Stoyanov, K. A.; Stateva, I. K.; Kjurkchieva, D. P.; Dimitrov, D. P.; Radeva, V. S.

    2015-03-01

    Results from UBVRI photometric observations of the pre-main sequence star GM Cep obtained in the period 2011 April-2014 August are reported in the paper. Presented data are a continuation of our photometric monitoring of the star started in 2008. GM Cep is located in the field of the young open cluster Trumpler 37 and over the past years it has been an object of intense photometric and spectral studies. The star shows a strong photometric variability interpreted as a possible outburst from EXor type in previous studies. Our photometric data for a period of over six years show a large amplitude variability (ΔV ~ 2.3 mag) and several deep minimums in brightness are observed. The analysis of the collected multicolour photometric data show the typical of UX Ori variables a colour reversal during the minimums in brightness. The observed decreases in brightness have a different shape, and evidences of periodicity are not detected. At the same time, high amplitude rapid variations in brightness typical for the classical T Tauri stars also present on the light curve of GM Cep. The spectrum of GM Cep shows the typical of classical T Tauri stars wide Hα emission line and absorption lines of some metals. We calculate the outer radius of the Hα emitting region as 10.4 ± 0.5 R⊙ and the accretion rate as 1.8 × 10- 7 M⊙ yr- 1.

  13. Effects of GM crops on non-target organisms

    USDA-ARS?s Scientific Manuscript database

    Crop genetically engineered to provide resistance to specific groups of insect pests have been adopted by millions of growers throughout the world. GM crops have become important tools in crop production and protection in many countries and contribute significantly to overall IPM programs. There, ...

  14. NMR-Metabolic Methodology in the Study of GM Foods

    USDA-ARS?s Scientific Manuscript database

    The 1H NMR methodology used in the study of genetically modified (GM) foodstuff is discussed. The study of transgenic lettuce (Lactuca sativa cv "Luxor") over-expressing the KNAT1 gene from Arabidopsis is presented as a novel study-case. The 1H NMR metabolic profiling was carried out. Twenty-two wat...

  15. EU Regulations Impede Market Introduction of GM Forest Trees.

    PubMed

    Custers, René; Bartsch, Detlef; Fladung, Matthias; Nilsson, Ove; Pilate, Gilles; Sweet, Jeremy; Boerjan, Wout

    2016-04-01

    Biotechnology can greatly improve the efficiency of forest tree breeding for the production of biomass, energy, and materials. However, EU regulations impede the market introduction of genetically modified (GM) trees so their socioeconomic and environmental benefits are not realized. European policy makers should concentrate on a science-based regulatory process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Public Acceptance of Plant Biotechnology and GM Crops.

    PubMed

    Lucht, Jan M

    2015-07-30

    A wide gap exists between the rapid acceptance of genetically modified (GM) crops for cultivation by farmers in many countries and in the global markets for food and feed, and the often-limited acceptance by consumers. This review contrasts the advances of practical applications of agricultural biotechnology with the divergent paths-also affecting the development of virus resistant transgenic crops-of political and regulatory frameworks for GM crops and food in different parts of the world. These have also shaped the different opinions of consumers. Important factors influencing consumer's attitudes are the perception of risks and benefits, knowledge and trust, and personal values. Recent political and societal developments show a hardening of the negative environment for agricultural biotechnology in Europe, a growing discussion-including calls for labeling of GM food-in the USA, and a careful development in China towards a possible authorization of GM rice that takes the societal discussions into account. New breeding techniques address some consumers' concerns with transgenic crops, but it is not clear yet how consumers' attitudes towards them will develop. Discussions about agriculture would be more productive, if they would focus less on technologies, but on common aims and underlying values.

  17. Reconnaissance study of the Taylor Mountains pluton, southwestern Alaska

    USGS Publications Warehouse

    Hudson, Travis L.; Miller, Marti L.; Klimasauskas, Edward P.; Layer, Paul W.

    2010-01-01

    The Taylor Mountains pluton is a Late Cretaceous to early Tertiary (median age 65 + or ? 2 Ma) epizonal, composite biotite granite stock located about 235 km (145 mi) northeast of Dillingham in southwestern Alaska. This 30 km2 (12 mi2) pluton has sharp and discordant contacts with hornfels that developed in Upper Cretaceous clastic sedimentary rocks of the Kuskokwim Group. The three intrusive phases in the Taylor Mountains pluton, in order of emplacement, are (1) porphyritic granite containing large K-feldspar phenocrysts in a coarse-grained groundmass, (2) porphyritic granite containing large K-feldspar and smaller, but still coarse, plagioclase, quartz, and biotite phenocrysts in a fine-grained groundmass, and (3) fine-grained, leucocratic, equigranular granite. The porphyritic granites have different emplacement histories, but similar compositions; averages are 69.43 percent SiO2, 1.62 percent CaO, 5.23 percent FeO+MgO, 3.11 percent Na2O, and 4.50 percent K2O. The fine-grained, equigranular granite is distinctly felsic compared to porphyritic granite; it averages 75.3 percent SiO2, 0.49 percent CaO, 1.52 percent FeO+MgO, 3.31 percent Na2O, and 4.87 percent K2O. Many trace elements including Ni, Cr, Sc, V, Ba, Sr, Zr, Y, Nb, La, Ce, Th, and Nd are strongly depleted in fine-grained equigranular granite. Trace elements are not highly enriched in any of the granites. Known hydrothermal alteration is limited to one tourmaline-quartz replacement zone in porphyritic granite. Mineral deposits in the Taylor Mountains area are primarily placer gold (plus wolframite, cassiterite, and cinnabar); sources for these likely include scattered veins in hornfels peripheral to the Taylor Mountain pluton. The granite magmas that formed the Taylor Mountains pluton are thought to represent melted continental crust that possibly formed in response to high heat flow in the waning stage of Late Cretaceous subduction beneath interior Alaska.

  18. Soluble salt accumulations in Taylor Valley, Antarctica: Implications for paleolakes and Ross Sea Ice Sheet dynamics

    NASA Astrophysics Data System (ADS)

    Toner, Jonathan D.; Sletten, Ronald S.; Prentice, Michael L.

    2013-03-01

    salt accumulations in soils of Taylor Valley, Antarctica, provide a history of paleolakes and the advance of the Ross Sea Ice Sheet (RSIS). In western Taylor Valley, soluble salt accumulations are relatively high and are composed primarily of Na+, Ca2+, Cl-, and SO42-. In eastern Taylor Valley, soluble salt accumulations are much lower and are composed primarily of Na+ and HCO3-. Na-HCO3-rich compositions in eastern Taylor Valley are formed through leaching, calcite dissolution, and cation exchange reactions and appear to influence the chemistry of nearby streams and lakes. The data presented here support hypotheses that a lobe of the RSIS expanded into eastern Taylor Valley and dammed proglacial paleolakes. However, in contrast to previous studies, our findings indicate that the RSIS advanced deeper into Taylor Valley and that paleolakes were less extensive. By comparing soluble salt distributions across Taylor Valley, we conclude that a lobe of the RSIS filled all of eastern Taylor Valley and dammed paleolakes in western Taylor Valley up to approximately 300 m elevation. Following ice retreat, smaller paleolakes formed in both western and eastern Taylor Valley up to about 120 m elevation, with prominent still-stands controlled by the elevation of major valley thresholds. At higher elevations, soluble salt accumulations are consistent with older soils that have not been affected by the most recent RSIS advance.

  19. Characterization of human lymphoid cell lines GM9947 and GM9948 as intra- and interlaboratory reference standards for DNA typing

    SciTech Connect

    Fregeau, C.J.; Elliott, J.C.; Fourney, R.M.

    1995-07-20

    The incorporation of reference DNA is crucial to the validation of any DNA typing protocol. Currently, reference DNA standards are restricted to molecular size DNA ladders and/or tumor cell line DNA. Either of these, however, presents some limitations. We have rigorously characterized two Epstein-Barr virus (EBV)-immortalized human lymphoid cell lines-GM9947 (female) and GM9948 (male)-to determine their suitability as alternative in-line standards for three widely employed allele profiling strategies. Twenty-one highly polymorphic VNTR-based allelic systems (7 RFLPs, 2 AmpFLPs, and 12 STRs) distributed over 12 chromosomes were scrutinized along with 3 gender-based discriminatory systems. The genetic stability of each locus was confirmed over a period of 225 in vitro population doublings. Allele size estimates and degree of informativeness for each of the 21 VNTR systems were compiled. The reproducibility of allele scoring by traditional RFLP analyses, using both cell lines as reference standards, was also verified by an interlaboratory validation study involving 13 analysts from two geographically distinct forensic laboratories. Taken together, our data indicate that GM9947 and GM9948 genomic DNAs could be adopted as reliable reference standards for DNA typing. 82 refs., 3 figs., 8 tabs.

  20. Immunogenicity of granulocyte-macrophage colony-stimulating factor (GM-CSF) products in patients undergoing combination therapy with GM-CSF.

    PubMed

    Wadhwa, M; Skog, A L; Bird, C; Ragnhammar, P; Lilljefors, M; Gaines-Das, R; Mellstedt, H; Thorpe, R

    1999-06-01

    In this study, we have assessed the development of neutralizing and nonneutralizing granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies in two groups of patients with metastatic colorectal carcinoma receiving two different GM-CSF products. Three clinical trials were carried out, and a combination of GM-CSF and a colon carcinoma-reactive antibody was used in the absence of any concomitant chemotherapy. Two different GM-CSF products, both rDNA-derived and produced in Escherichia coli, were used. Patients in Trial 1 received product X, and those in Trials 2 and 3 received product Y. Patients in Trial 2 also received interleukin 2 in an attempt to potentiate immune responses. After the first cycle of treatment, no GM-CSF antibodies were detected, but on subsequent therapy, 28 of the 38 patients tested receiving product Y (Trials 2 and 3) developed antibodies that bound to the GM-CSF product used for therapy. However, none of the patients developed antibodies that neutralized the biological activity of GM-CSF, as assessed using an in vitro bioassay. Furthermore, there was no in vivo impairment in GM-CSF-induced expansion of leukocytes, neutrophils, and eosinophils in the patients. In contrast, 19 of the 20 patients given product X (Trial 1) developed GM-CSF binding antibodies, and 9 of these patients were shown to develop antibodies that neutralized the biological activity of GM-CSF. The presence of the latter was associated with a significant reduction in GM-CSF-induced expansion of leukocytes, neutrophils, and eosinophils in patients. Therefore, product X appears to be more immunogenic than product Y. Immunochemical characterization confirmed that the specificity of the antibody responses varied depending on the product used for therapy. Whereas sera from Trial 1 patients treated with product X showed the presence of antibodies with strong recognition of GM-CSF proteins, sera from patients treated with product Y showed varied recognition of GM

  1. Comparative antitumor effect among GM-CSF, IL-12 and GM-CSF+IL-12 genetically modified tumor cell vaccines.

    PubMed

    Miguel, A; Herrero, M J; Sendra, L; Botella, R; Algás, R; Sánchez, M; Aliño, S F

    2013-10-01

    Genetically modified cells have been shown to be one of the most effective cancer vaccine strategies. An evaluation is made of the efficacy of both preventive and therapeutic antitumor vaccines against murine melanoma, using C57BL/6 mice and irradiated B16 tumor cells expressing granulocyte and macrophage colony-stimulating factor (GM-CSF), interleukin-12 (IL-12) or both. Tumor was transplanted by the injection of wild-type B16 cells. Tumor growth and survival were measured to evaluate the efficacy of vaccination. Specific humoral response and immunoglobulin G (IgG) switch were evaluated measuring total IgG and IgG1 and IgG2a subtypes against tumor membrane proteins of B16 cells. In preventive vaccination, all treated groups showed delayed tumor growth. In addition, the group vaccinated to express only GM-CSF achieved 100% animal survival (P<0.005). Vaccination with GM-CSF+IL-12-producing B16 cells yielded lesser results (60% survival, P<0.005). Furthermore, all surviving animals remained disease-free after second tumor implantation 1 year later. The therapeutic vaccination strategies resulted in significantly delayed tumor growth, mainly using B16 cells producing GM-CSF+IL-12 cytokines, with 70% tumor growth inhibition (P<0.001)-although none of the animals reached overall survival. The results obtained suggest that the GM-CSF+IL-12 combination only increases the efficacy of therapeutic vaccines. No differences in classical regulatory T cells were found among the different groups.

  2. Bright and durable field emission source derived from refractory taylor cones

    DOEpatents

    Hirsch, Gregory

    2016-12-20

    A method of producing field emitters having improved brightness and durability relying on the creation of a liquid Taylor cone from electrically conductive materials having high melting points. The method calls for melting the end of a wire substrate with a focused laser beam, while imposing a high positive potential on the material. The resulting molten Taylor cone is subsequently rapidly quenched by cessation of the laser power. Rapid quenching is facilitated in large part by radiative cooling, resulting in structures having characteristics closely matching that of the original liquid Taylor cone. Frozen Taylor cones thus obtained yield desirable tip end forms for field emission sources in electron beam applications. Regeneration of the frozen Taylor cones in-situ is readily accomplished by repeating the initial formation procedures. The high temperature liquid Taylor cones can also be employed as bright ion sources with chemical elements previously considered impractical to implement.

  3. Loss of GM-CSF signalling in non-haematopoietic cells increases NSAID ileal injury

    PubMed Central

    Han, Xiaonan; Gilbert, Shila; Groschwitz, Katherine; Hogan, Simon; Jurickova, Ingrid; Trapnell, Bruce; Samson, Charles; Gully, Jonathan

    2014-01-01

    Background Administration of granulocyte-macrophage colony stimulating factor (GM-CSF) relieves symptoms in Crohn's disease (CD). It has been reported that reduced GM-CSF bioactivity is associated with more aggressive ileal behaviour and that GM-CSF-null mice exhibit ileal barrier dysfunction and develop a transmural ileitis following exposure to non-steroidal anti-inflammatory drugs (NSAIDs). STAT5 signalling is central to GM-CSF action. It was therefore hypothesised that GM-CSF signalling in non-haematopoietic cells is required for ileal homeostasis. Methods Bone marrow (BM) chimeras were generated by reconstituting irradiated GM-CSF receptor (gm-csfr) β chain or GM-CSF (gm-csf) deficient mice with wild type BM (WTBM→GMRKO and WTBM→GMKO). Intestinal barrier function and the response to NSAID-induced ileal injury were examined. Expression of gm-csf, gm-csfr or stat5 in Caco-2 and HT-29 intestinal epithelial cell (IEC) lines was knocked down and the effect of GM-CSF signalling on IEC survival and proliferation was determined. Results Elevated levels of GM-CSF autoantibodies in ileal CD were found to be associated with dysregulation of IEC survival and proliferation. GM-CSF receptor-deficient mice and WTBM→GMRKO chimeras exhibited ileal hyperpermeability. NSAID exposure induced a transmural ileitis in GM-CSF receptor-deficient mice and WTBM→GMRKO chimeras. Transplantation of wild type BM into GM-CSF-deficient mice prevented NSAID ileal injury and restored ileal barrier function. Ileal crypt IEC proliferation was reduced in WTBM→GMRKO chimeras, while STAT5 activation in ileal IEC following NSAID exposure was abrogated in WTBM→GMRKO chimeras. Following knock down of gm-csf, gm-csfr α or β chain or stat5a/b expression in Caco-2 cells, basal proliferation was suppressed. GM-CSF normalised proliferation of Caco-2 cells exposed to NSAID, which was blocked by stat5a/b RNA interference. Conclusions Loss of GM-CSF signalling in non-haematopoietic cells

  4. 5 CFR 531.242 - Setting pay upon loss of GM status.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Setting pay upon loss of GM status. 531... Setting pay upon loss of GM status. (a) On loss of status as a GM employee under § 531.241 (except as... be set as provided in § 531.215. A GM employee's off-step GS rate at the grade before demotion is...

  5. 5 CFR 531.242 - Setting pay upon loss of GM status.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Setting pay upon loss of GM status. 531... Setting pay upon loss of GM status. (a) On loss of status as a GM employee under § 531.241 (except as... be set as provided in § 531.215. A GM employee's off-step GS rate at the grade before demotion is...

  6. Simulation eines rekonfigurierbaren Gm-C filter arrays

    NASA Astrophysics Data System (ADS)

    Henrici, F.; Becker, J.; Manoli, Y.

    2007-06-01

    Es wird ein Gm-C Filter für den Einsatz in rekonfigurierbaren Analogfiltern (FPAAs) präsentiert. Das Filter ist auf den Einsatz in FPAAs mit hexagonalem Grid und auf den Verzicht auf Transmissiongates optimiert. Trotzdem können nicht nur die Parameter der instanziierten Filter geändert werden, sondern auch ihre Struktur. Beim Design des digital programmierbaren Transkonduktors musste auf die hohe Anzahl parallel geschalteter, gleichartiger Transkonduktoren und ihre parasitären Kapazitäten Rücksicht genommen werden. Ein FPAA mit 49 Gm-Zellen erreicht in Simulationen in einem 130 nm 1.2 V CMOS Prozess eine maximale Bandbreite von 164 MHz. Die Verzerrung beträgt weniger als -70 dB bei einem 50m V @1 MHz Signal.

  7. Do Russia and Eastern Europe need GM plants?

    PubMed

    Skryabin, Konstantin

    2010-11-30

    Russia, Ukraine and Kazakhstan are the leading agricultural producers, especially for potato, sugar beet and sunflower. The cumulative effect of adverse climatic conditions, high weediness and losses related to viruses and pests (without any insecticide and herbicide treatments) led to losses amounting to 40-80% of potential production in the Russian Federation and other mentioned countries. We have used new biotechnology methods to obtain several crops (potato, sugar beet, sunflower and others) tolerant to abiotic and biotic stresses. For the first time - on the basis of domestic varieties bred by Russian scientists - GM potato varieties have been obtained, resistant to Colorado beetle. These GM potato varieties were recognised as being as safe as traditional ones and have been registered for food use. Using this technology, new biotechnological sugar beet lines tolerant to herbicides were also obtained.

  8. 5 CFR 531.245 - Computing locality rates and special rates for GM employees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Computing locality rates and special... Gm Employees § 531.245 Computing locality rates and special rates for GM employees. Locality rates and special rates are computed for GM employees in the same manner as locality rates and special...

  9. Rayleigh-Taylor instability with finite current relaxation

    NASA Astrophysics Data System (ADS)

    Silveira, F. E. M.; Orlandi, H. I.

    2016-04-01

    In this work, we explore the influence of perturbative wavelengths, shorter than those usually considered, on the growth rate of the Rayleigh-Taylor modes. Therefore, we adopt an extended form of Ohm's law which includes a finite relaxation time of the current density due to inertial effects of charged species in the plasma. The restoring force density that acts upon charged species close to the mode rational surface takes into account a new term which is usually neglected with respect to the motional electromotive force. We find that the width of the resistive layer can be interpreted in terms of the "height" of free fall in a constant gravitational field, in the Alfvén time interval. We also show that the charged species must fall "down" in the constant gravitational field in order that the static state of equilibrium of the system becomes unstable to the linear perturbation. Through the principle of conservation of energy, we find a general formula which gives the growth rate γ of the Rayleigh-Taylor modes. When the new term becomes negligible with respect to the motional electromotive force, we recover the standard result of the Rayleigh-Taylor instability, which establishes that γ scales with the plasma resistivity η as γ ˜ η 1 / 3 . However, in the opposite limiting situation, we find that γ does not depend any longer on the plasma resistivity and scales now with the electron number density n e as γ ˜ ne - 1 / 2 . Further developments of our theory may contribute to improve our understanding on the excitation mechanisms of resistive plasma instabilities by transient phenomena such as shock waves.

  10. High Speed Solution of Spacecraft Trajectory Problems Using Taylor Series Integration

    NASA Technical Reports Server (NTRS)

    Scott, James R.; Martini, Michael C.

    2008-01-01

    Taylor series integration is implemented in a spacecraft trajectory analysis code-the Spacecraft N-body Analysis Program (SNAP) - and compared with the code s existing eighth-order Runge-Kutta Fehlberg time integration scheme. Nine trajectory problems, including near Earth, lunar, Mars and Europa missions, are analyzed. Head-to-head comparison at five different error tolerances shows that, on average, Taylor series is faster than Runge-Kutta Fehlberg by a factor of 15.8. Results further show that Taylor series has superior convergence properties. Taylor series integration proves that it can provide rapid, highly accurate solutions to spacecraft trajectory problems.

  11. Pruning to Increase Taylor Dispersion in Physarum polycephalum Networks.

    PubMed

    Marbach, Sophie; Alim, Karen; Andrew, Natalie; Pringle, Anne; Brenner, Michael P

    2016-10-21

    How do the topology and geometry of a tubular network affect the spread of particles within fluid flows? We investigate patterns of effective dispersion in the hierarchical, biological transport network formed by Physarum polycephalum. We demonstrate that a change in topology-pruning in the foraging state-causes a large increase in effective dispersion throughout the network. By comparison, changes in the hierarchy of tube radii result in smaller and more localized differences. Pruned networks capitalize on Taylor dispersion to increase the dispersion capability.

  12. Theoretical and Experimental Studies of Magneto-Rayleigh-Taylor Instabilities

    SciTech Connect

    Lau, Yue Ying; Gilgenbach, Ronald

    2013-07-07

    Magneto-Rayleigh-Taylor instability (MRT) is important to magnetized target fusion, wire-array z-pinches, and equation-of-state studies using flyer plates or isentropic compression. It is also important to the study of the crab nebula. The investigators performed MRT experiments on thin foils, driven by the mega-ampere linear transformer driver (LTD) facility completed in their laboratory. This is the first 1-MA LTD in the USA. Initial experiments on the seeding of MRT were performed. Also completed was an analytic study of MRT for a finite plasma slab with arbitrary magnetic fields tangential to the interfaces. The effects of magnetic shear and feedthrough were analyzed.

  13. Statistical approach of weakly nonlinear ablative Rayleigh-Taylor instability

    SciTech Connect

    Garnier, J.; Masse, L.

    2005-06-15

    A weakly nonlinear model is proposed for the Rayleigh-Taylor instability in presence of ablation and thermal transport. The nonlinear effects for a single-mode disturbance are computed, included the nonlinear correction to the exponential growth of the fundamental modulation. Mode coupling in the spectrum of a multimode disturbance is thoroughly analyzed by a statistical approach. The exponential growth of the linear regime is shown to be reduced by the nonlinear mode coupling. The saturation amplitude is around 0.1{lambda} for long wavelengths, but higher for short instable wavelengths in the ablative regime.

  14. Photographic copy of architectural drawings for Building 4315: Taylor & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photographic copy of architectural drawings for Building 4315: Taylor & Barnes, Architects & Engineers, 803 W. Third Street, Los Angeles California, O.C.E. Office of Civil Engineer Job No. Muroc ESA 210-50 and 210-44, Military Construction: Muroc Flight Test Base, Muroc, California, Utility Yard & Shops: Carpenter & Paint Shop, Utility Shop & Lavatory, Plan & Elevations, Sheet No. 4 of 8, May 1945. Reproduced from the holdings of the National Archives, Pacific Southwest Region - Edwards Air Force Base, North Base, Utility & Paint Shop, Second & E Streets, Boron, Kern County, CA

  15. Simulating the Rayleigh-Taylor instability with the Ising model

    SciTech Connect

    Ball, Justin R.; Elliott, James B.

    2011-08-26

    The Ising model, implemented with the Metropolis algorithm and Kawasaki dynamics, makes a system with its own physics, distinct from the real world. These physics are sophisticated enough to model behavior similar to the Rayleigh-Taylor instability and by better understanding these physics, we can learn how to modify the system to better re ect reality. For example, we could add a vx and a vy to each spin and modify the exchange rules to incorporate them, possibly using two body scattering laws to construct a more realistic system.

  16. Hypertension as a complication of Taylor spatial frame.

    PubMed

    Changulani, Manesh; Bradbury, Mark; Zenios, Michalis

    2009-11-01

    Circular external fixators in children are widely used for limb lengthening, deformity correction and the treatment of fractures. We report a case of successful management of hypertension in a 13-year-old treated with a Taylor spatial frame after a road traffic accident and a tibial fracture. A heightened awareness of the association of hypertension and external fixators is required to improve patient outcomes. Outcomes are improved by prompt diagnosis and treatment of hypertension, preventing hypertensive end-organ damage, choice of an appropriate first line antihypertensive treatment, and not subjecting children to invasive investigations looking for an alternative secondary cause of hypertension.

  17. Saffman-Taylor instability for generalized Newtonian fluids.

    PubMed

    Mora, S; Manna, M

    2009-07-01

    We study theoretically the linear Saffman-Taylor instability for non-Newtonian fluids in a Hele-Shaw cell. After introducing the notion of generalized Newtonian fluid we calculate the associated Darcy's law. We derive the relation governing the growth rate of normal modes for a large class of non-Newtonian flows. For shear-thinning fluids at high shear rate our theory provides Darcy's laws free of the nonphysical divergences appearing in the classical approaches. We characterize fluids which develop instabilities faster than Newtonian fluids under the same hydrodynamical conditions. Another primary result that this paper provides is that for some shear-thickening fluids, all normal modes are stable.

  18. Bubble Counts for Rayleigh-Taylor Instability Using Image Analysis

    SciTech Connect

    Miller, P L; Gezahegne, A G; Cook, A W; Cabot, W H; Kamath, C

    2007-01-24

    We describe the use of image analysis to count bubbles in 3-D, large-scale, LES [1] and DNS [2] of the Rayleigh-Taylor instability. We analyze these massive datasets by first converting the 3-D data to 2-D, then counting the bubbles in the 2-D data. Our plots for the bubble count indicate there are four distinct regimes in the process of the mixing of the two fluids. We also show that our results are relatively insensitive to the choice of parameters in our analysis algorithms.

  19. Onset of cellular motion in Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Mullin, T.; Heise, M.; Pfister, G.

    2017-08-01

    Taylor-Couette flow between concentric rotating cylinders provides a prime example of a pitchfork bifurcation in hydrodynamic stability. However, more than 40 years ago, Benjamin pointed out difficulties in establishing quantitative links between models where periodicity is assumed along the length of the cylinders and calculations using the Navier-Stokes equations. A new model was recently advanced where it is claimed that the bifurcation which is relevant to the onset of cellular motion is the one between neighboring states. Here, we provide experimental data in support of this idea which explain why the onset of cellular motion is observed to be sharp whereas the periodic model bifurcation is highly imperfect.

  20. On Taylor-Series Approximations of Residual Stress

    NASA Technical Reports Server (NTRS)

    Pruett, C. David

    1999-01-01

    Although subgrid-scale models of similarity type are insufficiently dissipative for practical applications to large-eddy simulation, in recently published a priori analyses, they perform remarkably well in the sense of correlating highly against exact residual stresses. Here, Taylor-series expansions of residual stress are exploited to explain the observed behavior and "success" of similarity models. Until very recently, little attention has been given to issues related to the convergence of such expansions. Here, we re-express the convergence criterion of Vasilyev [J. Comput. Phys., 146 (1998)] in terms of the transfer function and the wavenumber cutoff of the grid filter.

  1. Lattice QCD for Baryon Rich Matter - Beyond Taylor Expansions

    NASA Astrophysics Data System (ADS)

    Bornyakov, V.; Boyda, D.; Goy, V.; Molochkov, A.; Nakamura, A.; Nikolaev, A.; Zakharov, V. I.

    2016-12-01

    We discuss our study for exploring the QCD phase diagram based on the lattice QCD. To go beyond the Taylor expansion and to reach higher density regions, we employ the canonical approach. In order to produce lattice data which meet experimental situation as much as possible, we propose a canonical approach with the charge and baryon number. We present our lattice QCD GPU code for this project which employs the clover improved Wilson fermions and Iwasaki gauge action to investigate pure imaginary chemical potential.

  2. Rayleigh-Taylor instability in quantum magnetized viscous plasma

    SciTech Connect

    Hoshoudy, G. A.

    2011-09-15

    Quantum effects on Rayleigh-Taylor instability of stratified viscous plasmas layer under the influence of vertical magnetic field are investigated. By linearly solving the viscous QMHD equations into normal mode, a forth-order ordinary differential equation is obtained to describe the velocity perturbation. Then the growth rate is derived for the case where a plasma with exponential density distribution is confined between two rigid planes. The results show that, the presence of vertical magnetic field beside the quantum effect will bring about more stability on the growth rate of unstable configuration for viscous plasma, which is greater than that of inviscous plasma.

  3. Nonlinear theory of the ablative Rayleigh-Taylor instability.

    PubMed

    Sanz, J; Ramírez, J; Ramis, R; Betti, R; Town, R P J

    2002-11-04

    A fully nonlinear sharp-boundary model of the ablative Rayleigh-Taylor instability is derived and closed in a similar way to the self-consistent closure of the linear theory. It contains the stabilizing effect of ablation and accurately reproduces the results of 2D DRACO simulations. The single-mode saturation amplitude, bubble and spike evolutions in the nonlinear regimes, and the seeding of long-wavelength modes via mode coupling are determined and compared with the classical theory without ablation. Nonlinear stability above the linear cutoff is also predicted.

  4. Rayleigh-Taylor instability under a flat beam.

    PubMed

    Lenschen, M; Calvo, A; Cachile, M

    2010-01-01

    A theoretical and experimental study on the Rayleigh-Taylor instability of a thin liquid film is presented. The experiments were performed by coating the underside of a flat beam with uniform liquid film. The size of the beam is such that a linear arrangement of drops is formed allowing the measurement of the drops growth. The experimental growth of the drops has been compared to the results obtained from a stability analysis performed on the equation that controls the thickness evolution and an excellent agreement is found. In addition, both time and length scales of the phenomenon are established.

  5. Rayleigh-Taylor instability in a sedimenting suspension.

    PubMed

    Völtz, C; Pesch, W; Rehberg, I

    2002-01-01

    The temporal evolution of an interface between glycerin and a glycerin-sand suspension of small packing fraction (obtained using the hindered settling phenomenon) driven by gravity is experimentally investigated. The growth rates for the different wave numbers characterizing the developing front are determined by means of a Fourier analysis. To model the observed behavior, we apply the idea of the Rayleigh-Taylor instability for a homogeneous fluid with vertically varying density and viscosity (one-fluid model). A good agreement between the experimental and theoretical results is obtained.

  6. Rayleigh-taylor instability with magnetic fluids: experiment and theory

    PubMed

    Pacitto; Flament; Bacri; Widom

    2000-12-01

    We present experiments showing the Rayleigh-Taylor instability at the interface between a dense magnetic liquid and an immiscible less dense liquid. The liquids are confined in a Hele-Shaw cell and a magnetic field is applied perpendicular to the cell. We measure the wavelength and the growth rate at the onset of the instability as a function of the external magnetic field. The wavelength decreases as the field increases. The amplitude of the interface deformation grows exponentially with time in the early stage, and the growth rate is an increasing function of the field. These results are compared to theoretical predictions given in the framework of linear stability analysis.

  7. Weakly nonlinear theory for the ablative Rayleigh-Taylor instability.

    PubMed

    Garnier, J; Raviart, P-A; Cherfils-Clérouin, C; Masse, L

    2003-05-09

    A weakly nonlinear model is proposed for the Rayleigh-Taylor instability in the presence of ablation and thermal transport. The second harmonic generation efficiency of a single-mode disturbance is computed, as well as the nonlinear correction to the exponential growth of the fundamental modulation. Mode coupling in the spectrum of a multimode disturbance is thoroughly analyzed. The ablative stabilization can be clearly discussed because the derived formulas for the evanescent ablation rate are in agreement with previously known results for incompressible, inviscid, irrotational, and immiscible fluids [S. W. Haan, Phys. Fluids B 3, 2349 (1991)]; M. Berning and A. M. Rubenchik, Phys. Fluids 10, 1564 (1998)

  8. Asymptotic behavior of the Rayleigh-Taylor instability.

    PubMed

    Duchemin, Laurent; Josserand, Christophe; Clavin, Paul

    2005-06-10

    We investigate long time numerical simulations of the inviscid Rayleigh-Taylor instability at Atwood number one using a boundary integral method. We are able to attain the asymptotic behavior for the spikes predicted by Clavin and Williams for which we give a simplified demonstration. In particular, we observe that the spike's curvature evolves as t(3), while the overshoot in acceleration shows good agreement with the suggested 1/t(5) law. Moreover, we obtain consistent results for the prefactor coefficients of the asymptotic laws. Eventually we exhibit the self-similar behavior of the interface profile near the spike.

  9. Rayleigh-Taylor instability with complex acceleration history.

    PubMed

    Dimonte, Guy; Ramaprabhu, Praveen; Andrews, Malcolm

    2007-10-01

    Experiments and numerical simulations are performed on the Rayleigh-Taylor instability with a complex acceleration history g(t) consisting of consecutive periods of acceleration, deceleration, and acceleration. The dominant bubbles and spikes that grow in the initial unstable phase are found to be shredded by the trailing structures during the stable deceleration phase. This reduces their diameter at the front and increases the atomic mixing such that the growth during the final unstable acceleration is retarded. The simulations are able to describe the bubble evolution only if broadband initial perturbations are assumed. Such a complex g(t) is useful for validating mix models.

  10. Nonstationary Rayleigh-Taylor instability in supernova ejecta

    SciTech Connect

    Ribeyre, X.; Hallo, L.; Tikhonchuk, V. T.; Bouquet, S.; Sanz, J.

    2007-11-15

    This paper studies the effect of a nonstationary shell acceleration on the development of the Rayleigh-Taylor instability (RTI) in supernovae remnants (SNRs). Two groups of solutions describing acceleration and deceleration phase of the SNR shell are obtained. Using a special transformation (co-moving coordinate frame), an exact dispersion relation for nonstationary RTI is derived. It is shown that compressible and incompressible branches are separated for the spherically symmetric flow and only the former is unstable. The exact analytic solution is compared to a simpler WKB-like analysis and a good agreement is shown, which proves that this analysis can be useful and easily extended to further applications.

  11. THE RAYLEIGH-TAYLOR INSTABILITY IN SMALL ASPECT RATIO CONTAINERS

    SciTech Connect

    RIVERA, MICHAEL K.; ECKE, ROBERT E.

    2007-01-22

    We present experimental measurements of density and velocity obtained from the mixing zone of buoyancy driven turbulence initiated by the Rayleigh-Taylor instability in a small aspect ration chamber (a chamber who's vertical height is significantly larger than its lateral dimesion). The mixing front propogates at a slightly slower rate than the expected t{sup 2} behavior obtained from earlier experiments and numerics. Once the front has propogated significantly far away, we observe that the mixing zone develops to a statistically stationary state. In this stationary state, the spectral distributions of energy and density deviate from the familiar k{sup -5/3} ubiquitous to turbulence in three dimensions.

  12. 2. Photographic copy of architectural elevations for Building 4505, Taylor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photographic copy of architectural elevations for Building 4505, Taylor & Barnes, Architects & Engineers, 803 W. Third Street, Los Angeles California, O.C.E. Office of Civil Engineer Job No. A(9-10), Military Construction: Materiel Command Flight Test Base, Muroc, California, Hangar and Auxiliary Buildings: Hangar Type P-A, Exterior Elevations, Sheet No. 18, March 1944. Reproduced from the holdings of the National Archives, Pacific Southwest Region - Edwards Air Force Base, North Base, Hangar, End of North Base Road, Boron, Kern County, CA

  13. 1. Photographic copy of architectural plan for Building 4505, Taylor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photographic copy of architectural plan for Building 4505, Taylor & Barnes, Architects & Engineers, 803 W. Third Street, Los Angeles California, O.C.E. Office of Civil Engineer Job No. A(9-10), Military Construction: Materiel Command Flight Test Base, Muroc, California, Hangar and Auxiliary Buildings: Hangar Type P-A, Floor Plan & Roof Plan, Sheet No. 16, March 1944. Reproduced from the holdings of the National Archives, Pacific Southwest Region - Edwards Air Force Base, North Base, Hangar, End of North Base Road, Boron, Kern County, CA

  14. Pruning to Increase Taylor Dispersion in Physarum polycephalum Networks

    NASA Astrophysics Data System (ADS)

    Marbach, Sophie; Alim, Karen; Andrew, Natalie; Pringle, Anne; Brenner, Michael P.

    2016-10-01

    How do the topology and geometry of a tubular network affect the spread of particles within fluid flows? We investigate patterns of effective dispersion in the hierarchical, biological transport network formed by Physarum polycephalum. We demonstrate that a change in topology—pruning in the foraging state—causes a large increase in effective dispersion throughout the network. By comparison, changes in the hierarchy of tube radii result in smaller and more localized differences. Pruned networks capitalize on Taylor dispersion to increase the dispersion capability.

  15. Signposts of Planet Formation in the Disk of GM Aur

    NASA Technical Reports Server (NTRS)

    Hornbeck, Jeremy; Grady, Carol; Williger, Gerard; Brown, A.; Perrin, M.; Wisniewski, J.

    2011-01-01

    Rice et al. noted that transitional disks hosting massive Jovian-mass planets should have suppressed accretion onto the star, while bringing about an absence of silicate emission. Their models also predict systems with less massive planets should permit small grain dust and some gas to filter into the cavity, leaving larger grains confined to the outer disk. Such systems are expected to have polarized light originating within the cavity, silicate emission, and small-grain reflection nebulosity detectable in FUV high-contrast imagery. A further consequence is that molecular gas should be less abundant in the inner disk due to photodissociation by the stellar FUV radiation field. GM Aur is a T-Tauri star/transitional disk system, where both silicate emission and a 24 AU cavity has been detected. We continue the analysis of GM Aur with FUV and optical HST imagery and report the presence of small-grain reflection nebulosity detected from 1400 - 2000 A in the cavity region, as well as a molecular outflow that has an inner radius corresponding to the cavity wall. These data, together with the presence of silicate emission, suggest that GM Aur hosts a planet with likely mass between 1 and 5 Mass of Jupiter

  16. CFU-GM assay for evaluation of drug myelotoxic activity.

    PubMed

    Pessina, Augusto; Bonomi, Arianna

    2007-11-01

    To study hematotoxicity of compounds on the myeloid cell compartment, the authors describe a standard procedure developed as a workable good laboratory practices-compliant protocol to determine the in vitro myelotoxic effect of drugs and chemicals. Specific protocols are presented to prepare human and murine myeloid progenitors (CFU-GM) for testing in a validated CFU-GM assay. Details are given for performing a screening test when toxicity data are not available and for passing on to an accurate inhibitory concentration-determination phase. To quantify the potential hematotoxicity of xenobiotics from their direct adverse effects on CFU-GM, the unit describes how to manage the results by means of an algorithm able to predict the acute xenobiotic exposure levels that cause maximum tolerated decreases (MTD) in absolute neutrophil count (ANC). A protocol describes a miniaturized application of the procedure in 96-well plates for high-throughput screening of compounds or for testing compounds that are available in very small quantities.

  17. G-CSF and GM-CSF in Neutropenia

    PubMed Central

    Mehta, Hrishikesh M.; Malandra, Michael; Corey, Seth J.

    2015-01-01

    Granulocyte Colony Stimulating Factor (G-CSF) and Granulocyte/Macrophage Colony Stimulating Factor (GM-CSF) are used widely to promote the production of granulocytes or antigen presenting cells (APC). The Food and Drug Administration approved G-CSF (filgrastim) for the treatment of congenital and acquired neutropenias and for mobilization of peripheral hematopoietic progenitor cells for stem cell transplantation. A polyethylene glycol modified (PEGylated) form of G-CSF is approved for the treatment of neutropenias. Clinically significant neutropenia, rendering an individual immunocompromised, occurs when their number is less than 1500/µl. Current guidelines recommend their use when the risk of febrile neutropenia is greater than 20%. GM-CSF (sargramostim) is approved for neutropenia associated with stem cell transplantation. Because of its promotion of APC function, GM-CSF is being evaluated as an immunostimulatory adjuvant in a number of clinical trials. More than 20 million persons have benefited worldwide, and more than $5 billion sales occur annually in the United States. PMID:26254266

  18. Cloning of canine GM-CSF and SCF genes.

    PubMed

    Shin, I S; Nam, M J; Park, S J; Youn, H Y; Han, H R

    2001-12-01

    Cytokines have pleiotropic regulatory effects on hematopoietic cells and many other cell types that participate in host defence and repair processes. Granulocyte-macrophage colony-stimulating factor (GM-CSF) mediates the growth and differentiation of granulocytes and macrophages and regulates the biological functions expressed by mature cells of these lineages. Stem cell factor (SCF) is a multifunctional cytokine involved in hematopoiesis, melanogenesis and gametogenesis. In order to determine the complementary DNA (cDNA) of canine GM-CSF and canine SCF, cDNA clones were generated from lipopolysaccharide (LPS) stimulated peripheral blood mononuclear cells (PBMCs) and bone marrow cells by reverse transcription PCR amplification. The canine GM-CSF cDNA obtained in this study contains an open reading frame encoding 144 amino acid residues and has 53-75% homology with those of human, cat, sheep, pig, cow and mouse, Canine SCF cDNA consist of an open reading frame encoding 274 amino acid residues and shares 81-92% homology with those of human, cat, pig, cow and mouse.

  19. Clustering effects of GM1 and formation mechanisms of interdigitated liquid disordered domains in GM1/SM/CHOL-supported planar bilayers on mica surfaces

    NASA Astrophysics Data System (ADS)

    Shang, Zhiguo; Mao, Yanli; Tero, Ryugo; Liu, Xinli; Hoshino, Tyuji; Tanaka, Motohiko; Urisu, Tsuneo

    2010-09-01

    We have observed by atomic force microscopy that an interdigitated liquid disordered domain (ILDD) is formed in the ganglioside (GM1)/sphingomyelin (SM)/cholesterol (CHOL) bilayers on a mica surface and accelerates the formation of fibriller Aβ agglomerates. By studies of the mechanisms using molecular dynamics simulations, we conclude that the ILDD structure is formed as a result of the phase separation to SM- and GM1-rich domains on the mica surface induced by the effects of GM1 clustering and the interaction between the GM1 head group and the water layer adsorbed in the ditrigonal cavity on the mica surface.

  20. Central nervous system inflammation is a hallmark of pathogenesis in mouse models of GM1 and GM2 gangliosidosis.

    PubMed

    Jeyakumar, M; Thomas, R; Elliot-Smith, E; Smith, D A; van der Spoel, A C; d'Azzo, A; Perry, V Hugh; Butters, T D; Dwek, R A; Platt, F M

    2003-04-01

    Mouse models of the GM2 gangliosidoses [Tay-Sachs, late onset Tay-Sachs (LOTS), Sandhoff] and GM1 gangliosidosis have been studied to determine whether there is a common neuro-inflammatory component to these disorders. During the disease course, we have: (i) examined the expression of a number of inflammatory markers in the CNS, including MHC class II, CD68, CD11b (CR3), 7/4, F4/80, nitrotyrosine, CD4 and CD8; (ii) profiled cytokine production [tumour necrosis factor alpha (TNF alpha), transforming growth factor (TGF beta 1) and interleukin 1 beta (IL1 beta)]; and (iii) studied blood-brain barrier (BBB) integrity. The kinetics of apoptosis and the expression of Fas and TNF-R1 were also assessed. In all symptomatic mouse models, a progressive increase in local microglial activation/expansion and infiltration of inflammatory cells was noted. Altered BBB permeability was evident in Sandhoff and GM1 mice, but absent in LOTS mice. Progressive CNS inflammation coincided with the onset of clinical signs in these mouse models. Substrate reduction therapy in the Sandhoff mouse model slowed the rate of accumulation of glycosphingolipids in the CNS, thus delaying the onset of the inflammatory process and disease pathogenesis. These data suggest that inflammation may play an important role in the pathogenesis of the gangliosidoses.

  1. On spatial pattern of concentration distribution for Taylor dispersion process

    NASA Astrophysics Data System (ADS)

    Wu, Zi; Fu, Xudong; Wang, Guangqian

    2016-02-01

    Taylor dispersion is a key concept in many fields. In the present paper, we characterize the pattern of the complete spatial concentration distribution for laminar tube flow; the obtained simple description is shown to represent the nature of Taylor dispersion. Importantly, we find that during the approach to the longitudinal normality of the transverse mean concentration at the time scale of R2/D (R is the tube radius and D is the molecular diffusivity), the solute concentration becomes uniformly distributed across a family of invariant curved transverse surfaces instead of the flat cross-sections in the traditional view. The family of curved surfaces is analytically determined, and a transformation is devised for the previously obtained analytical solution to discuss the decay of the concentration difference across the curved surfaces. The approach to a uniform concentration across the flat cross-sections to the same degree (~3% by concentration difference percentage), achieved at a time-scale of 100 R2/D, is shown to be the natural consequence of the longitudinal separation of the concentration contours on the curved surfaces.

  2. Non-linear characteristics of Rayleigh-Taylor instable perturbations

    NASA Astrophysics Data System (ADS)

    Fan, Zhengfeng; Luo, Jisheng

    2008-04-01

    The direct numerical simulation method is adopted to study the non-linear characteristics of Rayleigh-Taylor instable perturbations at the ablation front of a 200 μm planar CH ablation target. In the simulation, the classical electrical thermal conductivity is included, and NND difference scheme is used. The linear growth rates obtained from the simulation agree with the Takabe formula. The amplitude distribution of the density perturbation at the ablation front is obtained for the linear growth case. The non-linear characteristics of Rayleigh-Taylor instable perturbations are analyzed and the numerical results show that the amplitude distributions of the compulsive harmonics are very different from that of the fundamental perturbation. The characteristics of the amplitude distributions of the harmonics and their fast growth explain why spikes occur at the ablation front. The numerical results also show that non-linear effects have relations with the phase differences of double mode initial perturbations, and different phase differences lead to varied spikes.

  3. The Inhibition of the Rayleigh-Taylor Instability by Rotation

    PubMed Central

    Baldwin, Kyle A.; Scase, Matthew M.; Hill, Richard J. A.

    2015-01-01

    It is well-established that the Coriolis force that acts on fluid in a rotating system can act to stabilise otherwise unstable flows. Chandrasekhar considered theoretically the effect of the Coriolis force on the Rayleigh-Taylor instability, which occurs at the interface between a dense fluid lying on top of a lighter fluid under gravity, concluding that rotation alone could not stabilise this system indefinitely. Recent numerical work suggests that rotation may, nevertheless, slow the growth of the instability. Experimental verification of these results using standard techniques is problematic, owing to the practical difficulty in establishing the initial conditions. Here, we present a new experimental technique for studying the Rayleigh-Taylor instability under rotation that side-steps the problems encountered with standard techniques by using a strong magnetic field to destabilize an otherwise stable system. We find that rotation about an axis normal to the interface acts to retard the growth rate of the instability and stabilise long wavelength modes; the scale of the observed structures decreases with increasing rotation rate, asymptoting to a minimum wavelength controlled by viscosity. We present a critical rotation rate, dependent on Atwood number and the aspect ratio of the system, for stabilising the most unstable mode. PMID:26130005

  4. Rayleigh-Taylor instability of viscous fluids with phase change.

    PubMed

    Kim, Byoung Jae; Kim, Kyung Doo

    2016-04-01

    Film boiling on a horizontal surface is a typical example of the Rayleigh-Taylor instability. During the film boiling, phase changes take place at the interface, and thus heat and mass transfer must be taken into consideration in the stability analysis. Moreover, since the vapor layer is not quite thick, a viscous flow must be analyzed. Existing studies assumed equal kinematic viscosities of two fluids, and/or considered thin viscous fluids. The purpose of this study is to derive the analytical dispersion relation of the Rayleigh-Taylor instability for more general conditions. The two fluids have different properties. The thickness of the vapor layer is finite, but the liquid layer is thick enough to be nearly semi-infinite in view of perturbation. Initially, the vapor is in equilibrium with the liquid at the interface, and the direction of heat transfer is from the vapor side to the liquid side. In this case, the phase change has a stabilizing effect on the growth rate of the interface. When the vapor layer is thin, there is a coupled effect of the vapor viscosity, phase change, and vapor thickness on the critical wave number. For the other limit of a thick vapor, both the liquid and vapor viscosities influence the critical wave number. Finally, the most unstable wavelength is investigated. When the vapor layer is thin, the most unstable wavelength is not affected by phase change. When the vapor layer is thick, however, it increases with the increasing rate of phase change.

  5. Simulating Hamiltonian Dynamics with a Truncated Taylor Series

    NASA Astrophysics Data System (ADS)

    Somma, Rolando

    2015-03-01

    One of the main motivations for quantum computers is their ability to efficiently simulate the dynamics of quantum systems. Since the mid-1990s, many algorithms have been developed to simulate Hamiltonian dynamics on a quantum computer, with applications to problems such as simulating spin models and quantum chemistry. While it is now well known that quantum computers can efficiently simulate Hamiltonian dynamics, ongoing work has improved the performance and expanded the scope of such simulations. In this talk, I will describe a very simple and efficient algorithm for simulating Hamiltonian dynamics on a quantum computer by approximating the truncated Taylor series of the evolution operator. This algorithm can simulate the time evolution of a wide variety of physical systems. The cost of this algorithm depends only logarithmically on the inverse of the desired precision, and can be shown to be optimal. Such a cost also represents an exponential improvement over known methods for Hamiltonian simulation based on, e.g., Trotter-Suzuki approximations. Roughly speaking, doubling the number of digits of accuracy of the simulation only doubles the complexity. The new algorithm and its analysis are highly simplified due to a technique for implementing linear combinations of unitary operations to directly apply the truncated Taylor series. This is joint work with Dominic Berry, Andrew Childs, Richard Cleve, and Robin Kothari.

  6. Taylor-Fourier spectra to study fractional order systems

    NASA Astrophysics Data System (ADS)

    Barbé, Kurt; Lauwers, Lieve; Gonzales Fuentes, Lee

    2016-06-01

    In measurement science mathematical models are often used as an indirect measurement of physical properties which are mapped to measurands through the mathematical model. Dynamical systems describing a physical process with a dominant diffusion or dispersion phenomenon requires a large dimensional model due to its long memory. Ignoring a dominant difussion or dispersion component acts as a confounder which may introduce a bias in the estimated quantities of interest. For linear systems it has been observed that fractional order models outperform classical rational forms in terms of the number of parameters for the same fitting error. However it is not straightforward to deal with a fractional order system or long memory effects without prior knowledge. Since the parametric modeling of a fractional system is very involved, we put forward the question whether fractional insight can be gathered in a non-parametric way. In this paper we show that classical Fourier basis leading to the frequency response function lacks fractional insight. To circumvent this problem, we introduce a fractional Taylor-Fourier basis to obtain non-parametric insight in the fractional system. This analysis proposes a novel type of spectrum to visualize the spectral content of a fractional system: Taylor-Fourier spectrum. This spectrum is fully measurement driven which can be used as a first to explore the fractional dynamics of a measured diffusion or dispersion system.

  7. [Principles of deformity correction using the Taylor Spatial Frame].

    PubMed

    Eidelman, Mark; Chezar, Avraham

    2005-02-01

    Developed in the fifties, the Ilizarov ring external fixator was first introduced to the West in the eighties of the twentieth century. The technique has become widely accepted for the treatment of a wide variety of limb pathologies including complex fractures, deformity correction and limb lengthening. The Taylor Spatial Frame (TSF) was developed by Charles Taylor in the mid nineties. This system is basically a ring external fixator, drawing on the theoretic foundation from the theory of projected geometry and the mechanical bases from the Stewart platforms. This combination provides a stable external fixation device with an outstanding ability for manipulation of the bone fragments in any given direction, and correction of the most complex deformities. Following the application of the frame, internet-based software will provide an instant treatment plane for the correction of the deformity. This will then be carried out by the patient himself until the achievement of an anatomical reduction of the fracture, lengthening or deformity correction. This combination of a stable external fixation device and the accuracy of the computer based technology, makes the TSF the treatment of choice in the precise correction of limb deformities. This review presents an overview of the theoretical foundation and methods of using the TSF, with an emphasis on the advantages of this system and the capabilities in the correction of skeletal deformities.

  8. Experimental Study of Rayleigh-Taylor Instability Using Paramagnetic Fluids

    NASA Astrophysics Data System (ADS)

    Tsiklashvili, Vladimer; Likhachev, Oleg; Jacobs, Jeffry

    2009-11-01

    Experiments that take advantage of the properties of paramagnetic liquids are used to study Rayleigh-Taylor instability. A gravitationally unstable combination of a paramagnetic salt solution and a nonmagnetic solution is initially stabilized by a magnetic field gradient that is produced by the contoured pole-caps of a large electromagnet. Rayleigh-Taylor instability originates with the rapid removal of current from the electromagnet, which results in the heavy liquid falling into the light liquid due to gravity and, thus, mixing with it. The mixing zone is visualized by back-lit photography and is recorded with a digital video camera. For visualization purposes, a blue-green dye is added to the magnetic fluid. The mixing rate of the two liquids is determined from an averaged dye concentration across the mixing layer by means of the Beer-Lambert law. After removal of the suspending magnetic field, the initially flat interface between the two liquids develops a random surface pattern with the dominant length scale well approximated by the fastest growing wavelength in accordance with the viscous linear stability theory. Several combinations of paramagnetic and nonmagnetic solutions have been considered during the course of the research. A functional dependence of the mixing layer growth constant, α, on the properties of the liquids is a primary subject of the present study.

  9. Rayleigh-Taylor mixing with space-dependent acceleration

    NASA Astrophysics Data System (ADS)

    Abarzhi, Snezhana

    2016-11-01

    We extend the momentum model to describe Rayleigh-Taylor (RT) mixing driven by a space-dependent acceleration. The acceleration is a power-law function of space coordinate, similarly to astrophysical and plasma fusion applications. In RT flow the dynamics of a fluid parcel is driven by a balance per unit mass of the rates of momentum gain and loss. We find analytical solutions in the cases of balanced and imbalanced gains and losses, and identify their dependence on the acceleration exponent. The existence is shown of two typical sub-regimes of self-similar RT mixing - the acceleration-driven Rayleigh-Taylor-type mixing and dissipation-driven Richtymer-Meshkov-type mixing with the latter being in general non-universal. Possible scenarios are proposed for transitions from the balanced dynamics to the imbalanced self-similar dynamics. Scaling and correlations properties of RT mixing are studied on the basis of dimensional analysis. Departures are outlined of RT dynamics with space-dependent acceleration from canonical cases of homogeneous turbulence as well as blast waves with first and second kind self-similarity. The work is supported by the US National Science Foundation.

  10. Rayleigh-Taylor mixing with time-dependent acceleration

    NASA Astrophysics Data System (ADS)

    Abarzhi, Snezhana

    2016-10-01

    We extend the momentum model to describe Rayleigh-Taylor (RT) mixing driven by a time-dependent acceleration. The acceleration is a power-law function of time, similarly to astrophysical and plasma fusion applications. In RT flow the dynamics of a fluid parcel is driven by a balance per unit mass of the rates of momentum gain and loss. We find analytical solutions in the cases of balanced and imbalanced gains and losses, and identify their dependence on the acceleration exponent. The existence is shown of two typical regimes of self-similar RT mixing-acceleration-driven Rayleigh-Taylor-type and dissipation-driven Richtymer-Meshkov-type with the latter being in general non-universal. Possible scenarios are proposed for transitions from the balanced dynamics to the imbalanced self-similar dynamics. Scaling and correlations properties of RT mixing are studied on the basis of dimensional analysis. Departures are outlined of RT dynamics with time-dependent acceleration from canonical cases of homogeneous turbulence as well as blast waves with first and second kind self-similarity. The work is supported by the US National Science Foundation.

  11. A novel control strategy for a Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Bouabdallah, A.; Oualli, H.; Mekadem, M.; Boukrif, M.; Saad, S.; Gad-El-Hak, M.

    2015-11-01

    Advancing transition is desired in applications where heat, mass, or momentum transfer needs to be augmented. On the other hand, delaying transition is imperative in crystal growth devices, where all instabilities are to be avoided in order to prevent the appearance of geometrical irregularities in the resulting crystal. The hydrodynamic stability of a viscous flow in a closed, fully filled Taylor-Couette system is considered in the present numerical study. The fluid evolves in an annular cavity between the rotating inner cylinder and the outer fixed one. The base flow is axis-symmetric with two counter-rotating vortices each wavelength. The Taylor number varies in the range of 0-50. Numerical simulations are implemented on a finite-volume CFD code. The control strategy involves a pulsatile motion superimposed separately on the inner and outer cylinder's cross-section, with maximum amplitude of, respectively, 5% and 15% of the radius. The frequency varies in the range of 0-100 Hz. The objective is to localize the transition and to assess the flow's response to the imposed boundary motions. Substantial advancement of transition is found when the inner cylinder's cross-section is varied, while this transition is delayed when the outer cylinder's cross-section is pulsating.

  12. Instability vaccination: A structural design to reduce Rayleigh Taylor instability

    NASA Astrophysics Data System (ADS)

    Esmaeili, Amin

    2013-10-01

    Instability vaccination can be defined as designing a structure to stimulate the system in order to develop immunity against its instability. In this work we have tried to do this stabilization by a new technique. Previously some suppression of R-M instability was done by insertion of magnetic field, but in this work we have tried to do this suppression by proposing a configuration similar to the shape of instability, we call it instability vaccination. This design will reduce the rotations (mostly rotations of Rayleigh Taylor instability) in the fluids that cause more mixing and instabilities. In this paper, we consider the evolution of the interface between two ideal semi-infinite fluid surfaces, using two-dimensional Riemann solver, to solve the Euler equations. First, we performed evolution of a rectangular disorder between the 2 surfaces using two-dimensional Riemann problem for the equations of Euler. Next, the interface was replaced with a perturbation that was part rectangular and part semi-circular (like a mushroom). The simulation was continued till some time steps using the HLL method. We have seen that the rotations of Rayleigh Taylor (R-T) instability were decreased in the second case. Email: amin@cavelab.cs.tsukuba.ac.jp

  13. On spatial pattern of concentration distribution for Taylor dispersion process

    PubMed Central

    Wu, Zi; Fu, Xudong; Wang, Guangqian

    2016-01-01

    Taylor dispersion is a key concept in many fields. In the present paper, we characterize the pattern of the complete spatial concentration distribution for laminar tube flow; the obtained simple description is shown to represent the nature of Taylor dispersion. Importantly, we find that during the approach to the longitudinal normality of the transverse mean concentration at the time scale of R2/D (R is the tube radius and D is the molecular diffusivity), the solute concentration becomes uniformly distributed across a family of invariant curved transverse surfaces instead of the flat cross-sections in the traditional view. The family of curved surfaces is analytically determined, and a transformation is devised for the previously obtained analytical solution to discuss the decay of the concentration difference across the curved surfaces. The approach to a uniform concentration across the flat cross-sections to the same degree (~3% by concentration difference percentage), achieved at a time-scale of 100 R2/D, is shown to be the natural consequence of the longitudinal separation of the concentration contours on the curved surfaces. PMID:26867803

  14. Effects of microbubbles on Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Tasaka, Yuji; Murai, Yuichi; Watamura, Tomoaki; Takeda, Yasushi

    2009-11-01

    Effects of micro-bubbles on Taylor-Couette flow has been examined by means of ultrasonic velocity profiling (UVP) for wide range of the Reynolds number, 1 <=Re/Rec<=18, where Rec is the critical Reynolds number for the onset of the primary instability. O(10 μm)-diameter hydrogen bubbles generated by electrolysis of water was dispersed into the fluid layer of water between the vertical, co-axial cylinders. The radius ratio of the cylinders and the aspect ratio are 0.905 and 20, the maximum void fraction estimated by input power for the electrolysis is smaller than 0.1 %. Different flow pattern of the rising bubbles are observed in the spatio-temporal velocity distribution measured by UVP; i.e. free rising and snake-like rising. Axial wavelength of the Taylor vortices show no clear influence of bubbles, but the frequency of the azimuthal traveling wave is reduced by bubbles. Since the number of the traveling waves on the azimuthal plane is the same in the conditions, single phase and with bubbles, the reduction of the frequency means the reduction of the traveling velocity of the wave. Facts to change the traveling velocity, the aspect ratio, the radius ratio, the axial wavelength of the vortices and the number of waves, are no difference on the both cases, therefore, we guess the decrease of the shear rate of the fluid due to micro-bubbles induces this reduction of the traveling speed.

  15. The Inhibition of the Rayleigh-Taylor Instability by Rotation.

    PubMed

    Baldwin, Kyle A; Scase, Matthew M; Hill, Richard J A

    2015-07-01

    It is well-established that the Coriolis force that acts on fluid in a rotating system can act to stabilise otherwise unstable flows. Chandrasekhar considered theoretically the effect of the Coriolis force on the Rayleigh-Taylor instability, which occurs at the interface between a dense fluid lying on top of a lighter fluid under gravity, concluding that rotation alone could not stabilise this system indefinitely. Recent numerical work suggests that rotation may, nevertheless, slow the growth of the instability. Experimental verification of these results using standard techniques is problematic, owing to the practical difficulty in establishing the initial conditions. Here, we present a new experimental technique for studying the Rayleigh-Taylor instability under rotation that side-steps the problems encountered with standard techniques by using a strong magnetic field to destabilize an otherwise stable system. We find that rotation about an axis normal to the interface acts to retard the growth rate of the instability and stabilise long wavelength modes; the scale of the observed structures decreases with increasing rotation rate, asymptoting to a minimum wavelength controlled by viscosity. We present a critical rotation rate, dependent on Atwood number and the aspect ratio of the system, for stabilising the most unstable mode.

  16. Shock, release and Taylor impact of the semicrystalline thermoplastic polytetrafluoroethylene

    NASA Astrophysics Data System (ADS)

    Bourne, N. K.; Brown, E. N.; Millett, J. C. F.; Gray, G. T.

    2008-04-01

    The high strain-rate response of polymers is a subject that has gathered interest over recent years due to their increasing engineering importance, particularly in load bearing applications subject to extremes of pressure and strain rate. The current work presents two specific sets of experiments interrogating the effect of dynamic, high-pressure loading in the regime of the phase II to phase III pressure-induced crystalline phase transition in polytetrafluoroethylene (PTFE). These are gas-gun driven plate- and Taylor impact. Together these experiments highlight several effects associated with the dynamic, pressure-induced phase transitions in PTFE. An elevated release wave speed shows evidence of a pressure-induced phase change at a stress commensurate with that observed statically. It is shown that convergence between analytic derivations of release wave speed and the data requires the phase II to III transition to occur. Taylor impact is an integrated test that highlights continuum behavior that has origin in mesoscale response. There is a rapid transition from ductile to brittle behavior observed that occurs at a pressure consistent with this phase transition.

  17. Nonlinear equilibrium states in viscoelastic Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Nicolaou, Laura; Page, Jacob; Zaki, Tamer

    2016-11-01

    Viscoelastic Taylor-Couette flow exhibits a variety of instabilities, some of which can arise in the absence of inertia altogether. Nonlinear solutions of the equilibrium states are sought, where the distorted mean flow is unchanged and the finite-amplitude instability waves are saturated. A key assumption in the theory is that nonlinearity is restricted to the action of the perturbations on the mean flow. Therefore, the perturbation shape is preserved throughout its growth and saturation, and is specified as a weighted sum of the unstable, linear eigenmodes. At low elasticity, a single unstable mode exists in the form of a stationary Taylor vortex, and the predicted saturated state compares favourably with direct numerical simulation (DNS). DNS reveals that the higher harmonics are an order of magnitude weaker than the fundamental frequency, which substantiates the assumption adopted in the theory. At moderate elasticity, multiple modes become unstable, including axially-travelling elastic rolls and stationary vortices. Equilibrium solutions built from superpositions of these modes explain observations from experiments in the literature over a range of shear rates.

  18. Pattern Dynamics in Taylor Vortex Flow with Double Hourglass Geometry

    NASA Astrophysics Data System (ADS)

    Wiener, Richard; Olsen, Thomas

    2005-11-01

    In previous investigations ootnotetextWiener et al., Phys. Rev. E 55, 5489 (1997) & Phys. Rev. Lett. 83, 2340 (1999) we have demonstrated experimentally that Taylor vortex flow in an hourglass geometry undergoes a period-doubling cascade to chaotic pattern dynamics that can be controlled by proportional feedback with small perturbations. The hourglass geometry creates a spatial ramp in the Reynolds number. This results in a region of supercritical vortex flow between regions of subcritical structureless flow that provide the pattern with soft boundaries that allow for persistent dynamics. For a range of reduced Reynolds numbers, the Taylor vortex pattern exhibits persistent dynamics consisting of drifting and stretching vortices punctuated with phase slips. Each phase slip corresponds to the generation of a new vortex pair. We are currently investigating the phase dynamics of Tayor vortex flow with a double hourglass geometry which consists of two regions of supercritical flow in which phase slips occur, separated by a narrow region of subcritical flow. Initial results indicate that at some reduced Reynolds numbers there is synchronization between the vortex dynamics in the two regions, both in the temporal occurrence of the phase slips as well as the drift directions of the vortices.

  19. Transition to turbulence in Taylor-Couette ferrofluidic flow

    PubMed Central

    Altmeyer, Sebastian; Do, Younghae; Lai, Ying-Cheng

    2015-01-01

    It is known that in classical fluids turbulence typically occurs at high Reynolds numbers. But can turbulence occur at low Reynolds numbers? Here we investigate the transition to turbulence in the classic Taylor-Couette system in which the rotating fluids are manufactured ferrofluids with magnetized nanoparticles embedded in liquid carriers. We find that, in the presence of a magnetic field transverse to the symmetry axis of the system, turbulence can occur at Reynolds numbers that are at least one order of magnitude smaller than those in conventional fluids. This is established by extensive computational ferrohydrodynamics through a detailed investigation of transitions in the flow structure, and characterization of behaviors of physical quantities such as the energy, the wave number, and the angular momentum through the bifurcations. A finding is that, as the magnetic field is increased, onset of turbulence can be determined accurately and reliably. Our results imply that experimental investigation of turbulence may be feasible by using ferrofluids. Our study of transition to and evolution of turbulence in the Taylor-Couette ferrofluidic flow system provides insights into the challenging problem of turbulence control. PMID:26065572

  20. Soluble Salt Accumulations in Taylor Valley, Antarctica: Implications for Paleolakes and Ross Sea Ice Sheet Dynamics

    NASA Astrophysics Data System (ADS)

    Toner, J. D.; Sletten, R. S.; Prentice, M. L.

    2012-12-01

    Soluble salt accumulations in Taylor Valley, Antarctica, provide a history of paleolakes and the advance of the Ross Sea Ice Sheet (RSIS). We measured soluble salts in 89 soils throughout Taylor Valley in soil-water extractions. In western Taylor Valley, soluble salt accumulations are relatively high and are comprised primarily of Na, Ca, Cl, and SO4. In eastern Taylor Valley, soluble salt accumulations are much lower and are comprised primarily of Na and HCO3. Salt compositions measured in soil-water extractions are highly influenced by the dissolution of sparingly soluble salts (e.g. calcite and gypsum) and cation exchange reactions. Furthermore, during soil-water extractions, Ca from calcite or gypsum dissolution exchanges with exchangeable Na, K, and Mg. These processes can strongly influence both the total salt content measured in soils and ionic ratios. Thus, it is important to consider the effects of these reactions when interpreting soluble salt accumulations measured in soil-water extractions. Calcite dissolution and cation exchange reactions also appear to have a widespread natural occurrence, resulting in the Na-HCO3 compositions of soils, streams, and lakes in eastern Taylor Valley. The soluble salt data supports the hypotheses that a lobe of the RSIS expanded into eastern Taylor Valley and dammed proglacial paleolakes. However, in contrast to previous studies, our findings indicate that the RSIS advanced deeper into Taylor Valley and that paleolakes were less extensive. By comparing soluble salt distributions across Taylor Valley, we conclude that a lobe of the RSIS filled all of eastern Taylor Valley and dammed paleolakes in western Taylor Valley up to 300 m elevation. Following ice retreat, smaller paleolakes formed in both western and eastern Taylor Valley up to about 120 m, with a prominent still stands at 80 m that was controlled by the elevation of a major valley threshold.

  1. Lyso-GM2 ganglioside: a possible biomarker of Tay-Sachs disease and Sandhoff disease.

    PubMed

    Kodama, Takashi; Togawa, Tadayasu; Tsukimura, Takahiro; Kawashima, Ikuo; Matsuoka, Kazuhiko; Kitakaze, Keisuke; Tsuji, Daisuke; Itoh, Kohji; Ishida, Yo-Ichi; Suzuki, Minoru; Suzuki, Toshihiro; Sakuraba, Hitoshi

    2011-01-01

    To find a new biomarker of Tay-Sachs disease and Sandhoff disease. The lyso-GM2 ganglioside (lyso-GM2) levels in the brain and plasma in Sandhoff mice were measured by means of high performance liquid chromatography and the effect of a modified hexosaminidase (Hex) B exhibiting Hex A-like activity was examined. Then, the lyso-GM2 concentrations in human plasma samples were determined. The lyso-GM2 levels in the brain and plasma in Sandhoff mice were apparently increased compared with those in wild-type mice, and they decreased on intracerebroventricular administration of the modified Hex B. The lyso-GM2 levels in plasma of patients with Tay-Sachs disease and Sandhoff disease were increased, and the increase in lyso-GM2 was associated with a decrease in Hex A activity. Lyso-GM2 is expected to be a potential biomarker of Tay-Sachs disease and Sandhoff disease.

  2. GM-CSF: a role in immune and inflammatory reactions in the intestine

    PubMed Central

    Egea, Laia; Hirata, Yoshihiro; Kagnoff, Martin F

    2012-01-01

    Granulocyte macrophage colony-stimulating factor (GM-CSF) is a cytokine that promotes myeloid cell development and maturation, and dendritic cell differentiation and survival in vitro. Growing evidence supports the notion that GM-CSF has a major role in some inflammatory and autoimmune reactions and in the host’s response to pulmonary infection, but few studies have addressed its functions and importance in the GI tract. Recent studies demonstrated that administration of GM-CSF can result in clinical improvement in patients with Crohn’s disease. Mice deficient in GM-CSF (GM-CSF−/−) developed more severe intestinal and systemic infection after an enteric infection, and more severe colitis in response to enteric exposure to dextran sodium sulfate. Both the severity of infection and colitis were largely prevented by GM-CSF administration. Such studies indicate that GM-CSF has an important role in the regulation of intestinal immune and inflammatory responses. PMID:21108592

  3. Chemical Synthesis of GM2 Glycans, Bioconjugation with Bacteriophage Qβ, and the Induction of Anticancer Antibodies

    PubMed Central

    Yin, Zhaojun; Dulaney, Steven; McKay, Craig S.; Baniel, Claire; Kaczanowska, Katarzyna; Ramadan, Sherif; Finn, M. G.

    2016-01-01

    The development of carbohydrate-based antitumor vaccines is an attractive approach towards tumor prevention and treatment. Herein, we focused on the ganglioside GM2 tumor-associated carbohydrate antigen (TACA), which is overexpressed in a wide range of tumor cells. GM2 was synthesized chemically and conjugated with a virus-like particle derived from bacteriophage Qβ. Although the copper-catalyzed azide–alkyne cyclo-addition reaction efficiently introduced 237 copies of GM2 per Qβ, this construct failed to induce significant amounts of anti-GM2 antibodies compared to the Qβ control. In contrast, GM2 immobilized on Qβ through a thiourea linker elicited high titers of IgG antibodies that recognized GM2-positive tumor cells and effectively induced cell lysis through complement-mediated cytotoxicity. Thus, bacteriophage Qβ is a suitable platform to boost antibody responses towards GM2, a representative member of an important class of TACA: the ganglioside. PMID:26538065

  4. The interactome of soybean GmWRKY53 using yeast 2-hybrid library screening to saturation.

    PubMed

    Tripathi, Prateek; Rabara, Roel C; Choudhary, Mani Kant; Miller, Marissa A; Huang, Ying-Sheng; Shen, Qingxi J; Blachon, Stéphanie; Rushton, Paul J

    2015-01-01

    Soybean GmWRKY53 functions in both biotic and abiotic stress signaling. Using GmWRKY53 as a bait yeast 2-hybrid library screening to saturation isolated multiple independent fragments for many interacting proteins, enabling delineation of minimal interacting domains and computation of a confidence score. Multiple independent clones coding for the LATE ELONGATED HYPOCOTYL clock protein GmLCL2 (MYB114) were isolated and the binding site for GmWRKY53 was mapped to 90 amino acids separate from the MYB domain. This suggests a direct input from the clock on GmWRKY53 activity. The GmWRKY53-interacting proteins also included 3 water stress-inducible AP2/ERF transcription factors. One of these (Glyma03g26310) is one of the most strongly water stress induced genes in soybean roots, suggesting that GmWRKY53/ERF complexes regulate water stress responses.

  5. GM-CSF enhances tumor invasion by elevated MMP-2, -9, and -26 expression

    PubMed Central

    Gutschalk, Claudia M; Yanamandra, Archana K; Linde, Nina; Meides, Alice; Depner, Sofia; Mueller, Margareta M

    2013-01-01

    Granulocyte–macrophage colony-stimulating factor (GM-CSF) promotes tumor progression in different tumor models in an autocrine and paracrine manner. However, at the same time GM-CSF is used in cancer therapies to ameliorate neutropenia. We have previously shown in GM-CSF and G-CSF expressing or negative skin or head and neck squamous cell carcinoma that GM-CSF expression is associated with a highly angiogenic and invasive tumor phenotype. To determine the functional contribution of GM-CSF to tumor invasion, we stably transfected a GM-CSF negative colon adenocarcinoma cell line HT-29 with GM-CSF or treated the same cell line with exogenous GM-CSF. While GM-CSF overexpression and treatment reduced tumor cell proliferation and tumor growth in vitro and in vivo, respectively, it contributed to tumor progression. Together with an enhanced migratory capacity in vitro, we observed a striking increase in tumor cell invasion into the surrounding tissue concomitant with the induction of an activated tumor stroma in GM-CSF overexpressing or GM-CSF treated tumors. In a complex 3D in vitro model, enhanced GM-CSF expression was associated with a discontinued basement membrane deposition that might be mediated by the increased expression and activation of MMP-2, -9, and -26. Treatment with GM-CSF blocking antibodies reversed this effect. The increased presence and activity of these tumor cell derived proteases was confirmed in vivo. Here, expression of MMP-26 protein was predominantly located in pre- and early-invasive areas suggesting MMP-26 expression as an early event in promoting GM-CSF dependent tumor invasion. PMID:23634280

  6. Renal distribution of ganglioside GM3 in rat models of types 1 and 2 diabetes.

    PubMed

    Novak, Anela; Režić Mužinić, Nikolina; Cikeš Čulić, Vedrana; Božić, Joško; Tičinović Kurir, Tina; Ferhatović, Lejla; Puljak, Livia; Markotić, Anita

    2013-12-01

    Ganglioside GM3 is particularly abundant in the kidney tissue and is thought to play an important role in the maintenance of the charge-selective filtration barrier of glomeruli. Altered expression of ganglioside GM3 was pathologically related with glomerular hypertrophy occurring in diabetic human and rat kidneys. Considering the role of GM3 ganglioside in kidney function, the aim of this study was to determine the difference in expression of GM3 ganglioside in glomeruli and tubules using immunofluorescence microscopy both in rat models of types 1 and 2 diabetes mellitus. Diabetes was induced with streptozotocin (55 mg/kg for type 1 diabetes and 35 mg/kg for type 2 diabetes) injection to male Sprague-Dawley rats which were fed with normal pellet diet (type 1 diabetes) or high-fat diet (type 2 diabetes). Rats were sacrificed 2 weeks after diabetes induction, frozen renal sections were stained with primary antibody GM3(Neu5Ac) and visualized by secondary antibody coupled with Texas red. In addition, renal gangliosides GM3 were analyzed by high-performance thin-layer chromatography followed by GM3 immunostaining. Immunofluorescent microscopy detected 1.7-fold higher GM3 expression in tubules and 1.25-fold higher GM3 in glomeruli of type 1 diabetes mellitus compared with control group. Type 2 diabetes mellitus rats showed slight GM3 increase in whole kidney, unchanged GM3 in glomeruli, but significant higher GM3 expression in tubules, compared with control animals. Taking into consideration increased tubular GM3 content in both types of diabetes, we could hypothesize the role of GM3 in early pathogenesis of diabetic nephropathy.

  7. 43 CFR 4170.2-1 - Penal provisions under the Taylor Grazing Act.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Penal provisions under the Taylor Grazing Act. 4170.2-1 Section 4170.2-1 Public Lands: Interior Regulations Relating to Public Lands (Continued...-EXCLUSIVE OF ALASKA Penalties § 4170.2-1 Penal provisions under the Taylor Grazing Act. Under section 2 of...

  8. 43 CFR 2091.7-2 - Segregative effect and opening: Taylor Grazing Act.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregative effect and opening: Taylor Grazing Act. 2091.7-2 Section 2091.7-2 Public Lands: Interior Regulations Relating to Public Lands... LAWS AND RULES Segregation and Opening of Lands § 2091.7-2 Segregative effect and opening: Taylor...

  9. An Attempt to Extend Taylor-Spence Drive Theory to Vocational Choice Behavior

    ERIC Educational Resources Information Center

    Sharf, Richard S.

    1972-01-01

    Predictions were made from Taylor-Spence drive theory about vocational choice behavior. Although the results did not specifically support the predictions made from Taylor-Spence theory, they indicated the potential usefulness of certain concepts in this theory and suggested several lines of inquiry for further research. (Author)

  10. Limb lengthening combined with deformity correction in children with the Taylor Spatial Frame.

    PubMed

    Iobst, Christopher

    2010-11-01

    It is difficult to replicate the regular rate and rhythm described by Ilizarov while lengthening with the Taylor Spatial Frame. The purpose of the study was to examine whether this breach of Ilizarov's principles has any deleterious effect on the ability of children to make healthy regenerate bone. A retrospective case-control study was performed comparing pediatric patients undergoing primarily lengthening with Taylor Spatial Frame rings and struts, and patients undergoing lengthening with Taylor Spatial Frame rings and Ilizarov clickers. Fifteen patients had primarily lengthening with Taylor Spatial Frame rings and struts, and six patients had lengthening with Taylor Spatial Frame rings and Ilizarov clickers. Statistically, there was no significant difference between the two groups in terms of age, latency, pre-operative bone length percentage, and average length gained. The lengthening index for the strut group (1.79 months/cm) was significantly different from the clicker group (1.33 months/cm) with P=0.012. For a pediatric patient with lower extremity long bone deformities in multiple planes, the Taylor Spatial Frame is an excellent option. However, the surgeon should anticipate a slightly longer duration of treatment with the Taylor Spatial Frame compared to Ilizarov frames and plan his/her fixation accordingly. For the straightforward lengthening of pediatric long bones without significant concomitant deformity, our results indicate that the Ilizarov method appears to be superior to the Taylor Spatial Frame struts and should still be considered the gold standard.

  11. Taylor-Made Education: The Influence of the Efficiency Movement on the Testing of Reading Skills.

    ERIC Educational Resources Information Center

    Allen, JoBeth

    Much of what has developed in the testing of reading harkens back to the days of the "Cult of Efficiency" movement in education that can be largely attributed to Frederick Winslow Taylor. Taylor spent most of his productive years studying time and motion in an attempt to streamline industrial production so that people could work as…

  12. Numerical integration based on nested Taylor decomposition of univariate functions under fluctuationlessness approximation

    NASA Astrophysics Data System (ADS)

    Baykara, N. A.; Gürvit, Ercan

    2014-10-01

    The application of the Fluctuationlessness theorem to the remainder term of Taylor decomposition on which both sides are integrated has been already worked on. In this work the novelty brought to the previous work is to apply the Fluctuationlessness theorem to the remainder part which, itself also is decomposed in Taylor sense.

  13. An Attempt to Extend Taylor-Spence Drive Theory to Vocational Choice Behavior

    ERIC Educational Resources Information Center

    Sharf, Richard S.

    1972-01-01

    Predictions were made from Taylor-Spence drive theory about vocational choice behavior. Although the results did not specifically support the predictions made from Taylor-Spence theory, they indicated the potential usefulness of certain concepts in this theory and suggested several lines of inquiry for further research. (Author)

  14. Dismissal of a Sociologist: The AAUP Report on Carl C. Taylor.

    ERIC Educational Resources Information Center

    Larson, Olaf F.; Williams, Robin M., Jr.; Wimberley, Ronald C.

    1999-01-01

    Examines the dismissal in 1931 of distinguished sociologist Carl C. Taylor after 11 years as an influential faculty member and dean at the State College of Agriculture and Engineering of North Carolina. Reviews the subsequent investigation by the American Association of University Professors. Highlights Taylor's career and contributions at…

  15. The soybean GmDi19-5 interacts with GmLEA3.1 and increases sensitivity of transgenic plants to abiotic stresses

    PubMed Central

    Feng, Zhi-Juan; Cui, Xiao-Yu; Cui, Xi-Yan; Chen, Ming; Yang, Guang-Xiao; Ma, You-Zhi; He, Guang-Yuan; Xu, Zhao-Shi

    2015-01-01

    Drought-induced (Di19) proteins played important roles in plant growth, development, and abiotic stress responses. In the present study, a total of seven Di19 genes were identified in soybean. Each soybean Di19 gene showed specific responses to salt, drought, oxidative, and ABA stresses based on expression profiles. With a relatively higher transcript level among Di19 members under four stress treatments, GmDi19-5 was selected for detailed analysis. Inhibitor assays revealed that ABA inhibitor (Fluridone) or H2O2 inhibitor (DMTU) was involved in the drought- or salt-induced transcription of GmDi19-5. The GUS activity driven by the GmDi19-5 promoter was induced by salt, PEG, ABA, and MV treatments and tended to be accumulated in the vascular bundles and young leaves. A subcellular localization assay showed that GmDi19-5 protein localized in the nucleus. Further investigation showed that GmDi19-5 protein was involved in the interaction with GmLEA3.1. Overexpression of GmDi19-5 increased sensitivity of transgenic Arabidopsis plants to salt, drought, oxidative, and ABA stresses and regulated expression of several ABA/stress-associated genes. This present investigation showed that GmDi19-5 functioned as a negative factor under abiotic stresses and was involved in ABA and SOS signaling pathway by altering transcription of stress-associated genes. PMID:25852726

  16. Synthesis and characterization of N-parinaroyl analogs of ganglioside GM3 and de-N-acetyl GM3. Interactions with the EGF receptor kinase

    NASA Technical Reports Server (NTRS)

    Song, W.; Welti, R.; Hafner-Strauss, S.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    A specific plasma membrane glycosphingolipid, known as ganglioside GM3, can regulate the intrinsic tyrosyl kinase activity of the epidermal growth factor (EGF) receptor; this modulation is not associated with alterations in hormone binding to the receptor. GM3 inhibits EGF receptor tyrosyl kinase activity in detergent micelles, in plasma membrane vesicles, and in whole cells. In addition, immunoaffinity-purified EGF receptor preparations contain ganglioside GM3 (Hanai et al. (1988) J. Biol. Chem. 263, 10915-10921), implying that the glycosphingolipid is intimately associated with the receptor kinase in cell membranes. Both the nature of this association and the molecular mechanism of kinase inhibition remain to be elucidated. In this report, we describe the synthesis of a fluorescent analog of ganglioside GM3, in which the native fatty acid was replaced with trans-parinaric acid. This glycosphingolipid inhibited the receptor kinase activity in a manner similar to that of the native ganglioside. A modified fluorescent glycosphingolipid, N-trans-parinaroyl de-N-acetyl ganglioside GM3, was also prepared. This analog, like the nonfluorescent de-N-acetyl ganglioside GM3, had no effect on receptor kinase activity. Results from tryptophan fluorescence quenching and steady-state anisotropy measurements in membranes containing these fluorescent probes and the human EGF receptor were consistent with the notion that GM3, but not de-N-acetyl GM3, interacts specifically with the receptor in intact membranes.

  17. Synthesis and characterization of N-parinaroyl analogs of ganglioside GM3 and de-N-acetyl GM3. Interactions with the EGF receptor kinase

    NASA Technical Reports Server (NTRS)

    Song, W.; Welti, R.; Hafner-Strauss, S.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    A specific plasma membrane glycosphingolipid, known as ganglioside GM3, can regulate the intrinsic tyrosyl kinase activity of the epidermal growth factor (EGF) receptor; this modulation is not associated with alterations in hormone binding to the receptor. GM3 inhibits EGF receptor tyrosyl kinase activity in detergent micelles, in plasma membrane vesicles, and in whole cells. In addition, immunoaffinity-purified EGF receptor preparations contain ganglioside GM3 (Hanai et al. (1988) J. Biol. Chem. 263, 10915-10921), implying that the glycosphingolipid is intimately associated with the receptor kinase in cell membranes. Both the nature of this association and the molecular mechanism of kinase inhibition remain to be elucidated. In this report, we describe the synthesis of a fluorescent analog of ganglioside GM3, in which the native fatty acid was replaced with trans-parinaric acid. This glycosphingolipid inhibited the receptor kinase activity in a manner similar to that of the native ganglioside. A modified fluorescent glycosphingolipid, N-trans-parinaroyl de-N-acetyl ganglioside GM3, was also prepared. This analog, like the nonfluorescent de-N-acetyl ganglioside GM3, had no effect on receptor kinase activity. Results from tryptophan fluorescence quenching and steady-state anisotropy measurements in membranes containing these fluorescent probes and the human EGF receptor were consistent with the notion that GM3, but not de-N-acetyl GM3, interacts specifically with the receptor in intact membranes.

  18. A Review of GM-CSF Therapy in Sepsis

    PubMed Central

    Mathias, Brittany; Szpila, Benjamin E.; Moore, Frederick A.; Efron, Philip A.; Moldawer, Lyle L.

    2015-01-01

    Abstract Determine what clinical role, if any, GM-CSF may have in the clinical treatment of sepsis in the adult patient. Advancements in the management of sepsis have led to significant decreases in early mortality; however, sepsis remains a significant source of long-term mortality and disability which places strain on healthcare resources with a substantial growing economic impact. Historically, early multiple organ failure (MOF) and death in patients with severe sepsis was thought to result from an exaggerated proinflammatory response called the systemic inflammatory response syndrome (SIRS). Numerous prospective randomized controlled trials (PRCTs) tested therapies aimed at decreasing the organ injury associated with an exaggerated inflammatory response. With few exceptions, the results from these PRCTs have been disappointing, and currently no specific therapeutic agent is approved to counteract the early SIRS response in patients with severe sepsis. It has long been recognized that there is a delayed immunosuppressive state that contributes to long-term morbidity. However, recent findings now support a concurrent proinflammatory and anti-inflammatory response present throughout sepsis. Multiple immunomodulating agents have been studied to combat the immunosuppressive phase of sepsis with the goal of decreasing secondary infection, reducing organ dysfunction, decreasing ICU stays, and improving survival. Granulocyte-macrophage colony stimulating factor (GM-CSF), a myelopoietic growth factor currently used in patients with neutropenia secondary to chemotherapy-induced myelosuppression, has been studied as a potential immune-activating agent. The applicability of GM-CSF as a standard therapy for generalized sepsis is still largely understudied; however, small-scale studies available have demonstrated some improved recovery from infection, decreased hospital length of stay, decreased days requiring mechanical ventilation, and decreased medical costs. PMID

  19. GM as a route for delivery of sustainable crop protection.

    PubMed

    Bruce, Toby J A

    2012-01-01

    Modern agriculture, with its vast monocultures of lush fertilized crops, provides an ideal environment for adapted pests, weeds, and diseases. This vulnerability has implications for food security: when new pesticide-resistant pest biotypes evolve they can devastate crops. Even with existing crop protection measures, approximately one-third yield losses occur globally. Given the projected increase in demand for food (70% by 2050 according to the UN), sustainable ways of preventing these losses are needed. Development of resistant crop cultivars can make an important contribution. However, traditional crop breeding programmes are limited by the time taken to move resistance traits into elite crop genetic backgrounds and the limited gene pools in which to search for novel resistance. Furthermore, resistance based on single genes does not protect against the full spectrum of pests, weeds, and diseases, and is more likely to break down as pests evolve counter-resistance. Although not necessarily a panacea, GM (genetic modification) techniques greatly facilitate transfer of genes and thus provide a route to overcome these constraints. Effective resistance traits can be precisely and conveniently moved into mainstream crop cultivars. Resistance genes can be stacked to make it harder for pests to evolve counter-resistance and to provide multiple resistances to different attackers. GM-based crop protection could substantially reduce the need for farmers to apply pesticides to their crops and would make agricultural production more efficient in terms of resources used (land, energy, water). These benefits merit consideration by environmentalists willing to keep an open mind on the GM debate.

  20. The numerical solution of ordinary differential equations by the Taylor series method

    NASA Technical Reports Server (NTRS)

    Silver, A. H.; Sullivan, E.

    1973-01-01

    A programming implementation of the Taylor series method is presented for solving ordinary differential equations. The compiler is written in PL/1, and the target language is FORTRAN IV. The reduction of a differential system to rational form is described along with the procedures required for automatic numerical integration. The Taylor method is compared with two other methods for a number of differential equations. Algorithms using the Taylor method to find the zeroes of a given differential equation and to evaluate partial derivatives are presented. An annotated listing of the PL/1 program which performs the reduction and code generation is given. Listings of the FORTRAN routines used by the Taylor series method are included along with a compilation of all the recurrence formulas used to generate the Taylor coefficients for non-rational functions.

  1. Novel GM-CSF-based vaccines: One small step in GM-CSF gene optimization, one giant leap for human vaccines

    PubMed Central

    Yu, Ting-Wei; Chueh, Ho-Yen; Tsai, Ching-Chou; Lin, Cheng-Tao; Qiu, Jiantai Timothy

    2016-01-01

    ABSTRACT Granulocyte macrophage-colony stimulating factor (GM-CSF) is a potent immunomodulatory cytokine that is known to facilitate vaccine efficacy by promoting the development and prolongation of both humoral and cellular immunity. In the past years we have generated a novel codon-optimized GM-CSF gene as an adjuvant. The codon-optimized GM-CSF gene significantly increased protein expression levels in all cells tested and helped in generating a strong immune responses against HIV-1 Gag and HPV-associated cancer. Here, we review the literature dealing with the adjuvant activity of GM-CSF both in animal models and clinical trials. We anticipate that the codon-optimized GM-CSF gene offers a practical molecular strategy for potentiating immune responses to tumor cell-based vaccinations as well as other immunotherapeutic strategies. PMID:27560197

  2. GM crops and foods: what do consumers want to know?

    PubMed

    McHughen, Alan

    2013-01-01

    Agricultural biotechnology--GMOs--has a huge positive impact on farming and farmers but remains controversial among the skeptical public. Curious but anxious consumers, driven by scare stories and pseudo-science provided by anti-GMO activists, seek accurate and authoritative answers to their questions. Here, I address a sample of such queries directed to me from the public, including the ubiquitous "Is it safe?" and also discuss some of the shameful tactics used by anti-GM activists in the public debate to garner support at the cost of inciting unnecessary anxiety among the public.

  3. Synthesis and cytotoxicity assay of four ganglioside GM3 analogues.

    PubMed

    Qu, Huanhuan; Liu, Jian-Miao; Wdzieczak-Bakala, Joanna; Lu, Dan; He, Xianran; Sun, Wenji; Sollogoub, Matthieu; Zhang, Yongmin

    2014-03-21

    A concise and efficient synthetic route for preparation of four ganglioside GM3 analogues was described. The key step is a highly regioselective and stereoselective α-sialylation from a suitably protected glycoside acceptor with a sialyl xanthate to provide the sialo-oligosaccharide in good yield. The cytotoxic properties of the synthetic gangliosides were evaluated against normal human keratinocytes and human HCT116 and K562 cancer cells. Two of them exhibited good antiproliferative activity and displayed a better cytotoxicity against cancer cell than HaCaT normal cell. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Increased Expression of Simple Ganglioside Species GM2 and GM3 Detected by MALDI Imaging Mass Spectrometry in a Combined Rat Model of Aβ Toxicity and Stroke.

    PubMed

    Caughlin, Sarah; Hepburn, Jeffrey D; Park, Dae Hee; Jurcic, Kristina; Yeung, Ken K-C; Cechetto, David F; Whitehead, Shawn N

    2015-01-01

    The aging brain is often characterized by the presence of multiple comorbidities resulting in synergistic damaging effects in the brain as demonstrated through the interaction of Alzheimer's disease (AD) and stroke. Gangliosides, a family of membrane lipids enriched in the central nervous system, may have a mechanistic role in mediating the brain's response to injury as their expression is altered in a number of disease and injury states. Matrix-Assisted Laser Desorption Ionization (MALDI) Imaging Mass Spectrometry (IMS) was used to study the expression of A-series ganglioside species GD1a, GM1, GM2, and GM3 to determine alteration of their expression profiles in the presence of beta-amyloid (Aβ) toxicity in addition to ischemic injury. To model a stroke, rats received a unilateral striatal injection of endothelin-1 (ET-1) (stroke alone group). To model Aβ toxicity, rats received intracerebralventricular (i.c.v.) injections of the toxic 25-35 fragment of the Aβ peptide (Aβ alone group). To model the combination of Aβ toxicity with stroke, rats received both the unilateral ET-1 injection and the bilateral icv injections of Aβ25-35 (combined Aβ/ET-1 group). By 3 d, a significant increase in the simple ganglioside species GM2 was observed in the ischemic brain region of rats who received a stroke (ET-1), with or without Aβ. By 21 d, GM2 levels only remained elevated in the combined Aβ/ET-1 group. GM3 levels however demonstrated a different pattern of expression. By 3 d GM3 was elevated in the ischemic brain region only in the combined Aβ/ET-1 group. By 21 d, GM3 was elevated in the ischemic brain region in both stroke alone and Aβ/ET-1 groups. Overall, results indicate that the accumulation of simple ganglioside species GM2 and GM3 may be indicative of a mechanism of interaction between AD and stroke.

  5. Production of neutralizing granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies in carcinoma patients following GM-CSF combination therapy.

    PubMed

    Wadhwa, M; Bird, C; Fagerberg, J; Gaines-Das, R; Ragnhammar, P; Mellstedt, H; Thorpe, R

    1996-05-01

    In this study, the development of neutralizing and non-neutralizing GM-CSF antibodies and the clinical consequences related to the induction of these antibodies were analysed in 20 patients with metastatic colorectal carcinoma receiving a combination therapy of Escherichia coli-derived GM-CSF and a colon carcinoma-reactive MoAb in the absence of any concomitant chemotherapy. The recombinant human GM-CSF was administered subcutaneously for 10 days every month for 4 months. Following the first cycle of treatment, no GM-CSF antibodies were detected, but during subsequent therapy, 19 of the 20 patients studied developed GM-CSF binding antibodies. However, only a proportion (40%) of the 19 antibody-positive patients developed antibodies that neutralized the biological activity of GM-CSF in an in vitro bioassay. The presence of GM-CSF neutralizing antibodies was associated with a significant reduction in GM-CSF-induced expansion of leucocytes, neutrophils and eosinophils. Such clinical effects were not apparent in patients with non-neutralizing antibodies. Further characterization of sera from patients with neutralizing antibodies showed that, in most cases, the antibodies neutralized the biological activity of GM-CSF preparations derived using different expression systems (Chinese hamster ovary cells and yeast), suggesting that these antibodies may have the potential to cross-react with endogenously produced GM-CSF. These effects should be considered before therapeutic use of cytokines, particularly in patients who are not immunosuppressed, and therefore capable of mounting an effective immune response. Our results indicate that assessment of production of neutralizing antibodies induced during cytokine therapy can be used to predict diminished clinical response to further therapy.

  6. Increased Expression of Simple Ganglioside Species GM2 and GM3 Detected by MALDI Imaging Mass Spectrometry in a Combined Rat Model of Aβ Toxicity and Stroke

    PubMed Central

    Caughlin, Sarah; Hepburn, Jeffrey D.; Park, Dae Hee; Jurcic, Kristina; Yeung, Ken K.-C.; Cechetto, David F.; Whitehead, Shawn N.

    2015-01-01

    The aging brain is often characterized by the presence of multiple comorbidities resulting in synergistic damaging effects in the brain as demonstrated through the interaction of Alzheimer’s disease (AD) and stroke. Gangliosides, a family of membrane lipids enriched in the central nervous system, may have a mechanistic role in mediating the brain’s response to injury as their expression is altered in a number of disease and injury states. Matrix-Assisted Laser Desorption Ionization (MALDI) Imaging Mass Spectrometry (IMS) was used to study the expression of A-series ganglioside species GD1a, GM1, GM2, and GM3 to determine alteration of their expression profiles in the presence of beta-amyloid (Aβ) toxicity in addition to ischemic injury. To model a stroke, rats received a unilateral striatal injection of endothelin-1 (ET-1) (stroke alone group). To model Aβ toxicity, rats received intracerebralventricular (icv) injections of the toxic 25-35 fragment of the Aβ peptide (Aβ alone group). To model the combination of Aβ toxicity with stroke, rats received both the unilateral ET-1 injection and the bilateral icv injections of Aβ₂₅₋₃₅ (combined Aβ/ET-1 group). By 3 d, a significant increase in the simple ganglioside species GM2 was observed in the ischemic brain region of rats who received a stroke (ET-1), with or without Aβ. By 21 d, GM2 levels only remained elevated in the combined Aβ/ET-1 group. GM3 levels however demonstrated a different pattern of expression. By 3 d GM3 was elevated in the ischemic brain region only in the combined Aβ/ET-1 group. By 21 d, GM3 was elevated in the ischemic brain region in both stroke alone and Aβ/ET-1 groups. Overall, results indicate that the accumulation of simple ganglioside species GM2 and GM3 may be indicative of a mechanism of interaction between AD and stroke. PMID:26086081

  7. [Application of DNA extraction kit, 'GM quicker' for detection of genetically modified soybeans].

    PubMed

    Sato, Noriko; Sugiura, Yoshitsugu; Tanaka, Toshitsugu

    2012-01-01

    Several DNA extraction methods have been officially introduced to detect genetically modified soybeans, but the choice of DNA extraction kits depend on the nature of the samples, such as grains or processed foods. To overcome this disadvantage, we examined whether the GM quicker kit is available for both grains and processed foods. We compared GM quicker with four approved DNA extraction kits in respect of DNA purity, copy numbers of lectin gene, and working time. We found that the DNA quality of GM quicker was superior to that of the other kits for grains, and the procedure was faster. However, in the case of processed foods, GM quicker was not superior to the other kits. We therefore investigated an unapproved GM quicker 3 kit, which is available for DNA extraction from processed foods, such as tofu and boiled soybeans. The GM quicker 3 kit provided good DNA quality from both grains and processed foods, so we made a minor modification of the GM quicker-based protocol that was suitable for processed foods, using GM quicker and its reagents. The modified method enhanced the performance of GM quicker with processed foods. We believe that GM quicker with the modified protocol is an excellent tool to obtain high-quality DNA from grains and processed foods for detection of genetically modified soybeans.

  8. Deficiency of ganglioside GM1 correlates with Parkinson's disease in mice and humans.

    PubMed

    Wu, Gusheng; Lu, Zi-Hua; Kulkarni, Neil; Ledeen, Robert W

    2012-10-01

    Several studies have successfully employed GM1 ganglioside to treat animal models of Parkinson's disease (PD), suggesting involvement of this ganglioside in PD etiology. We recently demonstrated that genetically engineered mice (B4galnt1(-/-) ) devoid of GM1 acquire characteristic symptoms of this disorder, including motor impairment, depletion of striatal dopamine, selective loss of tyrosine hydroxylase-expressing neurons, and aggregation of α-synuclein. The present study demonstrates similar symptoms in heterozygous mice (HTs) that express only partial GM1 deficiency. Symptoms were alleviated by administration of L-dopa or LIGA-20, a membrane-permeable analog of GM1 that penetrates the blood-brain barrier and accesses intracellular compartments. Immunohistochemical analysis of paraffin sections from PD patients revealed significant GM1 deficiency in nigral dopaminergic neurons compared with age-matched controls. This was comparable to the GM1 deficiency of HT mice and suggests that GM1 deficiency may be a contributing factor to idiopathic PD. We propose that HT mice with partial GM1 deficiency constitute an especially useful model for PD, reflecting the actual pathophysiology of this disorder. The results point to membrane-permeable analogs of GM1 as holding promise as a form of GM1 replacement therapy.

  9. A novel subset of helper T cells promotes immune responses by secreting GM-CSF

    PubMed Central

    Zhang, J; Roberts, A I; Liu, C; Ren, G; Xu, G; Zhang, L; Devadas, S; Shi, Yufang

    2013-01-01

    Helper T cells are crucial for maintaining proper immune responses. Yet, they have an undefined relationship with one of the most potent immune stimulatory cytokines, granulocyte macrophage-colony-stimulating factor (GM-CSF). By depleting major cytokines during the differentiation of CD4+ T cells in vitro, we derived cells that were found to produce large amounts of GM-CSF, but little of the cytokines produced by other helper T subsets. By their secretion of GM-CSF, this novel subset of helper T cells (which we have termed ThGM cells) promoted the production of cytokines by other T-cell subtypes, including type 1 helper T cell (Th1), type 2 helper T cell (Th2), type 1 cytotoxic T cell (Tc1), type 2 cytotoxic T cell (Tc2), and naive T cells, as evidenced by the fact that antibody neutralization of GM-CSF abolished this effect. ThGM cells were found to be highly prone to activation-induced cell death (AICD). Inhibitors of TRAIL or granzymes could not block AICD in ThGM cells, whereas inhibition of FasL/Fas interaction partially rescued ThGM cells from AICD. Thus, ThGM cells are a novel subpopulation of T helper cells that produce abundant GM-CSF, exhibit exquisite susceptibility to apoptosis, and therefore play a pivotal role in the regulation of the early stages of immune responses. PMID:24076588

  10. Soybean GmDREBL Increases Lipid Content in Seeds of Transgenic Arabidopsis

    PubMed Central

    Zhang, Yu-Qin; Lu, Xiang; Zhao, Fei-Yi; Li, Qing-Tian; Niu, Su-Ling; Wei, Wei; Zhang, Wan-Ke; Ma, Biao; Chen, Shou-Yi; Zhang, Jin-Song

    2016-01-01

    A DREB-type transcription factor gene GmDREBL has been characterized for its functions in oil accumulation in seeds. The gene is specifically expressed in soybean seeds. The GmDREBL is localized in nucleus and has transcriptional activation ability. Overexpression of GmDREBL increased the fatty acid content in the seeds of transgenic Arabidopsis plants. GmDREBL can bind to the promoter region of WRI1 to activate its expression. Several other genes in the fatty acid biosynthesis pathway were also enhanced in the GmDREBL-transgenic plants. The GmDREBL can be up-regulated by GmABI3 and GmABI5. Additionally, overexpression of GmDREBL significantly promoted seed size in transgenic plants compared to that of WT plants. Expression of the DREBL is at higher level on the average in cultivated soybeans than that in wild soybeans. The promoter of the DREBL may have been subjected to selection during soybean domestication. Our results demonstrate that GmDREBL participates in the regulation of fatty acid accumulation by controlling the expression of WRI1 and its downstream genes, and manipulation of the gene may increase the oil contents in soybean plants. Our study provides novel insights into the function of DREB-type transcription factors in oil accumulation in addition to their roles in stress response. PMID:27694917

  11. Taylor's law and body size in exploited marine ecosystems.

    PubMed

    Cohen, Joel E; Plank, Michael J; Law, Richard

    2012-12-01

    Taylor's law (TL), which states that variance in population density is related to mean density via a power law, and density-mass allometry, which states that mean density is related to body mass via a power law, are two of the most widely observed patterns in ecology. Combining these two laws predicts that the variance in density is related to body mass via a power law (variance-mass allometry). Marine size spectra are known to exhibit density-mass allometry, but variance-mass allometry has not been investigated. We show that variance and body mass in unexploited size spectrum models are related by a power law, and that this leads to TL with an exponent slightly <2. These simulated relationships are disrupted less by balanced harvesting, in which fishing effort is spread across a wide range of body sizes, than by size-at-entry fishing, in which only fish above a certain size may legally be caught.

  12. Deformity correction in Haiti with the Taylor Spatial Frame.

    PubMed

    Alexis, Francel; Herzenberg, John E; Nelson, Scott C

    2015-01-01

    The Taylor Spatial Frame (TSF) is an external-fixator that corrects deformities in 6 axes, and can successfully manage disorders involving multiplanar deformities. In the developing-world, orthopaedic surgeons are often faced with deformities from neglected trauma and birth defects more severe than those typically seen in developed-countries. This article evaluates the applicability of TSF in the challenging medical environment of Haiti. At Haiti Adventist Hospital, the authors treated 80 cases using the TSF with a minimum follow-up of 1-year. Good results were observed in 99% of the cases (79 out of 80), approaching similar outcomes than those described in literature. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Numerical study of spherical Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Yang, R.-J.

    1989-01-01

    A new technique to simulate Taylor vortices in a spherical gap between a rotating inner sphere and a stationary outer one has been developed and tested. Paths leading to zero-, one-, and two-vortex flows are designed heuristically. Fictitious symmetric boundaries near the equator are imposed, and the choice of the location of the fictitious boundaries is determined by either one- or two-vortex flow being stimulated. The imposition of one or two fictitious boundaries during the initial calculation generates the state suitable for one-or two-vortex flow to exist. After removing the fictitious boundaries, the flow settles down into its own attractor. Using this method, the three steady flow modes can be simulated by using a half domain. The technique can converge to desired flows very fast, and its results show excellent agreement with experimental ones.

  14. Rayleigh-Taylor instability in accelerated solid media

    NASA Astrophysics Data System (ADS)

    Piriz, A. R.; Sun, Y. B.; Tahir, N. A.

    2017-01-01

    A linear study of the Rayleigh-Taylor instability based on momentum conservation and the consideration of an irrotational velocity field for incompressible perturbations is discussed. The theory allows for a very appealing physical picture and for a relatively simple description of the main features of the instability. As a result, it is suitable for the study of the very complex problem of the instability of accelerated solids with non-linear elastic-plastic constitutive properties, which cannot be studied by the usual normal modes approach. The elastic to plastic transition occurring early in the instability process determines the entire evolution and makes the instability exhibit behavior that cannot be captured by an asymptotic analysis.

  15. Viscous Rayleigh-Taylor instability in spherical geometry

    NASA Astrophysics Data System (ADS)

    Mikaelian, Karnig O.

    2016-02-01

    We consider viscous fluids in spherical geometry, a lighter fluid supporting a heavier one. Chandrasekhar [Q. J. Mech. Appl. Math. 8, 1 (1955), 10.1093/qjmam/8.1.1] analyzed this unstable configuration providing the equations needed to find, numerically, the exact growth rates for the ensuing Rayleigh-Taylor instability. He also derived an analytic but approximate solution. We point out a weakness in his approximate dispersion relation (DR) and offer a somewhat improved one. A third DR, based on transforming a planar DR into a spherical one, suffers no unphysical predictions and compares reasonably well with the exact work of Chandrasekhar and a more recent numerical analysis of the problem [Terrones and Carrara, Phys. Fluids 27, 054105 (2015), 10.1063/1.4921648].

  16. Recovering network topologies via Taylor expansion and compressive sensing

    SciTech Connect

    Li, Guangjun; Liu, Juan E-mail: liujuanjp@163.com; Wu, Xiaoqun E-mail: liujuanjp@163.com; Lu, Jun-an; Guo, Chi

    2015-04-15

    Gaining knowledge of the intrinsic topology of a complex dynamical network is the precondition to understand its evolutionary mechanisms and to control its dynamical and functional behaviors. In this article, a general framework is developed to recover topologies of complex networks with completely unknown node dynamics based on Taylor expansion and compressive sensing. Numerical simulations illustrate the feasibility and effectiveness of the proposed method. Moreover, this method is found to have good robustness to weak stochastic perturbations. Finally, the impact of two major factors on the topology identification performance is evaluated. This method provides a natural and direct point to reconstruct network topologies from measurable data, which is likely to have potential applicability in a wide range of fields.

  17. Rayleigh-Taylor stabilization by material strength at Mbar pressures

    NASA Astrophysics Data System (ADS)

    Remington, Bruce; Park, Hye-Sook; Lorenz, Thomas; Cavallo, Robert; Pollaine, Stephen; Prisbrey, Shon; Rudd, Robert; Becker, Richard; Bernier, Joel

    2009-11-01

    We present experiments on the Rayleigh-Taylor (RT) instability in the plastic flow regime of solid-state vanadium (V) foils at 1 Mbar pressures and strain rates of 1.e6-1.e8 1/s, using a laser based, ramped-pressure acceleration technique. High pressure material strength causes strong stabilization of the RT instability at short wavelengths. Comparisons with 2D simulations utilizing models of high pressure strength show that the V strength increases by factors of 3-4 at peak pressure, compared to its ambient strength. An effective lattice viscosity of 400 poise would have a similar effect. [1] Constitutive models, and theoretical implications of these experiments will be discussed. [1] H.S. Park, B.A. Remington et al., submitted for publication (July, 2009).

  18. Symmetry and stability in Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Golubitsky, M.; Stewart, I.

    1986-01-01

    The flow of a fluid between concentric rotating cylinders (the Taylor problem) is studied by exploiting the symmetries of the system. The Navier-Stokes equations, linearized about Couette flow, possess two zero and four purely imaginary eigenvalues at a suitable value of the speed of rotation of the outer cylinder. There is thus a reduced bifurcation equation on a six-dimensonal space which can be shown to commute with an action of the symmetry group 0(2) x S0(2). The group structure is used to analyze this bifurcation equation in the simplest (nondegenerate) case, and to compute the stabilities of solutions. In particular, when the outer cylinder is counterrotated, transitions which seem to agree with recent experiments of Andereck, Liu, and Swinney (1984) are obtained. It is also possible to obtain the 'main sequence' in this model. This sequence is normally observed in experiments when the outer cylinder is held fixed.

  19. Taylor's law and body size in exploited marine ecosystems

    PubMed Central

    Cohen, Joel E; Plank, Michael J; Law, Richard

    2012-01-01

    Taylor's law (TL), which states that variance in population density is related to mean density via a power law, and density-mass allometry, which states that mean density is related to body mass via a power law, are two of the most widely observed patterns in ecology. Combining these two laws predicts that the variance in density is related to body mass via a power law (variance-mass allometry). Marine size spectra are known to exhibit density-mass allometry, but variance-mass allometry has not been investigated. We show that variance and body mass in unexploited size spectrum models are related by a power law, and that this leads to TL with an exponent slightly <2. These simulated relationships are disrupted less by balanced harvesting, in which fishing effort is spread across a wide range of body sizes, than by size-at-entry fishing, in which only fish above a certain size may legally be caught. PMID:23301181

  20. Charge-Induced Saffman-Taylor Instabilities in Toroidal Droplets

    NASA Astrophysics Data System (ADS)

    Fragkopoulos, A. A.; Aizenman, A.; Fernández-Nieves, A.

    2017-06-01

    We show that charged toroidal droplets can develop fingerlike structures as they expand due to Saffman-Taylor instabilities. While these are commonly observed in quasi-two-dimensional geometries when a fluid displaces another fluid of higher viscosity, we show that the toroidal confinement breaks the symmetry of the problem, effectively making it quasi-two-dimensional and enabling the instability to develop in this three-dimensional situation. We control the expansion speed of the torus with the imposed electric stress and show that fingers are observed provided the characteristic time scale associated with this instability is smaller than the characteristic time scale associated with Rayleigh-Plateau break-up. We confirm our interpretation of the results by showing that the number of fingers is consistent with expectations from linear stability analysis in radial Hele-Shaw cells.

  1. Shercliff layers in strongly magnetic cylindrical Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Hollerbach, Rainer; Hulot, Deborah

    2016-07-01

    We numerically compute the axisymmetric Taylor-Couette flow in the presence of axially periodic magnetic fields, with Hartmann numbers up to Ha2 =107. The geometry of the field singles out special field lines on which Shercliff layers form. These are simple shear layers for insulating boundaries, versus super-rotating or counter-rotating layers for conducting boundaries. Some field configurations have previously studied spherical analogs, but fundamentally new configurations also exist, having no spherical analogs. Finally, we explore the influence of azimuthal fields Bϕ ∼r-1eˆϕ on these layers, and show that the flow is suppressed for conducting boundaries, but enhanced for insulating boundaries. xml:lang="fr"

  2. The cylindrical magnetic Rayleigh-Taylor instability for viscous fluids

    SciTech Connect

    Chambers, K.; Forbes, L. K.

    2012-10-15

    This paper considers a cylindrical Rayleigh-Taylor instability, in which a heavy fluid surrounds a light fluid, and gravity is directed radially inwards. A massive object is located at the centre of the light fluid, and it behaves like a line dipole both for fluid flow and magnetic field strength. The initially circular interface between the two conducting fluids evolves into plumes, dependent on the magnetic and fluid dipole strengths and the nature of the initial disturbance to the interface. A spectral method is presented to solve the time-dependent interface shapes, and results are presented and discussed. Bipolar solutions are possible, and these are of particular relevance to astrophysics. The solutions obtained resemble structures of some HII regions and nebulae.

  3. Linear analysis of incompressible Rayleigh-Taylor instability in solids

    NASA Astrophysics Data System (ADS)

    Piriz, A. R.; López Cela, J. J.; Tahir, N. A.

    2009-10-01

    The study of the linear stage of the incompressible Rayleigh-Taylor instability in elastic-plastic solids is performed by considering thick plates under a constant acceleration that is also uniform except for a small sinusoidal ripple in the horizontal plane. The analysis is carried out by using an analytical model based on the Newton second law and it is complemented with extensive two-dimensional numerical simulations. The conditions for marginal stability that determine the instability threshold are derived. Besides, the boundary for the transition from the elastic to the plastic regime is obtained and it is demonstrated that such a transition is not a sufficient condition for instability. The model yields complete analytical solutions for the perturbation amplitude evolution and reveals the main physical process that governs the instability. The theory is in general agreement with the numerical simulations and provides useful quantitative results. Implications for high-energy-density-physics experiments are also discussed.

  4. Rayleigh-Taylor instability in soft elastic layers

    NASA Astrophysics Data System (ADS)

    Riccobelli, D.; Ciarletta, P.

    2017-04-01

    This work investigates the morphological stability of a soft body composed of two heavy elastic layers attached to a rigid surface and subjected only to the bulk gravity force. Using theoretical and computational tools, we characterize the selection of different patterns as well as their nonlinear evolution, unveiling the interplay between elastic and geometric effects for their formation. Unlike similar gravity-induced shape transitions in fluids, such as the Rayleigh-Taylor instability, we prove that the nonlinear elastic effects saturate the dynamic instability of the bifurcated solutions, displaying a rich morphological diagram where both digitations and stable wrinkling can emerge. The results of this work provide important guidelines for the design of novel soft systems with tunable shapes, with several applications in engineering sciences. This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.'

  5. A novel technique for performing symmetric Taylor impact

    NASA Astrophysics Data System (ADS)

    Walley, S. M.; Taylor, N. E.; Williamson, D. M.; Jardine, A. P.

    2015-09-01

    A novel spring tensioned wire cradle arrangement has been developed to hold the target rod lightly but firmly in place when performing rod-on-rod (symmetric Taylor) impact in a vacuum. In addition, a soft capture system has been designed and used to decelerate both rods while reducing the chance of them colliding a second time. High-speed photography was used to obtain the profile of a pure aluminium target rod as a function of time. Photon Doppler Velocimetry (PDV) was also deployed to record the velocity of the rear of the target rod as a function of time. Voiding in the interior of recovered rods was investigated non-destructively using X-ray tomography. The data provides comprehensive validation information for predictive constitutive models.

  6. Size invariance of the granular Rayleigh-Taylor instability.

    PubMed

    Vinningland, Jan Ludvig; Johnsen, Øistein; Flekkøy, Eirik G; Toussaint, Renaud; Måløy, Knut Jørgen

    2010-04-01

    The size scaling behavior of the granular Rayleigh-Taylor instability [J. L. Vinningland, Phys. Rev. Lett. 99, 048001 (2007)] is investigated experimentally, numerically, and theoretically. An upper layer of grains displaces a lower gap of air by organizing into dense fingers of falling grains separated by rising bubbles of air. The dependence of these structures on the system and grain sizes is investigated. A spatial measurement of the finger structures is obtained by the Fourier power spectrum of the wave number k. As the size of the grains increases the wave number decreases accordingly which leaves the dimensionless product of wave number and grain diameter, dk, invariant. A theoretical interpretation of the invariance, based on the scaling properties of the model equations, suggests a gradual breakdown of the invariance for grains smaller than approximately 70 microm or greater than approximately 570 microm in diameter.

  7. Experiments of periodic forcing of Saffman-Taylor fingers

    NASA Astrophysics Data System (ADS)

    Torralba, M.; Ortín, J.; Hernández-Machado, A.; Poiré, E. Corvera

    2008-03-01

    We report on an experimental study of long normal Saffman-Taylor fingers subject to periodic forcing. The sides of the finger develop a low amplitude, long wavelength instability. We discuss the finger response in stationary and nonstationary situations, as well as the dynamics towards the stationary states. The response frequency of the instability increases with forcing frequency at low forcing frequencies, while, remarkably, it becomes independent of forcing frequency at large forcing frequencies. This implies a process of wavelength selection. These observations are in good agreement with previous numerical results reported in [Ledesma-Aguilar , Phys. Rev. E 71, 016312 (2005)]. We also study the average value of the finger width, and its fluctuations, as a function of forcing frequency. The average finger width is always smaller than the width of the steady-state finger. Fluctuations have a nonmonotonic behavior with a maximum at a particular frequency.

  8. Symmetry and stability in Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Golubitsky, M.; Stewart, I.

    1986-01-01

    The flow of a fluid between concentric rotating cylinders (the Taylor problem) is studied by exploiting the symmetries of the system. The Navier-Stokes equations, linearized about Couette flow, possess two zero and four purely imaginary eigenvalues at a suitable value of the speed of rotation of the outer cylinder. There is thus a reduced bifurcation equation on a six-dimensonal space which can be shown to commute with an action of the symmetry group 0(2) x S0(2). The group structure is used to analyze this bifurcation equation in the simplest (nondegenerate) case, and to compute the stabilities of solutions. In particular, when the outer cylinder is counterrotated, transitions which seem to agree with recent experiments of Andereck, Liu, and Swinney (1984) are obtained. It is also possible to obtain the 'main sequence' in this model. This sequence is normally observed in experiments when the outer cylinder is held fixed.

  9. Numerical study of spherical Taylor-Couette flow

    NASA Technical Reports Server (NTRS)

    Yang, R.-J.

    1989-01-01

    A new technique to simulate Taylor vortices in a spherical gap between a rotating inner sphere and a stationary outer one has been developed and tested. Paths leading to zero-, one-, and two-vortex flows are designed heuristically. Fictitious symmetric boundaries near the equator are imposed, and the choice of the location of the fictitious boundaries is determined by either one- or two-vortex flow being stimulated. The imposition of one or two fictitious boundaries during the initial calculation generates the state suitable for one-or two-vortex flow to exist. After removing the fictitious boundaries, the flow settles down into its own attractor. Using this method, the three steady flow modes can be simulated by using a half domain. The technique can converge to desired flows very fast, and its results show excellent agreement with experimental ones.

  10. The magnetic Rayleigh-Taylor instability in astrophysical discs

    NASA Astrophysics Data System (ADS)

    Contopoulos, I.; Kazanas, D.; Papadopoulos, D. B.

    2016-10-01

    This is our first study of the magnetic Rayleigh-Taylor instability at the inner edge of an astrophysical disc around a central back hole. We derive the equations governing small-amplitude oscillations in general relativistic ideal magnetodydrodynamics and obtain a criterion for the onset of the instability. We suggest that static disc configurations where magnetic field is held by the disc material are unstable around a Schwarzschild black hole. On the other hand, we find that such configurations are stabilized by the space-time rotation around a Kerr black hole. We obtain a crude estimate of the maximum amount of poloidal magnetic flux that can be accumulated around the centre, and suggest that it is proportional to the black hole spin. Finally, we discuss the astrophysical implications of our result for the theoretical and observational estimations of the black hole jet power.

  11. Lattice QCD at finite temperature and density from Taylor expansion

    NASA Astrophysics Data System (ADS)

    Steinbrecher, Patrick

    2017-01-01

    In the first part, I present an overview of recent Lattice QCD simulations at finite temperature and density. In particular, we discuss fluctuations of conserved charges: baryon number, electric charge and strangeness. These can be obtained from Taylor expanding the QCD pressure as a function of corresponding chemical potentials. Our simulations were performed using quark masses corresponding to physical pion mass of about 140 MeV and allow a direct comparison to experimental data from ultra-relativistic heavy ion beams at hadron colliders such as the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN. In the second part, we discuss computational challenges for current and future exascale Lattice simulations with a focus on new silicon developments from Intel and NVIDIA.

  12. Plasma transport driven by the Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Ma, X.; Delamere, P. A.; Otto, A.

    2016-06-01

    Two important differences between the giant magnetospheres (i.e., Jupiter's and Saturn's magnetospheres) and the terrestrial magnetosphere are the internal plasma sources and the fast planetary rotation. Thus, there must be a radially outward flow to transport the plasma to avoid infinite accumulation of plasma. This radial outflow also carries the magnetic flux away from the inner magnetosphere due to the frozen-in condition. As such, there also must be a radial inward flow to refill the magnetic flux in the inner magnetosphere. Due to the similarity between Rayleigh-Taylor (RT) instability and the centrifugal instability, we use a three-dimensional RT instability to demonstrate that an interchange instability can form a convection flow pattern, locally twisting the magnetic flux, consequently forming a pair of high-latitude reconnection sites. This process exchanges a part of the flux tube, thereby transporting the plasma radially outward without requiring significant latitudinal convection of magnetic flux in the ionosphere.

  13. The Magnetic Rayleigh-Taylor Instability in Astrophysical Discs

    NASA Technical Reports Server (NTRS)

    Contopoulos, I.; Kazanas, D.; Papadopoulos, D. B.

    2016-01-01

    This is our first study of the magnetic Rayleigh-Taylor instability at the inner edge of an astrophysical disc around a central back hole. We derive the equations governing small-amplitude oscillations in general relativistic ideal magnetodydrodynamics and obtain a criterion for the onset of the instability. We suggest that static disc configurations where magnetic field is held by the disc material are unstable around a Schwarzschild black hole. On the other hand, we find that such configurations are stabilized by the space-time rotation around a Kerr black hole. We obtain a crude estimate of the maximum amount of poloidal magnetic flux that can be accumulated around the centre, and suggest that it is proportional to the black hole spin. Finally, we discuss the astrophysical implications of our result for the theoretical and observational estimations of the black hole jet power.

  14. Bubble acceleration in the ablative Rayleigh-Taylor instability.

    PubMed

    Betti, R; Sanz, J

    2006-11-17

    The highly nonlinear evolution of the single-mode Rayleigh-Taylor instability (RTI) at the ablation front of an accelerated target is investigated in the parameter range typical of inertial confinement fusion implosions. A new phase of the nonlinear bubble evolution is discovered. After the linear growth phase and a short constant-velocity phase, it is found that the bubble is accelerated to velocities well above the classical value. This acceleration is driven by the vorticity accumulation inside the bubble resulting from the mass ablation and vorticity convection off the ablation front. While the ablative growth rates are slower than their classical values in the linear regime, the ablative RTI grows faster than the classical RTI in the nonlinear regime for deuterium and tritium ablators.

  15. Linear analysis of incompressible Rayleigh-Taylor instability in solids.

    PubMed

    Piriz, A R; Cela, J J López; Tahir, N A

    2009-10-01

    The study of the linear stage of the incompressible Rayleigh-Taylor instability in elastic-plastic solids is performed by considering thick plates under a constant acceleration that is also uniform except for a small sinusoidal ripple in the horizontal plane. The analysis is carried out by using an analytical model based on the Newton second law and it is complemented with extensive two-dimensional numerical simulations. The conditions for marginal stability that determine the instability threshold are derived. Besides, the boundary for the transition from the elastic to the plastic regime is obtained and it is demonstrated that such a transition is not a sufficient condition for instability. The model yields complete analytical solutions for the perturbation amplitude evolution and reveals the main physical process that governs the instability. The theory is in general agreement with the numerical simulations and provides useful quantitative results. Implications for high-energy-density-physics experiments are also discussed.

  16. Rayleigh-Taylor stability boundary at solid-liquid interfaces.

    PubMed

    Piriz, A R; Sun, Y B; Tahir, N A

    2013-08-01

    A previous model for the Rayleigh-Taylor instability [A. R. Piriz, J. J. López Cela, and N. A. Tahir, Phys. Rev. E 80, 046305 (2009)] has been extended in order to study an interface between an elastic-plastic solid and a Newtonian liquid and determine the stability region given by the initial perturbation amplitude ξ(0) and wavelength λ. The stability region is found to be enhanced by the effect of the liquid viscosity, but it reaches an asymptote for a sufficiently high viscosity. In addition, it is also found that the boundary for the transition from the elastic to the plastic regime get closer to the stability boundary up to both boundaries coincide for a high enough liquid viscosity, thus making the onset of plastic flow a sufficient condition for instability.

  17. Viscous Rayleigh-Taylor instability in spherical geometry.

    PubMed

    Mikaelian, Karnig O

    2016-02-01

    We consider viscous fluids in spherical geometry, a lighter fluid supporting a heavier one. Chandrasekhar [Q. J. Mech. Appl. Math. 8, 1 (1955)] analyzed this unstable configuration providing the equations needed to find, numerically, the exact growth rates for the ensuing Rayleigh-Taylor instability. He also derived an analytic but approximate solution. We point out a weakness in his approximate dispersion relation (DR) and offer a somewhat improved one. A third DR, based on transforming a planar DR into a spherical one, suffers no unphysical predictions and compares reasonably well with the exact work of Chandrasekhar and a more recent numerical analysis of the problem [Terrones and Carrara, Phys. Fluids 27, 054105 (2015)].

  18. Collisional effects on Rayleigh-Taylor-induced magnetic fields

    SciTech Connect

    Manuel, M. J.-E.; Flaig, M.; Plewa, T.; Li, C. K.; Séguin, F. H.; Frenje, J. A.; Casey, D. T.; Petrasso, R. D.; Hu, S. X.; Betti, R.; Hager, J.; Meyerhofer, D. D.; Smalyuk, V.

    2015-05-15

    Magnetic-field generation from the Rayleigh-Taylor (RT) instability was predicted more than 30 years ago, though experimental measurements of this phenomenon have only occurred in the past few years. These pioneering observations demonstrated that collisional effects are important to B-field evolution. To produce fields of a measurable strength, high-intensity lasers irradiate solid targets to generate the nonaligned temperature and density gradients required for B-field generation. The ablation process naturally generates an unstable system where RT-induced magnetic fields form. Field strengths inferred from monoenergetic-proton radiographs indicate that in the ablation region diffusive effects caused by finite plasma resistivity are not negligible. Results from the first proof-of-existence experiments are reviewed and the role of collisional effects on B-field evolution is discussed in detail.

  19. Rayleigh-Taylor instability in soft elastic layers.

    PubMed

    Riccobelli, D; Ciarletta, P

    2017-05-13

    This work investigates the morphological stability of a soft body composed of two heavy elastic layers attached to a rigid surface and subjected only to the bulk gravity force. Using theoretical and computational tools, we characterize the selection of different patterns as well as their nonlinear evolution, unveiling the interplay between elastic and geometric effects for their formation. Unlike similar gravity-induced shape transitions in fluids, such as the Rayleigh-Taylor instability, we prove that the nonlinear elastic effects saturate the dynamic instability of the bifurcated solutions, displaying a rich morphological diagram where both digitations and stable wrinkling can emerge. The results of this work provide important guidelines for the design of novel soft systems with tunable shapes, with several applications in engineering sciences.This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.' © 2017 The Author(s).

  20. Kolmogorov scaling and intermittency in Rayleigh-Taylor turbulence.

    PubMed

    Boffetta, G; Mazzino, A; Musacchio, S; Vozella, L

    2009-06-01

    Turbulence induced by Rayleigh-Taylor instability is a ubiquitous phenomenon with applications ranging from atmospheric physics and geophysics to supernova explosions and plasma confinement fusion. Despite its fundamental character, a phenomenological theory has been proposed only recently and several predictions are untested. In this Rapid Communication we confirm spatiotemporal predictions of the theory by means of direct numerical simulations at high resolution and we extend the phenomenology to take into account intermittency effects. We show that scaling exponents are indistinguishable from those of Navier-Stokes turbulence at comparable Reynolds number, a result in support of the universality of turbulence with respect to the forcing mechanism. We also show that the time dependence of Rayleigh, Reynolds, and Nusselt numbers realizes the Kraichnan scaling regime associated with the ultimate state of thermal convection.

  1. Nonlinear saturation amplitude of cylindrical Rayleigh—Taylor instability

    NASA Astrophysics Data System (ADS)

    Liu, Wan-Hai; Yu, Chang-Ping; Ye, Wen-Hua; Wang, Li-Feng

    2014-09-01

    The nonlinear saturation amplitude (NSA) of the fundamental mode in the classical Rayleigh—Taylor instability with a cylindrical geometry for an arbitrary Atwood number is analytically investigated by considering the nonlinear corrections up to the third order. The analytic results indicate that the effects of the initial radius of the interface (r0) and the Atwood number (A) play an important role in the NSA of the fundamental mode. The NSA of the fundamental mode first increases gently and then decreases quickly with increasing A. For a given A, the smaller the r0/λ (λ is the perturbation wavelength), the larger the NSA of the fundamental mode. When r0/λ is large enough (r0 ≫ λ), the NSA of the fundamental mode is reduced to the prediction in the previous literatures within the framework of the third-order perturbation theory.

  2. Modified formula of Malus’ law for Glan Taylor polarizing prisms

    NASA Astrophysics Data System (ADS)

    Zhu, Huafeng; Song, Lianke; Chen, Jianwen; Gao, Hongyi; Li, Ruxin; Xu, Zhizhan

    2005-01-01

    A simple three-axis model has been developed, which has been successfully applied to the analysis of the light transmittance in spatial incident angle and the simulation of modified formula of Malus' law for Glan-Taylor prisms. Our results indicate that the fluctuations on the cosine squared curve are due to specific misalignments between the axis of the optical system, the optical axis of the prism and the mechanical axis (rotation axis) of prism, which results in the fact that different initial relative location of the to-be-measured-prism in the testing system corresponds to different shape of Malus' law curve. Methods to get absolutely smooth curve are proposed. This analysis is available for other kinds of Glan-type prisms.

  3. Nonlinear Rayleigh-Taylor growth in convergine geometry

    SciTech Connect

    Clark, D S; Tabak, M

    2004-04-26

    The early nonlinear phase of Rayleigh-Taylor growth is typically described in terms of the classic Layzer model in which bubbles of light fluid rise into the heavy fluid at a constant rate determined by the bubble radius and the gravitational acceleration. However, this model is strictly valid only for planar interfaces and hence ignores any effects which might be introduced by the spherically converging interfaces of interest in inertial confinement fusion. Here a generalization of the Layzer nonlinear bubble rise rate is given for a self-similar spherically converging flow of the type studied by Kidder. A simple formula for the bubble amplitude is found showing that, while the bubble initially rises with a constant velocity similar to the Layzer result, during the late phase of the implosion, an acceleration of the bubble rise rate occurs. The bubble rise rate is verified by comparison with numerical hydrodynamics simulations.

  4. Simulations of NOVA direct-drive Rayleigh-Taylor experiments

    SciTech Connect

    Weber, S.V.

    1990-11-03

    Directly driven Rayleigh-Taylor instability growth experiments being performed on NOVA have been simulated using the computer code, LASNEX. These experiments employ beams smoothed with random phase plates (RPP), and will later include smoothing by spectral dispersion (SSD). Samples are CH foils with or without imposed sinusoidal surface perturbations. Perturbation growth is diagnosed by means of x-ray backlighting. Calculated growth rates are fairly flat across the wavelength range of 20--80 {mu}m which can be accessed experimentally, and are moderately suppressed below classical growth rates. Perturbations of large enough initial amplitude that the contrast in the x-ray image is measurable from the start of the experiment quickly grow into the nonlinear regime. Smaller initial amplitudes result in a longer interval of linear growth, but the initial perturbation will not be detectable in the data. Structure which is predicted to develop from speckles in the RPP beam pattern, with and without SSD, is also presented.

  5. Vortical Effects on the Compressible Rayleigh-Taylor Instability

    NASA Astrophysics Data System (ADS)

    Wieland, Scott; Livescu, Daniel; Vasilyev, Oleg V.; Reckinger, Scott J.

    2016-11-01

    High fidelity wavelet based direct numerical simulations (WDNS) of compressible, miscible, and single mode Rayleigh Taylor instability (RTI) with a stratified background density have been completed in 2 and 3 dimensions. As the instability grows, vorticity dynamics are largely responsible for the self-propagation and growth of the bubble and spike. However, in the presence of a background stratification, the vortex interactions are significantly altered. In the case of low Atwood number RTI, this leads to previously unseen regimes, namely, the exaggeration of bubble and spike asymmetries for a weakly stratified background state and the complete suppression of RTI growth in the strongly stratified scenario. To better understand these results, the vorticity transport equation budget was compared to the simplified scenarios of vortex pairs (2D) and vortex rings (3D) moving in a stratified medium.

  6. Induction of Glycosphingolipid GM3 Expression by Valproic Acid Suppresses Cancer Cell Growth.

    PubMed

    Kawashima, Nagako; Nishimiya, Yoshiyuki; Takahata, Shouta; Nakayama, Ken-Ichi

    2016-10-07

    Glycosphingolipid GM3, a known suppressor of epidermal growth factor receptor (EGFR) phosphorylation, inhibits cell proliferation. Valproic acid, conversely, is known as an up-regulator of GM3 synthase gene (ST3GAL5). To test the possibility that valproic acid could inhibit EGFR phosphorylation by increasing the level of GM3 in cells, we treated A431 epidermoid carcinoma cells with valproic acid and found that valproic acid treatment caused an about 6-fold increase in the GM3 level but only a marginal increase in the GM2 level in these cells and that the observed increase in GM3 level was valproic acid dose-dependent. Consistent with this observation, valproic acid treatment induced GM3 synthase gene expression by about 8-fold. Furthermore, phosphorylation of EGFR was reduced, and cell proliferation was inhibited following valproic acid treatment. Consistent with these results, transient expression of GM3 synthase gene in A431 cells also increased cellular level of GM3, reduced phosphorylation of EGFR, and inhibited cell proliferation. Treatment with l-phenyl-2-decanoylamino-3-morpholino-l-propanol, an inhibitor of glucosylceramide synthesis, decreased the cellular level of GM3 and reduced the inhibitory effects of valproic acid on EGFR phosphorylation and cell proliferation. These results suggested that induction of GM3 synthesis was enough to inhibit proliferation of cancer cells by suppressing EGFR activity. Valproic acid treatment similarly increased the GM3 level and reduced phosphorylation of EGFR in U87MG glioma cells and inhibited their proliferation. These results suggested that up-regulators of GM3 synthase gene, such as valproic acid, are potential suppressors of cancer cell proliferation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Magnetic Shear, Rayleigh-Taylor Instability, And Prominence Threads

    NASA Astrophysics Data System (ADS)

    DeVore, C. Richard

    2012-05-01

    One striking feature of solar prominences is their very long, narrow threads of cool plasma that are observed in emission above the limb (and in absorption against the disk in filaments). It is generally accepted that this structure illuminates the prominence magnetic field, which both mechanical supports the cool mass against gravity and thermally insulates it against conduction from the surrounding hot corona. A mystery yet to be resolved is the origin of the narrow widths of prominence threads. We are investigating the hypothesis that it is fixed by a competition between the gravitational instability of a dense fluid (the prominence) residing above a dilute fluid (the corona) and the stabilizing influence of magnetic tension forces when the prominence field is distorted. It is well known (e.g., Stone & Gardiner 2007) that this process leads to the formation of ropes of dense fluid whose characteristic lengths are long parallel to the field (minimizing the increase in magnetic energy) but arbitrarily short perpendicular to the field (maximizing the release of gravitational energy). A key issue that has yet to be addressed is the effect on the Rayleigh-Taylor instability of shear in a magnetic field whose direction rotates continuously through the body of the prominence. Linear analysis indicates that marginal stability is reached for aspect ratios (parallel to perpendicular wavelengths) of about 25:1 for solar parameters; unstable modes have still larger ratios. High-resolution numerical simulations of initially monolithic slab prominences show developing fragmentation of the prominence/corona interface driven by the early, linear growth of the shear-modified Rayleigh-Taylor instability. Our investigation also is probing the nonlinear consequences of this evolution. This work was supported by NASA’s LWS TR&T program.

  8. DSMC Simulation of High Mach Number Taylor-Couette Flow

    NASA Astrophysics Data System (ADS)

    Pradhan, Sahadev, , Dr.

    2017-01-01

    The main focus of this work is to characterise the Taylor-Couette flow of an ideal gas between two coaxial cylinders at Mach number Ma = (U_w /√{ kbT_w / m }) in the range 0.01 < Ma < 10, and Knudsen number Kn = (1 / (√{ 2 } πd2 n_d (r _ 2 - r _ 1))) in the range 0.001 Taylor-Couette flow using DSMC method, wall slip in the temperature and the velocities are found to be significant. Slip occurs because the temperature/velocity of the molecules incident on the wall could be very different from that of the wall, even though the temperature/velocity of the reflected molecules is equal to that of the wall. Due to the high surface speed of the inner cylinder, significant heating of the gas is taking place. The gas temperature increases until the heat transfer to the surface equals the work done in moving the surface. The highest temperature is obtained near the moving surface of the inner cylinder at a radius of about (1.26 r_1).

  9. Unstable Titan-generated Rayleigh-Taylor Lakes Impact Ice

    NASA Astrophysics Data System (ADS)

    Umurhan, O. M.; Korycansky, D. G.; Zahnle, K. J.

    2014-12-01

    The evolution of surface morphology on Titan, Triton, and other worlds is strongly influenced by the interplay of various fluid dynamical processes. Specifically, overturning instabilities can easily arise due to the special circumstances of landform evolution that probably occurred on these worlds. On Titan, large impacts that formed basins like Menrva crater (and possibly Hotei Regio) would have generated impact-melt ice lakes unstably arranged over less dense ice. Cantaloupe terrains, for example as seen on Triton, may be the result of condensation of volatiles (methane, nitrogen) leading to unstably stratified layers of different compositions and densities. In each of these cases, Rayleigh-Taylor instabilities leading to large scale diapirism may be at play. In addition to the dynamics of these instabilities, other physical effects (e.g. heat diffusion, freezing/melting, porosity, temperature dependent viscosity) likely play an important role in the evolution of these features. In this ongoing study, we examine the properties of unstably stratified fluids in which the lower less-dense ice has a temperature dependent viscosity. Surprisingly, we find that there exists an optimal disturbance length scale corresponding to the fastest growth of the Rayleigh-Taylor instability. For unstably stratified layers of water (low viscosity heavy liquid lying above an ice whose viscosity increases with depth) the fastest growing mode corresponds to 40-60 km scales with overturn times of approximately 100 days. We present a detailed numerical stability analysis in a corresponding Boussinessq model (in the creeping flow limit) incorporating thermal conduction and latent heat release and we examine the stability properties surveying a variety of parameters. We have also developed a two-dimensional numerical code (a hybrid spectral/compact-differencing scheme) to model the evolution of such systems for which we shall present preliminary numerical results depicting the outcome of

  10. 75 FR 42281 - Continuation of the National Emergency With Respect To the Former Liberian Regime of Charles Taylor

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... Liberian Regime of Charles Taylor On July 22, 2004, by Executive Order 13348, the President declared a... connected to the former Liberian regime of Charles Taylor, pursuant to the International Emergency Economic... former Liberian President Charles Taylor and other persons, in particular their unlawful depletion...

  11. 76 FR 43799 - Continuation of the National Emergency With Respect to the Former Liberian Regime of Charles Taylor

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... With Respect to the Former Liberian Regime of Charles Taylor #0; #0; #0; Presidential Documents #0; #0... Respect to the Former Liberian Regime of Charles Taylor On July 22, 2004, by Executive Order 13348, the... of certain persons connected to the former Liberian regime of Charles Taylor, pursuant to...

  12. 78 FR 43751 - Continuation of the National Emergency With Respect to the Former Liberian Regime of Charles Taylor

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... Liberian Regime of Charles Taylor On July 22, 2004, by Executive Order 13348, the President declared a national emergency with respect to the former Liberian regime of Charles Taylor pursuant to the... Liberian President Charles Taylor and other persons, in particular their unlawful depletion of...

  13. Degradation of membrane-bound ganglioside GM1. Stimulation by bis(monoacylglycero)phosphate and the activator proteins SAP-B and GM2-AP.

    PubMed

    Wilkening, G; Linke, T; Uhlhorn-Dierks, G; Sandhoff, K

    2000-11-17

    According to our hypothesis (Fürst, W., and Sandhoff, K. (1992) Biochim. Biophys. Acta 1126, 1-16) glycosphingolipids of the plasma membrane are digested after endocytosis as components of intraendosomal and intralysosomal vesicles and membrane structures. The lysosomal degradation of glycosphingolipids with short oligosaccharide chains by acid exohydrolases requires small, non-enzymatic cofactors, called sphingolipid activator proteins (SAPs). A total of five activator proteins have been identified as follows: namely the saposins SAP-A, -B, -C, and -D, which are derived from the single chain SAP-precursor protein (prosaposin), and the GM2 activator protein. A deficiency of prosaposin results in the storage of ceramide and sphingolipids with short oligosaccharide head groups. The loss of the GM2 activator protein blocks the degradation of the ganglioside GM2. The enzymatic hydrolysis of the ganglioside GM1 is catalyzed by beta-galactosidase, a water-soluble acid exohydrolase. The lack of ganglioside GM1 accumulation in patients suffering from either prosaposin or GM2 activator protein deficiency has led to the hypothesis that SAPs are not needed for the hydrolysis of the ganglioside GM1 in vivo. In this study we demonstrate that an activator protein is required for the enzymatic degradation of membrane-bound ganglioside GM1 and that both SAP-B and the GM2 activator protein significantly enhance the degradation of the ganglioside GM1 by acid beta-galactosidase in a liposomal, detergent-free assay system. These findings offer a possible explanation for the observation that no storage of the ganglioside GM1 has been observed in patients with either isolated prosaposin or isolated GM2 activator deficiency. We also demonstrate that anionic phospholipids such as bis(monoacylglycero)phosphate and phosphatidylinositol, which specifically occur in inner membranes of endosomes and in lysosomes, are essential for the activator-stimulated hydrolysis of the ganglioside GM1

  14. Animal models of GM2 gangliosidosis: utility and limitations

    PubMed Central

    Lawson, Cheryl A; Martin, Douglas R

    2016-01-01

    GM2 gangliosidosis, a subset of lysosomal storage disorders, is caused by a deficiency of the glycohydrolase, β-N-acetylhexosaminidase, and includes the closely related Tay–Sachs and Sandhoff diseases. The enzyme deficiency prevents the normal, stepwise degradation of ganglioside, which accumulates unchecked within the cellular lysosome, particularly in neurons. As a result, individuals with GM2 gangliosidosis experience progressive neurological diseases including motor deficits, progressive weakness and hypotonia, decreased responsiveness, vision deterioration, and seizures. Mice and cats are well-established animal models for Sandhoff disease, whereas Jacob sheep are the only known laboratory animal model of Tay–Sachs disease to exhibit clinical symptoms. Since the human diseases are relatively rare, animal models are indispensable tools for further study of pathogenesis and for development of potential treatments. Though no effective treatments for gangliosidoses currently exist, animal models have been used to test promising experimental therapies. Herein, the utility and limitations of gangliosidosis animal models and how they have contributed to the development of potential new treatments are described. PMID:27499644

  15. GM's ultralite is racing toward greater fuel efficiency

    SciTech Connect

    Ashley, S.

    1992-05-01

    The Ultralite, the latest concept car from General Motors Corp. (Detroit), is a lightweight 1400-pound four-seat sedan that can go from 0 to 60 miles per hour in 7.8 seconds while providing 100-mile-per-gallon fuel economy at highway speeds. This paper reports that the car's impressive performance results from the combination of GM's efficient but peppy 1.5-liter three-cylinder two-stroke test engine and a low-mass stiff carbon-composite body, tub, and tunnel structure, which also allows for a spacious interior. Though the Ultralite's exterior dimensions are 18 inches shorter and 4 inches narrower than a four-door (five-passenger) Chevrolet Corsica, its seating comfort, headroom, and knee clearance are comparable. GM's new engineering test bed, a blend of cutting-edge automotive technology and off-the-shelf hardware, was designed to be highly integrated, so the internal architecture was engineered simultaneously with the exterior configuration. Initial emphasis was placed on designing the car from the inside out - developing the underlying architectures first. But reconciling these efforts with the generally conflicting demands of wind tunnel tests created design challenges, the Jim Lutz, the program's manager. Most of the interior packaging and outer body configuration issues were addressed up front by an interdisciplinary design team assembled only eight months before the car's introduction.

  16. Animal models of GM2 gangliosidosis: utility and limitations.

    PubMed

    Lawson, Cheryl A; Martin, Douglas R

    2016-01-01

    GM2 gangliosidosis, a subset of lysosomal storage disorders, is caused by a deficiency of the glycohydrolase, β-N-acetylhexosaminidase, and includes the closely related Tay-Sachs and Sandhoff diseases. The enzyme deficiency prevents the normal, stepwise degradation of ganglioside, which accumulates unchecked within the cellular lysosome, particularly in neurons. As a result, individuals with GM2 gangliosidosis experience progressive neurological diseases including motor deficits, progressive weakness and hypotonia, decreased responsiveness, vision deterioration, and seizures. Mice and cats are well-established animal models for Sandhoff disease, whereas Jacob sheep are the only known laboratory animal model of Tay-Sachs disease to exhibit clinical symptoms. Since the human diseases are relatively rare, animal models are indispensable tools for further study of pathogenesis and for development of potential treatments. Though no effective treatments for gangliosidoses currently exist, animal models have been used to test promising experimental therapies. Herein, the utility and limitations of gangliosidosis animal models and how they have contributed to the development of potential new treatments are described.

  17. Cutaneous dyspigmentation in patients with ganglioside GM3 synthase deficiency.

    PubMed

    Wang, Heng; Bright, Alicia; Xin, Baozhong; Bockoven, J R; Paller, Amy S

    2013-04-01

    Ganglioside GM3 synthase deficiency is a rare autosomal recessive metabolic disorder characterized by infantile onset of severe irritability and epilepsy, failure to thrive, developmental stagnation, and cortical blindness. Because of the lack of easily recognizable dysmorphism and specific neurologic manifestations, identification of patients with this condition is extremely challenging. Here we report on previously undescribed pigmentary abnormalities in 20 of 38 patients with GM3 synthase deficiency. All 20 of the patients showed freckle-like hyperpigmented macules, ranging in size from 2 to 5 mm in diameter and usually found bilaterally on the extremities, especially the dorsal aspects of the hands and feet. Seven of these patients also had depigmented macules and patches, especially on the face and extremities. These cutaneous changes were asymptomatic, and were not associated with the severity or particular phenotype of the neurologic disease. They became visible only after the first years of life with an increased incidence with advancing age. These distinct pigmentary features are not identified in 54 normal siblings, and may provide a useful clue in identifying patients with ganglioside metabolic disorders. Copyright © 2013 Wiley Periodicals, Inc.

  18. Development of a large cooling capacity single stage GM cryocooler

    NASA Astrophysics Data System (ADS)

    Yamada, K.

    2014-09-01

    Sumitomo Heavy Industries, Ltd. (SHI) has developed 4 K Gifford-McMahon (GM) cryocoolers for various cryogenic fields including Magnetic resonance imaging (MRI) systems. However, for the purpose of cooling high temperature superconductor (HTS) devices, the needs for cryocoolers with a large cooling capacity in the range of 20-30 K has been rapidly increasing. Recently, SHI developed a large cooling capacity single-stage GM cryocooler, for HTS applications. A typical cooling capacity is 46/52 W at 20 K or 85/96 W at 30 K with 6.9/7.9 kW input power at 50/60 Hz. The cooling capacity degradation caused by inclination is within 24%. And also, a low mechanical vibration and a low acoustic noise have been achieved because the displacer is driven by a motor instead of a pneumatic force. In addition, the cryocooler does not contain lead as a regenerator material, so it complies with restriction of hazardous substances (RoHS) directive.

  19. Science, politics, and the GM debate in Europe.

    PubMed

    Tencalla, Francesca

    2006-02-01

    Europe today stands at a crossroad, facing challenges but also opportunities. In its intent to make Europe a leading technology-based economy by 2010, the European Commission has identified biotechnology and genomics as fields for future growth, crucial for supporting the agricultural and food processing industry. Since first commercialization in 1996, GM crop areas have grown at double-digit rates, making this one of the most rapidly adopted technologies in agriculture. However, in contrast to other world areas and despite European Commission support, Europe has found itself 'bogged-down' in a polemic between opponents and supporters of plant biotechnology. As a result, planted areas have remained small. This stalemate is due to a lack of political leadership, especially at the Member State level, all the more surprising in light of European early development and competitive advantage with crop biotechnology. This situation proves once again that, for cutting-edge innovations, a solid science base alone is not sufficient. Acceptance or rejection of new technologies depends on interlinked political, economic, and societal factors that create a favorable or unfavorable situation at a given time. This article will look at GM crops in Europe and the role science and politics have played in the introduction of crop biotechnology.

  20. Differentiation of oligodendrocytes cultured from developing rat brain is enhanced by exogenous GM3 ganglioside.

    PubMed

    Yim, S H; Farrer, R G; Hammer, J A; Yavin, E; Quarles, R H

    1994-06-15

    Cultures consisting primarily of O-2A progenitor cells and immature oligodendrocytes with a few microglia and astrocytes were obtained by shaking primary cultures from neonatal rat brain after 12-14 days in vitro. Addition of 50 micrograms/ml exogenous Neu-NAc alpha 2-3Gal beta 1-4Glc beta 1-1'ceramide (GM3 ganglioside) to the cultures resulted in an increase in the number and thickness of cell processes that stained intensely for sulfatide and galactocerebroside (galC) in comparison to control cultures without added GM3. The treated cultures also contained fewer astrocytes than control cultures as revealed by immunostaining for glial fibrillary acidic protein (GFAP). Cells that immunostained for both GFAP and sulfatide/galC were very rare in control cultures but were frequently seen in the GM3-treated cultures, suggesting that these may represent cells changing their direction of differentiation away from type II astrocytes toward oligodendrocytes under the influence of GM3. These effects on the developing rat oligodendrocytes were specific for GM3 ganglioside and were not produced by adding GM1, GM2, GD3, or GD1a to the cultures. Lactosyl ceramide and neuraminyl lactose were also ineffective. When control cultures were initially plated on polylysine and incubated with [14C]galactose, GD3 was the principal labeled ganglioside. However, as the control cells differentiated over time in culture without the addition of exogenous GM3 and produced increasing amounts of myelin-related components, the incorporation of [14C]galactose into endogenous GM3 increased to become the predominant labeled ganglioside by 6 days after plating. Metabolic labeling of the GM3-treated oligodendrocytes with [14C]galactose revealed increased incorporation into galC and sulfatide in comparison to control cultures, but a decreased labeling of endogenous GM3. Similarly, incorporation of an amino acid precursor into the myelin-associated glycoprotein (MAG) was increased by GM3 treatment, but

  1. A high detection probability method for Gm-APD photon counting laser radar

    NASA Astrophysics Data System (ADS)

    Zhang, Zi-jing; Zhao, Yuan; Zhang, Yong; Wu, Long; Su, Jian-zhong

    2013-08-01

    Since Geiger mode Avalanche Photodiode (GmAPD) device was applied in laser radar system, the performance of system has been enhanced due to the ultra-high sensitivity of GmAPD, even responding a single photon. However, the background noise makes ultra-high sensitive GmAPD produce false alarms, which severely impacts on the detection of laser radar system based on Gm-APD and becomes an urgent problem which needs to be solved. To address this problem, a few times accumulated two-GmAPDs strategy is proposed in this paper. Finally, an experimental measurement is made under the background noise in sunny day. The results show a few times accumulated two- GmAPDs strategy can improve the detection probability and reduce the false alarm probability, and obtain a clear 3D image of target.

  2. Comparative Analysis of Two Industries for Validating Green Manufacturing (GM) Framework: An Indian Scenario

    NASA Astrophysics Data System (ADS)

    Rehman, Minhaj Ahemad Abdul; Shrivastava, Rakesh Lakshmikumar; Shrivastava, Rashmi Rakesh

    2016-07-01

    Green Manufacturing (GM) deals with manufacturing practices that reduces or eliminates the adverse environmental impact during any of its phases. It emphasizes the use of processes that do not contaminate the environment or hurt consumers, employees, or other stakeholders. This paper presents the comparative analysis of two Indian industries representing different sectors for validating GM framework. It also highlights the road map of the companies for achieving performance improvement through GM implementation and its impact on organisational performance. The case studies helps in evaluating the companies GM implementation and overall business performance. For this, a developed diagnostic instrument in the form of questionnaire was administered amongst employees in the companies respectively and their responses were analysed. In order to have a better understanding of the impact of GM implementation, the information about overall business performance was obtained over the last 3 years. The diagnostic instrument developed here may be used by manufacturing organisations to prioritise their management efforts to assess and implement GM.

  3. Comparative Analysis of Two Industries for Validating Green Manufacturing (GM) Framework: An Indian Scenario

    NASA Astrophysics Data System (ADS)

    Rehman, Minhaj Ahemad Abdul; Shrivastava, Rakesh Lakshmikumar; Shrivastava, Rashmi Rakesh

    2017-04-01

    Green Manufacturing (GM) deals with manufacturing practices that reduces or eliminates the adverse environmental impact during any of its phases. It emphasizes the use of processes that do not contaminate the environment or hurt consumers, employees, or other stakeholders. This paper presents the comparative analysis of two Indian industries representing different sectors for validating GM framework. It also highlights the road map of the companies for achieving performance improvement through GM implementation and its impact on organisational performance. The case studies helps in evaluating the companies GM implementation and overall business performance. For this, a developed diagnostic instrument in the form of questionnaire was administered amongst employees in the companies respectively and their responses were analysed. In order to have a better understanding of the impact of GM implementation, the information about overall business performance was obtained over the last 3 years. The diagnostic instrument developed here may be used by manufacturing organisations to prioritise their management efforts to assess and implement GM.

  4. Rare Variant of GM2 Gangliosidosis through Activator-Protein Deficiency.

    PubMed

    Brackmann, Florian; Kehrer, Christiane; Kustermann, Wibke; Böhringer, Judith; Krägeloh-Mann, Ingeborg; Trollmann, Regina

    2017-04-01

    GM2 gangliosidosis, AB variant, is a very rare form of GM2 gangliosidosis due to a deficiency of GM2 activator protein. We report on two patients with typical clinical features suggestive of GM2 gangliosidosis, but normal results for hexosaminidase A and hexosaminidase B as well as their corresponding genes. Genetic analysis of the gene encoding the activator protein, the GM2A gene, elucidated the cause of the disease, adding a novel mutation to the spectrum of GM2 AB variant. This report points out that in typical clinical constellations with normal enzyme results, genetic diagnostic for activator protein defects should be performed. Georg Thieme Verlag KG Stuttgart · New York.

  5. GM-CSF and GM-CSF receptor have regulatory role in transforming rat mesenteric mesothelial cells into macrophage-like cells.

    PubMed

    Katz, Sándor; Zsiros, Viktória; Dóczi, Nikolett; Szabó, Arnold; Biczó, Ádám; Kiss, Anna L

    2016-10-01

    During peritonitis, mesothelial cells assume macrophage characteristics, expressing macrophage markers, indicating that they might differentiate into macrophage-like cells. Twenty-five male rats were used for in vivo experiments. For in vitro experiments, a primary mesentery culture model was developed. The mesothelial cell to macrophage-like cell transition was followed by studying ED1 expression. In vitro primary mesenteric culture was treated with granulocyte-macrophage colony-stimulating factor (GM-CSF, 1 ng/ml). Blocking internalization of receptor-ligand complex, Dynasore (80 µM) was used. Acute peritonitis was induced by Freund's adjuvant's (1 ml) intraperitoneal injection. Immunohistochemistry: GM-CSF in vitro treatment resulted in a prominent ED1 expression in transformed mesothelial cells. Blocking the internalization, ED1 expression could not be detected. GM-CSF receptor (both α and β) was expressed in mesothelial cells in vitro (even if the GM-CSF was not present) and in vivo. Inflammation resulted in an increasing GM-CSF and GM-CSF-receptor level in the lysate of mesothelial cells. Mesothelial cells can differentiate into macrophage-like cells, and GM-CSF, produced by the mesothelial cells, has probably an autocrine regulatory role in this transition. Our results provide new data about the plasticity of mesothelial cell and support the idea that during inflammation macrophages can derive from non-hematopoietic sources as well.

  6. A study of thin-walled Taylor column under the influence of rotation

    NASA Astrophysics Data System (ADS)

    Lai, Kuan-Ruei; Chu, Chin-Chou; Chang, Chien-Cheng

    2016-11-01

    An extended study of thin-walled Taylor column under the influence of rotating cylinder is presented with very consistent results in numerical simulations and laboratory experiments. In the previous set-up, the Taylor column effect is produced under the influence of protruded cylinder from the top lid, and the thin-walled Taylor column is formed by draining of the fluid at the bottom. The primary interest of this study is to investigate the influence to thin-walled Taylor column when the cylinder is exerted with a relative rotation rate under very small Rossby number (Ro = U / fR) and Ekman number (Ek = ν / fR2) . The flow patterns are performed with different cylinder height ratios (h/ H) along with varying relative rotation ratio of cylinder to the background α = ω / Ω . Steady-state solutions being solved numerically in the rotating frame are shown to have good agreements with experimental flow visualizations on the resulting appearance of deformed thin-walled Taylor columns. As a result, the thin-walled Taylor column is observed to strengthen up with increasing α, and weakens with decreasing α. In addition, the weakening thin-walled Taylor column is observed to experience a break through transition near the bottom, which penetration diverged the recirculating region into two portions. Supported by the Ministry of Science and Technology, TAIWAN ROC, Contract No's 103-2221-E002-099-MY3; 105-2221-E002-097-MY3.

  7. Tanzanian farmers' knowledge and attitudes to GM biotechnology and the potential use of GM crops to provide improved levels of food security. A Qualitative Study

    PubMed Central

    2010-01-01

    Background Genetically Modified (GM) crops have been championed as one possible method to improve food security and individual nutritional status in sub Saharan Africa. Understanding and acceptability of GM crop technology to farmers and consumers have not been assessed. We developed a qualitative research study involving farmers as both producers and consumers to gauge the understanding of GM crop technology, its acceptability, and identifying issues of concern. Methods Nineteen individual interviews (10 male and 9 female) and five mixed gender focus group discussions with local farmers were conducted in 3 regions in Tanzania. Analysis took place concurrently with data collection. Following initial interviews, subsequent questions were adjusted based on emerging themes. Results Understanding, awareness and knowledge of GM crop technology and terminology and its potential risks and benefits was very poor in all regions. Receptivity to the potential use of GM crops was, however, high. Respondents focused on the potential benefits of GM crops rather than any potential longer term health risks. A number of factors, most significantly field trial data, would influence farmers' decisions regarding the introduction of GM crop varieties into their farming practice. Understanding of the potential improved health provision possible by changes in agricultural practice and food-related decision making, and the health benefits of a diet containing essential vitamins, minerals and micronutrients is also poor in these communities. Conclusion This study forms a basis from which further research work can be undertaken. It is important to continue to assess opinions and attitudes of farmers and consumers in sub Saharan Africa towards potential use of GM technologies whilst highlighting the importance of the relationship between agriculture, health and development. This will allow people in the region to make accurate, informed decisions about whether they believe use of GM

  8. Tanzanian farmers' knowledge and attitudes to GM biotechnology and the potential use of GM crops to provide improved levels of food security. A Qualitative Study.

    PubMed

    Lewis, Christopher P; Newell, James N; Herron, Caroline M; Nawabu, Haidari

    2010-07-12

    Genetically Modified (GM) crops have been championed as one possible method to improve food security and individual nutritional status in sub Saharan Africa. Understanding and acceptability of GM crop technology to farmers and consumers have not been assessed. We developed a qualitative research study involving farmers as both producers and consumers to gauge the understanding of GM crop technology, its acceptability, and identifying issues of concern. Nineteen individual interviews (10 male and 9 female) and five mixed gender focus group discussions with local farmers were conducted in 3 regions in Tanzania. Analysis took place concurrently with data collection. Following initial interviews, subsequent questions were adjusted based on emerging themes. Understanding, awareness and knowledge of GM crop technology and terminology and its potential risks and benefits was very poor in all regions. Receptivity to the potential use of GM crops was, however, high. Respondents focused on the potential benefits of GM crops rather than any potential longer term health risks. A number of factors, most significantly field trial data, would influence farmers' decisions regarding the introduction of GM crop varieties into their farming practice. Understanding of the potential improved health provision possible by changes in agricultural practice and food-related decision making, and the health benefits of a diet containing essential vitamins, minerals and micronutrients is also poor in these communities. This study forms a basis from which further research work can be undertaken. It is important to continue to assess opinions and attitudes of farmers and consumers in sub Saharan Africa towards potential use of GM technologies whilst highlighting the importance of the relationship between agriculture, health and development. This will allow people in the region to make accurate, informed decisions about whether they believe use of GM biotechnology is an appropriate way in which

  9. Action of granulopoiesis-stimulating cytokines rhG-CSF, rhGM-CSF, and rmGM-CSF on murine haematopoietic progenitor cells for granulocytes and macrophages (GM-CFC).

    PubMed

    Hofer, M; Vacek, A; Weiterová, L

    2005-01-01

    The aim of this study was to provide new data to the knowledge of mechanisms by which recombinant human granulocyte colony-stimulating factor (rhG-CSF), recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) enhance the numbers of colonies growing from hematopoietic progenitor cells for granulocytes and macrophages (GM-CFC) in the murine bone marrow. The in vitro technique for cultivating GM-CFC from normal bone marrow cells was used. For evaluation of stimulatory actions of the drugs studied, the factors themselves or sera of mice given these factors were added to the cultures. The factors or the sera were present in the cultures either as the only potentially stimulatory agents or acted jointly with a suboptimum concentration of recombinant murine interleukin-3 (rmIL-3). It was found that both rhG-CSF and rmGM-CSF stimulate the proliferation of GM-CFC by a combination of direct mechanisms (direct actions on the target cells) and indirect effects (effects mediated through the induction of other cytokines and/or growth factors in the murine organism). The rhGM-CSF exhibited somewhat weaker in vitro effects in comparison with the other two factors and only indirect effects were noted. Additional in vivo experiments documented that, in spite of differences in mechanisms of action of the individual drugs studied on murine bone marrow cells in vitro, equal in vivo doses of the factors induce quantitatively similar effects on the production of GM-CFC in vivo.

  10. Functional properties and expression quantitative trait loci for phosphate transporter GmPT1 in soybean.

    PubMed

    Song, Haina; Yin, Zhitong; Chao, Maoni; Ning, Lihua; Zhang, Dan; Yu, Deyue

    2014-02-01

    Phosphate (Pi) remobilization within a plant is critical for plant survival under Pi-limiting conditions. In this paper, a soybean Pi transporter gene, GmPT1, was characterized. A marked induction of GmPT1 transcript was observed in young leaves, mature leaves and lateral roots during long-term Pi starvation. Transgenic tobacco plants containing the GmPT1 gene were obtained using an Agrobacterium-mediated transformation system. Compared with wild-type plants, transgenic plants showed significant increases in phosphorus-use efficiency (PUE), photosystem II (PSII) function, total dry weight and seed weight under Pi-deficient conditions. GmPT1 expression levels and PUE were determined in a soybean recombinant inbred line population during a pot experiment that was conducted to measure chlorophyll fluorescence parameters, photosynthetic rate (PN ) and seed yield. Correlation analysis revealed that GmPT1 expression levels had significantly positive correlations with seed yield, PUE, PN and the quantum yield of PSII primary photochemistry (ΦPSII ). Expression quantitative trait loci (eQTL) mapping for GmPT1 revealed two eQTLs, one of which coincided with both the physical location of GmPT1 and a QTL associated with seed yield. These results suggest that GmPT1 plays a role in Pi remobilization, and it may be possible to improve soybean seed yields under Pi-limiting conditions by modulating GmPT1 expression levels.

  11. Association of GM4 ganglioside with the membrane surrounding lipid droplets in shark liver.

    PubMed

    Li, Yu-Teh; Sugiyama, Eiko; Ariga, Toshio; Nakayama, Jun; Hayama, Masayoshi; Hama, Yoichiro; Nakagawa, Hiroki; Tai, Tadashi; Maskos, Karol; Li, Su-Chen; Kasama, Takeshi; Ksama, Takeshi

    2002-07-01

    By TLC, GM4 was found to be the major ganglioside in the liver of six shark species examined: Odontaspis taurus, Negaprion brevirostris, Sphyrna lewini, Mustelus griseus, Mustelus manazo, and Prionace glauca. A detailed analysis of the glycosphingolipids (GSLs) in the liver of O. taurus (sand tiger shark) showed that it contained approximately 110 nmol of lipid-bound sialic acid per gram of wet tissue, of which 80% was GM4. By extracting the liver of O. taurus with chloroform/methanol, followed by chromatographic separation of GSLs using DEAE-Sephadex A-25 and Iatrobeads columns, we have isolated GM4 in pure form with a yield of approximately 5 mg per 100 g of wet tissue. The structures of both the sugar chain and the ceramide moiety of this GM4 were analyzed by chemical analysis, mass spectrometry, and NMR spectroscopy. Similar to GM4 isolated from other sources, 92% of fatty acids in the ceramide of this GM4 were 2-hydroxylated. However, unlike the long-chain bases found in other GSLs, the total long-chain bases in this GM4 were found to contain 43% octadecasphingenine and 50% nonadecasphingenine. Immunohistochemical analysis using a monoclonal antibody against GM4 revealed that the hepatocytes of both M. griseus (spotless smooth hound) and M. manazo (smooth hound) were filled with lipid droplets and GM4 was primarily associated with the membrane structure surrounding lipid droplets.

  12. [Granulocyte-macrophage colony-stimulating factor (GM-CSF), preclinical and phase I clinical investigations].

    PubMed

    Shen, B; Yang, Z; Xu, J

    1996-09-01

    To conduct preclinical studies and phase I trial of the recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). Pharmacodynamics, pharmacokinetic and toxicology of the rhGM-CSF were studied in animal models, and the safety was also evaluated in humans. The human bone marrow cells could be stimulated by purified rhGM-CSF to form multilineage colonies (CFU-GM and BFU-E). The rhGM-CSF administered for 7 days to Beagle dogs and monkeys subjected to 60Co r-ray irradiation was shown to induce both rapid and sustained increase in circulating leukocyte counts. Toxicology testing showed that the LD50 (i.v) was over 5000 micrograms/kg, and LD50 (i.p) over 10000 micrograms/kg in mice. Administration of the rhGM-CSF in excess of four times as much as clinical dosages was not associated with severe chronic toxicities. Most injected rhGM-CSF was excreted from urine, and did not accumulate in the body. In the phase I clinical trial, injecting 2.5-7.5 micrograms/day of rhGM-CSF was safe. It is effective and safe to use rhGM-CSF in the treatment of leukocytopenia.

  13. Soybean GmMYB73 promotes lipid accumulation in transgenic plants.

    PubMed

    Liu, Yun-Feng; Li, Qing-Tian; Lu, Xiang; Song, Qing-Xin; Lam, Sin-Man; Zhang, Wan-Ke; Ma, Biao; Lin, Qing; Man, Wei-Qun; Du, Wei-Guang; Shui, Guang-Hou; Chen, Shou-Yi; Zhang, Jin-Song

    2014-03-24

    Soybean is one of the most important oil crops. The regulatory genes involved in oil accumulation are largely unclear. We initiated studies to identify genes that regulate this process. One MYB-type gene GmMYB73 was found to display differential expression in soybean seeds of different developing stages by microarray analysis and was further investigated for its functions in lipid accumulation. GmMYB73 is a small protein with single MYB repeat and has similarity to CPC-like MYB proteins from Arabidopsis. GmMYB73 interacted with GL3 and EGL3, and then suppressed GL2, a negative regulator of oil accumulation. GmMYB73 overexpression enhanced lipid contents in both seeds and leaves of transgenic Arabidopsis plants. Seed length and thousand-seed weight were also promoted. GmMYB73 introduction into the Arabidopsis try cpc double mutant rescued the total lipids, seed size and thousand-seed weight. GmMYB73 also elevated lipid levels in seeds and leaves of transgenic Lotus, and in transgenic hairy roots of soybean plants. GmMYB73 promoted PLDα1 expression, whose promoter can be bound and inhibited by GL2. PLDα1 mutation reduced triacylglycerol levels mildly in seeds but significantly in leaves of Arabidopsis plants. GmMYB73 may reduce GL2, and then release GL2-inhibited PLDα1 expression for lipid accumulation. Manipulation of GmMYB73 may potentially improve oil production in legume crop plants.

  14. Soybean GmMYB73 promotes lipid accumulation in transgenic plants

    PubMed Central

    2014-01-01

    Background Soybean is one of the most important oil crops. The regulatory genes involved in oil accumulation are largely unclear. We initiated studies to identify genes that regulate this process. Results One MYB-type gene GmMYB73 was found to display differential expression in soybean seeds of different developing stages by microarray analysis and was further investigated for its functions in lipid accumulation. GmMYB73 is a small protein with single MYB repeat and has similarity to CPC-like MYB proteins from Arabidopsis. GmMYB73 interacted with GL3 and EGL3, and then suppressed GL2, a negative regulator of oil accumulation. GmMYB73 overexpression enhanced lipid contents in both seeds and leaves of transgenic Arabidopsis plants. Seed length and thousand-seed weight were also promoted. GmMYB73 introduction into the Arabidopsis try cpc double mutant rescued the total lipids, seed size and thousand-seed weight. GmMYB73 also elevated lipid levels in seeds and leaves of transgenic Lotus, and in transgenic hairy roots of soybean plants. GmMYB73 promoted PLDα1 expression, whose promoter can be bound and inhibited by GL2. PLDα1 mutation reduced triacylglycerol levels mildly in seeds but significantly in leaves of Arabidopsis plants. Conclusions GmMYB73 may reduce GL2, and then release GL2-inhibited PLDα1 expression for lipid accumulation. Manipulation of GmMYB73 may potentially improve oil production in legume crop plants. PMID:24655684

  15. Competing states in a Couette-Taylor system with an axial flow

    NASA Astrophysics Data System (ADS)

    Tsameret, Avraham; Steinberg, Victor

    1994-05-01

    We present experimental results on novel pattern states which were observed in the Couette-Taylor flow subjected to an axial flow, in a wide range of the control parameters. Propagating Taylor vortices (PTV's), stationary spirals (SSP's), and moving spirals (MS's) were found as a result of a different symmetry breaking. These modes exhibit different wave-number selection. Novel states originating from an interaction between these patterns were also found. A ``mixed phase'' of PTV's and SSP's was identified. A ``mode-competition'' state, in which the PTV's and MS's are alternated in the column, is also described. Finally, a ``disordered-Taylor-vortices'' state was observed and characterized.

  16. Quantum effects on the Rayleigh-Taylor instability in a horizontal inhomogeneous rotating plasma

    SciTech Connect

    Hoshoudy, G. A.

    2009-06-15

    The Rayleigh-Taylor instability is studied analytically in inhomogeneous plasma rotating uniformly in an external transverse magnetic field. The influence of the quantum mechanism is considered. For a stratified layer the linear growth rate is obtained. Some special cases that isolate the effect of various parameters on the growth rate of the Rayleigh-Taylor instability are discussed. It is shown that for some cases, the presence of the external transverse magnetic field beside the quantum effect will bring about more stability on the Rayleigh-Taylor instability.

  17. Interethnic genetic differentiation: GM polymorphism in eastern Senegal.

    PubMed Central

    Blanc, M; Sanchez-Mazas, A; Van Blyenburgh, N H; Sevin, A; Pison, G; Langaney, A

    1990-01-01

    Analysis of GM polymorphism has been performed on 1,806 individuals representing three sympatric ethnic groups--Bedik, Fulani, and Mandenkalu--of eastern Senegal. Haplotype frequencies estimated by maximum likelihood have been used to compute common genetic pools between the three samples and a number of other sub-Saharan African populations. Despite extreme linguistic and sociocultural differentiations and very high levels of endogamy, especially in the Bedik and Niokholo Mandenkalu, the three populations share about 90%-95% of their haplotype frequencies in a system which commonly provides strong genetic differentiations. This supports the view that, despite its importance at a large continental scale level, as it is discussed for a set of populations from many regions of sub-Saharan Africa, sociocultural differentiation usually has little effect on local genetic diversity. PMID:2105642

  18. G-CSF and GM-CSF in clinical trials.

    PubMed Central

    Antman, K. H.

    1990-01-01

    Hematopoietic growth factors have now been purified, cloned, and produced in bacteria and yeast. Those that are currently in clinical study include erythropoietin, GM-CSF, G-CSF, M-CSF (also called CSF-1), and multi-CSF (also called interleukin 3). Growth factor appear likely to enhance the recovery and function of circulating white cells after standard-dose cancer therapy and high-bone-dose cancer therapy with marrow transplant and to restore leukocyte numbers and competence in the acquired immune deficiency syndromes and myelodysplastic syndromes. Phase I, II trials in AIDS, in cancer patients receiving chemotherapy, in cases of myeloproliferative disease, and after bone marrow transplant have been published. The results of phase III studies are just becoming available. PMID:1705737

  19. Ablation front rayleigh taylor dispersion curve in indirect drive

    SciTech Connect

    Budil, K S; Lasinski, B; Edwards, M J; Wan, A S; Remington, B A; Weber, S V; Glendinning, S G; Suter, L; Stry, P

    2000-11-17

    The Rayleigh-Taylor (RT) instability, which occurs when a lower-density fluid accelerates a higher-density layer, is common in nature. At an ablation front a sharp reduction in the growth rate of the instability at short wave-lengths can occur, in marked contrast to the classical case where growth rates are highest at the shortest wavelengths. Theoretical and numerical investigations of the ablative RT instability are numerous and differ considerably on the level of stabilization expected. We present here the results of a series of laser experiments designed to probe the roll-over and cutoff region of the ablation-front RT dispersion curve in indirect drive. Aluminum foils with imposed sinusoidal perturbations ranging in wavelength from 10 to 70 pm were ablatively accelerated with a radiation drive generated in a gold cylindrical hohlraum. A strong shock wave compresses the package followed by an {approx}2 ns period of roughly constant acceleration and the experiment is diagnosed via face-on radiography. Perturbations with wavelengths {ge} 20 {micro}m experienced substantial growth during the acceleration phase while shorter wavelengths showed a sharp drop off in overall growth. These experimental results compared favorably to calculations with a 2-D radiation-hydrodynamics code, however, the growth is significantly affected by the rippled shock launched by the drive. We performed numerical simulations to elucidate the influence of the rippled shock wave on the eventual growth of the perturbations, allowing comparisons to the analytic model developed by Betti et al. This combination of experiments, simulations and analytic modeling illustrates the qualitative simplicity yet quantitative complexity of the compressible RT instability. We have measured the Rayleigh-Taylor (RT) dispersion curve for a radiatively-driven sample in a series of experiments on the Nova laser facility. Planar aluminum foils were ablatively-accelerated and the subsequent perturbation growth

  20. Ethical arguments relevant to the use of GM crops.

    PubMed

    Weale, Albert

    2010-11-30

    The Nuffield Council on Bioethics (NCOB) has published two reports (1999 and 2004) on the social and ethical issues involved in the use of genetically modified crops. This presentation summarises their core ethical arguments. Five sets of ethical concerns have been raised about GM crops: potential harm to human health; potential damage to the environment; negative impact on traditional farming practice; excessive corporate dominance; and the 'unnaturalness' of the technology. The NCOB examined these claims in the light of the principle of general human welfare, the maintenance of human rights and the principle of justice. It concluded in relation to the issue of 'unnaturalness' that GM modification did not differ to such an extent from conventional breeding that it is in itself morally objectionable. In making an assessment of possible costs, benefits and risks, it was necessary to proceed on a case-by-case basis. However, the potential to bring about significant benefits in developing countries (improved nutrition, enhanced pest resistance, increased yields and new products) meant that there was an ethical obligation to explore these potential benefits responsibly, to contribute to the reduction of poverty, and improve food security and profitable agriculture in developing countries. NCOB held that these conclusions were consistent with any practical precautionary approach. In particular, in applying a precautionary approach the risks associated with the status quo need to be considered, as well as any risks inherent in the technology. These ethical requirements have implications for the governance of the technology, in particular mechanisms for enabling small-scale farmers to express their preferences for traits selected by plant breeders and mechanisms for the diffusion of risk-based evaluations. Copyright © 2010 Elsevier B.V. All rights reserved.